The warpage of PVC board is the reason in many aspects. The main problem is that the stability of the floor has not been well controlled. Whether coiled floor or sheet floor, most of them appear in PVC floor with base. Due to the influence of environmental factors, the changes of thermal expansion and cold contraction of PVC floor are different, resulting in floor expansion or contraction. The changes of thermal expansion and cold contraction of different coefficients are different, so the floor warps. In floor production, attention should be paid to the rational use and balanced collocation of materials to reduce the deformation of the floor.
1. check whether the temperature of PVC board is too high during demoulding. If yes, reduce the barrel temperature.
2. is there any deformation caused by internal stress. If so, reduce the injection pressure.
3. is the cross section irregular and the shrinkage uneven. If yes, redesign the mold with uniform cross-section to make it fill evenly.
4. the demoulding pin is unbalanced. If so, adjust or dispose of the release pin.
The reasons for the warping of PVC sheets are as follows: firstly, the production process control of sheets is not in place, and good sheets need to have consistent paving density and symmetrical structure. If the difference is too large, the internal expansion and contraction of the plate will be inconsistent, resulting in internal stress. Second, the water content of the plate is not properly controlled. The water content of the plate exceeds or is lower than the ambient humidity, which is easy to cause warpage and deformation. Therefore, it is necessary to keep the water content within the normal range. Third, the plate density is unqualified. Low plate density will cause the processing surface to be not smooth and easy to absorb moisture and deform. Fourth, the waterproof performance of the board is unqualified, and it is easy to absorb moisture and deform. Fifth, the maintenance is unqualified. If the PVC board is not stored in a dry and ventilated environment, it is easy to affect the stability of the board, resulting in deformation and other problems.
From the mechanical point of view, the warping deformation of sheet metal is the result of internal stress release. If no measures are taken in the production process, the plate can not offset the internal stress, resulting in the warpage and deformation of PVC plate when it is made under pressure and high humidity.
