Resorcinol Adhesive System for Steel Cord & Fabric Reinforcement: RF-70, RA-65 in Tires & Belts

Oct 19, 2026 Beihua

A guide to building rubber-to-metal and rubber-to-fabric bond strength with pre-dispersed resorcinol-formaldehyde resin and cobalt/nickel activator masterbatches.

The Adhesion Challenge

Steel cord and fabric reinforcements often peel or show low H-pull values. A resorcinol-formaldehyde resin plus cobalt/nickel activator is the proven route to durable bonding.

How the System Works

RF-70 (resorcinol resin) reacts with the rubber phase during cure; RA-65 (cobalt/nickel activator) promotes the metal-to-rubber interface. Pre-dispersion avoids toxic resorcinol dust.

Dosage & Process

RF 2–4 phr together with RA 1–2 phr, added at the mixing stage. Cure temperature and time directly affect bond strength.

Applications

Tire belts, steel-cord conveyor belts, hose reinforcement and rubber-to-metal mounts.

TDS / Technical Data Sheet

Products RF-70 Resorcinol resin / RA-65 Activator
RF active content 70% min.
RA active content 65% min. Cobalt/Nickel complex
Carrier EPDM / SBR polymer
Appearance Brown granules
Bond test (H-pull) Reported per batch COA
Shelf life 9 months (resin sensitive to moisture)

SDS Highlights

Contains resorcinol and cobalt complex – classified as harmful if swallowed and a suspect carcinogen. Wear gloves, goggles and respiratory protection; avoid dust. Store tightly sealed and dry.

COA Sample

Batch No. RA25-0830
RF resin content 70.5%
RA activator content 65.3%
H-pull bond (N) 1180 (typical)
Peel strength Conforms
Result PASS

Product Information

Packaging 25 kg paper bag (RF and RA packed separately); 1,000 kg per pallet
MOQ 300 kg (approx. 12 bags)
Shipping port Shanghai Port / Ningbo Port, China
resorcinol adhesive system steel cord rubber adhesion RF-70 RA-65 tire belt adhesive

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