Selection of the appropriate processing method
The processing has a significant influence on the properties of the plastics. Both the technical processing of plastics and the mechanical processing influence the properties of the plastics.
By designing the flow path accordingly, it is possible, for example, to steer the molecular chains and thus align the component properties. The machining process can introduce or release additional stresses into a material which lead to distortion of the components.
In addition to the material properties, the technical and economical feasibility play a considerable role in the selection of the suitable processing method. Not every plastic can be processed with every method, and certain technical requirements may require special processing methods.
Engineering plastic components can be produced by two main processes: on the one hand with injection molding technology, in which the components are cast directly from the plasticized plastic under pressure into a mold; on the other hand, with the machining technology in which the components are machined by means of metal-cutting operations (turning, milling, drilling, etc.) and are brought into shape. Sometimes both processes are used in combination to ensure efficient material use on the one hand, and tight manufacturing tolerances on the other.
In addition, there are high-performance plastics such as PTFE or PI, which are not thermoplastic, i.e. cannot be processed in the melt. These materials are processed into semi-finished products for machining in a press/sintering process or pressed directly into components. This process allows the production of semi-finished products with more or less isotropic properties or the direct shaping of components with simple geometry.
More about the special features and requirements of the plastics to be processed you can find out here!