Why do some multilayer solid wood composite floors

2022-07-22
  • Detail

Multilayer solid wood composite floor is a composite floor made of multilayer plywood as the base material and solid wood veneer on the surface. The type of raw materials and processing technology of the substrate can lead to the bending and deformation of floor products. The factors causing deformation can be summarized as follows

multilayer solid wood composite floor is a composite floor made of multilayer plywood as the substrate and solid wood veneer on the surface. The type of raw materials and processing technology of the substrate can lead to the bending and deformation of floor products. The factors causing deformation can be summarized as follows:

1. The influence of raw materials

the raw material (veneer) of the base material is the same tree species, the drying shrinkage coefficient of the wood is similar, and the base material is not easy to deform. Sometimes mixed wood, especially wood with different density and dry shrinkage coefficient, is used to form asymmetric stress on both sides of the central layer of the substrate, causing bending or distortion of the floor substrate. Therefore, if miscellaneous wood is selected as the raw material of floor base material, try to choose trees with similar wood proportion and wood properties. Try to choose the same tree species in the symmetrical layers on both sides of the central layer of the substrate. If conditions permit, the production enterprise can sort the purchased raw materials according to tree species and wood properties

2. Influence of moisture content of veneer

when the moisture content distribution of veneer is large, for example, in the same substrate slab, the moisture content of some veneers is 7%, and the moisture content of some veneers is 14%. After gluing and hot pressing, the moisture content distribution of each part of the finished substrate plate is uneven, although the substrate plate is flat when it comes out of the press, and bending and distortion will occur when the moisture content is rebalanced. If the moisture content of individual areas in the slab is too high, delamination will also occur. Therefore, the moisture content of veneer should be controlled within the range of process requirements as far as possible. The veneer shall be coated evenly, and the moisture content of each layer and point of the slab before hot pressing can be balanced by appropriately extending the aging time

3. The influence of the internal stacking (overlapping) and separation (seam separation) of the substrate plate

the stacking and separation of the substrate plate will cause the plate to produce stress, and the effect of this stress on the whole substrate plate is not very obvious. When the substrate plate is sawed into floor strips, the stress points generated by the stacking and separation will lead to the deformation of the floor strips. If there is serious lamination within the three layers of the surface, during the use of the paint spraying floor, the visible light edge at the lamination (surface layer with thickness of 0.6mm) is clear. Therefore, the middle plate must be spliced to make the middle plate whole and reduce and avoid the overlap of the middle plate

4. The influence of the elastic surface of the veneer

the elastic surface will appear during the rotary cutting of the veneer. There are many cracks on one side near the tool, which we call the loose surface, and the other side is called the tight surface. For the same veneer, the tight side is the outer circle of the wood, and the loose side is the side near the center of the wood. The stress produced by the expansion and drying shrinkage of the tight surface is greater than that of the loose surface. During blank assembly, keep the tight side outward and form symmetry on both sides of the central layer of the substrate

5, the influence of sapwood and heartwood

there are differences in the dry shrinkage and expansion of sapwood and heartwood. When assembling billets, sapwood and heartwood should be mixed as much as possible. Prevent the phenomenon of sapwood on one side and heartwood on the other side of the central layer of the substrate

6. Influence of external environment on finished products

due to the thick paint film on the floor surface, water is not easy to enter and exit from the surface, and there is less paint on the back of the floor, so there is no continuous film, and water is easy to enter and exit from the back of the floor. The floor is flat when packing. If the packing box is damaged during transportation, moist air rushes in, and the back of the floor absorbs moisture, the floor bends towards the board after unpacking

in addition, many users do not install it immediately after unpacking the floor, and over select the color difference. If the balanced moisture content of the environment is higher than the moisture content of the floor, the moisture absorption on the back of the floor bends towards the board. If the balanced moisture content of the environment is lower than the moisture content of the floor, the moisture loss on the back of the floor bends downward. This change is not a quality problem

石家庄男科医院

成都神经内科医院

中山皮肤病医院

广州皮肤病医院

Copyright © 2011 JIN SHI