JPS595401B2 - Continuous plywood manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing continuous plywood by laminating and bonding a plurality of adhesive-coated veneers in the length direction and thickness direction.

In general, plywood is made by laminating and bonding the fibers of the veneers at right angles, but recently some plywood factories have started producing parallel plywood, which is made by laminating and bonding the fibers of the veneers parallel to each other. It began to be used primarily as a core material for furniture, building materials, etc.

In the present invention, plywood is a general term for both those whose fibers are perpendicular to each other and those whose fibers are parallel to each other, and are individually referred to as orthogonal plywood and parallel plywood.

The method of the present invention relates to a method for manufacturing continuous plywood, and the related technology is L V L (Lami nate
dVeneer Lumber - A laminated wood board, meaning a plank made by laminating and bonding multiple veneers in a continuous and multi-layered manner, with the ends of the veneers butted so that the fiber directions are parallel to each other. It is also used as a material for cutting into square columns and thick plates.

), but as shown in Table 1, there are differences between LVL and continuous plywood in the fiber direction of the constituent veneers or the relationship between the width and length directions of the endless product and the fiber direction of the veneer. It is something.

Regarding LVL, the following four methods have already been proposed (Wood Industry, Vol. 28-9, p. 396-397)
However, each has its own problems and has not yet reached the practical stage.

(1) Semi-continuous FPL method % method %) This is a log heated in a heating bath of about 40℃, peeled into a relatively thick veneer using a rotary lace, then cut with a clipper, and inserted into a multi-stage hot press dryer. do.

Once dried, the veneer is stored in a heat insulation box and heated to 100℃.
Keep at nearby temperature.

This preheated veneer then passes through a glue extender, where adhesive is applied to one side and enters the assembler, where the butt joints at the ends of the veneers (ends in the direction of the fibers) are spread out appropriately. The fibers are continuously stacked on top of each other, sent to a continuous press laminator, and pressed to form LVL that is continuous in the fiber direction.

This technology can produce orthogonal plywood by simply making the fiber direction of every other veneer at right angles, and parallel plywood by making all of them at right angles, but this method requires the development of a powerful continuous press laminator. However, it has not yet been put into practical use due to certain problems.

(2) Continuous FPL method % formula %) This is a process in (1) in which a continuous press dryer is placed in place of the multi-stage press dryer, and a continuous assembler is placed in place of the veneer assembler.
Compared to method (1), there is no need for a heat insulating box, the process is quick, there is no need to pre-cure the adhesive, and a higher temperature veneer can be used, making it possible to use cheaper phenolic adhesives.
Pressing time can also be shortened.

However, the development of such continuous press dryers and continuous assemblers is delayed, and it is thought that practical application will be even more difficult than (1).

(3) Continuous LVL method % formula %) If the veneer temperature is not high, it will take a long time to heat press the multilayer LVL all at once using a hot press, but first heat press the two center veneers, then press the If you add one sheet on each side one by one, the inside will harden somewhat faster after the second press, so you can reduce the overall pressing time considerably.

According to this principle, the veneers are fed through an endless belt press in the direction of the fibers, with the ends of each end one after the other, and one more endless belt press is placed each time a veneer is added on both sides in the thickness direction of the LVL. However, the adhesive is applied just before each endless belt press.

This method can also produce orthogonal plywood or parallel plywood simply by changing the fiber direction of the veneer, but it requires expensive endless belt presses to be placed in the first, second, third, etc. Even if such a high-performance, high-pressure endless belt press were developed, it would pose a major problem in terms of equipment cost.

(4) Intermittent LVL method %) This is the continuous LVL pro of (3)
This is a version of the cess that suits reality, and uses a single-stage intermittent press instead of a high-pressure endless press, which has not yet been developed, but this also requires the single-stage press to be arranged in the first, second, and third stages. There is a problem of inefficiency considering the equipment cost.

The inventors believe that these Pro-oceans have already been proposed.
As mentioned above, there are problems with the practicality of ss, and it cannot be applied to the production of continuous plywood as it is, so after various studies, we decided to change the laminated shape of adhesive-coated veneers to the shape of the press as shown in Figure 1. By forming the take-out side into a reverse step-like shape and the insertion side into a step-like shape, and pressing with a press attached to the step-like and reverse-step-like pressing molds (3 and 4) that match the laminated shape of the veneer, It has been discovered that a long plywood can be obtained by obtaining a large number of plywood materials 5 each having a reverse step-like shape and a step-like shape at both ends, and rejoining the materials at the step part and the reverse step part one after another in the next step. Obtained.

As a result of further intensive study based on these findings, the inventors made the laminated shape of the adhesive-coated veneers step-like on the insertion side of the press, and attached an inverted step-shaped stopper mold that matches the shape. By pressing with a press, a plywood material with a step-like insertion side end is obtained on the press clamping plate, and when the material is opened by the press, the plywood material is placed on the pressing plate of the press in the direction of the take-out side of the press (progressing direction). direction) so that the stepped end is located near the take-out side, and then place new adhesive-coated veneers so that each veneer in the stepped section is aligned, and the press insertion side is adjusted so that it fits the pressing mold. Laminated and pressed together in a stepped manner.

By repeating these steps, the present invention has been completed to obtain continuous plywood.

Note that the parallel plywood currently produced in the plywood industry is simply laminated and glued together with the fiber directions of the veneers used for orthogonal plywood parallel to each other, and only products of the same size as the veneer can be obtained. .

The method of the present invention not only laminates and adheres veneers in the thickness direction, but also connects the ends of the veneers in a butt-like manner in the length direction of the plywood. Alternatively, this is a method of obtaining a continuous length product, and has the advantage that only two corners are required compared to the current method in which four corners are cut off for each sheet.

Next, the present invention will be explained in more detail.

The veneer used in the present invention is mainly obtained by peeling raw wood with a rotary lace, and has a thickness of 1.5 mm to 20 mm.

If the thickness is thin, cracks on the back of the veneer will be reduced and a smooth surface will be obtained, but the number of layers will increase and the cost will increase.
It is necessary to make a selection by considering the stripping technology, purpose of use, cost, etc.

In addition, veneer has a moisture content of about 30% to 100% when it is peeled, and as it is, it cannot be joined without using an expensive epoxy or urethane adhesive for wet wood, and the product may shrink when drying. Since there are problems such as dry cracking of the surface veneer, it is thought that it is often used after being dried with a dryer, but the optimum moisture content may be selected depending on the purpose.

The higher the temperature of the veneer, the faster the adhesive will harden and the higher productivity will be, which is advantageous, but in general, the curing speed of the adhesive will greatly increase when the temperature exceeds 60 to 80°C, so 660°C
It is preferable to use the adhesive at a temperature higher than 80° C., more preferably 80° C. or higher, and particularly preferably 100° C. or higher, but it is necessary to shorten the time from adhesive application to pressing as much as possible, and speeding up by mechanization is desirable.

Note that the length of the veneer (the length in the longitudinal direction of the product plywood) does not need to be longer than the pressing plate of the press, and the plywood that has already been moved to the pressing mold or the removal side The length of the first stage remaining in the press is L2.
) can be the length LI L2).

Or if you use a longer press (LI L2)
You can use one with a length of ÷rl (an integer such as n=2.3.4, which indicates the number of veneers that can be lined up horizontally).

In addition, inexpensive short logs, which were conventionally considered waste wood, may be joined and peeled to a predetermined length, and the ends of the veneers may be formed into an interlocking shape such as a scarf or zigzag to provide sufficient strength. It is also a preferable method to use a product vertically joined by the method obtained.

Furthermore, it is preferable to form the butt ends of the veneers in a zigzag shape or scarf shape, which is better than a simple butt joint, and improves the strength of the plywood.

However, if the scarf or zigzag distance is long, there will be insufficient pressure on the veneer in this area, so it is preferable to use a matching mold.

A flat plate press is a press in which the pressing surfaces of the upper and lower pressing plates (1 and 2) are flat, as shown in Figures 1 to 3.
Generally plywood, particle board, hardboard,
You can use the press used to press-manufacture flat plate products such as melamine decorative boards and phenol laminates.

Note that the "take-out side" and "insertion side" of the press refer to the advancing direction of the pressed object as the take-out side, and the opposite direction as the insertion side.

In the method of the present invention, since the pressing die 3 is on the insertion side, the veneer does not necessarily have to be inserted from the insertion side of the press.
It may also be carried out from a direction perpendicular to the direction of movement of the object to be compressed.

Additionally, as ancillary equipment for the press, an endless belt is installed on the lower clamping plate to quickly move the object to be pressed, and a high-speed belt is installed on the lower clamping plate to quickly stack adhesive-coated veneers on the press clamping plate. It is preferable to install an assembler or the like.

The stepped mold 3 (used only when molding the head of continuous plywood, i.e. used only in the first press and removed immediately) and the reverse stepped mold 4 are made of metal, wood, plastic, rubber, or a combination of these. The height of each stair step is matched to the thickness of the corresponding veneer, and the stagger length of each step is matched to the stagger distance for each layer when laminating veneers, but all stair steps are not necessarily the same stagger distance. do not have to.

Further, if necessary, a cushioning material can be used between each stage of the mold, such as between the pressing mold and the clamping plate.

Also, the number of stages of the pressing mold can be the same as the number of veneer lamination stages, one less, or two stages less. However, when using a pressing mold with two fewer stages, Since pressure is not applied only to the shifted part of the veneer, this veneer part is easily deformed in the direction away from the clamping plate, and if the number of stages is the same, the usable length of the press clamping plate is only the length of one stage. Because of this, it is most preferable in practice to use a padding mold with one step less, except in the case of a scarf or zigzag pattern.

The stepped mold may be integrally molded of metal or the like and fixed to the clamping plate, but it is preferable to use one that can move back and forth in the direction of insertion and removal, and also to prevent variations in the length of the veneer in the fiber direction. Since the shifting distance may not be constant, a structure may be used in which plates of the same thickness as the veneer are stacked one on top of the other, and each component plate may be shifted independently in the direction of the insertion side and the removal side.

The shape of the end of the veneer, which abuts and extends in the fiber direction, is usually cut at 90 degrees to the fiber direction, but it can also be cut in a zigzag or scarf shape. Since the outer layer veneer is particularly preferable, it is preferable that the abutting mold is capable of moving forward and backward independently as a whole and/or for each constituent plate.

Adhesives that can be used in the present invention include epoxy, urethane, resorcinol, phenol, melamine,
Thermosetting resin adhesives such as urea-based, vinyl urethane-based, α-olefin-based, and zirconium-based modified vinyl emulsions, or adhesives containing one or more of these can be used, but if the intended use of the product LVL is For outdoor use or similar conditions, it is preferable to use epoxy, urethane, resorcinol, phenol, etc. adhesives; for indoor use or similar conditions, use melamine, urea, etc. It is preferable to use adhesives such as vinyl urethane-based, α-olefin-based, and zirconium-based modified vinyl emulsions.

In addition, from the viewpoint of productivity, adhesives such as resorcinol, phenol, melamine, urea, vinyl urethane, α-olefin, and zirconium-modified vinyl can be cured relatively quickly by raising the temperature of the veneer. It is advantageous because it is easy.

In particular, melamine-based and urea-based adhesives can be cured quickly by selecting a hardening agent, and there is also a method of applying the main agent and hardening agent separately to the surface of the veneer without mixing them in advance, and then mixing them on the surface of the veneer. If the (separate coating method) is used, it is possible to use a fast-curing curing agent that cures too quickly and cannot be mixed in advance.

Rapid curing is possible by using these methods in combination, so if highly efficient automatic lamination equipment is developed, it can be effectively utilized.

Epoxy and urethane adhesives are currently expensive, but those with specific formulations can bond even veneers with a moisture content of 100% or more, and plywood can be manufactured using undried veneers. Since it is possible to do this, dryer equipment is not required and there is no drying cost, so if the prices of these adhesives come down, they will become more practical.

In the method of the present invention, the adhesive must be thermosetting because the product is taken out of the press while still at a high temperature. Since the plywood is cooled, a thermoplastic adhesive can be used, but as the thickness of the plywood increases, it takes a long time to cool the inside, making it less practical.

The adhesive is applied using a roll coater, spray, flow coater, or equipment equivalent to these, and sprays, flow coaters, etc. are effective for the above-mentioned separation coating method.

In the stacking method of the present invention, the upper surface of the stairway part of the veneer is pressed with a pressing mold, and then a new veneer coated with adhesive is loaded, so that the part pressed with the pressing mold is free of adhesive. It is preferable to leave it uncoated.

In particular, some adhesives may bond strongly to the wooden surface of the veneer, but some may not adhere well to the surface of the adhesive that has already hardened, so care must be taken.

For this reason, it is preferable to apply adhesive only to the bottom surface starting from the second veneer from the bottom, without applying the adhesive to the veneer at the bottom, and stack the veneers one after the other.In this case, a roll coater is most suitable. .

When applying to the top surface of the veneer using a spray, flow coater, etc., apply by turning the veneer upside down and applying it to the bottom surface, or apply from the first stage of the veneer (5 □, 5 □, etc. in Figure 2). Instead of applying only to the surface corresponding to the staircase part and the topmost veneer, it is sufficient to apply it to the staircase surface of the object to be pressed in the press.

Of course, if the adhesive is of a type that is inexpensive and has no problem adhering to the adhesive-cured surface, such consideration is not necessary.

By applying adhesive to the outer surface of the front veneer and/or the outer surface of the back veneer of plywood and applying resin treatment to the surface at the same time as adhering the plywood, the water absorption rate from the grain surface of the veneer is reduced and corrosion is prevented. Effects include insect repellency, improved appearance and aesthetics, and improved surface strength.

In this case, it is preferable to use an endless coal board between the press clamping board (upper and/or lower) and the plywood.

The method for laminating adhesive-coated veneers is to stack them in advance in a predetermined shape outside the press, and then carry them into the press by rotation of an endless coal plate or endless belt installed on the press lower clamping plate 2. However, a method of directly laminating the pressed plywood on the take-out side of the lower pressing plate of the press so as to fit the stepped portion is preferable because the process and time are shortened.

Regarding the formation of the step-like part, the part where the veneer fibers are extended in a butting manner, that is, the part where the butt ends meet each other, is shifted by a distance (with the upper and lower veneers) that is preferably 5 to 30 times the thickness of the veneer. may be 10 to 30 times, particularly preferably 20 to 30 times or more.

In the part where the fibers are parallel to each other, there is no need to consider strength if the joint is perfect, but in reality, the occurrence of gaps at the butt part is unavoidable, so it is necessary to consider the strength depending on the accuracy of the joining process. The thickness may be appropriately set within the range of 1 to 20 times the thickness of the veneer.

However, if the end of the veneer is scarfed or zigzag processed to improve the joint strength, the shifting distance can be shortened and the pressing ability can be improved.

The compacting pressure of the present invention is 8 to 1 for low specific gravity materials such as lauan and china.
0 kg/cyyt, and 10 to 12 kg/i for high specific gravity materials such as birch, oak, and aviton, but if the veneer is thick and has large curvatures and dances, increase the pressure by 10 to 30% more.
It is preferable to make it high.

The pressing time cannot be easily specified because the curing time varies depending on the veneer temperature, laminated thickness, adhesive type, composition, amount of application, etc., but it should be decided experimentally in advance within a safe and highly productive range. It is.

It is preferable to maintain the temperature of the press clamping plate and the pressing mold constant using electricity, steam, hot water, hot oil, etc. Furthermore, if it is desired to measure the temperature rise within the press, application of high frequency electric energy is also effective.

In the present invention, the pressurized object is moved from the insertion side of the press to the removal side when opening the press, but the moving distance is from the insertion side end of the uppermost stacked veneer to the removal side of the press. It must be set within the distance to the end that can be pressurized with a predetermined pressure.

That is, the stepped portion is not removed from the press but remains within the take-out portion of the press.

This is to ensure that when the veneer to which adhesive has been newly applied is laminated and bonded while abutting against each step portion, sufficient pressing force is applied to exert sufficient adhesive strength.

Next, the effects of the present invention will be described.

First, Semi batch Press -Lam
Process and Continuous Press
Continuous press laminator in s-Lam Process, Continuous LVL Proc
Many of the endless belt presses used in ESS have not yet been developed and cannot be used unless they are developed in the future, and all of them are large-sized equipment, which poses the problem of increasing equipment costs and running costs in addition to development costs.
Although the termittent LVL Process does not use a particularly new press, it requires the use of a large number of single-stage presses, which increases the equipment cost.

In the method of the present invention, continuous plywood can be produced with a single flat press, which is already used everywhere, by using a simple pressing die and moving the object to be pressed from the insertion side to the removal side when opening the press. Therefore, it is significantly advantageous in terms of development cost and equipment cost.

As described above, the present invention forms a step-shaped plywood material on the insertion side on the lower pressure plate of the press by applying a veneer coated with adhesive using a mold and a flat plate press, and moves this to the take-out side of the press. After that, the newly applied veneers are laminated in a butt-like manner on the step-like part, pressed together, and then these operations are repeated to obtain a continuous long plywood. This is an extremely effective method industrially. .

Examples will be described below.

Example 1 (Figure 2) Thickness 5rIL11L1 Width 1500mm, Length 500.4
001300.200.5 iron plates of 100mm are inserted one sheet of cushion paper between each layer, stacked and fixed at a shift distance of 100mm each, and made into a reverse stepped mold 4 (a type that can be heated by passing a heating wire inside) ), length x width - 2600
It was attached to the insertion side end of the upper clamping plate 1 of a one-stage flat plate press having upper and lower clamping plates (1 and 2) of Wtm×1500 mm, and the temperatures of 1, 2 and 4 were adjusted to 135°C.

A lauan log with a length of 1,450 to 1,460 mm was cut using a rotary lace at a cutting distance of 1,400 nm to obtain an endless veneer with a thickness of 5.2 mm and a width of 1,400 nm. ) It was cut into pieces of 1,400 mm x 20,001 m in length to obtain a large number of undried fixed-length veneers.

The veneer was pressed and dried in a multistage hot press dryer at 130°C, and the thickness x width x length = 5 x 1400 x 2000 m.
A large number of dry hot veneers (5, to n) of m were obtained.

The veneers (5, to n) were taken out of the hot press dryer and used as needed.

A mixture of 100 parts by weight of an alkali phenol formaldehyde resin (Sumilite Resin PR-9300, manufactured by Jurezu Corporation) and 10 parts by weight of walnut powder was supplied to a spreader roll whose temperature was adjusted to 90°C.

Next, place 51 on top of 2 so that its longitudinal insertion side end is located at the insertion side end of 4, and then apply adhesive to the lower surface of 52 using the spreader roll described above. ,
Layer 51 in the same fiber direction with a shift distance of 100Tn7IL toward the take-out side from 5□, and then 10
Stack up to 56 with a shift distance of 0 and immediately weigh 10kg.
After tightening at a pressure of /d for 2.5 minutes, the cotton was opened.

Move the pressurized object (parallel plywood materials 5, to 56) over 2 by 2000 mm in the direction of the take-out side, and newly place 57 on top of 2 with the ends of 51 butting up. Immediately after applying the above-mentioned adhesive to the lower surface of 58, it was placed abutting against 52 and laminated up to 512 in the same manner.

Immediately compress the material at 10 kg/crrL for 6 minutes (Figure 2 shows this state), then open the cotton, move the material to be compressed as described above, repeat the same operation, and tighten the product in the length direction. Endless parallel plywood with orthogonal veneer fibers was manufactured.

The step part at the end of the parallel plywood that was finally pressed is cut off and placed on the take-out side above 2 when the next production starts, and used for joining to the reverse staircase part of the head.

In this example, the reverse staircase part at the head of the continuous parallel plywood of the first product was cut off because no pressure was built up, but if the pressing mold 3 is used only during the first pressing, the reverse staircase part at the head part can be discarded. It is not necessary to do so; for example, the head reverse step portion may be cut out and joined to the tail step portion, or vice versa.

When the parallel plywood obtained in this example was subjected to an adhesion test based on JIS-6851, the test piece cut from the staircase part had an average of 79 kg/cyst (breakage rate 80%),
Average after boiling for 72 hours: 73 kg/crtt (Breaking rate: 9
5%), parts other than the stairs normally have an average weight of 80kg/=(
Breakdown rate: 88%) Average weight after boiling for 72 hours: 79kg/ff1 (
The breakthrough rate was 97%), which was good enough to cause no practical problems.

In addition, the bending strength of the test piece of the product parallel plywood with the surface fibers on the tensile side showed a value of 94 to 97% of the strength of the part not including the step part.

Example 2 In Example 1, ■ The size of the dry hot veneer is thickness x length x width (fiber length) = 5 x 10 () OX 1400 threads, @ the veneer temperature is 110°C, ○ The adhesive compound is melamine formaldehyde resin adhesive (Jin Bakelite Sei Getalime MA-204
) is a mixture of 100 parts by weight, 10 parts by weight of wheat flour, and 21 parts by weight of ammonium chloride, and the spreader roll temperature is 2.
5℃, and ■ In this example, two veneer layers of 1000 mm are stacked each time one veneer of 2000 mm is lined up.
When the sheets were arranged side by side, the same good results as in Example 1 were obtained in terms of normal adhesive strength and normal bending strength.

Example 3 Six iron plates with a thickness of 5 am, a width of 1500 mi, a length of 200.400°, 600, 800, 1000.1200 were inserted one cushion film between each layer, and were laminated and fixed at a shift distance of 200+u+, A reverse step-shaped machine mold 4 (with heating wires passed inside it so that it can be heated) was made, and upper and lower clamping plates (1
and 2) was attached to the insertion side end of the upper clamping plate 1 of a one-stage flat plate press, and the temperatures of 1, 2, and 4 were adjusted to 135°C.

A lauan log with a length of 2060 to 2070 Wtm was cut using a rotary lace at a scoring distance of 20001 m to obtain an endless veneer with a thickness of 6.4 x width (length in the fiber direction) of 2000 mm, which was then cut into pieces of 1405 rItm using a clipper. A large number of undried veneers were obtained.

The veneers were compressed and dried using a multi-stage hot press dryer at 140° C. to obtain a large number of dry hot veneers (51 to m) each having a thickness of 6 nm and a size of 2000×1400 mm.

Next, a lauan log with a length of 1450 to 1460 m++ was cut using a rotary lace at a scoring distance of 1400 mm, with a thickness of 6.4 rnm and a width (length in the fiber direction) of 1400 m.
Obtain an endless veneer of m and cut it with a clipper to 2000 m.
A large number of undried fixed-length veneers were obtained by cutting into pieces of mm.

The veneers were pressed and dried in a multi-stage hot press dryer at 140°C to obtain a large number of dry hot veneers (5'1 to n) with a thickness of 6 mm and a size of 1400 x 2000 u+.

These veneers were removed from the dryer and used as needed.

5, as shown in FIG. (same as below)
Apply 200rn71 in the direction from 51 to the removal side.
The fiber directions of the veneers were stacked at right angles to each other with a shift distance of L, and the fiber directions of the veneers were successively crossed at right angles to each other with a shift distance of 200 mm, 52°5'2 p53, s/3).
The sheets were laminated to a depth of 100 mm, and then immediately pressed at a pressure of 10 Y/d for 3 minutes, and then opened.

Place the pressurized object 2000mm above 2 in the direction of the removal side.
Move it and place 55 on top of 2 so that the ends of 51 are butt-to-edge, and immediately after applying the adhesive 5', 5'1.
56° 5'6 t 57
The fiber directions of the veneers were sequentially orthogonally crossed and laminated until t 5'7 H5B.

Immediately tighten the cotton for 3 minutes at 10ky/i (Figure 3 shows this state), then open the cotton, move the object to be pressed as above, repeat the same operation, and endlessly orthogonally tighten the cotton. We manufactured plywood and cut out the front and rear staircase sections.

An adhesion test was conducted on the orthogonal plywood obtained in this example based on the JAS plywood standard, and the test piece cut out from the staircase part contained inside had a normal average weight of 17 kg/ff1 (breakage rate 90%) and was boiled for 72 hours. After average 14 kg/ant (
Breaking rate: 91%) The normal average weight for the parts other than the stairs is 16 kg.
/c1. (Breaking rate 100%), average 14 after boiling for 72 hours
kg/crA (breakthrough rate 97%), which was good enough to cause no practical problems.

The bending strength when the abutting portions of the surface fibers were on the tensile side was approximately 60 to 65% of the strength of the portions of the surface that did not include the abutting portions.

[Brief explanation of the drawing]

Figure 1 shows an example of the pressing state for creating the first stepped plywood material, Figure 2 shows the pressing state of parallel plywood in Example 1, and Figure 3 shows the pressing state of the parallel plywood in Example 1. It shows the pressed state of orthogonal plywood in Example 3. In the figure, 1 and 2 are upper and lower pressing plates, 3 and 4 are stepped and reverse stepped machine molds, 5 is plywood material, 5, ~512y5'l~7 are veneers, and 6 is for pressing and opening. Showing ram.

Claims (1)

[Claims] 1. In a method of manufacturing plywood by laminating and pressing veneers coated with adhesive using a flat plate press, a pressing mold in an advanced stage is used on the insertion side of the flat plate press, ) The veneers coated with adhesive are stacked in a stepped manner on the lower clamping plate so that the insertion side end of the veneer fits the mold, (b) the veneers are then compressed with a predetermined pressure, and the adhesive is applied. (c) When opening the cotton, move the pressed joint from the insertion side of the flat plate press to the take-out side, and so that the step-like part of the pressed piece remains on the take-out side of the flat press. , 2) Next, the veneers coated with adhesive are attached to each layer of veneer in the stepped portion of the object to be pressed, and the above step (a) is carried out at the same time, and (e) these steps are carried out sequentially. A continuous plywood manufacturing method characterized by repeated implementation. 2. The method for manufacturing continuous plywood according to claim 1, wherein the veneer temperature is 60° C. or higher. 3. A method for manufacturing continuous plywood according to claim 1 or 2, in which veneers of the same length are shifted by the same distance by at least five times the thickness and laminated in a stepwise manner. 4. Claim No. 4, which is obtained by cutting all or some of the veneers constituting the plywood, whose fibers are parallel to the advancing direction of the press, into a scarf shape or a zigzag shape at both ends on the wood end side. A method for producing continuous plywood according to item 1 or 2. 5. The adhesive is one or more selected from the group of resorcisol resins, phenol resins, melamine resins, benzoguanamine resins, acetoguanamine resins, urea resins, epoxy resins, polyurethane prepolymers, and incyanate compounds. The method for producing continuous plywood according to claim 1, 2, 3, or 4, which is a thermosetting resin composition containing at least one species. 6. Claims 1, 2, 3, 4 or 6, characterized in that the method for applying adhesive to the veneer does not apply adhesive to the upper part of each step of the staircase portion. The method for manufacturing continuous plywood according to item 5. j A patent claim characterized in that the method for applying adhesive to veneers is such that adhesive is not applied to the lowest veneer during stacking, and adhesive is applied to the lower surface of all other veneers. A method for manufacturing continuous plywood according to scope 1, 2, 3, 4, or 5.