Conveyor rollers, guides and wear strips: what lasts

A conveyor line stops for many reasons, but the wear strip is one of the quiet ones. Choose the wrong conveyor wear strip plastic and the part either wears into the product, squeals on every pass, or fails on a Friday night. Choose well and it runs for years with almost no attention.

This guide works through the duty that actually decides the grade: load, speed and temperature, then the polymers that cover almost every line, from cool rooms to ovens. It is written for maintenance engineers and buyers who want a part that lasts, and it points to the sectors we serve across our industries pages.

The duty behind a wear strip: load, speed, temperature

Start with the duty, not the material. A wear strip carries the load of the product and the belt, so the three numbers that matter are contact pressure, sliding speed and the temperature of the line. Their product, the PV value, sets whether frictional heat can escape or builds up until the surface softens.

Then add the environment. A dry bottle line, a wash-down filling hall and a bakery oven ask for very different polymers even when the shape is identical. A grade that is perfect on a cool dry line can swell, soften or embrittle in the next room, so the location is part of the specification.

The counterface matters as much as the duty. A polished stainless rail lets any of these polymers slide; a worn, pitted one abrades the strip and pushes the friction up. Before blaming the material, it is worth checking the surface the strip runs against.

UHMW-PE for low-friction, low-temperature duty

UHMW-PE is the default for dry, low-load, low-temperature conveying. It has one of the lowest coefficients of friction of any thermoplastic, it is extremely tough, and it absorbs impact without cracking. Against steel or stainless it wears slowly and quietly, which is why it dominates bottle and carton lines.

Its limits are stiffness and temperature. UHMW-PE creeps under sustained load, so it needs support at close centres, and it is not a high-temperature material: continuous service in air is generally kept below about 80 C. Above that it softens and its friction advantage fades.

Where a strip must be both slippery and structural, a backed profile or a different polymer is usually cheaper than fighting the creep. We cut UHMW-PE wear pads and strips to suit the rail, and the support spacing is worth agreeing at the drawing stage.

POM and PA66 where load and precision matter

Where the strip carries real load, or has to hold a tolerance, acetal and nylon take over. POM is stiff, dimensionally stable and machines to a fine finish, so it suits guide rails, star wheels and precision pads that must not grow or shrink with the weather.

PA66 is tougher and absorbs shock better, which helps on impact-heavy transfers and at the ends of a line. It is also hygroscopic, so a nylon strip in a wash-down area will move, and the fit has to allow for that. Both run well against steel at moderate PV, and both outlast UHMW-PE where the load is high and the line runs warm.

Filled grades are worth a look where plain acetal is marginal. A glass-filled POM or a molybdenum-disulphide-filled nylon raises stiffness and the PV limit, and often stretches the life of a loaded guide for a modest premium.

PEEK and PEI for ovens, hot-fill and steam

Hot-fill, baking ovens and steam tunnels rule out the commodity grades. PEEK handles continuous service up to about 250 C, keeps its stiffness and resists the abrasion of hot, dry product. PEI is a lower-cost step down, good to roughly 170 C, and is often enough for hot-fill lines that never see direct flame.

The trade-off is cost. A PEEK part can cost many times an acetal equivalent, so it is used where a line stop is expensive or where no other polymer survives. It pays to size the part properly: a thin, well-supported strip usually beats a thick one on a weak frame, and it uses less of an expensive material.

Rollers: bearings, tolerances and hygiene

A roller adds two complications to a wear strip: it must turn, and it must stay clean. A plastic roller with a stainless bearing is common, but the bore tolerance has to suit the polymer, because the two expand at different rates. Acetal and nylon are the usual choices, with UHMW-PE for gentle, low-load transfer points.

Hygiene matters on food and pharma lines. That means no crevices, grades that tolerate the cleaning chemicals, and a surface finish that does not trap product. A roller that runs true and cleans easily is worth more than one that is a little cheaper per piece, and a conveyor wear strip plastic part that sheds product is a contamination risk as well as a wear item.

The table matches the common materials to the duty they suit best.

Questions buyers ask about conveyor wear strip plastic

Which plastic is best for a wear strip?

There is no single best grade. On a dry, cool, low-load line UHMW-PE wins on friction and cost. Where the load or the temperature rises, POM, PA66, PEI and PEEK each take over a band of duty. The wrong answer is usually the one chosen on price alone.

Does temperature or load decide the grade?

Both do, and so does speed. Temperature sets the ceiling on which polymers are even possible, but load and speed decide the PV value and therefore the wear rate within that set. Define all three before asking for a quote.

Can I replace a metal wear strip with plastic?

Often yes, and it usually cuts noise, weight and the wear on the counterface. The part has to be supported against creep and sized for the load, so a straight thickness-for-thickness swap from steel is rarely the right solution.

Why does the cheapest strip cost the most?

Because the price is only the first line. A grade that wears twice as fast, squeals on the line or needs replacing during a shift carries a line-stop cost that dwarfs the material saving. Cost per year of service, not cost per kilo, is the number to compare.