Horizontal veneer planer. Equipment for the preparation and processing of sliced ​​veneer

Sliced ​​veneer is a thin layer of wood with a beautiful texture and color. Most often it is used as a facing material in the manufacture of furniture.

As a raw material for the production of sliced ​​veneer, rocks with a beautiful color and texture are usually used. This is wood of tropical species, as well as species growing in Russia. Most of the tropical woods used in the production of sliced ​​veneer come from Africa. Mainly used: akazhu (African mahogany), sapeli, sipo, kosipo, tpama-edinam, kotibe, framire, dibetu (African walnut). Tree species of India, Vietnam, Laos are also used. From domestic raw materials are used: ash, beech, oak, maple, elm, elm, walnut, chestnut, plane tree, velvet, birch bark, poplar, birch, alder, pear, apple, cherry, larch and others.

Planing veneer, like peeling, is cutting wood across the grain. A schematic diagram of the planing process is shown in fig. 37. As with peeling, veneer crimping is performed using a pressure ruler.

Rice. 37. Scheme of planing veneer:

1 - knife; 2 - pressure ruler; 3 - vanches

The thickness of the sliced ​​veneer depends on the type of wood. For scattered vascular hardwoods, it is 0.4; 0.6 and 0.8 mm (beech, walnut, apple, pear, red and lemon trees); for annular vascular – 0.8; 1.0 mm (oak, elm, mulberry, chestnut). wood veneer conifers has a thickness of 0.8; 1.0 mm.

Length of veneer sheets from 550 mm and above. Width depends on grade: grade I – not less than 120 mm, grade II – not less than 80 mm, veneer moisture content 8±2%.

The transverse cutting of logs into ridges is carried out according to the same technology as sawing logs into blocks before peeling.

For the production of sliced ​​veneer, cuts of logs must be limited to at least two flat or parallel surfaces, which are the base and the initial planing surface.

There are several ways of longitudinal cutting of ridges into vanches. The choice of cutting scheme is dictated by the size of the raw material, the type of wood and the desired texture.

The core in sliced ​​veneer is not allowed. Sapwood that has a light or abnormal coloration is also removed.

For cutting logs in the longitudinal direction, horizontal or vertical band saws and horizontal sawmill frames are used. The former are more widely used, as they provide high cutting accuracy, clean cuts and make it possible to saw logs of large diameters. Also widely used are highly specialized circular saws from Angelo Cremona (Italy), their distinctive feature is the ability to rotate the log at any angle around its longitudinal axis.

Hydrothermal treatment of logs before planing is considered by us in Section 4.3.

Veneer planing is carried out on horizontal, vertical or inclined veneer planers. Vanches are fed to veneer planing machines with the help of overhead cranes (or a hoist along a monorail).

Currently, horizontal machines of outdated models (FMM-3100, FMM-4000, DK-4000, etc.) are gradually being replaced by horizontal machines with a crank mechanism - DKV-3000, DKV-4000 (Czechoslovakia), inclined - TN28, TN35 , TA40 (Italy), as well as vertical type machines SM/36, SM/40, SM/46, SM/52 (Germany). Veneer planing machines from Angelo Cremona (Italy), Grenzebach-BSH (Germany), MZQ 200 brands are gaining popularity; 250 firms "Kami-Stankoagregat" (Russia), etc. (Fig. 38-40)

Veneer Slicers Capital Machine Co. Inc. (USA) are designed specifically for the production of thin veneers, they are capable of producing the thinnest veneer in the world - 0.005" (0.127 mm) thick. The maximum thickness of the veneer can go up to 0.250" (6.35 mm).

Rice. 38. Scheme of operation of a horizontal veneer planer: 1 - machine table, 2 - clamps; 3 - bars; 4 - support; 5 - pressure ruler; 6 - planer knife

Rice. 39. Horizontal veneer planer brand TN "Angelo Cremona"

Rice. 40. Vertical veneer planer brand TZ/E "Angelo Cremona"

On horizontal machines, cutting is carried out in a horizontal plane, the main working reciprocating movement is performed by a knife, and the movement of material supply is carried out in a vertical plane during idle, by an amount equal to the thickness of the layer being removed (veneer thickness). The disadvantage of this equipment is the forced braking of the caliper stroke before changing the direction of movement (violation of smooth running, equipment wear, cutting speed reduction).

On vertical machines, the material to be processed is placed on a carriage that reciprocates in a vertical plane. The knife is mounted on a support that periodically moves in a horizontal direction to remove wood of the required thickness. These machines are compact, convenient selection of veneer from the machine. But only one beam can be installed on the carriage.

Inclined machines are convenient for selecting veneer sheets. They are less energy intensive, have smaller dimensions (improved vertical machine).

The amount of veneer from one vanches (F, m 2) is determined by the formula:

where D is the diameter of the ridge from which the vanches is cut, taken in the middle of its length, mm;

H 1 - the height of the segment separated from the vanches during its longitudinal cutting, mm;

H 2 - the thickness of the board remaining after planing the vanches, mm;

S – veneer thickness, mm;

l is the length of the vanches, m;

b cf - the average width of the sheets, m.

During the planing process, veneer sheets are stacked in a pack (knul) in the sequence in which they exit the machine. This facilitates the selection of sheets by texture when gluing them on edge.

The produced veneer is dried, sorted, cut and packaged.

For drying, roller and belt dryers are used. Drying modes are softer than those of peeled veneer: drying temperature 80 ... 130 ° C; humidity - 15 ... 25%; drying time 6…35 min.

Price: $31,000 (1 962 025 ₽)

Designed for the production of sliced ​​veneer of various thicknesses. The operation of the machine provides…

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Planing is carried out in a reciprocating manner, which ensures high productivity and...

TekhLesProm offers customers from Moscow and other cities to buy woodworking equipment, including veneer planing machines. They are in demand in industries whose activities are related to the manufacture of furniture, parquet, container boards and various kinds facing materials.

Implemented planing machines allow you to produce high-quality, durable, noble and spectacular material. Devices provide processing by reciprocating movements. They are suitable for working with bar materials that have natural moisture.

What should I pay attention to when choosing a veneer planer?

The price for various modifications of veneer planers varies depending on their functionality, technical and operational parameters. When choosing, please note:

• on the feed rate of the material (the productivity of the equipment depends on this);
• the presence or absence of restrictions on the length of the blanks;
• the thickness of the resulting veneer;
• angle of inclination of the planer knife;
• electric motor power;
• maximum thickness and width of the workpiece.

We offer to order equipment by contacting the TekhLesProm manager by phone. Our consultant will outline the terms and conditions of delivery and answer all questions.

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The expression "veneered cabinet" today remains only in the memory of the older generation of compatriots, and our "new" furniture makers, who do not know professional terminology and speak their own, not understandable newspeak, have come up with the word "veneering" for themselves.

Meanwhile, since the time of Peter the Great, plywood has been called a thin layer, cut or sawn from the surface of not only wood, but even stone. moreover, the term arose from the Dutch fineer and the Swedish faner or fanret, and not at all from the German Furnier, as was once erroneously written in the Bolshoy Soviet encyclopedia and thoughtlessly replicated later on all Internet sites.

And what many people understand today as plywood was called glued plywood, that is, glued from several layers of peeled plywood, obtained in the form of a continuous tape in the process of peeling a block. Before gluing, this tape is cut into rectangular blanks, which were called veneers. Furniture makers used it as a sublayer when veneering (veneering) surfaces with planed (knife) plywood, and, in order not to make a difference that was originally implied, its sheets cut to size were also called veneer for brevity. And in 1978, the second word was quietly excluded from the standard for plywood, and it became generally incomprehensible who continued to veneer and who “venerated”. Therefore, it must be considered that the term “veneer” among furniture makers means planed plywood, which is used to line and veneer pieces of furniture.

Return to veneer

In the early 1990s, the foreign economic relations of our country were disrupted and the supply of raw materials for the enterprises operating at that time for the production of sliced ​​veneer completely stopped. The demand for it also fell sharply. This led to a halt in most planing industries and the transition of enterprises to the production of cabinet furniture using a “dry” technology - from laminated boards lined with thermosetting plastics in the form of single-layer films with sheet paper filler.

But in last years reverse process is observed. as the culture of furniture consumption and the material capabilities of our buyers grow, furniture products with natural veneer lining are becoming more and more in demand, and their lack of Russian market covered by imports. That is, for many of our furniture manufacturers there is an unfilled market niche that is not too late to occupy. This is facilitated by the fact that the country has created factories for the production of sliced ​​veneer, working on domestic raw materials (mainly oak), and the import of reconstructed veneer from Italy and China has been established.

Mastering the production of furniture products lined with natural veneer, in modern conditions can bring significant benefits to their manufacturer: the absence of intense competition with other manufacturers, increasing profitability, achieving brand awareness in the market for expensive products and creating their own brand.

But this, of course, is associated with the need to equip production with new equipment, the cost of which turns out to be very high. In addition, the country has completely lost the cadres of workers and technologists capable of working with veneer, and the heads of most enterprises do not even know what this technology looks like.

And today it is fundamentally different from the one used by carpenters half a century ago, it has been seriously improved compared to the one that existed at Soviet enterprises, and it is much more complicated than the one used today to make cabinet furniture using laminated or otherwise lined full-length wood boards.

This technology includes the following operations:

• longitudinal and transverse cutting (cutting) of veneer in knees (packs laid in the order of planing sheets) into blanks (plots);
• cutting out non-rectangular blanks from veneer for a figured set or for a set using the marquetry technique;
• splicing (rib gluing) of veneer plots into shirts;
• applying adhesive to the substrate;
• facing blanks with shirts made of natural veneer;
• removal of overhangs;
• sanding of veneered surfaces (white sanding).

Any enterprise that organizes a site for the preparation of natural veneer, first of all, must take care of its proper storage. For these purposes, a separate closed room with racks, necessarily equipped with a system for monitoring and maintaining air humidity, should be allocated. Overdried veneer becomes brittle, and its use leads to an increase in the number of rejects.

What machines do we need

Rice. 5. Guillotine shears that cut knoli with
high-precision cuts at any given angles
according to the program given by the CNC system

guillotine shears are used to cut veneer to size (Fig. 1), and in large-scale production - a combination of two such machines (with long and short knives) installed at an angle to each other. At enterprises with very high productivity, guillotine shears with two knives located in parallel can be used, which allow cutting two parallel edges of the knoli to a given width in one cut.

In recent years, edge-cutting machines have been used for cutting veneer, which were forced out of enterprises by guillotine shears. These machines are equipped with saw and vertical milling calipers that move in the horizontal direction (Fig. 2); they have smaller dimensions and weight than guillotine shears, lower cost; they make it possible to obtain in one pass a fugue on the edge of a veneer sheet, strictly perpendicular to its face, which is not always possible to achieve when using scissors, and do not require replacement of the guillotine knife for sharpening.

In the early 1970s, ribbed gluing of veneer plots began to be carried out using glass fiber with thermoplastic glue (glue thread), applied in a zigzag pattern across the junction of the plots in a special machine (Fig. 3). The glue thread is applied on the reverse side of the glued shirts, it does not need to be removed after the surface is veneered.

However, in recent years, machines for gluing veneer end-to-end, for a smooth joint, have again become widespread, which eliminates the formation of a gap between plots (Fig. 4). in the mid-60s of the last century, such machines replaced the equipment for gluing thick veneer (1.2 ... 1.5 mm) used at that time with gummed tape. Today, as a result of improvements in their design, they allow you to connect veneer with a thickness of 0.6 mm.

Veneer made from wood of many species is characterized by fragility along the fibers. Therefore, the prevention of cracking of its ends is of great importance. To do this, machines are used for gluing the ends with an adhesive thread similar to that used for edge gluing. it is applied in a straight line, parallel to both transverse edges of the plots from their non-front side.

Punching and straightening

The most expensive are veneered products, on the visible surfaces of which a figured set is used. There are quite a few varieties of it: “in height”, “in cross”, “in a checker”, “in an envelope”, with a frieze, “in a net”, etc. Almost each of them requires cutting non-rectangular plots, which are distinguished by high dimensional accuracy. It is almost impossible to cut them on conventional equipment without subsequent manual adjustment. Therefore, special guillotine shears were created that cut knoli with high-precision cuts at any given angles according to a program set by the CNC system (Fig. 5). However, the pattern of the elements cut out with such a machine is made by hand, for example, on a plastic mesh holding these elements, coated with thermoplastic adhesive. It is even more difficult to obtain a figured set of curvilinear elements, for which punching dies with special equipment are used, similar to those used in the shoe industry.

When cutting, gluing and subsequent veneering of blanks with natural veneer, the flatness of its plots and shirts is always of great importance. If the veneer has undulations, for example, as a result of improper drying after planing, it will not be possible to achieve High Quality rib gluing and cladding. Therefore, the veneer, which has a waviness along the edge, is first moistened, and then aged for some time in knolls in a cold press. Such an operation is obligatory before splicing short-sized veneer pieces into a toothed tenon along the length, followed by duplication and grinding of the front surface of the resulting tape.

Long veneer strips

With the transverse cutting of knees up to 4 m long into shorter plots, suitable measured waste up to about 300 mm long is inevitably formed. their use for facing workpieces significantly increases the useful yield of expensive material. The most common way to dispose of them is splicing on a toothed spike in the direction along the veneer fibers.

For splicing, special feed-through lines are used, which carry out zigzag cutting at both ends of the veneer segments and their connection (Fig. 6), gluing a transverse strip of paper or interlining at the joints and winding the resulting continuous strip of spliced ​​veneer into a roll (Fig. 7). Such veneer is used as a facing material for non-facial or invisible surfaces of furniture.

a layer of duplicating material can be applied on the wrong side of the rolled veneer tape, obtained by splicing its segments on a toothed spike along the length. To do this, glue is applied to it on a separate line, along the layer of which a continuous strip of porous material (non-woven fabric) is rolled, finally glued by heated shafts.

The resulting duplicated veneer is usually sanded on the front surface in machines specially designed for this purpose with sands of two or three numbers. The duplicated veneer can be used for veneering non-planar surfaces in membrane presses, moldings on wrapping lines, and after longitudinal cutting into narrow strips, as an edging material.

Rice. Fig. 7. Installation for winding the veneer tape into a roll. 6. Machine for cutting teeth at the ends of veneer pieces and gluing them into a tape

Removing overhangs and sanding before finishing

Peculiarity technological process production of furniture using veneer - the need for veneer blanks in detail. This makes it necessary to introduce into the technological chain the operations of removing overhangs and trimming parts according to the format, which requires the use of a double-sided sizing machine (with a carriage or a pass-through type), which simultaneously ensures the achievement of the exact size of the part and the perpendicularity of its longitudinal and transverse edges. In small businesses, they can be produced using a circular saw with a carriage, which is available in almost every production today. But the use of such a machine for sizing blanks is associated with high labor intensity, does not provide stable quality and accuracy of processing, and if there is a facing line, it does not correspond to its productivity.

At large enterprises, for sizing blanks with simultaneous removal of veneer overhangs, combined double-sided edge banding machines with units for sizing trimming, additionally equipped with supports for sanding the surface of the veneer edge. The final technological operation in the production of blanks lined with natural veneer, performed immediately before finishing, is the so-called white sanding.

In modern production, for this purpose, wide-band grinding machines. Moreover, for grinding veneer from wood of large-vessel species, such as oak or ash, it is sometimes necessary to use a cross-grinding machine, which, with its transverse belt, first grinds the wood fibers protruding like ridges to a certain height, and then brings the surface to the desired roughness with belts grinding along the fibers.

Mastering the production of furniture with veneer veneer is not an easy task that requires serious and costly decisions. And it cannot be argued that the payback of such production will be quick.

But an enterprise that has managed to master the technology of working with veneer will be able to take a strong position in the market and maintain it for many years.

Andrey DARONIN,
company "Media Technologies"
commissioned by LesPromInform magazine

Expensive varieties of timber are excellent raw materials for creating furniture, but not all people can afford such expensive products. In order to save precious wood species and reduce the cost final product and veneer was invented. This material is extremely popular today for facing furniture. Veneer 100% repeats the pattern, texture and shade of natural wood.

To create veneer in production, special machines are used. The veneer happens:

• shelled
• planed
• sawn.

Accordingly, the machine for the production of veneer is of three types.

To implement veneer peeling, raw materials must be pre-treated with steam in order to increase plasticity. After that, the logs are fed to the debarking machine, where the bark is removed from the workpiece, and with it dirt and sand, which often cause rapid blunting of peeling knives. With the help of a saw, the ridges are cut into blocks of a certain length. Churak must first be rounded, after which you can start peeling. The veneer strip that comes out of the peeler is placed on a conveyor that feeds it to the shears. Scissors cut the veneer into sheets of the required format. The veneer is stacked on the conveyor in a pack, which is taken out from under the shears and delivered to the dryer with the help of an electric loader. The products are dried in a roller dryer, then they are sorted on the conveyor and stacked according to grades in packs. Defective sheets can be glued. If there are knots on the sheets, they are sent to a veneer machine, where flaws are removed and decorated with veneer inserts.

Such a veneer machine allows you to get sheet material with a thickness of 1.5 to 5 mm from various types of timber. Most machines have a system that allows you to automatically set the log for further processing.

To increase the productivity and convenience of the operator, the machines are equipped with hydraulic center finder lifts, which themselves determine the appropriate axis of rotation of the workpiece and combine it with the axis of rotation of the centering shafts.

Peeling of steamed wood is used for pine, alder, birch timber. Plywood is made from peeled veneer.

First of all, the ridges are subjected to transverse cutting. During this procedure, the ridges are sawn into segments of the required length. All segments are sawn along, as a result of which a two-edged beam is formed. Sometimes it is cut in half. After that, the vanches are subjected to heat treatment in a steaming chamber or an autoclave.

Next, the vanches need to be cut on a veneer machine. Sliced ​​veneer is dried in roller dryers, trimmed and packed in packs. Each set contains a specific pattern. The shade and pattern of the wood must match in each set. It is for this reason that the veneer sheets, which are obtained from each vanches during planing, are folded, dried and packed in bundles in exactly the order in which they left the planer. When three vanches are planed at the same time, the veneer from each of them is stacked in three different packs. A bundle of veneer that is completed, dried, packed and tied with twine is called a knol.

The veneer machine allows you to create thin sheets from expensive varieties of timber that have an unusual texture. This material is great for veneer. Veneer creation methods:

• radial
• tangential
• radial-tangential
• tangential-end.

The most attractive raw material for creating veneer is oak wood. Such veneer is used for cladding rustic pieces of furniture in the elite segment.

In addition to oak veneer, in specialized stores you can find maple, beech, linden material, as well as mahogany.

The veneer is cut on specialized machines. It has a rather thin and fragile structure. In order to finish the surface with veneer, it must be interconnected to obtain a web rolled into rolls. The veneer is connected in two ways:

• gluing
• stitching.

These methods are equally popular in furniture production. The stitching of veneer is carried out on a machine or manually. For small workshops, manual devices for gluing or stitching veneer have been developed. Using a special device, the adhesive or thermal thread is heated, and applied in the form of a zigzag to the main side.

Today, veneer stitching machines are small machines that operate offline. Such a machine is controlled by one specialist. All work on them is carried out accurately, efficiently and quickly enough.

Hand-stitching is becoming less and less common, mainly in antique, restoration and author's workshops.

Copying machines are very helpful in creating a specific part from a template for small batches. The copy-milling machine is used both at enterprises engaged in the production of products for large wholesale clients, and in small workshops, as well as for domestic use. Industrial machines are able to create products in almost unlimited quantities. However, in this article we will talk about how to make a do-it-yourself copy-milling machine for small-scale furniture production.

March 21

21.05.2015

Sliced ​​veneer is a thin layer made from wood with a beautiful texture and color. It is used as a facing material for parts made of low-value wood, plywood and chipboard. The suitability of wood for the manufacture of sliced ​​veneer from it also depends on its structure, ability to be processed, finished and glued together, toxicological and strength properties, the presence of defects, etc. The structure of wood determines the thickness of the produced veneer. So, from wood of beech, walnut, maple, plane tree, pear, apple tree, poplar, birch, alder, hornbeam, sycamore, sweet cherry, red and lemon wood, Karelian birch, dimorphant, which has a scattered vascular structure, veneer is made with a thickness of 0.4 ; 0.6 and 0.8 mm. From the wood of oak, ash, elm, elm, mulberry, chestnut, velvet tree, acacia, zelkova, elm, which has an annular structure, veneer is obtained with a thickness of 0.8 and 1 mm. Veneer from coniferous wood - yew, larch and pine - is made with a thickness of 0.8 and 1 m. It is allowed to produce veneer from burls with a thickness of 0.4; 0.6 and 0.8 mm. The minimum thickness of sliced ​​veneer, in addition to the structure of wood, is determined by the ability of adhesives to seep through it, the convenience of working with veneer of this thickness and the possibility of finishing operations (grinding and scraping) after gluing it to the surface of the part. Depending on the direction of the cut, the veneer can be radial (R), semi-radial (PR), tangential (T) and tangential-end (TT), made from burls (burls). Length of veneer sheets from 550 mm and above. The width of the sheets depends on their grade: the first grade is at least 120 mm, the second grade is at least 80 mm. The moisture content of the veneer should be 8±2%. Specifications the admissibility of wood defects and processing defects is also stipulated in each of the grades of sliced ​​veneer. Surface roughness of oak, ash, elm, larch, pine veneer should be Rzmax Wood planing process. Sliced ​​veneer is obtained by cutting the wood in a plane parallel to the grain. Since the strength of wood across the grain is relatively low, it is important to avoid cracking during the manufacturing process. This will depend on the cutting mode and the condition of the workpiece before cutting it into veneer. The planing mode is predetermined by the angular parameters of the knife and the pressure bar and their relative position (Fig. 48). Knife sharpening angle in = 16... 18°. The value of the angle depends on the material of the knife, the type of wood and its temperature. Relief angle α = 1...2°. In order for the knife to penetrate into the wood not immediately with the entire cutting edge, it must be located in relation to the longitudinal axis of the ridge at an angle of 10-12 °. This will have a beneficial effect on the quality of the veneer, which also depends on the position of the ruler in relation to the knife. Their location is determined by the coordinates:

The correct setting of the ruler in relation to the knife ensures the crimping of the wood layer in the area where the knife is inserted into it, which eliminates the arbitrary propagation of a leading crack and the formation of large microroughnesses on the veneer surfaces.

On fig. 48, a shows a pressure ruler with an acute angle p "= 60 ... 70 °. Such rulers are used in the manufacture of veneer with a thickness of 1 mm or less. If a thicker veneer is produced, then a ruler with a pressure chamfer gives better results (Fig. 48 , b). The sharpness of the knife has a great influence on the roughness of the veneer. Therefore, it is desirable to maintain the radius of curvature of the knife blade within 5-7 microns, periodically dressing it with a whetstone. The radius of curvature of the working edge of the pressure ruler should be 150-200 microns. The roughness of the veneer is affected also the direction of movement of the knife in relation to the annual layers.This influence is different depending on the width of the annual layers and the width of the core rays.Thus, wood species with pronounced growth layers give good results when planing is done at an obtuse angle with respect to the tangent a - a (Fig. 49, a). For wood species with wide core rays, the best result is obtained if this angle is sharp (Fig. 49, b). But this question is not can be considered fully clarified due to the wide variety of wood species used, their different structure and physical and mechanical properties.

Equipment for obtaining sliced ​​veneer. The planing operation is performed on horizontal, vertical (Fig. 50) or inclined veneer planers. On machines of the first type (Fig. 50, a), the material being processed is installed on a horizontal table, and the cutting tool is mounted on a support that reciprocates in a horizontal plane perpendicular to the longitudinal axis of the workpiece. The caliper can receive translational movement from a special electric motor that transmits movement using a gear wheel and a gear rack or using a crank mechanism. The direction of movement in machines with a gear rack is changed by means of an electromagnetic clutch, which is activated by limit switches. The disadvantage of this design is the forced braking of the caliper stroke in front of a variable direction of movement, causing a violation of the smooth running, leading to premature wear of the machine guides and a decrease in cutting speed. On horizontal veneer machines, raw materials are processed with a length of 2-5 m, a height of up to 1.2 m. The number of double strokes of the caliper reaches 56 per minute. They are convenient in terms of installing the beam on the machine table. The large mass of the caliper helps to eliminate its vibration, which makes it possible to increase the productivity of the machine to 3000 - 4000 m2 of veneer per shift. However, these machines are bulky, they cannot adjust the speed of the forward and reverse stroke of the caliper, and if there is no mechanism for removing veneer from the machine, then productivity decreases, since in this case the number of double strokes should be no more than 16 per minute. The thickness of the remaining cuts is quite large (25 and 40 mm), which is necessary for reliable fastening of several workpieces on the machine table. For the convenience of changing the tool and regulating its position, machines have been created in which it is possible to separate the traverses from each other.
On machines of the second type - vertical (Fig. 50, b), the material being processed is placed on a carriage that reciprocates in a vertical plane. The cutting tool is mounted on a support that periodically moves along horizontal guides towards the material being processed to remove the next layer of the required thickness from its surface. The carriage is driven by a crank mechanism located on the reverse side of the machine. Machines of this type are compact, they have less mass of moving parts, convenient control of crimping, convenient selection of veneer sheets from the machine. The thickness of the remaining cuts is less than on machines horizontal type. The number of double strokes of the carriage reaches 90 per minute with a shorter stroke length. However, only one beam can be installed on the machine carriage, as a result of which their use is especially effective when working on large-sized raw materials. To improve the accuracy of manufacturing sliced ​​veneer in terms of thickness, machines have been created in which the cutting process is carried out when the carriage moves from bottom to top. Machines of the third type - inclined - are convenient from the point of view of the selection of veneer sheets, and they better use the inertial forces of moving parts. They are less energy intensive and have somewhat smaller dimensions. The greatest number of double moves they have is 56 per minute. Vanches in machines of modern designs are attached using mechanisms equipped with an electric or mechanical drive. To reduce the thickness of the remaining cuts, additional vacuum plates are proposed for fastening the vanches, which are installed on the carriage of a vertical type machine.
For the mechanization of cleaning veneer sheets cut from vanches from a horizontal veneer planer, which includes laying sheets in packs, it is proposed whole line mechanisms. As an example, consider the mechanism, the scheme of which is shown in Fig. 51. The device consists of two parts: veneer selector I and stacker II. Selector I is activated at the start of the working stroke of the caliper, and stacker II works continuously. During the working stroke of the caliper, the selector is filled with veneer sheets cut from the vanches. The veneer cut from the previous cycle fills the stacker at this time. When the cutting process ends, the selector stops working (this moment is shown in Fig. 51) and the whole system starts to move in the opposite direction, and the stacker that continues to work gives out veneer sheets, stacking them in stacks located below it. Then the cycle repeats. This stacker has certain disadvantages, but it works quite reliably.

IN Lately some foreign firms began to widely use eccentric peeling (Staylog). The material being processed is mounted on a special beam installed between the spindles of the peeling machine. The advantages of this method are greater productivity and the possibility of obtaining wider sheets of veneer having a uniform pattern. But this method is not suitable for all tree species.
Other operations of the technological process for the manufacture of sliced ​​veneer. The produced veneer is then dried, sorted, cut and packaged. For drying, roller and belt dryers are used. The possibility of using roller dryers depends on the horizontal distance between adjacent rollers and the thickness of the veneer. With a veneer thickness of less than 1 mm, the distance between the rollers should be 125-145 mm, which will prevent the front ends of the veneer from sagging and getting under the rollers. A significant drawback of roller dryers is their manual loading, which reduces the productivity of the dryer by almost 50%, as well as fluctuations in the final moisture content of veneer, reaching up to 3.2%. The mode of drying veneer in roller dryers depends on the thickness of the veneer, the type of wood, the initial moisture content of the veneer, the temperature of the veneer circulating in the dryer and the air velocity. Thus, veneer made from domestic wood species up to 1 mm thick at t = 100 ... 120 ° C at relative air humidity φ = 10 ... 25% is dried for 3.5-7 minutes. Tropical wood veneer is dried at a slightly lower coolant temperature.
Belt dryers with nozzle blowing, having three floors, compare favorably with roller dryers both in the quality of the veneer dried in them and in higher productivity, as they are equipped with veneer loading mechanisms. Each dryer must have a cooling chamber. The veneer is conditioned to equalize its moisture by holding in the shop for several hours. Dry veneer is sorted into two grades, taking into account the wood defects and processing defects present in it, the type of veneer and the width of the sheets. If the veneer is made from wood, the sapwood of which differs sharply in color from the heartwood (for example, oak), then the veneer sections with sapwood must be separated from the sheet. The finished veneer is packed in bundles with at least 10 sheets, which are then bundled into bundles weighing up to 500 kg and wrapped in two layers. polyethylene film or tar paper. Packages are placed between plank boards and tied with metal tape. Mechanisms specially created for this purpose are used to perform packing operations and account for veneer. Store veneer in closed dry rooms.
Output of sliced ​​veneer from raw materials. The output of veneer, depending on the diameter of the raw material and the scheme of its cutting, can be characterized by the data given in Table. 26.

Observations show that the wood species has a noticeable effect on the yield of sliced ​​veneer. At the same time, the smaller the average diameter of the raw material, the more unstable the yield. It is not possible to determine the yield of sliced ​​veneer from raw materials, taking into account its geometric dimensions and shape, due to the complexity of the latter. Such data are obtained only on the basis of experimental cutting of a batch of raw materials of a sufficiently large volume. The output of dry cut veneer Ssh = 0.8 mm from impersonal raw materials can be characterized by the following data,%: from beech wood 33, larch 24, oak 27, mahogany 46. Veneer yield different kind from raw materials of the 1st grade is given in table. 27.

An indicator is often used that characterizes the consumption of raw materials required for the manufacture of 1000 m2 of sliced ​​veneer,

Thus, the consumption of raw materials for the manufacture of 1000 m2 of veneer (8 = 0.8 mm) is, m3: beech 2.42, larch 3.35, oak 2.95, mahogany 1.74.
Waste generated during the processing of raw materials for sliced ​​veneer is distributed as follows, % of raw materials:

The yield of veneer from the raw material can be increased by processing the cuts. To do this, they are glued into blocks with a thickness of 200-300 mm and planed like ordinary blanks. For gluing cuts, the moisture content of which is above 30%, polyurethane or resorcinol-formaldehyde adhesives are used with preheating of the surfaces to be glued to t = 70°C. The duration of exposure in the clamped state should be at least 2 hours at W = 30 ... 50%, P = 0.12 MPa and at W = 50-70% and P = 0.08 MPa. Sometimes it is practiced to fasten the cuts on an auxiliary board with a thickness of 40-50 mm using round spikes with a diameter of 20-25 mm (at the ends of the cut), followed by trimming the ends of the veneer, in which holes from the spikes remain. The second way to increase the yield is to abandon the group method of longitudinal cutting into blanks, in which several parallel ridges of different diameters are processed. It may be economically justified to sell cuts to other consumers.
The productivity of the veneer machine. hourly productivity machine is defined as follows: in veneer sheets

The productivity of horizontal machines ranges from 400-700 m2/h, inclined - up to 800 m2/h, vertical - 1400-2300 m2/h. An increase in the number of double strokes of the caliper does not provide a noticeable increase in machine productivity. This can only be achieved by increasing the level integrated mechanization work on the entire area of ​​veneer production.