Some plastic materials are also compatible with the same machining processes as metals, such as milling or turning. As with metals, plastic polymers have different properties that contribute to their machinability, attributes, and prices. Plastics are generally categorized into two groups:
Thermoplastic materials can be heated, cooled, and reheated again without losing their basic properties. This means that they can be reformed again and again without undergoing permanent chemical changes. This makes thermoplastics ideal for machining processes, as waste material and mistakes can usually be recycled and reused to drive down costs.
There are a wide variety of thermoplastic options available. Polyetherimide, for example, has an extremely high dielectric strength and is frequently used in precision aerospace components. Polyethylene, polypropylene, and polyvinyl chloride (PVC) are popular thermoplastics used to create hundreds of different consumer, commercial, and industrial parts and products.
Common thermoplastics used in CNC Swiss Machining include:
Thermoset plastics undergo a chemical change during the first set of heating and cooling processes. They cannot be remelted or softened for further refinement or even recycling. They are also very brittle once they set, which can make machining extremely difficult. As such, thermoset plastics are generally not used in CNC Swiss machining applications.