How can we make the flame retardant of PP plates not frost or exude?

In the process of producing PP flame-retardant plates, a common problem is the exudation of flame-retardant materials. It is specifically manifested as powdering on the surface of the plate, which affects the adhesion of the plate surface, causes the plate to stick to the mold during part removal, and affects the transparency, etc.

First, let's analyze the reasons for the exudation.

On the one hand, PP is a non-polar material, while commonly used flame retardants are generally polar materials. This leads to a compatibility problem between the two at the contact surface. The worse the interfacial compatibility is, the more likely the exudation problem will occur.

On the other hand, affected by the environmental temperature, the substances inside the PP will gradually migrate to the surface, especially the small-molecule flame retardants. This is also the reason why phenomena such as mold sticking and mold fouling occur during the injection molding process. In addition, exudation may sometimes occur on the surface of the molded parts after they have been stored for a certain period of time. The migration rate of the flame retardant is positively correlated with the temperature. Within the decomposition temperature range of the flame retardant, its exudation rate increases significantly with the increase of temperature. At a constant temperature, the exudation is also related to time to a certain extent.

After understanding the reasons for the exudation, let's talk about how to prevent it:

1. Use grafting aids to increase the compatibility between the flame retardant and PP.

2. Increase the migration resistance between the flame retardant and the resin and reduce the migration rate of the low-molecular-weight flame retardant. This can be achieved by adjusting the components inside the flame retardant.