Types of EPDM O‑rings: peroxide and sulphur cured
EPDM (ethylene‑propylene‑diene monomer) is a versatile elastomer, cured via sulphur or peroxide vulcanisation. Thanks to its ozone resistance, UV stability, steam resistance and hydraulic fluid compatibility, it’s widely used in industrial seals, automotive, and plumbing.
Vulcanisation
Vulcanisation creates cross‑links among polymer chains to form flexible, strong O‑rings. The two methods—sulphur curing and peroxide curing—offer specific benefits depending on the application.
What is EPR?
EPR is an ethylene‑propylene copolymer. EPDM adds a diene, enabling sulphur vulcanisation. EPDM provides excellent cold flexibility, chemical resistance, and electrical insulation, making it ideal for EPDM O‑rings in refrigeration, HVAC and potable water.
EPDM O‑rings by curing type
Peroxide‑cured EPDM O‑rings
-
Performance: heat resistant up to 150 °C, longer lifespan, strong against pressure, alcohol, hot water, steam (up to 204 °C), hydraulic and brake fluids, organic acids.
-
SEO terms: high‑temperature EPDM O‑ring, food‑grade seals.
-
Limitations: not suited for petroleum fuels, mineral oils.
Sulphur‑cured EPDM O‑rings
-
Performance: great abrasion and tear strength; temperature range –55 °C to +120 °C; budget‑friendly; absorbs heavy dynamic loads.
-
SEO terms: economical EPDM seal, HVAC O‑ring.
Peroxide vs Sulphur cured – comparison
-
Flexibility: Sulphur > Peroxide
-
Heat resistance: Peroxide > Sulphur
-
Chemical stability: Peroxide > Sulphur
-
Cost: Sulphur = cheaper, Peroxide = costlier
-
Mechanical strength: Peroxide better, Sulphur better for tear/abrasion resistance
Comparison with other materials
-
EPDM‑NBR blend: for combined oil and weather resistance
-
Viton (FKM): superior hot water, brake fluid compatibility; premium price
-
Silicone (VMQ): excellent insulation but low mechanical strength
-
HNBR: high wear and mechanical durability
-
FFKM: top-tier chemical and thermal resistance up to 320 °C, ideal for aerospaceTypy o‑ringów EPDM: utwardzane nadtlenkiem i siarką