Plywood Production Line

Product Detail

Log processing plywood production process

Log → log sawing → wood section cooking → wood section peeling → veneer rotation cutting → veneer drying → veneer finishing → gluing group blank → prepressing → hot pressing → trimming → polishing → inspection grading → packing into storage

Veneer processing plywood production process

Veneer finishing → gluing group blank → prepressing → hot pressing → cutting into → sanding → inspection grading → packing into storage

Log sawing: imported log length is generally more than 6 meters, according to the length and quality of the process requirements for sawing, cut wood should be finished plywood size plus the length of processing allowance.For example, finished plywood with a width of 1220mmX2440mm is usually 2600mm or 1300mm in length.The length of log and the bending degree of log, defect and so on directly affect the rate of plywood, the waste that produces has small wood section, cut head and sawdust and so on, log sawing loss rate is generally in 3 ~ 10%.

1. Veneer rotary cutting: the most widely used veneer in plywood production is the rotary cutting method. The thickness of the surface and backplane is generally about 0.6mm, and the thickness of the core plate and long middle plate is generally about 1.8mm.The process loss is the largest, one is due to the wood segment roundness, a considerable part of the broken veneer can not be used;Second, the clamping head of the rotary cutting machine on both ends of the wood segment produces end loss;The third is the loss of wood core.The waste produced by veneer spinning is broken veneer and wood core, so it can be seen that the loss of veneer spinning is related to the material, diameter and equipment performance of wood segment, and this part of the loss rate is 15% ~ 25%.

2. Veneer drying: the veneer moisture content is very high after spinning, and the veneer must be dried to meet the requirements of gluing process.The size of wood becomes smaller after drying, which is called dry shrinkage.Due to the reduction of moisture content, the length, width and thickness of the veneer will dry shrinkage.Dry shrinkage loss is related to tree species, water content and thickness of veneer.Dry shrinkage loss rate is generally 4% ~ 10%.

3. Veneer finishing: Veneer finishing includes cutting, assembling and repairing.After drying strip veneer, pieces of veneer cut into specification veneer and splicing veneer, narrow strip veneer after splicing into a whole veneer, the whole defective veneer can be repaired to meet the quality requirements of the process.The amount of waste veneer produced by this process is related to the log material, the quality of rotating veneer, the quality of drying veneer and the familiarity of the operator with the veneer standard, and the loss rate is generally 4% ~ 16%.Directly imported veneer processing into plywood of the process loss rate is generally 2% ~ 11%.

4. Hot pressing: glue the group of good slabs through a certain temperature and a certain pressure firmly glued together.When hot pressing, wood is compressed gradually with the change of slab temperature and moisture content, and slab thickness decreases gradually.The loss is compression loss, and plywood hot pressing temperature, unit pressure, hot pressing time, tree species and moisture content and other factors, the loss rate is generally 3% ~ 8%.

5. Trimming: Cut hot-pressed wool board into specification board.Cut the amount of waste and plywood processing allowance, the size of the plywood, the larger the size, the smaller the edge loss rate, generally 6% ~ 9%.

6. Sanding: Sanding the surface of plywood to make the surface smooth and beautiful.The waste produced by this process is sanding powder. When the veneer is of good quality, the sanding amount is small, and the sanding loss rate is generally 2% ~ 6%.

Under the condition of normal material, the loss rate of plywood produced by log processing is generally 47% ~ 55%, and the loss rate of plywood produced by directly imported semi-finished veneer processing is generally 16% ~ 26%.