EN
PFAS-Free FKM Compound Engineered for Smartwatch / Sports Bracelet Bands
Product: FKM Rubber Compound (Fluoro rubber compound)
Hardness: 50A-90A
Color: Customizable
Typical applications: Watch Bands 、Valve Stem Seals 、 Transmission Seals 、 Hydraulic O-Rings
Certifications: RoHS, REACH 、PFAS-Free
Note: We only supply rubber compounds (customizable in hardness, color, and formulation).
- Description
- Specifications
- Key Properties
- FAQ
- Recommended Products
Description
FKM Fluororubber — A high-performance sealing material with excellent resistance to high temperatures, oils, and chemicals. Widely used in automotive, aerospace, industrial, and wearable device applications. PFAS-free eco-friendly formulations available. WINBEST can customize formulations according to your needs to provide you with the most suitable rubber compound.
Specifications
| Product Name | Fluororubber compound (FKM Rubber Compound) |
| Hardness(SHA) | 50A~90A |
| ASTM D-2000 Classification | HK |
| Tensile(Mpa) | 8 ~ 20 |
| Elongation at Break(%) | 125 ~400 |
|
Compression Set（%） 200℃70H |
<15 |
| Temperature Range | -40℃~+250℃ |
| Specific Gravity（g/cm³） | 1.81 ~1.86 |
| Resistances |
Resistance to fuel, concentrated acid, and other strong oxidizers |
| Perfect steam resistance(special recipe) | |
| Perfect steam resistance(special recipe) | |
| Excellent flame resistance | |
| Perfect vacuum resistance | |
| Curing Systems | Bisphenol / Peroxide |
| Bisphenol / Peroxide | Molding |
| Extrusion | |
| Formula & color | Custom |
| Shelf Life | 3 months |
Key Properties
-
High Temperature Resistance: Long-term service from -40°C to 250°C, with short-term resistance up to 250°C
-
Oil & Chemical Resistance: Excellent resistance to fuels, hydraulic fluids, lubricants, and various aggressive media
-
Weather & Aging Resistance: Resistant to UV and ozone, with stable long-term performance
-
Low Gas Permeability: Low gas permeation rate for reliable sealing
FAQ
1. What media is FKM not resistant to?
FKM has limited resistance to steam, hot water, polar solvents, low molecular weight organic solvents, and alcohol-based brake fluids. In addition, ketones, esters, and certain phosphate ester hydraulic fluids may also attack FKM. If your application involves contact with any of these media, please consult the WINBEST technical team to confirm formulation suitability.
2. What is PFAS-free FKM? Does it differ in performance from traditional FKM?
Traditional FKM uses low molecular weight PFAS surfactants as polymerization aids during synthesis, which may remain as residues and migrate into the environment. PFAS-free FKM (NFS-FKM) is polymerized using non-fluorinated surfactants.
Research data show that PFAS-free FKM has nearly identical molecular weight and molecular structure to traditional FKM, with comparable tensile properties, hardness, and chemical compatibility. For sealing applications, switching to PFAS-free FKM does not significantly affect elastomer performance.
3. Can your FKM compound be customized?
Yes. WINBEST can customize formulations according to your specific needs to provide the most suitable rubber compound. Whether you require hardness adjustment (Shore A50-95), color customization, optimized resistance to specific media, or PFAS-free eco-friendly formulations, our technical team can develop a tailored solution for you. Contact us to request samples and technical data.
4. How do I choose the right FKM grade for my application?
Grade selection depends on a combination of factors: operating temperature range, contact media type, hardness requirements, compression set requirements, regulatory compliance (e.g., FDA, USP Class VI), and curing system. We recommend providing your specific operating parameters, and the WINBEST technical team will recommend or customize a matching formulation for you.
