These pages provide design considerations & help with plastic moulding design to help you avoid common pitfalls caused by incorrect moulding design and save you both time & money. We're not advising what can or can't be achieved, as most moulding designs, features & materials can be accommodated - at a price.
- One way of saving yourself time and money, is to design the plastic moulding yourself, preferably using 3D CAD. You can then send us the CAD models in DXF, DWG, IGES, Parasolid, Pro-Engineer, SolidWorks format for us to give you more accurate quotes, create tool drawings and to manufacture mould tools with.
If you prefer, get a design company to create CAD models for you, but ensure you use one with experience of plastic moulding design. Alternatively, we could design the moulding for you, which has a number of advantages :-
- we understand your needs and can adapt the design, if necessary, to ensure that it can be injection moulded
- by getting Toolcraft to design your plastic moulding, you can have greater peace of mind and save time & money, as once approved, we can also make the mould tool and plastic mouldings.
Mouldings (red) & SLA
models can be
assembled to test 'fit'.
- If you'd like to see what your plastic moulding will look like before having a tool made, we can use the CAD files to make solid models of your parts - stereolithography or SLA models.
SLA models are made by a machine which reads the 3D CAD data & then uses a laser & a resin to build up SLA models in layers until the final model is made - you can use this to e.g. test the 'fit' in your assembly.
More examples & help with SLA models ? View how stereolithography process works
For functional models with snap fits, living hinges etc use SLS not SLA models
For details, view our explanation of the (SLS) selective laser sintering process
More help with plastic moulding design - Wall Thickness, Materials & Properties
- To help avoid sink marks (depressions) in the plastic mouldings and make them easier to manufacture, keep wall thickness' even and avoid thick areas by coring them out. As a guide, joining walls should be 50% of the thickness of the thickest section.
- If possible, state generic plastic material types on drawings e.g. 10% Glass Filled Polycarbonate rather than trade names e.g. Lexan 500R - if you prefer, please state e.g. Lexan 500R or equivalent. Also, try to specify a plastic material that adequately deals with your needs, rather than one that greatly exceeds them.
This enables us to purchase the moulding material you need from more than one manufacturer and thus, keep lead times to a minimum and save you money by keeping our plastic moulding prices to you at the same level for longer. For help with choosing plastic materials, please view our plastic material guide.
- Consider the environment that the plastic mouldings are going to be used in - will they need to have e.g. a certain mechanical strength, be clearly colour coded or protected from ultraviolet light or static damage ?
If so, ensure you state these requirements when asking for a plastic moulding quotation - without them, incorrect plastic materials could be suggested, inaccurate quotations given & even costly tool modifications incurred.