CMT Materials Foam can be used for thermoforming plugs
Material selection is based on process demands.
According to US-based CMT Materials, its Hytac syntactic foam is the only plug-assist material specifically engineered for thermoforming.
Epoxy and thermoplastic-based grades are said to be optimised for different types of plastic, temperature use, machining conditions, surface finish, durability and price.
The company explained that while each specific material can be used in a wide variety of applications, selecting the most suitable product reduces machining costs, improves material distribution, enhances clarity, reduces plastic build-up on the plug and maximises plug life.
The word “syntactic” refers to the fact that the plug-assist material is composed of hollow spheres held in suspension by some type of binder system, CMT noted. In the company’s materials, a thermoset binder is an epoxy system, which compares with a thermoplastic binder that is actually a high-performance plastic and said to be more durable in use. Solid polymer plugs reportedly lack the beneficial thermal transfer isolation characteristics of syntactic foam.
Since the foam is a combination of hollow glass microspheres bound together by epoxy, co-polymer blends or thermoplastic materials, it needs specific processing, the company said. Abrasive by nature, the foam requires sharp tools actually designed to cut abrasive plastics, the supplier explained.