Once you have decided on the prototype that you want to produce and the approximate materials that it is to be produced from, you need to work on the mould design and any features on the finished part that are influenced by this. If this is not taken into account, when removing the part from the mould issues can arise occurring from the "drag" of the wall on the plastic. These are generally cosmetic, but in more severe circumstances, can cause the final part to be misshapen, which can be eliminated by increasing the angle of the wall to reduce friction as the part is ejected from the mould. While small cosmetic defects may be acceptable in initial prototype samples, this is not the case for retail examples, so, as can be seen, the design of the mould has a large bearing on the final quality of the parts produced.

Another cosmetic aspect that can be altered or included by way of the mould is the final texture of the prototype. This is also dependent on the draft angle of the mould and so, as can be imagined, there must be a compromise between any 'drag' affecting the part and the textured surface of the mould used to create the textured finish, with the rougher the texture the greater the wall angle required. Ensuring you have a good engineer to advise on the correct draft angle is crucial in ensuring that your part is produced exactly to your specifications.

Finally, there are also ways in which the structural rigidity of the prototype can be improved as a result of slight changes in the design, but this may obviously be dependent on how this impacts on the end user experience of the product. Allowing all of the interior and exterior corners of the design to be more rounded ensures that the resin flows in a more efficient way through the mould which, in turn, reduces any likelihood of warping and creates a stronger overall product.

It is important to ensure that you have a competent and experienced moulding partner to help you produce both the initial prototypes, as well as the main production run once you are happy to proceed. NICE Rapid have many years' experience of project management, rapid prototype design and injection moulding. Please do not hesitate to contact us to discuss the requirements for your next project.