What process is best for electronic device casings?
There are many processes used in producing hard plastic cases. However, typically they would be injection molded from a tough plastic like ABS. The molds used to produce the casing would typically be CNC or EDM machined, polished, assembled and tested prior to use on an injection molding machine.
The first stage would be CAD modelling of the parts (for Rapid prototyping) followed by the cad modelling of the molds (for CFD and CAM programming) If a manufacturer wants to make a casing they would have the part rapid prototyped (3D printed). The prototype can then be tested to ensure that it is functional. If for instance it fitted together poorly, the parts would be re-designed, a new prototype made and then re-tested. This is an iterative process and often results in a few prints before obtaining an optimal design.
CFD- computational fluid dynamics is used to ensure that the plastic will flow easily and correctly through the molds, If it does not, then the molds may have to be redesigned. Engineers would be looking out for problems such as sink marks and voids which may be present in the parts due to poor part and/or mold design.
Only when the parts are approved would the design be sent out to the toolmaker to start producing the tooling. Although the prototype part may be expensive and take several hours to produce; the production cost of tooling and labor to mass produce a part will be many times greater.
The prototype can be made and tested in a matter of days where production tooling could take months. This saving in time can result in a product being brought to market early (maximising profit), design errors eliminated at source, weak points in the design are identified and corrected prior to manufacture as well as giving people the ability to see, touch and feel a product before it is actually mass produced.
Models can be prototyped from any 3D CAD design saved as an STL. However, CAD design files in IGES or STEP format will be needed for tooling. 3D printers import a 3D solid model, mostly in STL format. The model is processed by the rapid prototyping machine software into a sliced model. All rapid prototyping systems work in basically the same way. Parts are built by adding thin layers of material one on top of the other until the model is generated. Once you have a final prototype design we can build your mold.