How the Rubber Part Design Process is Benefiting from 3D Printing
“3D printing is increasingly used for rubber-like part prototyping. Unfortunately, due to process and material considerations, we’re still not able to 3D print actual rubber parts. However, recent advances in rubber-like polymeric materials, such as thermoplastic elastomers (TPE’S), have provided new opportunities in this innovative area.”
One such example is this cable end-cap for an aerospace application depicted below. The 3D printed sample is on the left and the finished moulding on the right.
Fig 1 - Aerospace electrical cable gland
These materials are now increasingly used to realistically emulate elastomeric characteristics. This includes features such as Shore A hardness values which measure the hardness of rubber from very soft and flexible to hard with almost no flexibility at all. At the moment, grades are available from 30 degrees (Soft), up to 80 degrees (Hard) in 10-degree increments (30, 40, 50 etc).
Faster, more efficient, and lower cost development
Engineers from the Aerospace, Automotive, Medical, Industrial, and a variety of other industries are realizing the benefits of 3D printing to prototype their great ideas and turn them into successful rubber parts, faster, more efficiently, and at a lower cost. These benefits include:
Finding and fixing problems earlier in the design process.
Carrying out visual evaluation, fit, function and refinement.
Speeding up the whole development process. 3D printed parts are available in days from receipt of order whereas prototype tooling takes up to six weeks with additional time required to mould parts. Saving time is a huge benefit!
Communicating ideas more effectively than a computer model by handling critical details.
Building confidence by producing functional prototypes to see how they look and perform before further investment in tooling.
Reducing development costs. Traditional prototype tools for seals, gaskets, and mouldings typically cost up to £1000 (~1300 US$) and then the individual parts will cost on the order of £10 (~13 US$) each, depending on material type, whereas 3D printed parts are usually under £100 (~130 US$) each.
A flexible approach to design
The great thing about 3D printing is you can simulate your rubber part in a range of Shore A values and multiple design ideas can also be created without the need to tool for each. This means you can produce different design versions to evaluate options before moving to the more expensive tooling stage. Parts can also be produced with a smooth surface finish and combine both rigid and flexible elements, ideal for over-moulding, seals, gaskets, and mouldings.
An excellent choice for exploring options and reducing risk
3D printing is an excellent choice if you’re unsure about your design and want to explore different options and reduce risk. It can also be extremely useful if you haven’t worked much with rubber parts by providing an opportunity to feel and see what the parts will look like. In this respect, it’s perfect for new to market ideas, to promote and gain funding prior to budget approval, or when you are producing parts for an end customer where the benefits of being able to show and discuss a functional part are obvious.
Fig 2 - Various 3D printed rubber samples including a flexible ink reservoir, bulkhead gasket, push buttons, a subsea connector, an automotive gasket, and an electrical enclosure.
Looking to the future
Whilst 3D printed metals are currently too expensive to warrant their use in prototype tooling, manufacturers are keeping an eye on developments in 3D printed resin technologies. Current materials are unable to withstand the heat and pressure required for injection and transfer moulding; however, as newer materials and techniques evolve, this situation could well change.
Remember the 3”Ds” of 3D printing rubber-like parts
If you recognize some of the opportunities outlined in this article then we recommend the following:
Do choose a manufacturing partner with capabilities in this area
Do speak with them about opportunities to experiment with your designs
Do celebrate when you achieve a faster, more efficient, and lower-cost design.
Andrew Piper is the Managing Director of DP Seals a renowned, global custom rubber seals, gaskets, and mouldings manufacturer.
