There are many Polymer insulators manufacturers in the world, and China is the leader of the insulator market, where the insulator manufacturer has rich experience.

How do the Polymer insulators manufacturers manufacture the products?
There are three main materials for polymer insulator, and they need to be treat first and then moulding.
The strength of the bond is greater than the tearing strength of the silicone rubber itself.
Fiber glass rod: inspection—cutting and abrasion—cleaning and drying
End fitting: inspection—cleaning
The gaps between the fittings are sealed during the molding process to avoid moisture ingress to the fiber glass rod.

Polymer insulators manufacturers will do a series of tests for polymer insulators, and this will ensure the quality of the products.