Cold pressing technology for cold pressing glue of plywood

Abstract

The invention relates to the technical field of plywood cold pressing, and discloses a plywood cold pressing glue cold pressing process which comprises the steps of wood board slitting, wood board drying, veneer gluing, blank assembling and cold pressing, the assembled boards are placed on a cold press, the assembled blanks are pressed through the cold press with the stable pressure, the pressure is kept at 1.2 MPa, the pressing time is 4-12 hours, the assembled blanks are turned over, and the plywood cold pressing glue cold pressing process comprises the steps of wood board cutting, wood board drying, veneer gluing, blank assembling and cold pressing. The back side of the group blank is pressed, the pressure is kept at 1.2 MPa, the pressing time is 2-6 hours, the plate stands for 24-48 hours after pressure relief, and the adhesive is completely cured. According to the cold pressing technology for the cold pressing glue of the plywood, through pressing fit of the upper side and the lower side of the plywood, the plywood is attached more tightly, the veneers of the plywood are not prone to cracking and separating, the plywood is not prone to deformation due to double-face pressing fit, and the quality of the plywood is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cold pressing of plywood, and specifically to a cold pressing process for cold pressing glue of plywood. Background Art

[0002] Plywood is a three-layer or multi-layer plate material made by slicing wood segments into veneers or planing wooden squares into thin woods, and then gluing them with adhesives. Usually, an odd number of veneers are used, and the fiber directions of adjacent veneers are glued perpendicular to each other. The cold pressing process of plywood refers to applying glue to the dried veneers and then pressing them through a cold press to cure the glue layer into a firm plywood. In the existing cold pressing process of plywood, when pressing the plywood, the plywood is not pressed on both sides, resulting in incomplete pressing of the plywood, easily causing the veneers of the plywood to crack and separate from each other, and reducing the quality of the plywood. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] In view of the deficiencies of the prior art, the present invention provides a cold pressing process for cold pressing glue of plywood, which has the advantage of improving the pressing quality of plywood and solves the problem of incomplete pressing of plywood.

[0005] (2) Technical Solutions

[0006] To achieve the above object, the present invention provides the following technical solutions: A cold pressing process for cold pressing glue of plywood, comprising the following steps:

[0007] S1. Cut the wood board;

[0008] S2. Dry the wood board;

[0009] S3. Apply glue to the veneer;

[0010] S4. Assemble the embryo;

[0011] S5. Cold pressing: Place the assembled board on the cold press, press the assembled board through a cold press with stable pressure, keep the pressure at 1.2 MPa, the pressing time is 4 to 12 hours, turn over the assembled board, press the back side of the assembled board, keep the pressure at 1.2 MPa, the pressing time is 2 to 6 hours, and let the board stand for 24 - 48 hours after releasing the pressure until the adhesive is completely cured;

[0012] S6. Sand.

[0013] Preferably, in S1. Cut the wood board: Cut the board into wood boards with the same thickness, and control the error of the wood board thickness within 0.2 mm;

[0014] S2. Dry the wood board: Use a dryer to dry the wet veneer after rotary cutting to a moisture content between 10% - 12%;

[0015] S3. Veneer Gluing: If the number of veneers to be laminated is odd, the middle veneer is glued on both sides, the remaining veneers are glued on both sides, and the outermost veneers are not glued; if the number of veneers to be laminated is even, one of the two middle veneers is glued on both sides, the rest are glued on one side, and the outermost veneers are not glued.

[0016] S4. Lamination: The glued veneers are assembled, and the grain direction of the outermost veneer is consistent with the length direction of the laminated blank.

[0017] S6. Sanding: Cut and trim the excess parts around the plywood formed after cold pressing, and then sand the surface of the trimmed plywood.

[0018] Preferably, in S4. Lamination: When laminating the veneers, the veneers are stacked and combined one by one, the fiber directions of adjacent layers of veneers are perpendicular to each other, and one end and one side of the veneers are aligned.

[0019] Preferably, in S1. Cutting the Wood Board: The board is cut into veneers with a thickness of 1.5 mm to 5 mm by a cutting machine.

[0020] Preferably, in S2. Drying the Wood Board: The temperature of the air flow in the dryer is controlled between 100°C and 250°C.

[0021] Preferably, in S3. Veneer Gluing: The adhesive and the curing agent are mixed and used in proportion.

[0022] Compared with the prior art, the present invention provides a cold pressing process for cold pressing glue of plywood, which has the following beneficial effects:

[0023] 1. In this cold pressing process for cold pressing glue of plywood, through the lamination on both sides of the plywood, the plywood is more closely bonded, making it difficult for the veneers of the plywood to crack and separate from each other. Moreover, with double-sided lamination of the plywood, the plywood is not easily deformed, improving the quality of the plywood.

[0024] 2. In this cold pressing process for cold pressing glue of plywood, the wet veneers are dried to a moisture content between 10% and 12%, increasing the humidity of the veneers, which can reduce the amount of adhesive used and will not reduce the strength of the plywood, saving resources and reducing the processing cost of the plywood. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural diagram of the cold pressing process of the plywood of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Please refer to Figure 1 , a cold pressing process for cold pressing glue of plywood, comprising the following steps:

[0028] S1. Cutting the wood board: Cut the board into wood boards with the same thickness, and control the error of the wood board thickness within 0.2 mm; Cut the board into veneers with a thickness of 1.5 mm to 5 mm through a cutting machine.

[0029] S2. Drying the wood board: Use a dryer to dry the wet veneer after rotary cutting to a moisture content between 10% and 12%; Control the temperature of the air flow in the dryer between 100°C and 250°C.

[0030] Drying the wet veneer to a moisture content between 10% and 12% can increase the humidity of the veneer, reduce the amount of adhesive used, and will not reduce the strength of the plywood, saving resources and reducing the processing cost of the plywood.

[0031] S3. Coating glue on the veneer: When the number of veneers for pressing is odd, coat glue on both sides of the veneer in the middle position, coat glue on both sides of the remaining veneers, and do not coat glue on the veneers on the outside; When the number of veneers for pressing is even, coat glue on both sides of one of the two veneers in the middle position, coat glue on one side of the remaining veneers, and do not coat glue on the veneers on the outside; Mix and use the adhesive and the curing agent in proportion.

[0032] S4. Forming the embryo: Assemble the veneers coated with glue, and keep the grain direction of the outermost veneer consistent with the length direction of the embryo formation; When forming the veneer embryo, stack and combine the veneers one by one, and the fiber directions of adjacent layers of veneers are perpendicular to each other, and one end and one side of the veneers are aligned.

[0033] S5. Cold pressing: Place the embryo-formed board on a cold press, and press and combine the embryo through a cold press with stable pressure. Keep the pressure at 1.2 MPa, and the pressing time is 4 to 12 hours. Flip the embryo and press the back side of the embryo. Keep the pressure at 1.2 MPa, and the pressing time is 2 to 6 hours. After releasing the pressure, let the board stand for 24 - 48 hours until the adhesive is completely cured.

[0034] S6. Sanding: Cut and trim the excess parts around the plywood formed after cold pressing, and then sand the surface of the trimmed plywood.

[0035] Lamination on both the upper and lower sides of the plywood makes the plywood fit more tightly, preventing the veneers of the plywood from cracking and separating from each other easily. Moreover, double-sided lamination of the plywood makes the plywood less likely to deform, improving the quality of the plywood.

[0036] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cold pressing process for cold pressing of plywood, characterized in that: The following steps are involved: S1, cutting wood boards; S2, wood board drying; S3, veneer gluing; S4, histoembryo; S5, cold pressing: Place the assembled sheet on a cold press, press the assembly together with a stable pressure cold press, keep the pressure at 1.2MPa, and press for 4 to 12 hours. Turn the assembly over, press the back side of the assembly together, keep the pressure at 1.2MPa, and press for 2 to 6 hours. After the pressure is released, let the sheet stand for 24-48 hours, and the adhesive will be completely cured. S6. Sanding.

2. The cold pressing process for cold pressing of plywood according to claim 1, characterized in that: S1. Cutting wood boards: Cut the boards into wood boards of the same thickness, and the error of the thickness of the wood boards is controlled within 0.2mm; S2. Wood board drying: Use a dryer to dry the peeled wet veneer to a moisture content between 10% and 12%; S3, veneer gluing: if the number of veneers pressed together is odd, the veneer in the middle is double-sidedly glued, the other veneers are double-sidedly glued, and the veneers on the outside are not glued; if the number of veneers pressed together is even, one of the two veneers in the middle is double-sidedly glued, the other veneers are single-sidedly glued, and the veneers on the outside are not glued; S4, assembly: the glued veneers are assembled, and the direction of the outermost veneer along the grain is consistent with the length direction of the assembly; S6. Sanding: Cut and trim the excess parts around the plywood formed after cold pressing, and then sand the trimmed plywood surface.

3. The cold pressing process for cold pressing of plywood according to claim 1, characterized in that: S4. Assembly: When assembling veneers, the veneers are stacked one by one, with the fiber directions of adjacent layers of veneers perpendicular to each other, and one end and one side of the veneers aligned.

4. The cold pressing process for cold pressing plywood according to claim 1, characterized in that: S1. Cutting wood boards: Cut the boards into single boards with a thickness of 1.5mm to 5mm by a cutting machine.

5. The cold pressing process for cold pressing plywood according to claim 1, characterized in that: S2. Wood board drying: Control the temperature of the air flow in the dryer between 100°C and 250°C.

6. The cold pressing process for cold pressing plywood according to claim 1, characterized in that: S3. Gluing of veneer: Mix the adhesive and curing agent in proportion.

Images