Perlite can be added to plastic resins to reduce the overall weight of the molded parts. The lightweight and porous nature of expanded perlite can help achieve weight reduction while maintaining structural integrity.

Perlite's excellent thermal insulating properties make it suitable for injection molding applications where heat insulation is essential. Adding perlite to plastic materials can help reduce heat transfer and improve energy efficiency.

Perlite can serve as a filler material in some injection molding applications. Its lightweight and non-reactive nature can be advantageous in situations where the goal is to increase the volume of the plastic without significantly changing its properties.