At some point, many product teams find themselves in the situation where they are encountering issues with their existing part, such as a rubber gasket, plastic grip, metal sleeve, etc. in the field. Cracking issues, comfort and convenience concerns, or new standards for biocompatibility. When these times come, silicone is frequently recommended as an option. But the transition will require redesign costs, tooling costs and the costs of validation, which all need to be clearly justified.
Before you decide to switch an existing application to silicone, it helps to look at real application patterns across industries where the change clearly improves performance or reduces risk. Based on more than ten years of OEM/ODM silicone manufacturing experience from Dongguan HT Silicone & Rubber Co., Ltd, this Guide will assist engineers and sourcing managers determine when switching to silicone is a sound decision and when it is not.
Key Reasons to Consider Switching to Silicone
The special combination of properties of silicone makes it stand out from many other materials, which are unable to achieve such properties under demanding conditions. This will typically be a case-by-case decision, not just based on overall ‘appeal’.
When Temperature Is the Main Driver
Some rubbers and plastics will harden, crack or lose sealing ability outside of certain temperature ranges. Silicone is flexible and elastic at a wide range of temperatures, typically -60°C to +230°C or higher, depending on the grade. This stability helps to ensure automotive under-hood parts or industrial appliances do not leak and fail prematurely when subjected to heat cycles. If the current material is being distorted or embrittled by the conditions it is subjected to in its operating environment, then its resistance to temperature is a strong factor to consider to replace it with silicone rather than rubber.
Application Patterns Where Switching to Silicone Clearly Makes Sense
Some applications have been proven to work well by silicone conversion. These are the patterns we are most frequently seeing to create good ROI.
Seals and Gaskets in Harsh or High-Temperature Environments
The transition is often worthwhile for automotive engine bays, appliance door gaskets and industrial equipment that’s exposed to heat, steam or mild chemicals. Some traditional EPDM/neoprene can compress permanently with time, whereas silicone has excellent compression set resistance and sealing force. This leads to less warranty work and more reliable field products.
Soft-Touch and Comfort Interfaces in Consumer and Medical Products
Rigid plastic or stiff rubber materials can be abrasive or tiring to wear on tool grips, personal care device handles, wearable straps, and medical interfaces. Silicone provides a flattering skin feel that enhances the user experience and perception of the product. Switching to medical-grade or skin-contact silicone will often be worth the cost when comfort has a direct impact on customer satisfaction or repeat use.
Outdoor and UV-Exposed Products Where Old Rubber Cracks
Traditional elastomers used for outdoor equipment grips, weather exposed bumpers and protective sleeves are prone to chalking, cracking and degradation with exposure to sunlight and ozone. Silicone’s exceptional UV and weather resistance ensures long-lasting beauty and functionality of parts. Changes typically result in longer product life for brands that cater to exterior use or for marine or automotive applications.
Parts Requiring Skin Contact, Food-Contact or Medical Compatibility
Many legacy materials cannot meet the requirements for food-grade, LFGB, FDA or biocompatibility compliance when regulations or safety standards call for it. Silicone can be easily certified, and provides softness and durability. The switch is almost a requirement for a lot of Kitchenware parts, baby product interfaces and wearable medical pads.
When Switching to Silicone Does NOT Make Sense
Silicone is not an all-inclusive repair. Honest evaluation involves identifying circumstances under which it is better to keep up with the existing material or select another elastomer.
When Oil, Fuel, or Strong Solvents Are Involved
Typical silicone will swell or break down in petroleum oils, fuels, and some very aggressive solvents. Typically, fluorosilicone or other materials are best suited for fuel system applications or heavy equipment that are subject to hydrocarbons. Rotating to a standard silicone would probably not extend the service-life, but shorten it.
When Ultra-Tight Tolerances or High Abrasion Resistance Are Critical
Silicone is less hard and rigid than a majority of engineering plastics or metals. It may not maintain tight tolerances or wear resistance in high precision mechanical interfaces or locations where there is constant friction and wear. Some applications—such as heavy-duty gears or sliding systems—may well remain in the original material.
When Costs or Revalidation Risk Are Too High for Small Gains
Where the current part already satisfies requirements, the cost of new tooling, testing and regulatory revalidation may not provide significant advantages when the risk level of the component is low. A change for the sake of being “popular” with “silicone” is not usually worth it. Instead, concentrate on applications where measurable pain points can be found.
Application-Based Decision Framework
An organized approach avoids emotionally or trend driven decisions. If you have a moment, reflect on the following essential questions:
Questions to Ask Before Switching Materials
- What are the reasons for this current part to fail or to underperform?
- What is the importance of this to the other safety, performance, or user satisfaction?
- How much is the quantity of products expected to be produced and how long is their lifetime?
- Will the budget, time, and resources be available for design changes, prototyping and extensive testing?
- Do there exist regulatory/compliance needs which the new material must meet?
When deciding on silicone versus other options such as advanced rubbers or TPEs, or coatings, it is important to insure an application-based decision.
Real-World Scenarios Where Teams Have Switched to Silicone
Automotive gasket upgrade: A client requiring a replacement gasket for their heat sensitive engine parts chose to replace the rubber gasket with a silicone, high-temperature version. As a result of the extended thermal cycling, sealing force was maintained on the new parts with a significant reduction in field failures.
Consumer electronics grip improvement: Wearable device maker from hard plastic to custom silicone overmolding on contact surfaces. Results showed increases in user comfort scores, drop protection and the premium soft-touch feel enhanced brand perception.
An outdoor equipment manufacturer switched to silicone handles that are resistant to UV degradation. After years of exposure to the sun, the new grips remained flexible and beautiful, cutting down return rates and improving product reputation.
Medical interface project: A medical device project was redesigned to use medical-grade silicone pads for patient interfaces, achieving greater biocompatibility with an enhanced experience for extended contact time.
In both instances, the switch was made because there was a specific application problem that had been identified.
How to Plan and Execute a Material Switch to Silicone
The transition project reduces risks.
- Identify clearly the performance gaps with the existing material.
- Determine silicone grades and compare to other grades.
- Re-design geometry, tolerances and mounting if necessary.
- Choose the appropriate processing technique (compression molding, LSR injection, etc.).
- Prototype and test in realistic conditions.
- Full compliance testing and documentation.
- Qualify production tooling and put in place quality controls.
Managing Risk During a Material Change
Always conduct full testing prior to full-scale production. Pilot Runs are used to identify problems early on. Keep records as a means of traceability, particularly in regulated industries. Having a reliable manufacturer with in-house mold making and testing services facilitates the whole process.
Summary: Switch When the Application Demands It, Not Just Because Silicone Is Popular
When silicone has already been shown to be successful in similar applications or the material currently being used cannot meet the temperature, environmental, comfort or compliance requirements, then the replacement of an existing part with silicone will yield the greatest improvements. The advantages of the use of the tool and validation costs should clearly outweigh.
At HT Silicone & Rubber Co., Ltd, we assist clients with these decisions on a daily basis, with material application that is tailored to their specific needs, by testing and prototyping their products as well as by delivering large-scale production. If you are considering changing materials, please provide us with your part specifications and operating conditions. We will give you honest advice on silicone; whether it is the right path or not, and give you a package that is just for your specific needs.
