In the production process of PVC coated foam board, the problem of bubble breaking is a more common but difficult phenomenon. The following is an analysis of the typical causes and countermeasures.
First of all, the poor quality of raw materials is one of the important reasons for bubble breaking. If the purity of the PVC resin is not enough, or the decomposition temperature of the blowing agent is not appropriate, it may cause foaming. For example, the use of low-quality blowing agents may produce uneven gas release during the foaming process, resulting in excessive local pressure, which causes the cell to burst.
Improper setting of processing parameters is also a key factor. If the extrusion temperature is too high, the foaming agent will decompose prematurely, the gas will escape too fast, and the bubble wall can not withstand the pressure and break. The temperature is too low, it will lead to poor plasticization of the material, and also affect the stability of the bubble.
In addition, unreasonable mold design may also cause bubble bursting. For example, the flow channel design of the mold is unreasonable, resulting in uneven flow of materials in the mold, uneven distribution of local pressure, and easy to cause bubble breaking.
In view of the above reasons, corresponding countermeasures can be taken.
For raw materials, suppliers should be strictly screened to ensure the use of high-quality PVC resin and suitable blowing agents.
In terms of process parameters, it is necessary to find the most suitable extrusion temperature, pressure and other parameters through many tests and optimization.
In the mold design, it is necessary to combine the characteristics of the product and production requirements to carry out reasonable flow channel design and structural optimization.
In short, it is of great significance to deeply understand the reasons for the bursting of the foam of PVC skin foam board and take effective countermeasures for improving product quality and production efficiency.
