Plastic conveyor chain: where it is applied
Plastic conveyor chain for food lines: standards, module types, advantages over metal chain and areas of application.
A plastic conveyor chain is a flexible traction element of polymer modules that has replaced metal chain on most food lines. It is light, corrosion-resistant and quiet. In this article we break down what materials plastic chain is made of, what standards apply and where it outperforms metal.
What a plastic conveyor chain is
A plastic chain consists of separate polymer links joined by axles. Unlike a continuous belt, the chain has a rigid surface and moves on sliding guide rails. It comes in two main formats: a narrow top chain from 60 mm wide for transporting bottles, jars and containers, and a wide modular mat assembled from many chain tracks.
Top chain is especially common on filling and packaging lines: it easily passes curves in the horizontal plane, so curved routes are built from it without additional turntables. The modular mat is wider and carries more load — we covered it separately in our articles on conveyor belts.
Materials of plastic chain
The polymer for the chain is chosen by product, temperature and load. Each material has its area:
- POM (acetal) — the most common: rigid, low friction, holds its shape well. The base choice for dry lines.
- PP (polypropylene) — chemically resistant, light, for wet zones and aggressive detergents.
- PA (polyamide, nylon) — strong and tough, for shock loads and heavier containers.
- PE (polyethylene) — for low temperatures, including freezer chambers.
For direct contact with open product we choose materials certified to EU 1935/2004 or FDA 21 CFR. For lines with a metal detector there are metal-detectable modules with an additive the detector sees.
Standards and technical parameters
Plastic chain is produced to a number of industry standards that set the pitch and width of modules. This ensures interchangeability — chain from different manufacturers of the same standard fits the same sprockets. Below are indicative characteristics of common sizes.
| Chain type | Pitch | Working temperature | Pull load |
|---|---|---|---|
| Top chain POM 82 mm | 38.1 mm | -20 °C … +60 °C | up to 1250 N |
| Top chain PP 100 mm | 38.1 mm | 0 °C … +90 °C | up to 800 N |
| POM module pitch 25 | 25.4 mm | -20 °C … +60 °C | up to 8000 N/m |
| PP module pitch 50 | 50.8 mm | 0 °C … +90 °C | up to 6000 N/m |
Engineer’s tip. A plastic chain barely elongates under load but reacts noticeably to temperature: it expands when heated. On lines with a temperature swing we always build a thermal compensation gap into the tensioning unit, otherwise a heated chain bends in a “hump” between sprockets.
Advantages over metal chain
Plastic chain has displaced metal on food lines for several reasons. It does not rust — water, steam and detergents do not threaten it, whereas a metal chain in a wet zone needs constant lubrication and still corrodes. It is about three times lighter, which reduces drive load and energy consumption. It runs quieter — polymer on polymer slides almost silently. And it needs no lubricant in the product contact zone, which is critical for hygiene: a lubricated metal chain is a source of contamination.
Metal remains where plastic does not cope: very high temperatures, heavy abrasive loads, extreme forces. But for most food applications a plastic chain is the rational choice.
Where plastic chain is used
On our projects plastic chain works on beverage filling lines, packaging, transport of containers between operations, on curved routes with turns, in washing and cooling zones. Top chain is convenient for routing bottles and jars singly, the modular mat for group transport and product in bulk.
The guide rails along which the chain slides deserve a separate mention. This is not a trifle: it is exactly on the rails that the main friction occurs, and the load on the drive and the chain’s own lifespan depend on their material. We use rails of wear-resistant ultra-high-molecular-weight polyethylene (UHMW-PE) — it has a very low friction coefficient against polymer and needs no lubrication. On curved sections the rails have additional side guides that keep the chain in the turn radius. We add worn rails to the maintenance schedule as a consumable: when a rail wears through, the chain starts scraping against the frame metal, and wear sharply accelerates.
Conclusion
A plastic conveyor chain is a light, corrosion-resistant and hygienic traction element that has replaced metal on the vast majority of food lines. The module material is chosen by product and temperature, and industry standards ensure interchangeability. If you are designing a filling or packaging line — get in touch, and we will select a chain type for your product and route. More on the topic under the tag conveyor.
