What are the common problems of pvc foam boardWhat are the common problems of pvc foam board
The surface of pvc foam board is very smooth, high hardness, not easy to have scratches, often used in making cabinets, furniture, etc., but in use, many people will react to some problems, affecting the overall beauty, for this reason we Get up and analyze.
PVC foam board problem:
1. The insufficient stability of this foam material will affect the whole board surface, the board surface will be yellow, the foam sheet is brittle, and the insufficient melt strength will cause the foam sheet to have large cells and the longitudinal section foam is very long. To determine whether the melt strength is insufficient, the direct method is to press the sheet wrapped on the middle roll with your fingers after the three rolls. When the melt strength is good, you can feel the elasticity. If it is difficult to bounce after pressing, it indicates that the melt strength is poor.
2. The outer slip is good for demoulding, which is good for the surface finish of the sheet. The outer slip is too little. The temperature in the 4 zone of the extruder is not easy to control and it is easy to heat up. This will cause the temperature of the confluence core to be high, and large bubbles and strings appear in the middle of the sheet. For blistering, yellowing and other problems, the surface of the plate is not smooth.
3. Internal slip is good for plasticization and melt fluidity. Insufficient internal slip is difficult to control the thickness of the board surface. It is shown that the middle of the plate is thin and thin on both sides. The internal slip is much, and the phenomenon of high temperature of the confluent core is easy to occur. The phenomenon that the surface of the board is not smooth.
The key factor to improve the quality of this foaming material is to improve the melt strength of PVC. From the analysis of processing characteristics of polymer materials, there are many ways to improve the strength of PVC melt, but the effective way is to add additives to improve the melt strength. And lower the processing temperature.