Product Overview
The Food Grade Liquid Silicone (LSR) Switch Button is a high-performance input component engineered for electronic equipment requiring long service life, environmental resilience, and compliance with strict food contact safety standards. Manufactured via precision injection molding of medical and food-grade liquid silicone rubber, this product combines soft tactile feedback, reliable sealing performance, and exceptional durability to address the limitations of traditional plastic, thermoplastic elastomer (TPE), and solid silicone buttons.
Core selling points include IP67-rated waterproof performance, 1,000,000+ actuation cycle lifespan, food contact safety certification, and customizable design flexibility. Unlike conventional switch buttons, this LSR variant maintains stable performance across extreme temperature ranges, resists degradation from UV exposure, cleaning chemicals, and repeated friction, making it suitable for consumer, commercial, and industrial electronic devices deployed in harsh or hygiene-sensitive environments. The product supports full customization of shape, color, surface texture, conductive insert integration, and marking options to match specific device design and functional requirements.
Technical Specifications
Material Properties
ParameterStandard ValueTest Method
Base MaterialFood Grade Platinum-Cured Liquid Silicone RubberISO 10993 / FDA 21 CFR 177.2600
Curing SystemPlatinum Addition Curing (no peroxides, no residual byproducts)Internal Material Validation
Food Contact ComplianceMeets FDA 21 CFR 177.2600, EU 1935/2004, LFGB (German Food and Feed Code)Third-Party Laboratory Testing
BiocompatibilityISO 10993-5 (Cytotoxicity: Grade 0), ISO 10993-10 (Skin Irritation: Non-irritating)ISO 10993 Series Standards
Chemical ResistanceResistant to 95% ethanol, isopropyl alcohol, mild detergents, food oils, and weak acids/basesASTM D471
UV ResistanceΔE < 2 after 1000 hours of accelerated UV exposure (QUV-A 340nm, 0.89W/m²@340nm, 60°C)ASTM G154
Flame RetardancyUL94 V-0 (optional standard grade is UL94 HB)UL 94
Physical Performance
ParameterStandard ValueTest Method
Hardness Range30 Shore A ~ 80 Shore A (customizable in 5 Shore A increments)ASTM D2240
Tensile Strength≥ 7.5 MPaASTM D412
Elongation at Break≥ 450%ASTM D412
Tear Strength≥ 25 kN/mASTM D624
Compression Set≤ 15% (22 hours @ 70°C, 25% compression)ASTM D395 Method B
Abrasion Loss≤ 20 mm³ after 1000 cycles (10N load, CS-17 wheel)ASTM D4060
Operating Temperature Range-40°C ~ 200°C (short-term exposure up to 230°C for 1 hour)UL 746B
Actuation Force50 g ~ 500 g (customizable based on user ergonomic requirements)IEC 60512-16-1
Actuation Travel0.5 mm ~ 3.0 mmInternal Dimensional Testing
Waterproof RatingIP67 (1 meter depth for 30 minutes, no water ingress)IEC 60529
Electrical Insulation Strength≥ 20 kV/mmASTM D149
Conductive Contact Resistance≤ 100 Ω (for versions with integrated carbon or silver conductive pills)IEC 60512-2-1
Service Life≥ 1,000,000 actuation cycles (no functional failure, no visible wear)ASTM D430
Process Parameters
ParameterStandard ValueNote
Molding ProcessLiquid Silicone Injection MoldingTolerance control: ±0.02 mm for critical dimensions
Secondary ProcessingAvailable silk screen printing, laser etching, pad printing, plasma surface treatmentPrinting adhesion: 5B rating per ASTM D3359 cross-hatch test
Insert Molding CompatibilitySupports overmolding on PC, ABS, PET, metal substrates, and integrated conductive carbon/silver pillsBond strength between LSR and substrate ≥ 3 MPa
Color CustomizationPantone, RAL, or custom color matchingΔE < 1 between production batches
Surface Finish OptionsMatte (standard), glossy, textured, soft-touch coatingRa value for standard matte finish: 0.8 μm ~ 1.6 μm
Batch Production Lead Time7~15 working days for custom orders, 3~5 working days for standard stock sizesDependent on order volume and customization complexity
Product Advantages
1. Industry-Leading Waterproof and Dustproof Performance
The one-piece LSR molding design eliminates assembly gaps common in multi-component buttons, achieving a consistent IP67 waterproof rating. The elastic properties of LSR allow the button to form a tight, permanent seal with device housings, preventing ingress of water, dust, food particles, and cleaning chemicals even after long-term repeated actuation. This performance eliminates the risk of short circuits and internal corrosion in devices used outdoors, in kitchens, or in high-humidity industrial environments, reducing device failure rates by 65% compared to non-sealed TPE buttons.
2. Exceptional Wear Resistance and Long Service Life
Formulated with high-purity fumed silica reinforcement, this LSR button exhibits 3x higher abrasion resistance than solid silicone and 5x higher than general TPE materials. The 1,000,000+ actuation cycle lifespan ensures consistent tactile feedback and functional performance for 5+ years of daily use, even in high-frequency applications such as public access terminals and commercial kitchen equipment. Surface markings applied via laser etching or sealed silk screen printing resist fading from repeated friction and chemical cleaning, maintaining legibility for the full product lifecycle.
3. Food Contact Safety and Hygienic Design
Platinum-cured LSR contains no BPA, phthalates, PVC, or peroxide curing residues, meeting the strictest global food contact safety standards. The non-porous surface of LSR prevents the growth of bacteria and mold, and can withstand repeated cleaning with commercial-grade disinfectants, high-temperature dishwashing, and steam sterilization without deformation or performance degradation. This makes the button suitable for devices used in food processing, foodservice, and medical patient-facing applications where hygiene is a critical requirement.
4. Stable Performance Across Extreme Environments
Unlike plastic and TPE buttons that become brittle at low temperatures or soft and deformed at high temperatures, this LSR button maintains consistent actuation force, elasticity, and dimensional stability across a -40°C to 200°C operating range. It also resists UV-induced discoloration and cracking, making it suitable for outdoor electronic devices, automotive interior and exterior controls, and industrial equipment deployed in unconditioned environments. The material’s inherent low compression set ensures the button retains its sealing performance and tactile feedback even after long-term compression storage.
Applications
Food and Beverage Industry Equipment
- Commercial coffee machines, blenders, and sous vide cookers: Meets food contact safety requirements, resists staining from coffee, oils, and food residues, and withstands daily cleaning with hot water and disinfectants.
- Food processing control panels and weighing scales: Waterproof sealing prevents ingress of flour, water, and food particles, while the non-slip surface ensures reliable operation even with greasy or wet hands.
- Restaurant POS systems and self-service ordering kiosks: Long service life supports high-frequency daily use, and laser-etched markings resist fading from repeated cleaning.
Medical and Healthcare Devices
- Patient monitoring equipment and portable diagnostic devices: Biocompatible material avoids skin irritation during patient contact, and waterproof performance allows for disinfection with 75% ethanol and other medical-grade disinfectants.
- Surgical instrument controls and dental equipment: Withstands autoclave sterilization cycles (121°C, 15 psi) without deformation, and the non-porous surface prevents cross-contamination between patients.
- Home health devices such as blood pressure monitors and nebulizers: Soft, ergonomic actuation reduces user fatigue for elderly or mobility-impaired patients.
Consumer and Outdoor Electronics
- Wearable devices, smart watches, and fitness trackers: Low-profile design, sweat resistance, and skin-friendly properties ensure long-term wearing comfort, while IP67 waterproofing supports use during swimming and showering.
- Outdoor communication devices and portable power stations: Extreme temperature resistance and UV stability ensure reliable operation in desert, alpine, and rainy outdoor environments.
- Bathroom electronics such as electric toothbrushes, smart mirrors, and shower speakers: Waterproof sealing prevents water and steam ingress, extending device service life in high-humidity environments.
Industrial and Automotive Controls
- Factory automation control panels and HMI (human-machine interface) devices: Resists degradation from industrial lubricants, cleaning chemicals, and dust, and long service life reduces maintenance costs for high-frequency industrial use.
- Automotive interior and exterior control buttons: Withstands temperature fluctuations from -40°C in winter to 120°C in parked vehicle interiors, and UV resistance prevents yellowing and cracking from sun exposure.
- Public access terminals such as elevator buttons, parking payment machines, and ticket vending machines: High wear resistance supports tens of thousands of daily actuations without performance degradation.
Selection Guide
Hardness Selection
- 30~40 Shore A: Recommended for applications requiring soft, ergonomic tactile feedback, such as medical patient devices, wearable electronics, and low-actuation-force consumer products. The lower hardness provides a more comfortable press experience but requires thicker wall designs to maintain structural stability.
- 50~60 Shore A: General-purpose grade suitable for most consumer electronics, kitchen appliances, and commercial equipment. Balances soft tactile feedback, structural rigidity, and sealing performance, making it the standard option for most use cases.
- 70~80 Shore A: Recommended for high-frequency, high-load applications such as industrial control panels, public access terminals, and automotive buttons. Higher hardness provides improved wear resistance and dimensional stability, and supports higher actuation forces for applications requiring deliberate user input.
Size Specifications
- Standard stock sizes include circular buttons (diameter 6 mm, 8 mm, 10 mm, 12 mm, 15 mm) and square buttons (8x8 mm, 10x10 mm, 12x12 mm, 15x15 mm) with 1.0 mm standard actuation travel and 150 g standard actuation force.
- Custom size, shape, and actuation travel are available for design-integrated applications. For overmolded buttons, provide the substrate material and dimensional drawings to ensure optimal bonding strength and sealing performance.
- For waterproof applications, ensure the button flange width is at least 1.5 mm larger than the housing cutout to form a reliable compression seal. Our engineering team can provide free design reviews to optimize sealing performance for your specific device housing.
Material Grade
- Standard Food Grade: Meets FDA 21 CFR 177.2600 and EU 1935/2004 standards, suitable for general food contact and consumer electronics applications.
- LFGB-Grade: Meets the stricter German LFGB food contact requirements, recommended for products sold in the EU market or applications involving direct contact with high-fat foods or infant products.
- Medical Grade: Meets ISO 10993 biocompatibility standards, suitable for medical devices, patient-facing equipment, and products requiring skin contact for extended periods.
- Flame-Retardant Grade: UL94 V-0 rated, recommended for industrial equipment, automotive electronics, and devices requiring compliance with flammability safety standards.
Quality Assurance
Our LSR switch buttons are manufactured in an ISO 9001:2015 and ISO 13485:2016 certified production facility, with a comprehensive quality control process covering raw material incoming inspection, in-process monitoring, and finished product testing. All raw materials are batch-tested for purity and compliance with food and medical safety standards before entering production, with full material traceability maintained for every production lot.
In-process quality control includes 100% dimensional inspection of critical features, real-time monitoring of injection molding parameters, and random sampling for tensile strength, compression set, and hardness testing. Finished products undergo 100% functional testing including actuation force verification, sealing performance testing, and marking adhesion testing, with 0.5% of each lot subjected to accelerated life cycle testing (100,000 actuation cycles) to validate long-term performance.
All products come with a 2-year warranty against manufacturing defects, including cracking, fading, sealing failure, and functional degradation under normal use conditions. We can provide full certification documentation including FDA, LFGB, EU 1935/2004, ISO 10993, and UL94 test reports upon request, as well as custom PPAP (Production Part Approval Process) documentation for automotive and industrial clients.