High performance plastic machining will benefit from dedicated tools and know-how.
Fluoropolymer especially tend to be soft, but resilient. Moreover, the industry requires lots of filled fluoropolymers, also known as compounds, and therhave a strong wear-effect on tools. These polymers are also well-known for their quite high thermal expansion, especially when compared to metal. They also feature low thermal conductivity, as they are often used as thermal insulators. With all these thermal properties, a fine control of tool speed and feed is necessary to produce high quality parts. For high tolerances and best surface finishing, machining must be adapted to these materials with unique properties.
For example, virgin PTFE or Teflon basic shapes are easy to machine. They have low strength when compared to usual engineering polymers, like polyamide. But its high coefficient of expansion makes it difficult to achieve tight tolerances. On the contrary, PEEK based composites are quite hard and require their own CNC procedures. But their stability, with a coefficient of thermal expansion near that of metal, easily allow tight tolerances and surface finish. This is especially true for composites in the XC®2 range, with continuous carbon fibers.
Therefore, machined parts made of high performance plastics often need dedicated tools for best results. Such tools improve surfaces finishes and take into account the internal stresses of the material, which are relieved during machining.
While they can be supplied as basic-shapes or semi-finished products, optimized machining by 3P is preferred for monitored quality.