Best Five Tips For Moulding Design

We know that you are experts at what you do and we like to think that we are the same. To ensure your product is manufactured to the highest quality and in the quickest time frame, we would like to give you five important points that may help you when starting on a new rapid tooling project:

1.) Texture: Texture is important in injection moulding designs, as it negates the need for a secondary process to be undertaken to create texture on your product. Using modern techniques, quite intricate and uniform textures can be created within the moulding process, allowing your product to stand out from the crowd, whilst reducing cost of manufacture. A good project engineer will be able to advise whether a texture process is suitable for your design and how this is best incorporated in the mould.

2.) Process, process, process: Like ‘location, location, location’ the process mantra is one of the most important aspects in rapid tooling. When you send us your initial CAD designs for your project, our experienced engineers use extensive modelling techniques to test and refine the mould, so as to ensure a high quality product. For example, the ‘gate’ which allows the injected material to flow into the mould and create the product is a crucial part of the design – get the size or placement of this incorrect and your finished job will not be up to scratch. Removal of the gate also leaves a small mark or ‘scar’ on the product and this should be taken into account when thinking of the aesthetics of the finished product.
‘Shrinkage’ – when the injected material starts to cool shrinkage can occur, which obviously has to be taken into account when deciding on the volume of injected material initially used. Cooling can also have an impact on the radius of corners and thickness of walls, many parts of which are important facets of the final product.
‘Ejection’ – when the finished parts are released from the separated mould a ‘parting line’ will be created, delineating the two parts of the mould that were used in production. As with the gate, designing your final product in such a way so as to take into account the ‘parting line’ ensures that the aesthetics are kept and your product looks as good as possible.

3.) Draft: This is the process that allows the plastic parts to be ejected successfully out of the mould on completion. Ensuring that this is taken into account in the design of the mould reduces damage to parts when they are ejected, as well as prolonging the life of the mould by reducing friction and, therefore, wearing of the mould surface.

4.) Materials: The choice of both mould and product material is very important. For mould materials, steel will obviously last longer than aluminium and so the higher cost of manufacture of the mould will be offset in a larger number of items produced. Similarly, the material the item is produced out of is also important, as this can wear the mould rapidly if is quite abrasive. Cooling time, shrinkage, malleability and required wall thickness all have a bearing on the materials used and it is important to consult a professional moulding engineer if you are unsure of the materials required for either the mould or product.

5.) Wall Thickness: Ensuring the correct wall thickness for the final product is very important, especially when producing parts for batteries and other products which require clear delineation under high temperature conditions. Even though many inexperienced companies state that wall thickness is unable to be specified, this is not actually the case and we can include such values in the Design For Manufacture or DFM document. The placement of different areas of the design in the mould has a large bearing on the finished product and our skilled engineers can advise you on the best design.