Which cover should I choose for a vulcanized belt: rubber, PVC or silicone?

Question

Accepted Answer

Direct answer: Match the cover to the product and to the temperature. Natural rubber covers give the best general grip and abrasion resistance, PVC covers suit oily, wet or sticky products that have to release, and silicone covers are used where heat or tackiness rules out rubber.

Belt with a green PVC cover bonded to the carrying surface — PVC cover bonded to the carrying surface: low friction and easy release (600L-35+3PVC).

Cover options at a glance

Cover	Typical working temperature	Best for	Avoid when
Natural rubber	About -20 C to +70 C, short peaks higher	General conveying, grip on inclines, abrasion resistance	Oil or solvent contact, continuous heat above about 80 C
PVC	Up to about 70 C to 80 C	Oily, wet or sticky products, low friction release, wet areas	Hot product, sharp heavy impact, very cold ambient
Silicone	Up to about 180 C, higher for short peaks	Hot parts, tacky products, release applications	Heavy abrasion, oil immersion, high load per unit width

These are planning ranges, not guarantees. The final choice depends on the product, the load per millimetre of belt width and the duty cycle. Confirm the grade with us before committing a machine to it.

Thickness and surface finish

Cover thickness is usually 1 mm to 6 mm. Thin covers keep the belt flexible on small pulleys; thick covers absorb impact and last longer under sharp, lumpy material. Covers can be supplied smooth, with a fabric impression, grooved, or with cleats and edge walls added in the same vulcanizing cycle.

Belt with a natural rubber cover bonded on the back — Natural rubber cover for grip and abrasion resistance (S8M-680-30+6NR).

Four mistakes we see most often

Specifying rubber for an oily product. The cover swells, softens and starts peeling at the edges within weeks.
Using PVC where the product arrives hot. The cover softens and the splice becomes the first failure point.
Asking for a thick cover on a small pulley. The belt goes stiff and splice fatigue life drops sharply.
Ignoring the edges. Bonded edge strips are usually worth specifying when the belt tracks against a skirt or a guide rail.

Where cover quality actually shows

At the splice. A cover that is bonded in the same heat and pressure cycle as the belt body stays continuous across the joint. A cover that is glued on cold will lift at the splice first, and then water and fines get under it and travel along the belt.

Vulcanized belt with a rubber cover, ready for splicing — Cover and belt body cured together, so the surface stays continuous across the splice (S8M-680-30+6NR).

Tell us the product and the temperature

Send the material, its temperature, the belt width and the pulley diameters to sales@goodlybelts.com, or use the enquiry form. We will recommend a cover grade and thickness and quote the belt with the splice included.

Request a cover recommendation