In order to offer Precision Plastics Machining, the behavior of plastics for engineering must be well known.
Plastic’s worst enemy, temperature. As a consequence of temperature, different thermoplastics can vary in size.
Keep in mind that the efforts for machining plastic are lower than in metals. We must also reduce the clamping on the plastic to avoid tensions and deformation that can be produced by an excess of closure in the jaws. When machining plastics, it is necessary to control the heat that can be generated during work, to avoid releasing stresses and consequently obtaining parts out of parallelism.
There are 56 thermoplastic names on the market, in accordance with ISO10438 / DIN7728, without considering the different combinations (additives, PTFE, Fibers, etc …). For a good plastic machining it is necessary to determine the tools correctly, advances and revolutions.
That is why, as a specialized engineering in plastic machining, we can offer our advice so that your application develops with the required success and useful life.
Engineering plastics are a perfect substitute for applications where metals are used. Always under previous study, taking into account the working and environmental conditions of its application, we can propose a possible change.
It is necessary to review the design in tolerances. Due to the visco-elastic behavior of different plastic materials, they can present greater thermal expansion than metals. Among the different plastic materials there are them with greater thermal expansion and others with high dimensional stability.
It is advisable for plastic machining:
- Lightweight holding methods. Avoid straining the plastic.
- Sharp edges are not recommended for internal machining.
- Chamfer the vertices for a smooth transition between the plastic part and the cutting tool.
- Avoid threading on the plastic. It is preferable to apply self-tapping or helicoidal bushings.
- As far as possible, use soluble lubricants. Note there are materials with an amorphous structure that can undergo chemical attack in contact with these products, break down, crystallize and crack more easily.