PVC foam board is a closed-cell, durable, free foam PVC sheet material. The main raw material used to make PVC foam boards is polyvinyl chloride. Polyvinyl chloride has the characteristics of moisture resistance and corrosion resistance, and it can be easily sawn, carved, drilled, or painted to meet the needs of numerous customers.

During the PVC foam board extrusion process, there may be some quality problems due to different factors. This article will discuss 5 factors that affect the quality of PVC foam board and their possible solutions.

• 5 factors affecting the quality of PVC foam board

Following, we have listed the main factors that affect the quality of PVC foam board:

1. Stability

Insufficient stability will affect the entire surface of the PVC foam broad. In addition, stability problems will cause the surface of the entire PVC foam board to turn yellow, and the sheet of the PVC foam board will become brittle.

2. Melt strength

Excessive foaming agents, low processing temperatures, or poor-quality foam regulators can cause insufficient melt strength. Insufficient melt strength will cause the cells of the foam board to be larger. As a result, the longitudinal sections will be longer.

3. Lubrication

The lubricant of PVC foam board is divided into external and internal lubricants. If the amount of external lubricant is too little, there will be large bubbles and yellowing in the middle of the broad. However, if the amount of internal lubricant is insufficient, it will result in uneven thickness of the PVC foam board.

4. Dispersion

Temperature is the most intuitive problem of the quality of PVC foam board. If the temperature is too high, the melt viscosity will decrease and reduce the dispersibility of the pigment. Inhomogeneous dispersion of pigments will result in a rough surface of the board.

5. Size and uniformity of the bubble holes

PVC is a straight-chain molecule with a short molecular chain and low melt strength. In the process of bubble nucleus expansion, the melt is not enough to cover the bubbles, sthe gas is easy to overflow and merges into large bubbles. For this reason, it is difficult to reduce the density further if the cells are large and scattered.

• Solutions

Below, we have listed some possible solutions to poor-quality PVC foam boards.

1. For the yellowing of the board surface caused by insufficient stability, the material processing temperature should be reduced, or an appropriate amount of stabilizer and lubricant should be added.

2. If the middle of the PVC foam board turns yellow, it is necessary to reduce the temperature of the mold and the screw; and add an appropriate amount of white heat-absorbing foaming agent to absorb excess heat.

3. If the PVC foam board has bubble holes or bubble stratification, it is necessary to reduce the amount of foaming agent or use a regulator with a strong melt.

4. The uneven flow of raw materials will cause the surface of the PVC foam board to bend. The solution is to reduce the amount of external lubricant first, and then adjust the amount of internal lubricant. At last, the PVC foam board needs to be fully cooled to solve the problem of surface curvature.

• Product recommendation: Boyu PVC foam board production line

Apart from the above factors that will affect the quality of PVC foam board, it is also important to have the right machinery. Boyu Plastic Machinery Co Ltd offers a comprehensive PVC foam board production line. The equipment of the PVC foam board production line includes an extruder, T-die, forming platform, 16 rollers traction machine, cutting machine, and stacking system. Our machines and electrical components both have CE certification. Boyu PVC foam broad production line can increase the extruder's production capacity and guarantee the product's quality.

Contact us for more information about the PVC foam board production line.