In PP flame-retardant plates, can fillers be added to form the flame-retardant plates? And how much filler is more appropriate to add?

During the production process of PP plates, fillers are added due to considerations from multiple aspects. The main considerations are as follows: 

1. Low cost to reduce production costs. Commonly used fillers include raw materials such as calcium carbonate, talcum powder, and barium sulfate. The prices of these fillers range from 1,000 yuan per ton to 5,000 yuan per ton, which is much lower than the cost of PP raw materials and other additives, thus achieving the goal of reducing costs. 

2. Enhance the toughness of the plastic and improve the surface hardness. Generally, PP plates have certain requirements for the hardness of the finished product, but the hardness of PP itself cannot meet these requirements, so fillers are needed to enhance it. 

3. High melting point, which can improve the flame retardancy and Vicat softening point of the filled material. 

4. It can effectively reduce the shrinkage rate of the filled material. Some products have requirements for deformation, and the products should not change too much. This can be solved by adding mica powder. 

However, adding fillers not only has advantages but also brings problems. Issues such as whether the fillers are uniformly distributed and dispersed in the PP matrix, and the molecular affinity between the surface of the filler particles and the non-polar polypropylene need to be addressed. 

In a word, fillers can be added to PP plates, but it is recommended not to add too much. An amount of 5-10% is appropriate.