Flexible or elastomeric components are present in most assemblies, whether you need a simple gasket, a seal, a more intricate connector. However, these components can be tricky to manufacture and not compatible for every manufacturing process. For example CNC milling rubber is only effective when the elastomer is nearly rigid. Anything softer than the hardness of a shopping cart wheel will be pushed around by the cutter instead of being shaped.
To help you choose a suitable process to produce your parts, this article takes a look at the technologies available for your flexible part project and their typical applications.
If you need a quick flexible prototype within a few days: the quickest solution is 3D Printing. They are great for producing 1-off to a handful of flexible prototypes and geometries easily and at a lower cost.
Some common applications include: flexible lattice structures, sealing rings and gaskets, shoe soles, soft grip handles, smartphone cases, and fasteners.
Whilst 3D Printing has the speed advantage, vacuum casting, also known as urethane casting, is a cost-effective option if you need between a handful to 50 detailed and flexible parts in soft-rubber-like resins.
Polyurethane resins like Hei-Cast T0387 and 8400 used in vacuum casting are typically available from around 35 – 90 Shore A, which are great for testing prototypes in different shore hardness. Urethane cast parts can also be easily dyed to achieve coloured parts.
Some common applications include: simulating overmoulded grips, coloured flexible parts, small batch rubber parts, medical equipment, and detailed rubber models.
If you need parts with full functionality: the ultimate option is rapid injection moulding. With injection moulding, natural or synthetic, can be moulded into many forms and shapes. Prototype injection moulding is a reliable method of rubber and rubber-like parts with accuracy.
The main disadvantage is that manufacturing the mould takes time and is more costly but the process offers a wide range of ‘real’ materials that exhibits excellent elastic properties including EDPM rubber, TPU, TPE, TPV, etc. and shore hardness values from 35A to 90A. It is excellent for serial production prototypes and cost-efficient for low-volume functional parts from quantities between 100 and up.
Some common applications include: overmoulded grips, vibration dampening components, electrical enclosures, and medical devices.
Need help picking a technology for your flexible/rubber prototypes? A good place to start is by determining the quantity needed and considering the degree of clarity required for your parts. Other points to establish include: the purpose of your part, level of hardness required, complexity of the part, and any environmental requirements.
Please note that the details above just act as a guide. To get help with your project, upload your design to our Get in Touch form and include details like quantity, material or surface finishing requirements (if any), and an expert from our team will get back with a quote and advice within 48 hours or less.
