Screen printing consists in forcing ink onto the printed material through a stencil applied to the mesh. This is a very common printing method, characterized by high quality image transfer to any material, including those inaccessible to all other types of printing, saturation, large thickness and stability of the ink layer, low productivity, a large number of applications, including not only printing, but even electronics. .

Screen printing technology

A frame with a metal or polymer mesh stretched over it acts as a printing plate. The number of threads in the mesh depends on the characteristics of the work being performed and on the method of applying a stencil to it, on average it is 50-150 threads per cm. The thickness of the paint layer depends on the thickness of the threads and the distance between them. At the origin of this method, silk stretched over a wooden frame was used as a mesh, which is why screen printing is also called silk-screen printing.

The image can be formed on the grid in a direct and indirect way.

• The direct method consists in applying a copying solution (colloidal polymer solution) to the grid. The solution is then dried to form a photosensitive soluble copy layer. An image is exposed on it, while the blank areas harden, and the printing ones are subsequently washed out with water.
• An indirect method consists in applying an image to a special film material with a copy layer. A copy of the image is being processed, whitespace elements are solidified. Then the copy is rolled to the grid.
• The combined method is a combination of the two above. The image is applied to the grid, previously connected with the copying material and copying solution. This allows you to create more durable forms and achieve high definition printing.

Printing occurs as follows: the printing form is placed on the form holder. The material to be sealed is installed in a horizontal position, its immobility is ensured by stops and vacuum. The paint is fed onto the mold, then with the movement of the squeegee it is pressed into the mesh, while the squeegee pushes through the mesh and simultaneously cuts off the remaining paint. Then the form is removed, and the printed material is removed to dry.

The production of printing products in the stencil method is carried out both manually and by means of special printing machines.

Areas of application of the screen printing method

A variety of surfaces are printed using the silk screen printing method: paper, fabric, plastic, glass, metal. In addition, the stencil method allows you to print uneven surfaces. All this leads to the use of screen printing in various industries.

Due to the high quality of image transfer and low cost when printing small runs, silk screen printing is used in the production of representative printing products: printing business cards, postcards, folders, invitations, creating booklets with a circulation of 50 copies. and others. In addition, screen printing allows the use of inks that are difficult to use for digital printing, such as metallized (gold, silver). On large runs, printing in gold and silver, as well as other colors from the Pantone palette, is carried out in an offset way, and small runs can be printed with silk-screen printing.

silkscreen- silk screen printer. The profession is suitable for those who are interested in drawing, world artistic culture and labor and economy (see the choice of profession for interest in school subjects).

Features of the profession

silkscreen- This is a mesh screen printing. The image is applied with paints on a grid (made of silk or other durable material) stretched over a frame (sections of the grid corresponding to the gaps in the composition are covered with a paint-impervious composition); when printing, the ink is pressed through the holes of the mesh stencil onto the surface of the product.

Multi-color images are applied in several steps: in one step - one paint. It is believed that this printing method originated in ancient times, and screen printing acquired its modern look in the middle of the 20th century.

Screen printing can be applied to paper, plastic, glass, fabrics, etc. This method is used to print instrument scales, colorful drawings and inscriptions on T-shirts or sports bags, multi-colored badges, and a complex repeating pattern on porcelain dishes. For the manufacture of silk-screen printing stencils, thin, durable fabrics with a rare weave of threads are used. For these purposes, fabrics made of natural silk were first used, hence the name of this technique - silk screen printing. Advances in chemistry have made it possible to replace stencils made from natural fibers with synthetic ones. Also used and metal mesh forms.

Today there are various silk-screen printing machines: automatic, semi-automatic, manual. The silkscreen master makes stencils from special materials, uses them to apply images to products, and dries them using a UV installation. In some large enterprises where the division of labor is practiced, he may be responsible for any one operation.

However, a printer can master several printing methods at once. Suppose, in addition to silk-screen printing, he can work in pad printing, thermal transfer printing. Such a person becomes the core of production, on which not only the volume and quality of products depend, but also the overall success of the company, which can expand its range.

Workplace

The silk screener can work at printing, textile enterprises, in souvenir workshops, at enterprises of the electronic, automotive, glass industries.

Important qualities

Silk-screen printing requires such qualities as accuracy, a penchant for manual labor, the ability to deal with monotonous operations.

A serious obstacle to work is an allergy to paints.

Skills and abilities

It is necessary to understand screen printing technology, be able to work on screen printing equipment, know the features of the materials and dyes used.

Where do they teach

Silk-screen printing can be mastered in special courses.

To apply a multi-color pattern to a panel, a fashionable emblem, a sports flag and a pennant, a T-shirt and a jacket, providing an intricate image with perky inscriptions, replicating all this is a relatively new type of screen printing called silkscreen printing, an activity that is quite feasible for a home craftsman. First, the image is applied to a silk mesh (hence the name) stretched over a frame. The sections of the grid that correspond to the gaps in the pattern are covered with a paint-impervious material. After that, the paint is applied to the mesh, it is pressed onto the surface that they want to cover with a pattern, with a special tool - a squeegee. In this way, a large number of impressions can be obtained. This is provided by simple equipment.

Rice. 1. Working table with cover A and paper cutter B, made from a hacksaw blade

First of all, you need a small table, in which the top cover is replaced by thick glass (Fig. 1. a). Under the table put a lamp for illumination. A regular extendable dining table will do. Having moved it apart, thick glass is placed instead of an additional section. You can not do without a good paper cutter (Fig. 1, b). Naturally, you can use special knives from the set for inlays. But it is not difficult to make a cutter yourself from a fragment of a hacksaw blade. You will also need a strong wooden frame, on which a very thin silk fabric is tightly stretched. It is necessary that the frame does not warp, therefore the best connection of its parts is in the “thorn” (Fig. 2).

Rice. 2. Frame with silk stretched over it

You can also pull a thin synthetic fabric onto the frame. For example, a faded synthetic silk handkerchief, preferably transparent. A thin nylon stocking is also suitable. Cut off the top and bottom of it. Cut the stocking lengthwise. You will get an almost square flap. In order not to “run” the loops, a metal strip heated on fire is carried out along the edges of the flap. They stretch the prepared material onto the frame, having previously moistened it with hot water - then, after drying, it will sit more tightly. The edges of the material are fixed from the sides of the frame with carnations with large hats and (optionally) adhesive tape. On top of the frame, silk is pressed with thin wooden planks. A very important tool is a squeegee, which is a plate of hard thick, 6 - 8 mm rubber, reinforced with a strip of tin on rivets for rigidity (Fig. 3). The working edge of the squeegee must be carefully aligned. It is desirable to have several such tools of different widths. For 1 squeegee pass

Fig.3. Hard rubber squeegee A - the main working tool; how B works for them - they cover the entire width of the picture, but do not go unnecessarily beyond its limits.

Of the materials, gauze is required, stretched over multi-tiered frames, on which the finished prints are dried (Fig. 4). In the technological process, an important place is occupied by paint, ordinary oil in tubes. Its colors win in brightness and juiciness if it is diluted on the basis of zinc white. The paint is added to the white in a ratio of 1: 2 or 1: 3 (by volume). It is also better to mix white with black paint. Mix the paint on thick wrapping paper. The finished mixture is kept for some time (from 1/2 to 3 days for different paints). This is necessary so that the excess oil is absorbed into the paper, otherwise the paint applied to the fabric forms an oil halo around itself. When the mixture is ready, it is placed on a piece of glass; add pentaphthalic varnish Pf-285 or Pf-286 and a desiccant (liquid calcium resinate). Approximately 3 plastic caps of a desiccant are added to the “cake” of paint 12 - 15 cm (this is how bottles with this liquid are usually closed). It is necessary that the paint as a result of all these operations acquire the consistency of thick sour cream. The mixture is prepared for the upcoming work (in advance), and for the future. Over time, the paint will be covered with a film, which is removed before work and 1. an incomplete lid of the desiccant is added.

Rice. 4. Tiered drying frames

We will consider the technology of silk-screen printing on the example of the manufacture of emblems and pennants. The best material for this is satin, white or colored, which is cut into pieces of the desired size.

But first they develop a drawing. For example, you decide to make an emblem (like the one shown in Fig. 5). It is performed in 2 colors - orange and brown. Color 3 is the color of the fabric on which the pattern will be applied. On whatman paper, draw life-size with paints or pencils what you have in mind. You can apply letters and numbers using ready-made plastic stencils that are on sale. Any emblem, pennant must have a colored border. Through this, beauty is achieved; in addition, due to the paint, the edges of the fabric become rigid and do not crumble. To the right and left of the finished drawing, marks are placed that will help to correctly combine colors. At the pennant or flag, a hem for suspension is marked.

Rice. 5. Tracing paper for emblems- each color matches

Now they take a small piece of tracing paper (best of all, the one intended for ink), put it on the sketch and circle it (all the details are orange (Fig. 5, B). Brown details are circled on another sheet of tracing paper (Fig. 5, C). It is necessary to take into account that the paint that will be applied the second slightly overlaps the pattern applied by the first paint - this way you can avoid unwanted breaking of lines and voids. flag. It will also need to be covered with paint so that “the edges do not crumble. It is enough to turn around the hem with a narrow colored frame. With the pointed tip of the cutter, cut out all the details of the picture from both cripples. After that, rub one side of a small piece of thick glass, so that the tracing paper can easily separate from it.The prepared glass is placed on the main pattern with the processed surface up.On the glass - tracing paper with cut out details, aligning them with the pattern. A frame with stretched silk is placed on tracing paper, glass and a drawing under it, pressed for a while - fig. 3b). If in the intended composition there are details that are cut out separately, then after applying the frame, they are precisely combined with the pattern right through the silk, moving each detail with the tips of 2 needles.

Next, with a thin brush, they begin to apply NC varnish through silk onto tracing paper. Having grabbed the tracing paper to the silk, varnish is applied to the working edge of the squeegee and the tracing paper is passed through the silk. This operation is repeated 4 times, allowing the varnish to dry. As a result, the varnish should cover the entire tracing paper lying under the silk with a thin even layer. Blotting paper is placed on a thick wooden block. An inverted frame is placed on it so that the tracing paper is on top. With a brush dipped in acetone, the varnish is carefully removed from the silk in the cut out areas and blotted with a piece of cotton cloth.

So, the tracing papers corresponding to one color are finally glued with varnish on the silk and the varnish is removed from the exposed areas of the silk. (And the size of the frame allows, so all the tracing papers are placed on silk; otherwise, you can make another frame or reuse the same one).

Satin fabric, prepared for drawing a picture or inscription, is carefully smoothed with an iron, cut to size with some margin. A cut-out flap is placed on the table, and a frame is placed on top so that the tracing paper is between the satin and the silk stretched over the frame. A rubber squeegee is dipped in paint and carried out along the pattern from top to bottom (Fig. 3, B). When passing the squeegee for the first time, make sure that its plane is at an angle of 45 degrees to the surface. The paint remains in the open areas of the drawing. The second time is carried out with a squeegee according to the pattern, holding it at an angle of 80 degrees. to the surface of the silk. This operation removes excess ink from the print. The pressure of the squeegee is necessary so that both the silk is not stretched and the paint is pushed through. Raising the frame, the fabric is separated from the silk mesh. With the tip of the needle, carefully remove the fibers of the fabric adhering to the silk. Having made the required number of prints (more than 100 can be obtained from 1 tracing paper), the silk mesh is washed with a cloth moistened with turpentine. Shreds with prints (so far 1-color) are laid out to dry. After 1 day, start applying a different color. The second tracing paper is carefully combined, using marks, with a colored sketch drawing. At this stage of work, you will need a lower backlight. As already described, the entire procedure for applying paint is repeated. After another 1 day, if necessary, you can apply a third color.

Rice. 6. The location of the pattern, glass, tracing paper and frame before applying varnish.

After the paint has dried, the edges of the emblems or pennants are cut off so that the cut passes through the painted areas - then the fabric will not crumble. As it was said at the very beginning, multi-color drawings and inscriptions can also be applied to clothes using the silk-screen printing method. Cotton fabrics work best for this. It should only be warned that the pattern applied to them can only withstand gentle washing. For knitwear, this method is not applicable; other dyes are required. Oil paint, not elastic enough, can crumble when stretched. Photography on fabric is now becoming more common in the design of interior elements of an apartment, household items. Obtaining black and white images, drawing portraits, drawings on curtains, bags, (scarves, clothes, etc.) is available to anyone involved in photography. flexibility and resistance to light and moisture, often even surpassing a normal image in terms of image quality.The fabric is selected depending on the nature of the transmitted pattern.To get a halftone image (portrait, landscape), light 1-tone fabrics are taken - cambric, silk, knitwear , chiffon. - Line art - any, including coarse fabrics (for example, canvas). Negatives for printing on fabrics are suitable for almost any format - 2.4x3.6 cm, 9x12, 13x18 cm and more. Usually negatives are used medium contrast and density. Shooting is carried out on amateur films such as "Photo" and photographic "FT". They are processed (depending on the goal pursued) in ordinary, fine-grained or 6 contrast developers. Before printing, the negatives are thoroughly cleaned of dust and retouched if necessary. The photosensitive layer applied to the fabric usually has a very low sensitivity. And the fabric prepared in this way is intended only for contact photo printing from a negative, the size of which corresponds to the size of the design intended for decoration. For the same reason, [the copying process can be carried out in very weak daylight or artificial light. The copying process - the technology for obtaining a photographic image on fabric - consists of the following stages. This is, firstly, the preliminary preparation of the fabric. Next - applying a photosensitive layer to the fabric. Drying the sensitized tissue. Exposing it under the negative. Image development. Processing tissue in an intermediate solution (only for some methods). Rinse fabric in water. Fixing an image. Washing the copy in water. Drying and final ironing of the copy with an iron.
The fabric intended for processing is washed in hot water with soap. Rinse properly in running water. Dry and slightly damp smooth with a warm iron. It is not recommended to blue and starch the fabric.

There are many ways to obtain a photosensitive mixture applied to a fabric base. One of these mixtures is based on iron salts. The solution for “feeling” the tissue in this case is prepared with the following composition: 3.5 g of oxalic acid, 5 g of ferric alum, 20 ml of 10% ammonia solution, up to 100 ml of water. A higher sensitivity is created by replacing the alum in this solution with the same amount of lemon-ammonia iron - “brown” or “green”. Ammonia solution will need 2 times less. Oxalic acid is dissolved in 50 ml of distilled (or boiled) water. Alum is dissolved in the same amount of water. In both cases, the water temperature is 60 degrees. Then both solutions are poured together. And after this solution has cooled, a solution of ammonia is added to it, stirring continuously. This recipe is suitable in the presence of "green" iron. If “brown” lemon-ammonia iron is used in the solution, then the solution is heated to a boil and only after that, while stirring, the ammonia solution is added. The “brown” iron salt will then turn into a “green” one. The citric-ammonia iron recipe is preferred when printing under artificial light. The sensitive solution can be stored in a dark cool place for about 1 - 1.5 ms.

The “feeling” of a fabric stretched on a frame in the form of a hoop is carried out by immersing it in a light-sensitive solution poured into clean glass or porcelain dishes. “Feel” - well impregnated with a solution - only the place on which the image will be printed. Then the fabric is lightly wrung out and hung to dry in a room with a dim electric light. A wooden beam is attached to the lower end with buttons to protect the fabric from twisting. The dried fabric is ironed with a hot iron.

Exposure is carried out in a contact way - by overlaying the emulsion layer of a black-and-white negative on the emulsion layer of the fabric. It is necessary that the light source for exposure is strong (sunlight, fluorescent lamps). Halftone negatives only expose in direct sunlight. Exposure (2 - b min) is determined empirically and depends on the time of year. The alum solution is mainly suitable for imaging normal negatives. The contrast can be increased by adding about 0.2 g of potassium dichromate per 100 ml of the solution. The exposed area of ​​the fabric is again stretched onto the frame and lowered for 3-4 seconds into a developing solution (poured into a cuvette with a layer 1-1.5 cm thick, temperature 20 degrees) of the following composition:

3 g of ammonium nitrate, 1 g of silver nitrate, up to 100 ml of boiled water.

Having developed, the tissue is again wrung out and transferred for 0.5-1 min in a 0.1% (intermediate) solution of hydrochloric acid to clarify the image. And then rinse in water for 5 seconds, removing the remnants of the solution. Fixation (2-3 min) is carried out in 1% sodium thiosulfate solution. Fixing more than 5 minutes or increasing the concentration of thiosulfate leads to a weakening of the image (halftones and small details disappear). Final washing (4 min) - in running water. Drying - at 20 deg. Fixer and intermediate bath - 1-time use. Such an image is quite durable and can withstand repeated washing without boiling.

Color images on fabrics. The method of obtaining them is based on the property of chromic acid salts to pass under the influence of light in a chromium oxide compound and form a mordant, which gives insoluble compounds with coloring substances. The dye obtained in this way quite reliably resists the action of snow, air, acids and alkalis. “Sensing” a cotton or silk fabric (or its section), immerse in a bath of the following composition: 50 g of ammonium dichromate, 5 g of ammonium metavanadium, up to 1 liter of water. The fabric is then dried at temperatures up to 25 degrees. (a higher one causes a modification of the sensitive layer, which is expressed in the color of white areas and veiling of the image). The processed tissue is exposed in a copy frame under the negative until the entire image is developed, after which it is thoroughly washed in water. The washed and dried print can be stored for several days. Before dyeing in any color, the printed fabric is soaked in warm water. Various aniline dyes are used as coloring agents. Moreover, these dyes can be mixed with each other, creating the necessary range. The dye solution with the cloth immersed in it is brought to a boil and kept at this temperature for 15-20 minutes. After that, the fabric with the imprint is thoroughly rinsed with water. And, if the colors have learned not quite clean, they are dipped in a warm solution of soap or soda. At the end of this operation, the print is properly washed.

To get prints on calico, silk and satin, another method is also used, suffering from a photosensitive layer. First, prepare the following solution: 17 g of regular sugar, 1 g of tartaric acid, up to 100 ml of hot water. Boil for about 1 min. Then, removing from heat and stirring, add 0.5 g of borax to the solution. After about 6 hours, the sludge is drained. 4 g of table salt are dissolved in it and filtered. The fabric is evenly laid on the surface of this solution and left in it for 1 minute, until the wrong side becomes damp. Then the fabric is removed, dried, ironed on the reverse side with an iron and silvered for 1-2 minutes in a 10% solution of silver nitrate. After drying, the fabric is printed under the negative. The finished print is dyed and fixed. The method of obtaining a photograph on fabric using an albumin (egg) emulsion gives a moisture-resistant, fragile print. Preparation of the emulsion: protein from 3 fresh eggs is mixed with 100 ml of distilled<или кипяченой) воды. Смесь затем сбивают в течение 5 ми” до образования пены, дают отстояться в вливают в нее 1 л воды, содержащей по 8 г хлористого натрия и хлористого аммония”. Переливают в большую емкость. Сильно взбалтывают. Эмульсией можно пользоваться лишь через 12 ч. Чтобы получить на ткани светочувствительный слой, ее в течение 3 мин пропитывают эмульсией и сушат, предохраняя от скручивания. Перед печатью обработанную ткань “очувствляют” к свету в растворе нитрата серебра 0“ г AgN03 в 100 мл воды). С этой целью ее в растянутом виде равномерно опускают на поверхность раствора. Сенсибилизацию проводят при желтом свете. Сушат ткань в темноте. От слишком быстрой сушки на ткани могут появиться пятна. Ткань при сушке растянута.

Printed in a contact way on a copy frame. Lead printing for 15-20 minutes or longer. For example, at the window. The fixation and staining of the image is carried out using the following bend-fixer: 50 g of lead nitrate, 150 g of sodium thiosulfate, 1 liter of water. First, silver nitrate is dissolved in 400 ml of water, and thiosulfate is dissolved in 600 ml. To obtain a working solution, the first solution is poured into the second and the mixture is allowed to stand for a day. In the bend-fixer, the fabric remains for 5-10 minutes until the image acquires a warm brown tone. The finished print is washed for about 1 hour in running water, but not under running water. If you need to copy large areas of fabric. It is convenient to use special copy boxes or illuminated screens with fluorescent lamps. To correct the image on the fabric, caused by slight overexposure or underexposure during exposure, you can use the usual attenuating or enhancing solution. Complete removal of the image is in some cases achieved by the application of a concentrated farmer's attenuator.

Photo fabric FT-1, which is commercially available, is used to obtain photo prints from negatives by contact and projection printing methods and is made on the basis of artificial silk fabric. FT requires an emulsion coating - it has already been coated with an emulsion of the type used on Unibrom photographic paper. It is characterized by high whiteness and a neutral black color of the resulting image. FT prints convey fine details, shadows, tones and midtones well. It is this material that is most suitable for the manufacture of photo-stained glass, photo screens and fireplace photo screens, paintings, lampshades, decorating apartment interiors. Available not only in sheets, but also in rolls, with a width of 90 cm, it allows you to make semi-solid black and white images with high magnification.

One of myselfOne of the most universal and most ancient printing methods is silk-screen printing, or silk-screen printing. With a story about her, we continue the theme of printing on souvenirs.

The Big Encyclopedic Dictionary gives the following definition of silk screen printing: “ reproduction of text and graphics by forcing ink through the holes of the printing plate (polymer, silk or copper mesh, covered with a protective layer in the blank areas) » . When preparing the grid (stencil), its printing areas remain open, that is, they let the ink through, and the areas corresponding to the gaps in the image are covered with a composition that is impervious to ink. The thickness of the paint layer depends on the thickness of the mesh cells and can vary from normal 10-12 microns to 500 or more with several rollings.

This is a universal technology for applying images to products made of paper, plastic, film, leather, glass, ceramics, fabric, and even metal and stone. It is possible to work both on flat surfaces and on curved forms of material. Therefore, naturally, silk-screen printing is very actively used for printing on souvenirs and advertising and image products: T-shirts, baseball caps, umbrellas, balls, computer mouse pads, flags, lighters, mugs, ashtrays, etc.

From the history of screen printing

The term "silk-screen printing" (serigrafia) etymologically consists of two roots: seri (from the Greek - silk) and grafia (from Greek -writing, picture). That is the origin of the name refers to the work associated with the decoration of silk or with creating images with it. Traditionally, it is assumed that silk screen printing originated in China, as well as almost all things, the exact origin of which is not known.

Existing hypotheses about the Chinese origin of silk-screen printing are based on the fact that silk began to be produced in this country 1200 years before ad. However, silk was directly involved in the development printing at least 2400 years later.

There is a version that silkscreen originated near the Mediterranean Sea, in the area between Mesopotamia and Phoenicia. Many similarities indicate that inventors silk-screen printing, which was then regarded as art, were the Phoenicians.

This small Semitic people who lived in a narrow strip of land located approximately in the territory of modern Lebanon between the 13th and 3rd centuries BC AD, famous for his sea voyages . The Phoenicians sailed across the Strait of Gibraltar to the Canary Islands, as far north as Great Britain. In addition, they sailed throughout the Mediterranean basin. The Phoenicians were engaged in trade and used their coastal cities as ports for export. goods of own production and imported from other countries.

Archaeological finds and historical research show that f The Inicians extracted purple, a red substance for dyeing fabrics, from the secretion of the gland of one mollusk. His began to be used for dyeing clothes. The coloring of fabrics was not manual, but rapidly repetitive. But how could the Phoenicians reproduce the repetitive dyeing of fabrics when at that time there was no information about the equipment that could allow it? Cansuggest that the Phoenicians or some neighboring people found a way to reproduce patterns on fabric using technologies that, of course, have nothing to do Yu t with modern ones, but represent the birth of the "multiplier system", the "image repetition" system. However, the Chinese origin cannot be completely excluded.

So the birth of silkscreen can be seen as the appearance technology based on the repetition of relatively simple patterns using special matrices, "stamps", on which paint was rolled tampons made by from various materials.

hardly liv silkscreen immediately a frame appeared , but we can assume a significant simplification of the process through primitive printing using a "stamp".

Stamp printing, which had many shortcomings primarily due to an insufficient layer of pigment when used on thick and absorbent fabrics, has undergone a bunch of improvements in the following centuries.

W A significant improvement in the method occurred around 1185-1333. in the city of Kamakura, that was then the capital of Japan. All kinds of art flourished in this city, including printing: samurai armor and horse decorations were decorated. At first, the usual stencil method was used for this. Then a brilliant innovation was invented: since the image reserve,obtained only by cutting out the material, did not hold the whole design together, the image was cut out and pasted on a grid consisting of threads made from human hair stretched over a wooden frame. Thus, the image was held together in all its parts, and the presence of fine hair became invisible when the swab, moistened with pigment, was pressed against the decorated fabric.

Numerous examples of Japanese stencils, made from hair or fine silk fabrics, testify to how silk-screen printing began to take on more and more of the characteristics inherent in this type of printing. Nowadays.

In Europe, the spread of the method took place mainly in England., as well as in France, where around 1750 Jean Patillon began producing wallpaper.

In the second half of the 18th century, this technology spread throughout the world. And especially in America, where furniture, walls, fabrics and metal products were decorated with the help of silk-screen printing.

The fabric for the "printed frame", which was previously made from hair, began to be made from silk threads and muslin, but with this fabric was still very difficult to work.

Big step forward was made in 1907 when a certain Simon from Manchester patented the process of screen printing through silk fabric.She guaranteed higher resistance to tension, greater dimensional stability and the use of rubber rollers (hereinafter rubber squeegees) for applying the paint. The invention was cataloged under the title Silk Screen Printing (printing with a silk sieve).

So The name "silkscreen" is quite recent. However, silk screen printing was not considered as a new incarnation of graphics, as a real printing process, but had, in fact, a subordinate position, was considered secondary method, a special type of printing.The rapid introduction of the method into industry began during the First World War, when chain stores began to appear in the United States. Each network had to have its own corporate identity - signs, shop windows, aprons, hats with company symbols. But all this was required in small print runs - 50, 200, in extreme cases, 1000 pieces. For traditional printing - the circulation is unprofitable, and for silk screen printing - injust right. This is how the silk-screen printing niche arose. The niche began to expand, capturing more and more new areas of application, the method improved, and as a result turned into an independent industry, perfectly positioned on the market. M All kinds of substrates, from fabrics to posters, from postcards to labels, up to license plates for cars, began to be printed using the silkscreen method.

Ukraine and post-Soviet countries

In the USSR until 1985 by screen printing, the tasks of finishing bookbinding covers, printing books for the blind in Braille, and in the electronics industry - manufacturingprinted circuit boards and electronic circuits. The method was also used in the porcelain industry for decorating dishes both by direct application of the image and by the decal method. Screen printing has been used in other industries usually for drawing a simple line image on various parts and products. A we are interested in the actual souvenir e and branding use of screen printing was most often manifested in the production of promotional products (posters, posters, etc.).The main supplier of printing inks was the Torzhok Plant of Printing Inks (TZPK), the nets were produced by the Rakhmanovsky Silk Plant. By 1985, they mastered the production of screen meshes with a density of up to 140 nit . /cm. The development of new materials, equipment and scientific research was actively carried out by the Kyiv branch of the All-Russian Research Institute of Polygraphy, in which in 1961 a screen printing laboratory was organized. The results of theoretical studies obtained in the 60-80s have not lost their relevance today. Have been developed different photosensitive compositions - film based on PVA and liquid photopolymerizable. Film layers were introduced into production at the Krasnoyarsk Chemical Plant. The photopolymerizable composition "Polyset" was prepared directly at enterprises and screen printing departments according to a special recipe. In some places it is still used today, despite the large variety of ready-made copy compositions produced developed countries.

Thus, the domestic industry almost completely provided for the needs of screen printing at that time. The fall of the totalitarian regime immediately led to two opposite processes. On the one hand, the demand of society for printed products, especially for souvenirs and advertising, has increased. This was facilitated by the development of business, and the integration of Ukraine into the global information space, and the growth of a multi-party political system. On the other hand, many state enterprises fell into decay. The Kiev branch ceased to be a branch of VNIIKP, and turned into the Ukrainian Research Institute of Special Types of Printing. The range of screen printing materials produced by the domestic industry has been greatly reduced. Against the background of the collapse of large enterprises, small-scale industries began to appear and multiply, which satisfied the interest in silk-screen printing products. Screen printing is seen as a production that can be opened at minimal cost. This was the impetus for its development in the new economic conditions. If earlier souvenirs with company symbols, T-shirts and baseball caps with the names of sports teams or rock bands were practically not produced in the USSR, then with the beginning of perestroika, many so-called cooperatives quickly saturate the market with products of this kind. True, the level of quality was rather low, but those entrepreneurs who saw the prospect sought to raise it.

With the emergence of new screen printing enterprises and the expansion of its areas of application, there was a need for consumables. And as a result, there was an offer from foreign manufacturers through dealers: by the mid-90s, many companies had opened offering consumables and equipment for screen printing from various manufacturers, for example, Italian materials and equipment Argon, Saati, Swiss materials Foteco, Sefar, German materials and equipment Marabu, Proll, Bochonow, English materials Sericol, Autotype, including used equipment.

Screen printing in our country is entering a new level of development. In many enterprises, manual machines are being replaced by more accurate and productive professional equipment. And yet today, despite the interest in more productive and accurate semi-automatic printing equipment, most enterprises still make do with manual ones. The share of automatic and semi-automatic machines in the structure of the screen printing equipment fleet in the post-Soviet space, according to various experts, ranges from 10 to 30%. However, the opinion that the equipment fleet will develop in the direction of increasing the share of semi-automatic machines is unanimous. The vast majority of enterprises are small, employing up to 20, and according to some estimates - up to 10 people. Enterprises with a staff of 20 to 50 people account for up to 10% of their total number. The average monthly production capacity of a screen printing enterprise is, according to experts, from 100,000 to 250,000 ink prints. In many factories and screen printing departments, the level of plate processes remains low. “Handicraft” methods of stretching nets on frames and exposing the copy layer are still used, which do not make it possible to achieve the optimal quality of printing plates and, as a result, the optimal quality of the finished product. In most cases, liquid copy compositions (emulsions) are used. They are applied manually by watering from a squeegee-ditch. The use of capillary and cut-out films is extremely limited due to their high cost, although they are known - mainly films from Autotype and Foteko. Inks are used in a wide variety of types: solvent evaporation-cured (the most common type of ink), water-based, UV-cured, plastisol (for printing on cotton fabrics). The paints of the Torzhok plant (TZPK), the Italian company Agron and the English Sericol are still the most widely used. Quality requirements are increasing every day against the background of a general increase in the level of printing products. Many screen printing enterprises and departments employ not professional printers, but specialists from other industries, who often do not fully master all the subtleties of the technology. Literature from which you can get the necessary information is not enough.

If, say, in the electronics industry, the use of screen printing has noticeably decreased, then interest in its capabilities for applying images to a variety of materials has sharply increased: textiles, plastics, metal, glass and ceramics, wood, various types of cardboard, etc. A large share of the work (about 30% of the total volume) performed by the screen method at domestic enterprises is various types of printing on textiles. Most stencil enterprises and sites are not limited to the production of any one type of product, but perform work for several industries. Thus, many printing companies that produce various types of sheet products or perform UV varnish finishing are also engaged in printing on textiles, as well as mastering various types of transfer printing.

The stencil equipment fleet is being updated, although not as fast as we would like. So far, automatic and semi-automatic machines are used only in large and less often in medium-sized enterprises. At small enterprises, manual, often home-made equipment prevails - in the amount of no more than two or three machine tools. According to experts, the biggest prospects on the market in the coming years have high-precision semi-automatic screen printing of at least A3 format, which can replace manual machines. In general, the industry expects an increase in the degree of automation of equipment and, consequently, productivity. Production volumes over the next 10 years will also grow, the level of quality, which is quite good at many enterprises, will continue to rise. According to experts, a serious breakthrough is expected in the field of high-quality multi-color printing.

Applications, advantages and weaknesses

Silk screen printing is called one of the most versatile printing methods, and yet there is a classification of silk screen printing applications.

1. Small screen printing. It includes everything that is flat printing on various substrates, especially on PVC, as well as on paper and cardboard, the print format does not exceed 100x140 cm. This is printing of products for various purposes.

2. Large screen printing. Flat printing of formats exceeding 100x140 cm.

3. Printing on small items . It is possible to decorate pens, lighters, key chains and other souvenirs. Rotary semi-automatic machines are used for printing on round objects. Here Very palpable competition pad printing(see previous "Printing Courier") , although the image made by silkscreen is counts more resistant to abrasion.

4. Textile printing (printing fabrics) . This is printing on fabric in reels, on cuts using desktop printing techniques, mechano-textile, carpet machines, machines with rotating cylinders. ABOUT a broad branch related to the textile industry. Textile printing is one of the most diverse and important sectors of the economy in many countries.

5. Textile printing on finished products . Printing on finished products (t-shirts, small items). It is carried out with the help of machines called "carousel machines".

6. Screen printing on plates and metals. Associated with metal production and processing, anodizing, sheet stamping, pickling, roasting, etc.

7. Screen printing on glass. It is used in the automotive industry and in the production of electrical household appliances. There are also special applications that can be attributed to the promotional and souvenir field, for example, printing on glass products.

8. Screen printing on bottles. Widely used in cosmetic, pharmaceutical and some other industries.

9. The printed circuit board industry. Includes everything that can be done today by screen printing in the processing of electronic circuits, both general use and professional, multi-layer, conductive, etc.

10. Additional screen printing.

Covers all those applications, special, additional and specific, which are not included in the groups listed above.

As already noted, silk-screen printing is actively used in a variety of advertising and souvenir industries. Another interesting type of application, starting from the 20th century, has been the fine arts (which, by the way, with a certain amount of cynicism, can also be considered as a kind of “souvenir”). Silk-screen printing was introduced into art by representatives of pop art, famous lovers of industrial technologies - Andy Warhol, Roy Lichtenstein, Jasper Johns. Silkscreen printing is basically a democratization of the art process, a way to get the work of your favorite artist without spending too much money on it. Few can afford to buy their favorite paintings. An ideal solution for fans of this or that artist can be a print that costs much less.

Boris Velsky, head of the non-profit organization Moscow Studio, says: “Recently, we had an unusual order. In the living room, one of the walls was made of huge metal plates. And they have a huge fish printed on them, a trout. Its length is thirteen, and its height is three and a half meters. An unusually spectacular spectacle turned out!

Silk-screen printing looks very good on old metal, but the life of such an object, unfortunately, is short - the material quickly rusts and the image is lost. The solution to the problem may be the use of artificially aged metal, fixed in this state. Silk-screen printing looks especially impressive on fabric. With its help, you can get curtains with prints of your favorite painting, designer bedspreads and draperies. Boris Velsky: "One of the most memorable orders of recent times is a library in a country house. The room was draped with printed fabric, and it turned out to be a kind of tent of a colonial army colonel ... We also recently made an apartment-yacht. The curtains and drapery on the ceiling were made in the shape of the sails, and on them - the drawings of the ships. The current trend is silk-screen printed wallpaper, paper or silk.

The advantages of screen printing experts usually include the following characteristics:

1. simplicity of the process;

2. equipment available at a relatively low price;

3. the ability to print on materials of various types, on almost any surface, even embossed;

4. significant thickness of applied paint and specific silk-screen brightness of paints;

5. durability of printed materials due to the thick ink layer;

6. savings in printing relatively small and medium runs;

7. special solutions that are not possible or less effective when working with other printing methods, for example, phosphorescent, silver, translucent inks, glitters, scented image (!) and, for equal cost, better coverage.

To summarize, the main advantage of screen printing can be called versatility.

The main problem of screen printing is the instability of the tone during printing (the stencil wears out, the stencils are changed every 2 hours). In addition, screen printing is spreading in a completely erratic way in the most dissimilar industries, as a result of which it could not be too industrialized. Hence - and the lack of obligatory methods and "canons" of silk-screen printing, and the absence of large, as in offset, equipment manufacturers. Although the latter is not always a disadvantage.

Another negative of silk-screen printing is problems with large print runs. It is physically impossible to quickly make a large order, because the ink used in screen printing is very thick and viscous. And even modern and fully automated production cannot significantly increase the speed of the squeegee, the drying of the paint (the latter process, by the way, requires considerable production space). With screen printing, the print speed is several times lower than, for example, with offset printing. Too large runs can therefore be produced unacceptably long, and too small can be unprofitable. Experts recommend using the screen printing method in the manufacture of products with a circulation of several hundred to five thousand copies.

Technical process and some basic properties of screen printing

Briefly, the process of silk screen printing is as follows: and a wooden frame with stretched "silk" (now they use polyester fabric) is applied with a special emulsion and dried. Then a photoform is placed on the frame (film with printed four colors (CMYK - blue, red, yellow and black; if additional colors are needed, then films for them are also needed). After color separation, stencils are prepared. Photoform illuminated under a special lamp.After illumination, the frame is washed with water, in dry out, as a result of which a printed matrix. Matrix fix in a silk-screen machine, paint is poured. H and the printed product. The ink passes to the material through a fine mesh, and a special knife (squeegee) must go through each print. After applying paint to the material, it should be dried. Prints with a pattern are laid out on special racks or hung on special hangers.

Often silk-screened perceive as a simple process, in which it is enough to use a sieve cloth and pass paint through it.

In fact, there is a specificity in the silk-screen printing process that makes it unique. compared to, for example, making tea through a strainer or filtering sand . The principle by which the squeegee extrudes the paint through the sieve cloth, achieving a uniform and controlled passage, counts The fundamental law of silkscreen printing is: "The passage of ink through the opening of the sieve cell occurs in a controlled manner only when it is possible to achieve a thixotropic effect with a suitable squeegee under the correct pressure."This means that only in the presence of the viscosity variability factor can the screen printing process be carried out. It is enough just to check the passage through the stencil form of other non-screen printing materials. It will immediately become apparent that the process doesn't happen in the right way cells get clogged and the material is not smeared after passing.

So what is thixotropy? "Thixotropy is the ability of a liquid to change its viscosity when agitated or heated and return to its original viscosity at rest, when agitation ends, and to the temperature prior to agitation." Thixotropy is that process of forced change of the silkscreen ink, which allows it to pass correctly from one side of the sieve fabric to the other in the printing plate and accurately reproduce the printed image.

Viscosity is the amount of internal friction or resistance that adjacent fluid layers encounter when sliding against each other. Viscosity is also incorrectly called« liquid density" or " the opposite of fluidity» . Viscosity is directly affected by temperature, which is of great importance in the screen printing process. Viscosity is measured using viscometers, among which we mention the Engler viscometer, called by some "Ford glass", and the Brookfield viscometer, most used in the field of paints.

The controlled variation in viscosity, which we will define as thixotropy, allows the ink to more easily pass through the meshes of the stencil sieve fabric, or cliché, and also acts in such a way that the ink does not stick together the substrate and stencil form and they are perfectly separated from each other at a considerable speed. If something goes wrong during the printing process, the substrate does not separate from the stencil form and remains glued to it with paint.

The phenomenon due to which the ink, when passing through the cells of the sieve fabric, cannot completely separate from the stencil form and acts as an adhesive between the stencil form and the substrate, gluing them together is called« sticky effect».

« sticky effect» found quite often and depends on many factors. It may appear if:

-the paint is too viscous or incorrectly diluted;

-the image is blurry and the paint goes beyond the edges of the gelatin, which is why, remaining on it, it is not completely removed and sticks together the stencil form and the substrate;

-the paint is too cold and the thixotropic effect does not occur;

-the print speed is incorrect, possibly too fast;

-paint thinner is not suitable and makes it too sticky;

-the substrate is poorly adhered to the printing plane or the exhaust system for sheets has a weak pressure;

-sieve fabric is poorly stretched, too few "newtons" and very little return force;

-the squeegee is too rounded, which is why the theoretical closure line is too wide;

-environmental factors such as static electricity exacerbate the defect.

Another thing - textile printing. Here changeability of thixotropy is not always achieved, but only in some cases, since it is not required to print with a high degree of image definition. The fabric behaves like blotting paper, so the screen printing process is partial, without varying viscosity.

Another important concept of professional silkscreen jargon-« paint coverage": it is her " the ability to prevent the visibility in the light of the tone of the color that is printed with this ink". That is, if printed in white on black good coverage, only white will be visible. If the black color remains partially visible, then the paint will not cover tightly. The concept of coverage associated with silkscreen inks is actually directly related to the concept of haze:"m The opacity of paint is its property not to allow light rays to pass through itself, it is the opposite of transparency».

Types of coatings applied by silk-screen printing.

colored paints. Silk-screen printing allows you to apply colorful layers of various thicknesses on the printed material, which depends on the structure of the grid. In offset, the thickness of the ink layer can also be adjusted, but within small limits. Since the layer thickness in silkscreen is many times greater than in offset, the intensity of the ink on the print will be significantly higher. Moreover, as a rule, opaque inks are used in screen printing, which means that it is easy to print, for example, yellow ink on blue paper. Moreover, the yellow will remain yellow, and will not turn into a barely noticeable green, as it would be in offset printing.

Covering whites. Very interesting graphic effects are obtained when using opaque white paint. You can, for example, put it on a dark base (tinted paper, gray cardboard, etc.), and print the image on top of it on a conventional offset printing machine - naturally, after the silkscreen ink dries. Covering white is also available for offset printing, but it is still not possible to obtain such a quality coating, due to the fact that the ink layer in offset is 5-7 times thinner. No less interesting is the result of printing with opaque white on transparent plastic. For example, if a halftone image is printed on plastic with an offset, and a white opaque paint is applied on top with a stencil, you will get a bright, saturated image that looks through a layer of plastic. In this way, it is possible to produce, for example, transparent labels or promotional materials for the design of points of sale (POS materials).

Gold, silver, metallic paints. In principle, both gold and silver can be applied in the usual offset way. However, as already mentioned, due to the greater thickness of the ink layer in screen printing, the metallic effect is much higher. Moreover, it has been observed that offset-applied metallic inks take longer to dry. Therefore, if efficiency is important, then stencil plating can be a good solution.

Fluorescent paints. There are quite a few types of such paints, but only with the use of screen printing can you get a really bright, saturated, fluorescent image - again, due to the greater thickness of the paint layer. Such inks are used for a variety of printed materials, including both quite ordinary and quite exotic ones: glass, metal, leather, wood, various plastics, etc., each of which has its own special ink formulations. So, the number of options for these same types of paints is huge.

You might get the impression that due to the high intensity of screen inks and the large thickness of the ink layer, you can get a very rich and bright image, close to photographic, or halftone. This is absolutely not true. As a rule, silk-screen printing is not used for printing halftone images, here it loses to offset in all respects. The exception is cases when it is simply technologically impossible to use offset, for example, when printing on fabrics, vinyl. Therefore, it is more correct to use silk-screen printing for printing even solids, continuous sealing, line printing without exact alignment, etc. But it is best suited for finishing.

Among the special effects achieved with silk screen printing, one of the most interesting is thermal rise. Used to give volume to texts or logos. Text or other design elements are printed in one color. Thermal rise in full color printing is done in such a way that the ink being processed should be the last ink in the process of applying to paper. For example, if you want to give a light relief to the waves when printing a seascape, thermal powder is added to the blue ink. The powder used in full-color printing must be colorless, otherwise color reproduction may be impaired. Interesting effects can be achieved by mixing different types of thermal powder. For example, mixing blue process ink and clear and silver powders gives the print a metallic effect. It is possible to use varnish sealing followed by thermal lifting with colored powders. This technique is undesirable for texts typed in small size or font with thin strokes. Thermal lifting techniques are applicable to both glossy and matte surfaces. Thermal lifting on films or PVC that are sensitive to temperature effects must be carried out with careful selection of the thermal regime of exposure.

Organization of silk-screen production and basic equipment

For the organization of production will require enough elementary conditions:

Premises 20-30 square meters (need electricity 220 V and water);

Computer (can be bought inexpensive and install the program Corel Draw);

Laser black and white printer;

Screen printing machine ( can be done to save money on one's own);

exposure camera;

Desirable cutter (better to buy);

Accessories (squeegee, cuvette, mesh, frames, dryers, paints and other chemicals).

Total, according to experts, the initial costs should be about 15 thousand hryvnia plus working capital.The personnel of the enterprise working with silk-screen printing must n include two mandatory positions: designer (can be taken part-time) and printer (preferably two).

According to Russian printing researchers (unfortunately, such calculations were either not carried out in Ukraine or simply unknown), ri competent marketing organization company payback in 1 month.

printed equipment can be divided into four types, differing depending on the material on which the image is applied: machines for printing on flat and roll materials, cylindrical surfaces and textiles. Machines for printing on roll materials and cylindrical surfaces can only be automated. The remaining machines (for textiles and flat materials) are manual and automated.

Manual machines for flat materials and textiles are small-format, large-format and carousel. Small-format manual machines print on flat materials, the format of which does not exceed 40x60 centimeters, up to 30 millimeters thick. Accordingly, large-format manual machines are able to apply an image to the material, up to 100x140 format with the same thickness. Carousel type printing presses are designed for printing on textiles.

Many manufacturers are getting into screen printing due to the low cost of equipment, as this is practically the only type of printing in which it is possible to use manual equipment. It costs much less than automatic and allows you to print small and medium runs, which are most often ordered. To get a picture made by silk-screen printing, it is necessary to have printing, laboratory and auxiliary equipment. And a few private rooms.

The simplest machine looks rather poor, but even it can be worked. Among its shortcomings are the absence of any adjustments, vacuum suction, difficulty in matching colors, the presence of backlash (the printed frame wobbles, so it is not easy to print in several colors on it). The main plus is the negligible price of such a machine and the simplicity of design.

Another level of machines is more convenient, although the setting is manual (combinations). Counterweights provide automatic frame lifting, which facilitates the printing process. Bearings ensure smooth running of the printed frame. There is no backlash. A working press, usually used for printing large runs in a small number of colors. The highest level - manual machines with micrometric registers. There can be both simple printed units and ready-made machines with a vacuum table. Micrometric registers allow for precise adjustment for next color printing. You can print a full color (like a color photo) image. On such machines, high-quality multi-color printing products are printed.

An important parameter is the size of the printed surface of the table. For different types of products, it is more convenient to use a machine of the appropriate format, this allows you to save on consumables.

Examples and a brief description of some printing machines on flat surfaces.

The simplest desktop manual machine - MT-45A (Ming Tai). The machine can be used for rather rough work, such as one- or two-color labels for marking flat objects, one-color leaflets, etc. The in-plane adjustments are located on the printed plate.

Hand knot for screen printing - MT-50A (Ming Tai) can be attached to any table. It is a plate into which two stand-tripods are soldered, enabling the sliders of the frame fastening device to move up and down up to 10 cm. It has micrometric registers on the TPF fastening unit. The machine allows you to print small runs of box blanks, postcards, panels, book covers, as well as posters, posters.

Floor Standing Manual Screen Printing Machine with Vacuum Table MT-50V (Ming Tai) used for sequential multi-color and full-color screen printing on sheet materials up to 50 mm thick (paper, cardboard, plastic, self-adhesive materials, tin, glass and any flat finished products up to 50 mm high). Structurally, all the printing units of this machine are made of metal, they consist of a printing mechanism with an adjustable counterweight and a vacuum table with a special plastic coating that is insensitive to moisture and polished with high precision to evenly cover the printed sheet with ink. The print engine's micro-registers are thin and finely threaded and actuated with a slight movement to print very precise registrations sufficient for full color and photographic images. After printing all impressions in one color (before applying the next color) or finishing multi-color printing, you can not do without a rack for drying impressions. Designed for professional use, these racks are equipped with shelves made of a special moisture-resistant metal alloy, and the design is optimally matched and combines the possibility of intensive air circulation and space saving.

Semi-automatic machine for printing on flat and cylindrical surfaces - model SCF-550(Technical Ind. Co.). Machine productivity up to 800 cycles/hour. When manually fed on the machine, you can print up to 1000-1200 full-color prints per shift. The SCF-550 is equipped with a fixed height printing table. During the working cycle, the contact of the frame with the product occurs due to the lowering of the printed assembly on the vacuum table during flat printing or on the device for synchronizing the rotation of the printed object with the horizontal movement of the stencil when printing on a cylinder.

The printing machine is equipped with a microprocessor-controlled pneumatic drive. All nodes are mounted on a rigid and vibration-resistant carrier frame.

Another example of a roll-to-roll screen printing machine is Labelmen PWS-310. The Labelmen PWS-310 machine can be single color or dual color. The width of the roll of the printed material is 310 mm, the print format is up to 300 x 300 mm.

The printing form of screen printing is neutral to the composition of paints and varnishes. It does not interact with them, either on a physical or chemical level. This makes it possible to work with water-soluble paints, with alcohol-based and volatile solvent paints, with oil-based paints and with special paints with various additives for special effects (protective, heat-sensitive, fluorescent, phosphorescent, reflective, metal-containing, pearlescent and paints odor), which are usually physically or chemically aggressive. The same can be said about the composition of varnishes. Roll feeding makes it possible to work with very thin materials that have low rigidity and do not pass in sheet-fed machines, as well as with thick materials that can be wound on a roll.

The flat printing plate, the flat support surface and the complete immobility of the printed material, the printing plate and the support surface during the ink transition ensure high print quality. The supply of the printed material is cyclic, with preliminary unwinding. During the ink transition, the printed material, the supporting surface and the form are immobilized. This makes it possible to work with very thin stretchy materials, to obtain accurate ink registration on the print, and to produce products with high print quality. Labelmen PWS-310 roll-to-roll screen printing machines operate at speeds up to 60 prints/min. The computer system for positioning the printed material by the control mark and vacuum fixing ensure accurate alignment of inks on the print during multiple printing from roll to roll. It promotes and prints with virtually no waste.

Additionally, tunnel UV or IR dryers, a roll winder for printing from roll to roll, cutting, embossing, roll slitting and roll cutting into separate sheets can be installed in line with the screen roll machine. This allows you to get ready-made two-color advertising printed products in one working cycle of the machine, which makes the production of low-circulation two-color (multi-color, in several passes) printed products profitable. The Labelmen PWS-310 machines can also be used for screen printing one or two color images on prints printed with other printing methods, when working from roll to roll.

There are also more professional, semi-automatic machines for printing on sheet materials. They are equipped with a micro-drive system, a vacuum table, an automatic squeegee movement device, with the possibility of attaching the "Take off" system, that is, automatic removal of the sheet after printing for transportation to the drying device.

Such machines allow you to print large runs of calendars, brochures, art albums, posters, box cuts, posters, with full-color prints or UV varnishing, with a three-dimensional paint layer accessible only to the screen printing method, finishing with various types of decorative varnishes and glitters, and the ability to print large formats at an affordable cost of equipment.

Machines for printing on cylindrical surfaces(bottles, mugs, glasses, accessories for cylindrical industrial equipment, bottles, jars for the perfumery and cosmetics industry).

To apply a durable multi-color image to a mug, bottle or other object of a similar shape, the above-described semi-automatic stencil machines of the SCF series are often used. To print on cylindrical and conical surfaces, a tool for printing on cylinders (fixing device) is installed on the machine, the forced rotation of which (and, consequently, of the product) is synchronized with the movement of the printing plate.

Print by textiles(T-shirts, T-shirts, jackets, baseball caps, work clothes, flags, pennants, that is, almost the “most souvenir” goods).

The principle of screen printing on textiles is not much different from printing on other materials. But the printing itself, as a rule, is carried out using the “wet-on-wet” method, that is, the second ink color is superimposed on the first one almost immediately, after a short drying of the top layer of the first ink print (fixing). As a result of this, and also due to the fact that inks for printing on textiles differ in their composition and properties from inks for graphic printing, the method of drying the finished prints will also be different.

The simplest manual machine for printing on T-shirts, T-shirts, work clothes is an analogue of the machine MT-45A, with one printing unit, differing only in the type of printing table - it is designed so that clothes can be "put on" on a flat rectangular table. Unfortunately, the possibilities of such a machine are too limited. In order to obtain a machine for single or multi-color printing with the possibility of obtaining high-quality prints, the number of printing tables is increased, as well as the number of printing units so that the upper and lower tiers can rotate relative to each other, resembling a carousel. So you can apply the second and subsequent layers of paint without removing the product from the table.

Very important factors for choosing a machine are the presence of the same micro-registers for each section of the printing carousel, as well as the presence of high-quality traps (devices for positioning the printed assembly over the subject table at the time of printing). An example of machines that meet these conditions are carousels of the series Practice production Aeroterm. On such machines, you can print on work clothes, sports bags, T-shirts, T-shirts. The indisputable advantage of such models is an affordable price with good quality and reliability of these machines. The main consumers of such carousels are start-up advertising and production companies and small manufacturing enterprises.

The next level of professionalism are manual vertical lathes of the series Printex (Aeroterm). Reliable rigid construction, high register accuracy and ergonomic design have made these machines leaders in their class. They are designed for multi-color and full-color printing on T-shirts, work clothes, scarves, cuts of various textiles, etc.

For firms specializing in the production of textiles or the production of large volumes of printed textiles, carousels of the series type are more relevant. Chameleon production M&R. Firstly, these machines have a three-level pyramid design, which allows, if necessary, to expand four- and six-color models up to 10 colors. Secondly, the profile design of the supporting frame ensures maximum rigidity and lightness of the carousel during operation. Thirdly, all parts that perceive significant dynamic loads are made of hardened materials with increased wear resistance, and aluminum alloy work tables are covered with a layer of special rubber that is resistant to paints, solvents and heat. All this, as well as the increased accuracy of all adjustable mechanisms, will allow you to print a lot, with high quality, without stopping production for additional adjustments, adjustments and equipment repairs, and, therefore, increase the life of the machine and get the expected profit.

Screen printing laboratory equipment is designed for the preparation of screen printing forms. It is a pneumatic copy frame, an exposure device and an exposure unit. Laboratory equipment is designed for the manufacture and restoration of the main thing: a screen printing form. Auxiliary equipment includes dryer trolley, intermediate infrared dryer, doctor blade grinding machine. Finished prints are placed on the dryer trolley, an intermediate infrared dryer is used to polymerize inks when printing on carousel machines.

Printing, manual and auxiliary equipment is the main equipment for silk screen printing. But do not forget about fan heaters and hydro guns, cutters, laminators, heat presses, foil machines, booklet makers, staplers, consumables and inventory, as well as a fully equipped computer. However, by owning hand-held screen printing equipment, as well as by professionals who, in turn, are proficient in screen printing technology, you can get quality products.

Technology in detail

We bring to your attention a detailed description of the technological process of silk-screen printing and the main devices and materials, taking into account the recommendations of Russian specialist Andrey Barkov.

After preparing the photoform on a computer in the Corel Draw graphics editor, it must be printed on a special film for laser printers (it comes in two types: matte and glossy). You need to print on a laser printer with a resolution of 600 dpi (or 1200 dpi). Another way is photo output, some printing houses provide such a service.

The next stage of the process is matrix fabrication. Screen printing form (stencil, matrix, template) is a frame with a mesh fabric stretched over it. The fabric is then covered with a photosensitive substance and exposed together with a film-diapositive. Places of the printed form, which were not covered with a transparencies, do not dissolve in water, harden. And closed places are washed with water. Such a stencil can be used several times, which is very convenient.

Important properties of a screen printing stencil are the number of cells and the thread diameter. For example, 120 threads per centimeter, the diameter of each thread is 34 microns. It is best when the number of threads per centimeter is greater, and the thread diameter is smaller. Today, fabrics are made with up to 200 threads per centimeter. These values ​​affect such important indicators as image clarity, print speed, ink drying.

Nets made of nylon (polyamide) fabric have been used for a long time because they have several attractive qualities: strength, good abrasion resistance, elasticity. These qualities make it possible to print with nylon fabric meshes on convex objects and use a variety of materials. There is a modified nylon fabric that has a lower elongation than the regular one.

Monofilament nets can be made from polyester fabric, a classic silkscreen material. Such meshes are resistant to wear and chemicals, and in addition, they have a number of qualities that are remarkable for screen printing: smooth surface, low elongation, resistance to climatic changes. Monofilament nets provide good ink penetration, reproduction of the finest details, and dry quickly. There is also a modified polyester fabric that is used for stenciling - it is more durable and does not stretch. The market for stencil fabrics today is developing every day.

A special emulsion is applied to the frame with a mesh ("silk"). For these purposes, a squeegee-cuvette is used. The emulsion is dried with a hair dryer.

Illumination is carried out as follows: glass is placed on the stand, and the frame is placed on top with the grid up, then the photoform is applied with toner to the emulsion (now it will become a mirror image), glass is again on top. This combination is placed under a lamp, usually an ultraviolet or halogen lamp, for a few minutes. Then, with the help of cold water, the matrix is ​​washed and again dried with a hair dryer. Minor flaws are corrected with special retouching. The matrix is ​​fixed in the machine, paint is poured and forced through the matrix onto the paper using a squeegee.

Having printed the required amount of products, it is necessary to wash the frame with solvents, wash the squeegee. The matrix, if the order is completed in its entirety, must be washed off, and if in the future it will need to be returned to, then it is saved.

The quality of the resulting product depends largely on squeegee, the figure shows the structure of this tool. Rubber is clamped with bolts. Rubber should be squeegee, it comes in different colors and hardness. Usually three types - soft, medium and hard. Soft is used mainly for printing on fabrics. Rigid for printing high-precision, high-quality printed products. Medium - for general printing, packaging, round surfaces.

You can try to replace branded rubber with oil and petrol resistant rubber, but such savings can hardly be called profitable. A squeegee with proper use will last a long time, but the quality suffers when replaced.

Frame made of hardwood, aluminum and steel, usually in the form of a parallelogram. The purpose of the frame is to hold the mesh fabric, and to hold it evenly. Wooden frames were used before and are used now. This is natural, because the cost, weight and plasticity make wood an indispensable material. In addition, there is a special technology for stretching the mesh on the frame, which not all silk-screen printers own.

And the tree allows anyone to fix the grid with staplers on their own. Such "manual" work provides not very accurate tension, however, it is often used in Ukraine, especially for small format products.

Unfortunately, wood is not a strong enough material - it bends, curves and absorbs water - the owners of wooden windows are probably aware of this. Nevertheless - and this is also known - if you cover the tree with varnish, then it resists the destructive effects of water and solvent for a longer time.

The advantage of aluminum for frame construction is that it is very light. This is an invaluable feature, especially for large format frames. Also, the aluminum frame can withstand a large mesh tension force. But aluminum is not without drawbacks: the high cost of welding, high oxidation ability, as well as problems with gluing the mesh.

Frames made of steel are much stronger than others, are inexpensive, durable. But steel weighs a lot and is prone to corrosion. The last drawback of steel can be dealt with if you use "stainless steel" to make the frame. Such a frame, however, weighs even more steel, but it is not subject to corrosion.

Special devices for tensioning the mesh of a pneumatic type, for example, series Max Newton production M&R. Their action is based on the work of pneumatic cylinders with grippers for attaching the sieve. The control unit provides tension control in two directions. The grips are made with a special coating that prevents the fabric from slipping during operation. The model of such a device is selected depending on the maximum TPF format. The number of working pneumatic units will also depend on this.

However, in the domestic practice of screen printing, steel and stainless steel frames are used infrequently. We believe that this is facilitated by the fact that it is impossible to manually stretch the mesh over the steel frame. And since the practice of doing everything ourselves is quite often used in our country, they prefer wood to make frames.

So, for the manufacture of frames of small formats, it is better to use steel and wood. In the first case, because it weighs less, in the second, because it curves. For a large format frame, aluminum is the best choice.

If you still practice "manual labor", it is better to make the frame into a spike. Sometimes the corners of the frame are cut off. The frame must be cleaned with emery and varnished well with nitro-lacquer, drying oil several times, and then dried. The size of the frame should be 4-6 cm larger than the printed format on each side. A spade of 4-5 cm is made from above and below.

Main characteristic sieves- his number. The number means the number of threads per square centimeter, the more of them, the thinner the sieve and finer details can be printed on such a sieve.

Usually, for printing high quality printed products, sieve numbers from 120 to 160 are used. Rougher numbers are used for printing on cardboard, packaging 70-100. For printing on fabrics with special plastisol inks, numbers 40-80 are suitable.

Mechanical and pneumatic sieve tensioning systems are much more convenient than manual ones. Self-tensioning frames are also popular. The quality of the sieve tension on them is much better than manual. But the price of such systems is quite high.

To do everything by hand, you need to stretch the sieve well on the frame; the quality of the print largely depends on the tension of the sieve. The easiest way to do this is by hand, but the stretch is uneven. A more convenient way is to use special tongs.

Pulling the sieve by hand is best done with two people. A piece of sieve with a spade of 4-5 cm should be well wetted in warm water. It is laid out on top of the frame, stretched and fixed on one side of the sieve on the frame with the help of buttons, carnations with a wide hat or, better, brackets from a construction stapler. The opposite edge of the sieve is clamped in the middle into the tongs and, using the handles of the tongs as a lever, the sieve is pulled. Then it is again fixed with buttons or a stapler. Pulling the sieve with tongs, fix the entire side. It remains to repeat the procedure on the other two sides.

The frame is re-varnished with nitro-lacquer along with a sieve along the edges. When doing this, make sure that the varnish does not get on the stretched surface of the sieve. After the varnish dries, you can varnish again, for reliability.

Illumination process.

Most often, it uses two main lighting schemes: a lamp from above or a lamp from below. During illumination, those areas of the emulsion that are exposed to light are tanned. And those that were under the toner (photoform - positive) are not tanned. After exposure, these areas are easily washed off with water. And on the matrix on the emulsion remains a copy-reversal (inversion) of the photoform. When printing through the washed holes, the ink is pressed through. To obtain a high-quality matrix, it is necessary to press the photoform as tightly as possible to the emulsion layer. This is done either with clamps or with the help of a vacuum clamp, which requires a compressor. As already mentioned, glass is placed on the stand, smaller than the frame. Then comes the frame, printed side up. Now the photoform, it is placed on the printed side of the frame with a layer of emulsion applied. The photoform is placed with a toner on the emulsion (when printing, the photoform is output as a regular sheet, without mirroring). A mirror image of the photoform appears on top. On top of the photoform - glass smaller than the frame. You need 2 glasses for each size of the matrices.

Glass at the edges should not be sharp, smoothed. (so as not to damage the sieve). It remains to fix it all with clamps in all corners or diagonal corners of the frame. It remains only to turn on the lamp.

When illuminated, the distance from the lamp to the frame with the photoform should be 1.5 diagonals of the photoform, the angle of incidence of the rays on the frame should not exceed 60 degrees. The illumination time can be determined manually with a stopwatch, or you can use a photo relay with a timer through which we connect the lamp.

For exposure, you can also use exposure cameras, which in their design resemble exposure cameras for illuminating polymers. Such chambers have a vacuum clamp and grooves along the perimeter for the location of the stencil frame with the grid. Depending on the format of the form, you can choose exposure cameras, for example, NuArc production M&R, Ming Tai.

To choose the right exposure time, take a sheet of thick black paper. On the photoform, several identical images are printed one under the other, it is desirable that they also include small text. Fix the photoform on the frame with transparent adhesive tape. And with a felt-tip pen on the photoform next to each image write the time: 2 minutes, 2.30; 3.00; 3.30; 4.00; 4.30; 5.00.

The frame is installed under the lamp and all but one part of the photoform is covered with a sheet of paper. Turn on the lamp for 2 minutes, then slide the sheet of paper and open the next part. And the illuminated one also needs to be covered with something. Turn on the lamp for 2 minutes 30 seconds. So, moving this "window", all parts are highlighted. For example, photoforms are illuminated from a distance of 55 cm for 4 minutes, 25 seconds with a halogen lamp power of 1.5 kW. AZOCOL POLY PLUS S-RX emulsions are used. So there will be a different time for other lamps and emulsion. The exposure time also depends on the sieve number and the number of emulsion layers.

For matrix washing the container (this may be a bath) is filled with cold water by 10-20 cm. The frame with the illuminated emulsion is placed horizontally in the water. The water should completely cover the frame. The frame is rinsed, and after a while the unexposed areas of the emulsion are washed out, the stencil gradually appears. Shake off water from the matrix, and then, holding the frame horizontally, dry it with a hairdryer. If, after a long rinse, the matrix was poorly washed (this means that the matrix was overexposed, it will be necessary to reduce the exposure time), we direct a jet of water under pressure to unwashed areas, the text, without stopping the jet in one place so as not to blur the stencil, and only from the inside framework. In this way, the intersected matrix can be washed.

If, when washing the frame in a container with water, the matrix is ​​completely washed off, or small details are blurred, then the frame is underexposed with the emulsion. It will be necessary to increase the exposure time.

One of the advantages of screen printing is the ability to stencil regeneration, which means they can be used multiple times. Once a stencil is no longer needed for one run, it can be saved and used for another order. There is a stencil regeneration technology, which is based on removing the past emulsion layer from it. It should be noted here that successful regeneration of a screen printing plate is possible only if exposure is carried out in accordance with all the rules. Otherwise, it may be difficult to remove the old layer.

The process of stencil regeneration is inextricably linked with the interaction with a wide variety of chemicals. Therefore, it is important for a silk screen printer to use goggles, gloves, and a respirator. So, to restore the stencil, you need to: clear the grid of paint, remove the old emulsion layer and shadow images. At the same time, it should be remembered that the stencil is not eternal: the paint is cleaned with the help of solvents, which gradually corrode the mesh. Therefore, the stencil "wears out" over time and can be used a limited number of times.

Any hostess knows - to clean a stain or dishes from food, the easier it is, the faster it is done. It's the same with silkscreen ink. After the print is finished, the ink must be washed off the stencil immediately, or this will be almost impossible to do after some time has passed. Special solvents are used to clean the grid from paint. The old emulsion layer is removed with the help of special oxidizing preparations that soften it. These can be powders, tablets or ready-made solutions. Then the drug is evenly applied to the stencil and after a while washed off with a strong pressure of water.

Before we talk about deleting shadow images, let's first define what shadow images actually are. The ink used in screen printing contains pigments. When the paint is applied to the stencil, these pigments penetrate the threads of the mesh stretched over the frame and color them. Then the grid is multi-colored. The resulting effect is called "shadow images". Remove shadow images, again, using special tools. This process occurs in the following sequence: the stencil is moistened with an activator-cleaner and an alkaline paste is applied to it. After 10-30 minutes, the stencil is washed with a strong stream of water.

Important point - vacuum table device. As a printed surface of the table, thick plexiglass (plexiglass), plastic or stainless steel is more often used. An important requirement for the surface: it must be smooth and flat, without bumps, swellings and cracks. Small holes of 1.5-2 mm are drilled over the entire surface of the table. The distance between them is 1.5-2 cm.

On the reverse side of the table, a rubber gasket is fixed, or a window insulation in the form of a hose. A sheet of plexiglass or plastic with a suction hole is attached to the gasket. The gap between the table and the sheet of plastic should be from 0.5 to 1.5 cm. Air is pumped out of the gap, and air is sucked in through the holes in the table. Thus, any sheet of paper sticks to the table and does not move. This allows you to achieve accurate registration when printing in multiple colors.

You can increase the suction force by filling some of the holes with sheets of paper. And, on the contrary, if the suction is too strong, loosen it by removing the sheets from the holes. To create a vacuum suction device firms that sell equipment also offer compressors. You can also use an ordinary vacuum cleaner or a fan for this. Vacuum suction is used to work on flatbed printing machines, it is not needed for printing on cylindrical surfaces or on fabrics.

A little about photosensitive emulsions They can be divided into four groups. Emulsions of the first group are resistant to solvent-based paints, but are "afraid" of water. Emulsions of the second group are resistant to water-based paints and plastisols. The emulsions of the third group are universal, and with the help of the emulsions of the fourth group, a thicker layer of paint can be obtained. To get a good stencil, you need the photo emulsion to cover the grid evenly. On the printed side of the grid put 1-2 layers, on the side of the squeegee 1-4 layers of emulsion. The stencil is then dried.

Although there are a fair number of emulsions on the market, some printers prefer to produce emulsions by hand. Most often, those who have problems with the supply or with the price of imported emulsions.

The main disadvantage of a homemade emulsion is a short shelf life. The rest of the shortcomings can be written off, since the cost of a home-made emulsion is 50 times lower than a branded emulsion.

For the production of an emulsion in artisanal conditions, it is required: gelatin about 2 cu. see and ammonium dichromate (NH4) 2CR2O7, in the common people "chromic". Gelatin in granules is placed in a two-hundred-gram glass glass and half filled with cold water. In a couple of hours, the gelatin swells. In the meantime, "chrompic" is dissolved in a glass of water (50 g) until a saturated solution is obtained.

The next step: you need to completely dissolve the gelatin in water. To do this, pour water into the pan, place a glass of gelatin in it and heat it, stirring, so that the gelatin dissolves.

The resulting brew and bright orange "sauce" must be thoroughly mixed. This should be done in a dark room with a red lamp.

The finished emulsion is stored in the dark for no more than a week. It is applied to the frame, like a conventional emulsion, with a squeegee cuvette, but in the dark with a red lamp. The illumination process is the same. The matrix is ​​washed out with slightly warm water. After printing, to wash off the unnecessary matrix and clean the sieve for the next one, a solution of caustic soda is used.

There is another recipe. The emulsion created according to it can be stored for a longer time:

1. Gelatin, 50 g.

2. Ammonium bichromate (NH4)2CR2O7, 6 g.

3. Ammonia 10%, 20ml.

4. Citric acid, 3 g.

5. Water, 80-100 g.

Matrix retouching for printing in one color is not too difficult. In the light on the matrix, in addition to the design, small holes-breakthroughs in the emulsion layer will be noticeable in places. They need to be retouched. For these purposes, a special retouching (for example, KIWOFILLER) is best suited. All these breakdowns are covered with retouching, using a match or a brush, and then dried with a hairdryer. Retouching for printing products is resistant to solvents, but is easily dissolved and washed off with water. With the help of retouching, you can print from one matrix in several colors. First, one color on the matrix is ​​smeared with retouching and the other is left open. After printing the required circulation, the color covered with retouching is washed off with water, and the printed one is smeared. Then the second color is printed from the same matrix, thereby saving the emulsion, instead of two or three matrices, one is produced.

It is not recommended to save and replace retouching, it is spent very economically, it lasts for a year or more. And yet, some people replace retouching with nitro varnish (washed off with acetone) or PVA-type glue, resistant to solvents, but soluble in water.

For preparing the frame for printing You need a wide tape and thick paper. Having installed the frame in the grips of the machine, you need to pour paint into it. And then the paint will be squeezed through the areas open from retouching and emulsion. Paint can flow freely along the edges of the matrix, these slots are closed with adhesive tape. Although many experts advise covering all edges with retouching, using tape is much more economical.

Before installing the frame in the grips, you can simply lay out the corners of the frame from the inside with tape. When using a small matrix or 2-3 matrices on one frame, part of the inner side of the frame can be covered with thick paper, fixed along the edge with adhesive tape. True, having printed the desired color, you will have to tear off the adhesive tape, clean the frame and seal it again with adhesive tape.

Sometimes you can print several colors from one frame by simply blocking them with cardboard partitions with adhesive tape. Having printed one color, it is simply glued on the printed side with adhesive tape and ink is poured into the adjacent cell, printing the next color.

Consider paints for printing printed products. Screen inks have high viscosity and strong hiding power. The great advantage of screen printing is the ability to use a wide variety of inks for printing. In silkscreen printing, you can print with glossy and matte inks, print with gold, silver, print with white ink or transparent varnish. With this technology, you can achieve a wide variety of decorative effects that are not available with printers.

Silk-screen printing ink should be thick, in the condition of good sour cream or mayonnaise. Another quality indicator: the paint should be saturated, well pigmented, opaque.

The most famous specialty screen printing ink has the acronym TNPF(Stencil), produced in Torzhok, Russia, it is known throughout the CIS. At some point, the plant fell apart and practically did not produce paint, but now the crisis has passed. More precise technical information can be found on the plant's website. The plant also produces special paints for glass, metal and plastic. Standard prices - from 5 to 20$ per kg.

For printing, inks on organic solvents of firms are also used. Sericol(England), Marabu(Germany) and Apollo(England). To work with “complex surfaces”, paints from the company RUCO. These paints are widely used in the design of bottles and jars for cosmetics, plastic bottles for household chemicals, machine oils, gasoline, and food packaging. They are represented by 15 basic colors, a bitmap set (cyan, yellow, magenta and black) plus gold and silver. Mixing system" RUCOLOR 2" allows you to get any shade from the base colors according to generally accepted catalogs Pantone.

Instead of a special screen ink, you can use offset ink. You need to add varnish to it, since the paint is matte and dries for a rather long time.

Specialty paints can also be replaced with regular alkyd enamels, which can be bought at any hardware store with a good selection of colors. Unfortunately, most enamels are too fluid to print, so you have to work with them.

First recipe. An open jar of paint is put on a slow fire and boiled, stirring occasionally, for 15-20 minutes. Until the condition is like that of a thick jelly, bubbles on the surface emerge, but do not burst immediately. You need to try first in small containers. And with experience comes an intuitive feeling when the paint is ready. Cooking paint improves pigmentation, varnish evaporates. Another observation: when cooling, the paint becomes much thicker than when it is boiled.

The cooled ink is ready for printing. If it is too thick, dilute with enamel thinner, kerosene or white spirit.

Second recipe. You need to drive water into ordinary liquid enamel, then the enamel becomes thicker. Thus, from one can of enamel, two can be made. The paint must be used immediately - after standing for a while, water will begin to stand out from the enamel.

How to get matte from glossy paint? A soapy solution is driven into the glossy enamel. To get glossy from matte, you need to add alkyd varnish.

When for printing process everything is ready, the frame with the matrix is ​​​​fixed in the grips of the machine. Now we need to set up the frame. The distance from the lowered frame to the printed product should be about 3-5 mm. It is important that the printing press has the ability to adjust this distance. Some paint is poured into the frame.

The squeegee is taken in hand and the paint is rolled towards you. The pressure should be uniform, the movement should be smooth, but not slow. The squeegee is held at an angle. The idea of ​​printing is simple: they grab a little paint with a squeegee and push it through the matrix onto the surface to be printed, paper, self-adhesive, cardboard. Then the printed sheet (or other object) is removed, a new one is placed, and the same sequence of actions is repeated.

There are two printing options: rolled and unrolled. Roll-on, before printing, each time a layer of ink is rolled onto a matrix with a raised frame. This allows you to get a thicker layer of paint on the product. Used for printing with light colors on dark papers, cardboards. Without rolling, respectively, they print immediately on the product, without rolling paint. The lines are thinner, respectively, the paint layer is thinner. So more often print high-precision orders and full color.

There are also two ways to apply images. The first is contact, the second is non-contact. Non-contact is used very rarely - when using it, the material does not touch the mesh, and the paint is transferred from the mold using electrostatic forces. In the contact method, respectively, the grid is in contact with the printed material, and the ink is supplied with a squeegee.

If the matrix suddenly begins to float during printing, it must be wiped with a cloth with a solvent, then with a dry cloth. Sometimes, if the image is blurry, you need to change the distance between the frame and the table.

Problems that arise during printing often require small changes: change the pressure on the squeegee, change the angle of the squeegee, change the distance between the frame and the table, increase the vacuum suction. You can master the printing process in half an hour, the rest comes with experience.

Leaf base and color matching. To print long runs accurately, even in one color, it is necessary to fix the printed sheet in the right place, and place each next sheet in exactly the same place. This place is called "base". Usually, an angle is used to create a base. The corner is made from sheets of thick paper and attached to the printing table with adhesive tape or PVA glue. Further, each subsequent sheet is placed exactly in this corner, which allows you to achieve equally good alignment in large print runs. The corner is laid out on an exactly aligned sheet. If the surface of the printing table is made of plexiglass, that is, transparent, it is adjusted to the light. A lamp is placed under the table, a vacuum suction device is turned on, a sheet is placed on the table, a frame with a matrix is ​​lowered and the desired alignment is achieved through the light. The frame is lifted and a corner of thick paper is glued out, without removing the sheet and without turning off the suction cup. Other colors are adjusted in the same way.

With an opaque table top, you will need a sheet of thick transparent film - a film for photo output or photo forms is ideal. We need to fix one side of the film with adhesive tape, so that its main part is strictly under the frame with the matrix. After that, ink is poured and printed directly on the film, the vacuum suction is turned on and the sheet is adjusted according to the image printed on the film. Then the corner-base is fixed on the sheet. The following colors are adjusted in the same way.

The convenience of micrometric registers on the machine facilitates the alignment process. Here it is enough to tweak a little settings and continue typing. And there is no need to re-glue the base-corner.

To facilitate color matching, it is convenient to use adjustment marks for printing accuracy. They are placed on a color separation photoform at the corners of the image. Now, in order for one color to "get" into another, you need to combine the risks. It is problematic to match colors without risks when printing full-color or multi-color images.

This is, in general terms, silk-screen printing. A method that is clearly most focused on medium and small businesses, and also goes well with other types of printing. However, even such a universal and original technology does not exhaust the topic of souvenir printing.

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Silkscreen technology. The information below should not be considered as a direct guide to action. The information is an overview, the main task is to convey a certain minimum to those who have no idea what silkscreen / screen printing is.

Since there are many key points in the technological chain, we strongly recommend that you carefully study the literature on this topic and consult with equipment and material suppliers.

Silkscreen technology. Screen printing plate

Silk-screen printing technology implies, first of all, the production of a screen printing plate. For manufacturing, as a rule, aluminum rigid frames are used.

Roller frames and wooden frames are used much less frequently. The first due to the relative high cost, and the second, wooden frames - the most economical option, but not the best.

Using tensioners, a special mesh made of polyester or stainless steel is stretched, then the mesh in the stretched state is glued to the frame.

On the video: the process of tensioning the mesh on the high-end tensioner SAATI TOP12 is shown.

There are also simpler and cheaper mechanical tensioners. Some printers use roller frames as tensioners, although they are not designed for this. If they are used for their intended purpose, then there is no need for a separate tensioner and glue.

On the video: the process of tensioning the mesh on the roller frame

After the mesh is stretched and glued to the frame, using substances that fall under the general name "chemistry", the mesh is roughened and degreased.

We apply a photosensitive layer - these are photographic emulsions or capillary films.

A photographic emulsion is poured into a squeegee cuvette and applied on both sides of the grid.

In the video: applying the emulsion with a squeegee-ditch.

In the photo: drying cabinet for screen printing forms

With a large load of the stencil section, drying cabinets are used, in which several racks are placed.

The next stage of screen printing (silk-screen printing) technology is exposure. Exposure from color-separated films takes place in exposure devices with a vacuum clamp, as a rule, by contact.

In the photo: exposure device with a point light source

After exposure - development. Unexposed areas of the photolayer dissolve in water, illuminated areas remain on the grid. Development takes place on stands that have a backlight and do not allow splashing.

On the video: the process of preparing the grid before applying the emulsion, applying the emulsion, drying, exposure and development is shown.

The screen printing form is ready. The number of printing plates = the number of films = the number of colors that the design will be printed with. It should be noted that in most cases, the stencil can be removed from the grid and the photo layer applied again - i.e. make a new stencil (a process called "regeneration").

In the photo: this is what the stencil looks like when enlarged

Due to the characteristics of the equipment used, printing is divided into textile and graphic.

Silkscreen technology. Textile screen printing

Printing takes place on rotary machines. Printing plates are attached to the printheads, and T-shirts are put on the tables. The paint is pressed through the stencil with a squeegee. On manual machines, we print the first color on all T-shirts put on the tables, then the second color, etc. On automatic machines, printing occurs simultaneously on all print heads.

In the photo: a manual carousel machine for printing on T-shirts

When really good productivity is required, automatic textile carousels are used.

In the photo: automatic carousel machine for printing on T-shirts

In the direction of rotation of the tables, an intermediate dryer is installed - “drying”. On a manual press, it is placed in such a way as to dry the ink on one table while the printer prints on another. It is used when they do not print "wet-on-wet", that is, almost always. On an automatic machine, it is usually installed instead of the print head.

In the photo: intermediate dryers - "dryers" are used for multi-color printing

After the last color has been printed, the T-shirt is removed from the table and passed through a tunnel conveyor dryer for final drying. If performance is not needed, then an intermediate dryer can be used for final drying (plus: noticeable cost savings, minus: significant loss of performance - several times).

Silkscreen technology. Graphic screen printing

The classic version is a machine with one printing plate and a table that provides vacuum clamping of the product / distal materials. Multi-color printing is carried out sequentially: we print the first color on a certain run, dry it, change the printing form, print the next color, etc.

Semi Automatic Screen Printing Machine

Depending on the paints used, different types of dryers are used. UV dryers are used for drying paints, varnishes and other materials with UV curing.

Conveyor UV Dryer

IR conveyor dryer with air circulation in the tunnel - a high-performance alternative to the pile dryer (pictured: Turbo JetStar dryer)

Stalk dryer - an economical option for working with solvent paints

Instead of a conclusion

Each type of equipment listed above has different options both in design features and characteristics, and in price. Therefore, first of all, you need to decide on the tasks. At a minimum, this is:

Type of printing (textile or graphic)
Maximum print size
Maximum number of colors/paints
Maximum productivity (e.g. impressions/hour, shirts/shift, etc.)
Is full color printing planned?

For more information, see the section, the FAQ section, and other sections of our site.