New Material Calls For New Composite Routing Tools
There are new composite routing tools on the market specifically for a material that is composed of polyethylene terephthalate, which is commonly used for thermoforming. Different router bits are required for the different variations of this one material due to the unique characteristics that arise from the way that the material is composed. You can’t just use your favorite upcut wood router bits on this material, and you can’t use the same spindle speeds, feed rates and fixturing of you want to optimize finish and production rates.
The composite routing tools that are best for polyethylene terephthalate materials are those that are formulated to be used with softer materials, such as O flutes. These router bits are not as rigid and are less likely to cause cracking because of their unique geometry. Upcut wood router bits are not an option here, since they will not work with the CNC routers that are best for composites. There are various O flutes that can be used for the various polyethylene terephthalate materials, though, so it’s best to speak with an expert if you don’t have any prior experience with PET.
When programming a composite routing machine for cutting PET, there are a few considerations that will dramatically affect the production, scrap and finish. When the router bits enter the cut, they should be moving in a ramping and not a plunging action. Routing the perimeter of sharp corners should be programmed as a loop or exit ramp movement to prevent tool stops or dwells which can cause crack propagation, heat or burning. The composite routing machines should also have spindle speeds set at 18,000 RPM and feed rates between 200 to 350 inches per minute.
Composite routing should be done as quickly as possible, whether it is with polyethylene terephthalate materials or any other type of composite, but with proper technique and tool selection this should be easy to do time and time again.