PVC WPC FOAM BOARD F.A.Q
Common problems, causes and solutions of PVC foam board
1.The board is yellow. The extrusion temperature is too high or the stability is insufficient. The solution is to reduce the processing temperature. If the improvement does not improve, the formulation can be adjusted. The stabilizer and lubricant can be added appropriately. It can be changed one by one. It is easy to find out 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 temperature of the mold is also related to the amount of lubricant. Once again, it has a certain relationship with the white foaming agent.
3.The board is curved. Uneven material flow or inadequate cooling, the factors causing uneven material flow are generally large traction fluctuations or unbalanced internal and external lubrication in the formula. The factors of the machine are easy to eliminate. Formula adjustment generally adjusts internal lubrication under the premise of as little external lubrication as possible Very good results, while ensuring that cooling is evenly in place
4.Cells or layers of bubbles appear on the cross section. The reason can be attributed to one point, that is, the melt strength is not enough, the reasons for the insufficient melt strength are: 1. excessive foaming agent or insufficient foaming regulator or inconsistent ratio of the two, or quality problems of foaming regulator 2. plasticizing Bad, low processing temperature or excessive lubrication.
5.Uneven thickness of the board. Uneven material output, adjustable die lip opening, if the flow rate is too large, the choke bar can be adjusted, the formula is adjusted, generally the inner lubrication has more middle thickness, and the outer lubrication has more feeding on both sides.
6.Changes in the thickness and texture of plates that are likely to occur during the shift. The main reason is related to the mixing. After the last shift, the interval between mixing is long after the next shift. The mixing barrel is cooled well. The first pot is pre-plasticized, which is the same as before Differences are formed, and other conditions are unchanged, it is easy to produce fluctuations, which can be adjusted by adjusting traction, processing temperature or through management