When it comes to designing the perfect rubber sealing, there are a few design features to bear in mind to help achieve the optimum solution.
In this post, we explore these rubber sealing features further and provide information on the benefits and best uses for these types of gaskets.
Gasket design features to bear in mind
Ultimately, a more straightforward and more symmetrical geometry of your design means the easier it will be to produce and manufacture your gasket. Those more complicated geometries often require additional finishing techniques such as trimming and hollowing. The downside this then causes is that these additional processes begin to increase the cost of your overall project, as well as increase the cost of part rejections, especially when compared to those simpler designs.
Keeping it simple helps keep costs down, and tolerance levels much more friendly when it comes to production. Keeping parts symmetrical, avoiding overhangs, avoiding deep cuts, and sharp corners, are also recommended during the design phase.
When designing the perfect sealing product, it’s important to use the right filler material to match the application and environment it will be used within. The good news is there is now a variety of polymers and manufacturing processes, increasing the range of solutions on offer.
When working with chemical substances, we would recommend a range of chemical resistant materials such as Viton, EPDM, and AFLAS.
Consider rubber tolerance.
It’s essential to consider tolerance as part of your design process as elastomers are known to undergo a certain degree of shrinkage. Establishing parameters as soon as possible in the manufacturing and design stages helps to ensure that the right amount of solution can be developed for the specific application the gasket is intended for, ensuring optimal tolerance levels at all times.
Compare and contrast different materials using shore hardness.
The shore hardness scales use a durometer gauge to measure and compare different materials using a spring-loaded steel rod and compressing the surface of the sample.
In these cases, if, for example, you get a reading of 0, then this is equal to the maximum amount of indentation as possible. Whereas, a hardness of 100 shows exceptionally high resistance to indentation.
Shore hardness also provides a measure of stiffness and flexibility. This is good to know if you’re looking at a rubbers material resistance to bending.
Consider surface finishes.
It’s important to check what manufacturing processes will be used and if any of these processes will leave marks on your final product. Processes that can leave such marks include: –
- Ejector pin marks – pins contact the rubber
- Sprue marks – injector sprue impacts the mould cavity
- Draft lines – mould plates come together and potentially leave faint lines.
Are draft angles required?
In some manufacturing processes, draft angles will be used to help release the rubber product design from the mould without damage. In these instances, you need to consider your design and if these draft angles will be required as part of your overall process.
Think about cooling rates.
At SSP, we would recommend keeping all processes and procedures as uniform as possible to prevent uneven cooling during the moulding process. This also helps to avoid any chance of shrinkage and dips.
Rubber Gasket Process
Rubber moulding processes can consist of compression moulding, extrusions, and injection moulding, where liquid raw rubber is cured into a mould and shaped by heat and pressure.
From here, the mould cavity can then be cut to the desired shape and design.
Products such as seals, caps, hoses, gaskets, grips, knobs, buttons, rollers, bumpers, and much more can all be manufactured using this process.
Types of rubber seal designs
Static seal types:
- Axial seals
- Radial seals
- Crush seals
- Seals with dovetail glands
Dynamic seal types:
- Reciprocating seals
- Rotary seals
- Oscillating seals
Of course, taking everything into account, and depending on your requirements, will ultimately depend on your rubber sealing design.
For the best cost-saving, high-quality gaskets with reproducibility, designing simpler parts should always be your end goal.
At Specialist Sealing Products, we provide professional advice and guidance on all of the design stages to help keep manufacturing processes running as smoothly as possible.
Speaking to a gasket expert, like the team at SSP, helps to ensure you get the right rubber product design features you need, suitable to your application.
Helping to save you time and money, call us on 01535 274 776
Reference video: tarkka