Thermal expansion - shrinkage, Wood - plastic composite plate plate shows the phenomenon of thermal expansion and contraction, therefore, is also an important field of WPC research and development. Almost all (except for special engineering and aerospace design materials) solid material expansion and contraction with the temperature rise and decrease and almost linear changes.
At present, there are two main ways to reduce the expansion and contraction of WPC panels. First, change the Wood - plastic composite material formulation (to reduce the amount of plastic used, the use of different fillers to improve the fiber aspect ratio) and / or change the basic process (the faster the extrusion speed, the greater the degree of longitudinal orientation); Secondly, the use of more effective nails Or screws to plate the plate, thereby inhibiting the expansion and contraction of the wrapper. Of course, in these cases the stress must be released, and it can be predicted that the reaction force of some parts will cause the following joist foundation to reverse the damage or damage to the sheet itself. However, observation of these well-fixed and non-thermal expansion-contraction Wood - plastic composite sheets (eg GeodDeck) found that no damage was observed. However, when the fixtures (screws) were removed, the plates were given a guitar-like sound, indicating that they did bear a lot of stress.
All in all, the expansion and contraction of the Wood - plastic composite sheet is largely unpredictable and more dependent on the empirical value.
Therefore, in the installation of Wood - plastic composite floor, be sure to set aside 5mm expansion joints.