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Common problems and solutions in the production of PVC board
- Jul 12, 2018 -

Common problems and solutions in the production of PVC board:

1, the board surface is yellow.

The extrusion temperature is too high or the stability is insufficient. The solution is to reduce the processing temperature. If you do not see the improvement, you can adjust the formula, increase the stabilizer and lubricant properly, and change them one by one. It is easy to find the problem quickly and solve the problem at the fastest speed. .

2, the plate is yellow in the middle.

The main reason is that the temperature of the core of the barrel is high, and the amount of lubricant is also related. It has a certain relationship with the white foaming agent.

3, the board surface is curved.

Uneven flow or cooling is not in place, the factors causing uneven flow are generally large fluctuations in traction or uneven lubrication inside and outside the formulation. The factors of the machine are easy to be ruled out. The adjustment of the formula is generally adjusted under the premise of less external lubrication. Very good results, while ensuring that the cooling is in place.

4. There are cells or bubbles in the cross section.

The reason can be attributed to the fact that the strength of the melt is not sufficient, and the reasons for the insufficient melt strength are:

    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 problematic.

    2. Poor plasticization, low processing temperature or excessive lubrication

5, the thickness of the board surface is uneven.

Uneven discharge, can adjust the opening of the lip, if the flow rate is too large, the flow block can be adjusted, the formula is adjusted, the inner lubrication is more thick, and the outer lubrication is faster.

6. Changes in the thickness of the sheet, which are prone to occur during handover.

The main reason is related to the mixing. After the last shift, after the next shift, the mixing time is long, the mixing tank is well cooled, the first pot mix is pre-plasticized, and the mixture is mixed with before. Differences are formed, and fluctuations are easily generated under other conditions, and traction, processing temperature, or management can be solved.