Belt cleaning during operation: scrapers and brushes
Conveyor belt cleaning systems during operation: types of scrapers and brushes, replacement frequency and effectiveness of cleaning options.
Cleaning a conveyor belt during operation is not cosmetic but a working unit on which the line’s hygiene and the belt’s lifespan depend. Product stuck to the belt is carried over to drums and rollers, contaminates the return run and ultimately gets back onto clean product. In this article we break down the types of cleaning systems, how to choose a scraper or brush and when to replace them.
Why a belt must be cleaned on the move
On many products part of the material stays on the belt after discharge: sticky dough, sugar glaze, fine crumbs, oil, juice. This residue goes to the return run and creates several problems at once. It sticks to the tension drum and throws off the belt tracking. It contaminates the idler rollers, accelerating their wear. It accumulates under the frame and becomes a focus of bacterial growth. And worst of all — part of it returns to the working run and gets onto fresh product.
So a cleaning system is a mandatory unit of any conveyor with a sticky or bulk product. The belt is cleaned in two places: right after the discharge point on the drive drum and before the belt enters the working zone.
Types of cleaning systems
On our projects we use several types of cleaning devices, each for its own type of contamination:
- Primary cleaning scraper — a polyurethane blade pressed against the belt right after the drive drum, removes the bulk of the stuck product.
- Secondary cleaning scraper — installed lower along the return run, removes what the primary one missed.
- Rotating brush — a cylindrical driven brush, effective for profiled and perforated belts where a blade does not reach into the recesses.
- Spring-loaded scraper — pressure from springs that automatically compensates for blade wear.
- Water spray — a water jet paired with a scraper for very sticky products.
For modular and mesh belts brushes and water spray are used, since a rigid blade does not clean them. We covered the choice of the belt itself in more detail in our articles on conveyor belts.
Scraper materials and effectiveness
The scraper blade is chosen by product and belt type. A harder blade cleans better but wears the belt faster. Below is a comparison of typical options.
| Cleaning type | Material | Effectiveness | Belt wear |
|---|---|---|---|
| Primary scraper | Polyurethane 85–95 ShA | High | Moderate |
| Secondary scraper | Polyurethane, carbide | Very high | Low |
| Rotating brush | Nylon, polypropylene | Medium | Very low |
| Modular belt scraper | Polymer matched to module pitch | High | Low |
Engineer’s tip. The most common mistake in scraper operation is excessive pressure. It seems a harder-pressed blade cleans better, but in reality it only accelerates wear of both the belt and the scraper itself, while effectiveness barely grows. We set the pressure to the minimum at which the belt is still clean and check it weekly.
Replacement frequency
A scraper is a consumable element: the blade wears down and gradually loses contact with the belt. The replacement frequency depends on product, abrasiveness and duty cycle. A polyurethane primary scraper blade on an intensive line lasts 2–4 months, a secondary one 4–8 months, a nylon brush 6–12 months. These are guidelines: the real term is determined by a weekly inspection.
Signs that a scraper is due for replacement: stuck product has appeared on the return run, the blade is visibly worn or chipped, streaks of uncleaned belt have appeared. A worn scraper not only cleans worse but itself becomes a source of polymer crumbs.
How we integrate cleaning
A cleaning system is designed together with the conveyor, not bought in afterwards. We provide space for scrapers behind the drive drum, a tray to collect the removed product and convenient access for inspection and blade replacement without disassembling the conveyor. For food lines the tray is made of stainless steel with a slope for drainage, so the collected product does not stagnate.
An important nuance is the blade installation angle to the belt. A scraper can work in one of two positions: blade against the belt’s motion or with it. The against-motion position cleans more aggressively but loads the blade and belt more. The with-motion position is gentler and is used on delicate or thin belts. For profiled and modular belts we additionally check that the scraper does not catch the profile ridges — otherwise every belt revolution strikes the blade, and it quickly fails. On such belts a rotating brush, which follows the surface relief, is more reliable.
Conclusion
Cleaning the belt during operation is a mandatory unit that protects the line’s hygiene, belt tracking and roller lifespan. Scrapers are effective for flat belts, brushes and spraying for profiled and modular ones, and the blade material is chosen by product and abrasiveness. If product sticks to the belt on your conveyor — get in touch, and we will select a cleaning system for your product and belt. More on the topic under the tag maintenance.
