Overview
Silicone food-grade seals are elastomeric gaskets, O-rings, tri-clamp seals and custom sealing profiles manufactured from food-contact-compliant silicone rubber for use in food, beverage, dairy, pharmaceutical and medical processing equipment. Formulated to meet FDA 21 CFR 177.2600 and, where required, USP Class VI requirements, these seals are odorless, tasteless and chemically inert, so they do not impart flavor, color or contaminants to the product stream. OrroMFG produces food-grade silicone seals by compression molding, injection molding and precision CNC machining of molded sheet, supplying both standard sanitary gasket sizes and fully custom sealing geometries.
Platinum-cured silicone is the preferred formulation for hygienic service because the addition-cure system eliminates peroxide residues and by-products, resulting in very low extractables and excellent batch-to-batch consistency. Silicone remains flexible from -55°C to +200°C, withstands repeated steam and chemical cleaning cycles, and resists hardening, cracking and compression set better than most general-purpose rubbers. Our product range includes sanitary tri-clamp gaskets, flange gaskets, hygienic door and hatch seals, O-rings, screen and filter seals, and custom molded profiles with integral alignment features. Available hardness ranges from 30 to 70 Shore A allow engineers to tune sealing force, compression set and assembly effort to the specific equipment design.
Key Features
- Food and Pharmaceutical Compliance: Formulated to FDA 21 CFR 177.2600 and available in USP Class VI grades, with no plasticizers, peroxides or heavy-metal additives that could leach into product.
- Wide Temperature Range: Remains flexible from -55°C to +200°C (-67°F to +392°F), covering chilled, ambient, hot-fill, CIP and steam-sanitization conditions.
- Odorless and Tasteless: Chemically inert silicone does not release volatiles or alter the organoleptic properties of food, beverage or pharmaceutical products.
- Excellent Compression Set Resistance: Platinum-cured grades retain sealing force after repeated thermal and steam cycles, reducing re-torquing and leak checks.
- Superior Aging and Weather Resistance: Resists ozone, UV, oxidation and humidity, so seals do not crack or harden during long storage and outdoor washdown service.
- Easy Sanitary Cleaning: Smooth, non-porous, non-stick surfaces resist product build-up and are compatible with CIP, SIP, caustic and acid cleaning agents.
Material Specifications
| Property | Platinum-Cured Silicone (FDA) | General Purpose Silicone (VMQ) | Fluorosilicone (FVMQ) | Silicone Sponge |
|---|---|---|---|---|
| Density (g/cm³) | 1.10 - 1.25 | 1.10 - 1.30 | 1.25 - 1.40 | 0.40 - 0.90 |
| Tensile Strength (MPa) | 8 - 11 | 6 - 9 | 7 - 10 | 1.5 - 3.0 |
| Elongation at Break (%) | 400 - 700 | 300 - 600 | 250 - 450 | 150 - 300 |
| Tear Strength (kN/m) | 25 - 40 | 20 - 35 | 18 - 30 | 6 - 12 |
| Compression Set, 22h @ 175°C (%) | 10 - 20 | 20 - 35 | 15 - 25 | 25 - 40 |
| Hardness (Shore A) | 30 - 70 | 30 - 80 | 40 - 70 | 10 - 40 |
| Continuous Service Temp (°C) | 200 | 200 | 200 | 180 |
| Low Temperature Flexibility (°C) | -55 | -50 | -60 | -55 |
| Water Absorption (24h, %) | 0.1 - 0.3 | 0.1 - 0.5 | 0.1 - 0.3 | 0.5 - 2.0 |
| Dielectric Strength (kV/mm) | 20 - 25 | 18 - 25 | 18 - 22 | 8 - 15 |
| Food Contact Compliance | FDA 21 CFR 177.2600, USP Class VI | FDA compliant grades available | Limited | FDA compliant grades available |
Applications
Food & Beverage
Food-grade silicone seals are used in plate heat exchangers, homogenizers, filling and capping machines, mixers, blenders and conveyor equipment. They seal tri-clamp and DIN connections on dairy, brewery, juice and sauce lines, and hold a hygienic seal through daily CIP cycles with hot caustic and nitric acid. Their odorless, non-staining nature keeps product flavor profiles unchanged.
Pharmaceutical
In pharmaceutical manufacturing, platinum-cured silicone seals are specified for bioreactors, filtration housings, tablet presses, filling lines and cleanroom equipment. USP Class VI and low-extractable grades support validation work and minimize the risk of leachables entering sterile product streams, while withstanding repeated SIP steam cycles at 121-134°C.
Medical Devices
Medical-grade silicone seals are used in sterilization trays, respiratory and anesthesia equipment, dialysis and infusion devices, and diagnostic instruments. Silicone is biocompatible, autoclave and gamma sterilization compatible, and remains soft and flexible for patient-contact components and sealing interfaces on reusable instruments.
Water Treatment
Silicone food-grade seals are used in potable water valves, dosing pumps, filter housings, UV disinfection units and reverse osmosis skids. They resist chlorine, chloramine, ozone and hypochlorite dosing chemicals without leaching, and remain pliable in outdoor, UV-exposed installations.
Industrial Food Equipment and Packaging
Seals are fitted to vacuum packaging machines, form-fill-seal equipment, canning lines and aseptic filling heads, where frequent washdown with detergents and steam is standard. The wide temperature window allows one seal design to serve both hot-fill and chilled product runs.
Operating Conditions
- Temperature Range: -55°C to +200°C (-67°F to +392°F) continuous; short-term excursions to 250°C for silicone without fluorosilicone additives
- Pressure Rating: Suitable for static sealing duties from vacuum up to approximately 20 bar, depending on hardness, gland design and seal cross-section
- Steam and CIP Service: Withstands repeated steam-in-place cycles at 121-134°C and CIP with caustic, nitric acid and peracetic acid solutions
- Chemical Compatibility: Excellent with water, alcohols, dilute acids and bases, and food oils; limited resistance to concentrated solvents, fuels and aromatic hydrocarbons (choose fluorosilicone for these)
- Compression Range: Recommended 15-30% compression for static face seals, with gland fill maintained between 60% and 85%
- Vacuum Service: Suitable for vacuum sealing in food and pharmaceutical equipment when a low-outgassing post-cure is specified
- Sterilization Compatibility: Autoclave, gamma, ethylene oxide (EtO) and electron-beam sterilization with no significant property loss
- UV and Ozone Exposure: Excellent outdoor durability with no cracking or chalking during long-term washdown and sunlight exposure
Material Comparison
| Material | Temp Range | Chemical Resistance | Food Contact | Compression Set | Cost | Best For |
|---|---|---|---|---|---|---|
| Silicone (VMQ) | -55 to +200°C | Good (aqueous, food oils) | Excellent (FDA, USP VI) | Excellent | Medium | Sanitary seals, hot-fill, steam CIP, medical |
| Fluorosilicone (FVMQ) | -60 to +200°C | Very Good (fuels, solvents) | Limited | Good | High | Fuel and solvent contact, aerospace, low temp |
| EPDM | -50 to +150°C | Very Good (water, steam, ozone) | Good (FDA grades) | Good | Low | Steam, water, HVAC, outdoor seals |
| FKM (Viton) | -20 to +200°C | Excellent (chemicals, oils) | Good (FDA grades) | Very Good | High | Aggressive chemicals, high-temp oil sealing |
| Nitrile (NBR) | -30 to +100°C | Good (oils, greases) | Fair | Good | Low | Oil and fuel sealing, general industrial |
| PTFE | -200 to +260°C | Excellent | Excellent | Poor (cold flow) | Medium-High | Inert sealing, high purity, extreme temperature |
Choose silicone food-grade seals when:
- Food, beverage, dairy or pharmaceutical contact compliance is mandatory
- The seal must tolerate both hot-fill or steam cleaning and chilled product conditions
- Odorless, tasteless and non-staining sealing is critical to product quality
- Repeated CIP/SIP cycles require low compression set and long seal life
- Autoclave, gamma or EtO sterilization compatibility is needed
- Outdoor or UV-exposed washdown service rules out natural rubber and most nitrile grades
Customization Options
- Material Grades: Platinum-cured silicone, peroxide-cured silicone, FDA 21 CFR 177.2600 compliant, USP Class VI medical grade, fluorosilicone (FVMQ) and silicone sponge
- Hardness Range: 30 to 70 Shore A for dense silicone, 10 to 40 Shore A for sponge, with custom hardness available
- Seal Types: Tri-clamp gaskets, DIN and flange gaskets, O-rings, molded profiles, hatch and door seals, screen seals and custom cross-sections
- Size Range: From 5mm inner diameter O-rings to gaskets over 1000mm in diameter and extruded profiles of any practical length
- Color Options: Translucent, white, blue, red and custom pigmented colors for hygiene-zone identification and grade coding
- Tolerances: Molded to ISO 3302-1 Class M2 or tighter, with CNC-trimmed gaskets held to ±0.20mm
- Surface Finishes: Smooth molded finish, matte finish, and food-grade talc-free finishes for low-friction assembly
- Secondary Operations: Post-curing for low volatiles, CNC trimming, laser cutting of sheet gaskets, bonding and screen printing
- Custom Marking: Material grade, hardness, batch and approval references molded or printed onto the seal
- Design Support: Compression analysis, gland design review and rapid prototype molding for new equipment platforms
Quality Assurance
OrroMFG produces food-grade silicone seals under an ISO 9001:2015 certified quality system, with dedicated production and handling procedures for hygiene-critical components. Incoming silicone compounds are verified against their certificates of analysis for hardness, specific gravity, cure system and compliance statements, and every lot is confirmed as free from peroxide residues where platinum-cured material is specified. Material is quarantined until released, and batch records are retained to support full traceability from compound to finished seal.
In-process controls cover mold temperature and cure time, dimensional checks on cross-sections and inner diameters, and visual inspection for flash, porosity, knit lines and contamination. Finished seals are measured with optical comparators, profile projectors and coordinate measuring machines (CMM) for critical sealing dimensions, and hardness and compression set are verified on sampled parts. First article inspection (FAI) reports are issued for new tooling, and each shipment can be accompanied by a certificate of analysis (COA), FDA and USP compliance documentation, dimensional reports and material traceability records. Cleanroom packing and lot segregation are available for pharmaceutical and medical orders.
