4 Factors Affecting the Quality of PVC Foam Boards
If we want to ensure the quality and performance of the finished PVC foam board, we need to pay attention to many things in the manufacturing process. If the process of the PVC foam board is not good, it will greatly reduce the aesthetics, and even the safety performance cannot be guaranteed. Therefore, when the following problems occur in the PVC foam board, we must pay attention to it.
1. Insufficient stability
This will affect the entire surface of the PVC foam board, resulting in yellowing of the surface and large brittle fracture of the foam board.
2. Insufficient melt strength
This will cause the foamed sheet to have large cells and long vertical sections. The most direct way to distinguish whether the melt strength is not enough is to press the plate wrapped on the middle roll with your fingers behind the three rolls. When the melt strength is good, you will feel elasticity when you press it. If there is no way to bounce up after pressing, it indicates that the melt strength is weak.
Because of the large gap between the structure of the screw rod and the cooling method, it is impossible to distinguish whether the temperature is reasonable. Generally speaking, within the allowable load of the extruder, the temperature in the 3 to 5 zone is better, and it is also necessary to ensure that the PVC raw materials have good quality. Therefore, the quality and model specifications of the foaming regulator are particularly important, and the yellow and white styrofoam must cooperate well with each other.
3. Too much or too little lubricant
Lubricants are divided into outer lubricants and inner lubricants.
The external lubricant is beneficial to mold ejection and to the smoothness of the sheet surface. If the external lubrication slips too little, the temperature of the extruder is not easy to control, which will cause high temperature of the confluence core, large bubbles in the middle of the sheet, foaming, yellowing, and other problems, and the surface of the sheet will also be uneven. If there are more external lubricants, the dissolution will become more and more serious, which is mainly manifested in the dissolution of the structure in the abrasive tool and the outer slippery surface of the plate.
The internal lubricant is beneficial to the melting and the flow rate of the melt. If the internal lubricant is not enough, the surface cannot be manipulated. The main manifestation is that the thickness of the plate is thin on both sides. If the internal lubricant is too slippery, the temperature of the confluence core is likely to be high.
4. Poor dispersion will cause unevenness on the surface of the sheet
Process temperature control is a surface problem, but poor temperature control can cause essential problems. Increasing the production process temperature will reduce the stable time of raw materials and cause stability problems.
The original lubrication balance will be eliminated. Generally, it is mainly manifested as insufficient external lubrication, especially in the later external lubrication, the amount of external lubrication needs to be increased; the increase in temperature will also cause the melt strength to decrease, the foamed sheet cell expands, and the total number of cells decreases, the sheet is brittle and easy to crack; the increase in temperature reduces the melt strength and also reduces the melt viscosity.
The PVC foam board designed and manufactured by Sounda adopts a good manufacturing process and is used in many industries and fields. If you have a demand for this, you can send your demand to us, and we will give you a satisfactory answer as soon as possible.
As a professional supplier of advertising, digital printing, and construction materials, we have always been committed to providing customers with safe, environmentally friendly, and high-quality products. We have a strict production team and have established a complete quality inspection system, which can control the quality of products in all aspects. And we can also provide thoughtful one-stop service and develop effective solutions according to your diversified needs. If you are interested in our PVC foam boards, please contact us immediately!
