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What Are The Common Problems With PVC Foam Board?
- Dec 30, 2018 -

First, the board surface is yellow

Cause: The extrusion temperature is too high or the stability is insufficient.

Solution: Reduce the processing temperature. If you can't improve the formula, increase the stability, increase the stabilizer and lubricant properly, you can change it one by one. First, increase the stabilizer to see the effect, then adjust the lubrication to balance the lubrication, so it is easy to find out quickly. The problem is, solve the problem quickly.

 Second, the plate is yellowed in the middle

Reason: The temperature of the core of the first barrel is high, and the amount of the second lubricant is unreasonable, and it has a certain relationship with the white foaming agent again;

Solution: Appropriately reduce the mold temperature, screw temperature adjustment; appropriately increase the internal lubrication; add an appropriate amount of white endothermic foaming agent to absorb the excess heat released by the foaming agent AC decomposition process.

 Third, the board surface is bent

Cause: The flow is uneven or the cooling is not in place.

Solution: The factors causing uneven flow are generally traction fluctuations or uneven lubrication inside and outside the formula. The factors of the machine are easy to be ruled out. The formula adjustment is generally adjusted under the premise of less external lubrication (no paste occurs). It will have a good effect, while ensuring that the cooling is in place.

 Fourth, the cross section appears bubble or bubble layering

Reason: It can be attributed to one point, that is, the melt strength is not enough, and the cause of insufficient melt strength is 1. The foaming agent is excessive or the foaming regulator is insufficient or the ratio of the two is not coordinated, or the quality of the foaming regulator is 2. Poor, low processing temperature or excessive lubrication

Solution: Firstly reduce the amount of foaming agent and see how effective it is. If the effect is not large, add appropriate amount of regulator or switch to regulator with high melt strength. Second, if plasticization is poor, the processing can be appropriately improved. Temperature or appropriate reduction in lubricant usage.