about plywood production line

17/12/2021

Plywood production line refers to a kind of man-made board made by rotating logs into veneers with a rotary cutter, and then arranging veneers vertically according to the fiber direction, gluing and pressing them.

Plywood is an ideal product widely used in building formwork, interior decoration, all kinds of furniture, office supplies, combined speakers, packaging and exhibition. The plywood production line is divided into rotary cutting machine, veneer dryer, gluing machine, pre press, hot press, vertical and horizontal sawing machine, sanding machine, etc.
 

Technological process of processing and producing plywood

 

Process flow of log processing and production of plywood log - ◆ log sawing ◆ wood section cooking + wood section peeling → veneer rotary cutting → veneer drying → veneer finishing → gluing and blank forming ◆ preloading → hot pressing → edge cutting → sanding → inspection grading - packaging and warehousing.

 

Process flow of veneer processing and production of plywood veneer finishing + gluing blank pre pressing → hot pressing → cutting → sanding → inspection grading ◆ packaging and warehousing.

 

Processing process loss: in the whole production process of plywood, log sawing, veneer rotary cutting, veneer drying, veneer finishing, hot pressing and edge sanding have an impact on wood loss, which is divided into tangible loss (with processing residues) and intangible loss (drying shrinkage and compression). Wood loss is related to log species, log specifications, equipment conditions, process technology and finished board specifications.

 

Log sawing: the length of imported logs is generally over meters, and they shall be sawed according to the length and quality required by the process. The intercepted wood section shall be the length of finished plywood size plus machining allowance. For example, for the finished plywood with a width of 120mx2440mm, the length of the wood section is usually 600mm or 1300mm. The length of the log, the curvature and defects of the log directly affect the yield of plywood. The waste produced includes small wood segments, truncated heads and sawdust. The sawn loss rate of the log is 10%.
 

Veneer rotary cutting: veneer produced by rotary cutting method is the most widely used in plywood production. The thickness of face back plate is generally about 0.6mm, and the thickness of core plate and long medium plate is generally about 8mm. This process has the largest loss. First, due to the out of roundness of the wood section, a considerable part of the broken veneer can not be used; Second, the clamp head of the rotary cutting machine clamps both ends of the wood section, resulting in end loss; Third, wood core loss. The waste generated by veneer rotary cutting is broken veneer and wood core. It can be seen that the loss of veneer rotary cutting is related to the material, diameter and equipment performance of wood section, and the loss rate varies from% ~ 25%.

 

Veneer drying: the moisture content of veneer after rotary cutting is very high, and the veneer must be dried to meet the gluing requirements

 

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Technical requirements. After drying, the size of wood becomes smaller, which is called drying shrinkage. Due to the decrease of water content, the length, width and thickness of single Maple will shrink. The shrinkage loss is related to the tree species, moisture content and thickness of veneer. Shrinkage loss rate -- generally% ~ 10%.

Veneer rotary cutting: veneer produced by rotary cutting method is the most widely used in plywood production. The thickness of face back plate is generally about 0.6mm, and the thickness of core plate and long medium plate is generally about 8mm. This process has the largest loss. First, due to the out of roundness of the wood section, a considerable part of the broken veneer can not be used; Second, the clamp head of the rotary cutting machine clamps both ends of the wood section, resulting in end loss; Third, wood core loss. The waste generated by veneer rotary cutting is broken veneer and wood core. It can be seen that the loss of veneer rotary cutting is related to the material, diameter and equipment performance of wood section, and the loss rate varies from% ~ 25%.

 

Veneer drying: the moisture content of veneer after rotary cutting is very high, and the veneer must be dried to meet the gluing requirements

 

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Technical requirements. After drying, the size of wood becomes smaller, which is called drying shrinkage. Due to the decrease of water content, the length, width and thickness of single Maple will shrink. The shrinkage loss is related to the tree species, moisture content and thickness of veneer. Shrinkage loss rate -- generally% ~ 10%.
 

Veneer finishing: veneer finishing includes cutting, splicing and repair. The dried strip veneer and zero veneer are cut into specification veneer and splicing veneer. The narrow veneer is spliced into the whole veneer. The defective whole veneer can meet the quality requirements of the process through repair. The amount of waste veneer produced in this process is related to factors such as log material, rotary cutting veneer quality, dry veneer quality and operators' familiarity with veneer standards. The loss rate is generally 6 ~ 16%. The loss rate of this process for directly imported veneer processed into plywood is generally% ~ 11%.

 

Hot pressing: glue the glued slab firmly through a certain temperature and pressure. During hot pressing, with the change of slab temperature and moisture content, the wood is gradually compressed and the slab thickness is gradually reduced. The loss is compression loss, which is related to the hot pressing temperature, unit pressure and hot pressing time of plywood Tree species are related to factors such as moisture content, and the loss rate is generally 3% 6 ~ 8%.

 

Edge cutting: cut the hot pressed rough board into standard board. The amount of scrap from the cut corners is the same as that of plywood The larger the width of plywood, the smaller the edge cutting loss rate, which is generally. 6% ~ 9%.

 

Sanding: sanding the surface of plywood to make the surface smooth and beautiful. The waste produced in this process is sanding powder. When the veneer quality is good, the sanding amount is small, and the sanding loss rate is generally - 6%.

 

Under the condition of normal material, the loss rate of plywood produced by log processing is ~ 55%, and the loss rate of plywood produced by directly imported semi-finished veneer processing is generally% ~ 26%.

Veneer finishing: veneer finishing includes cutting, splicing and repair. The dried strip veneer and zero veneer are cut into specification veneer and splicing veneer. The narrow veneer is spliced into the whole veneer. The defective whole veneer can meet the quality requirements of the process through repair. The amount of waste veneer produced in this process is related to factors such as log material, rotary cutting veneer quality, dry veneer quality and operators' familiarity with veneer standards. The loss rate is generally 6 ~ 16%. The loss rate of this process for directly imported veneer processed into plywood is generally% ~ 11%.

 

Hot pressing: glue the glued slab firmly through a certain temperature and pressure. During hot pressing, with the change of slab temperature and moisture content, the wood is gradually compressed and the slab thickness is gradually reduced. The loss is compression loss, which is related to the hot pressing temperature, unit pressure and hot pressing time of plywood Tree species are related to factors such as moisture content, and the loss rate is generally 3% 6 ~ 8%.

 

Edge cutting: cut the hot pressed rough board into standard board. The amount of scrap from the cut corners is the same as that of plywood The larger the width of plywood, the smaller the edge cutting loss rate, which is generally. 6% ~ 9%.

 

Sanding: sanding the surface of plywood to make the surface smooth and beautiful. The waste produced in this process is sanding powder. When the veneer quality is good, the sanding amount is small, and the sanding loss rate is generally - 6%.

 

Under the condition of normal material, the loss rate of plywood produced by log processing is ~ 55%, and the loss rate of plywood produced by directly imported semi-finished veneer processing is generally% ~ 26%.
If you have any questions about plywood production line, please contact my email: admin@sinoeurocn.com