Designing your plastic part with strength in mind

When designing a part for manufacture, a crucial consideration is deciding how strong that part must be to carry out the job it will be asked to do.

And with plastic parts in mind, the strength of a part can mean different things for different items.

Ultimate strength

For instance, if we are looking at ultimate strength, this refers to the ability of a part to support a load. Think of a plastic chair or a plastic storage crate – both these items must be able to support a certain weight.

At Skar we will design and test parts well beyond the maximum load that it would be reasonable to expect them to carry.

Deformation

Another type of strength relates to deformation and a plastic part’s ability to deform its shape before returning to normal. An example of this is a clip or fastener that may have to bend or deform a certain way to clip onto an item.

For plastics parts, how they respond to certain stresses is an important consideration.  Typically, if a stress is applied for a short period of time, the part will return to its original shape once the stress is removed.  However, if the part is stressed over a longer period – it will become misshapen.

Impact

A third type of strength is how well designed a part is to withstand an impact. Car bumpers, which are manufactured through plastic injection moulding, fall into this category.  Their strength comes from how well they have been designed to flex to withstand a low speed impact.

Factors that will affect the strength of a plastic part include the type of material used, the wall thickness of the part, its shape, the temperature range it will be required to work in, and the likelihood of it being exposed to different chemicals.

Margin of safety

Any design will factor in a substantial margin of safety, as it is not always possible to control all aspects of production and use.

Once we have defined the type of strength a part requires and have information about all the other factors that might affect its performance, our team of specialists will be able to identify a suitable material and design for that part.