I believe that everyone has some understanding of the PVC foam board, PVC foam board in the process of production if the temperature control is not good, then what will happen? If the temperature is poorly distributed, the PVC foam board will not be smooth. We all know that if the surface of the board is not smooth, it is more troublesome to process it. For the process temperature control problem, the following let editors to tell you about it in detail.
In the extrusion process of PVC foamed board, there are mainly four types of problems, namely, stability, melt strength, lubrication, and dispersion. These four categories are all fundamental issues. Process temperature control is a superficial problem that is more intuitive than these four categories. However, if the temperature control is not good, it may easily induce the emergence of fundamental problems.
Increasing the temperature of the processing process will reduce the stability of the material and cause stability problems. The original lubrication balance will be broken. Generally, the external lubrication will be insufficient. Especially for the external lubrication at the later stage, the amount of external lubrication needs to be increased; the temperature increase will also lead to The melt strength decreases, the foamed sheet cells increase, the number of cells decreases, the sheet becomes brittle and easy to break, the temperature increase reduces the melt strength and also decreases the melt viscosity, the viscosity decreases, the shearing and dispersing ability decreases, and the dispersion decreases. In the case of a screw with low capacity, uneven dispersion sometimes occurs.