HYGIENIC DESIGN · OPEN EQUIPMENT · CONVEYORS
Key facts
- The six points belt edge, bed, return rollers, drive, transfer, frame
- Belt edge sealed or non fraying, no mechanical fasteners in the joint
- Bed rollers or rods rather than a solid plate, belt liftable for cleaning
- Drive drum motor, or motor below the product line on a drip tray with a drain pipe
- Transfer a removable catch tray, and dead plates that lift out without tools
- Frame welded closed profiles, no drilled holes, no exposed threads, no cable ties on the rail
Score your own conveyors, point by point
Module 4 of Intermediate Hygienic Design covers frameworks and feet, belt conveyors in depth, chutes, hoppers and weighers, and drives, bearings and cabinets, with a practical application video that walks the six points with you. Nine hours, online.
Points one and two: the belt edge and the bed
Start at the edge, not the running surface. Frayed fabric or metal lacing wicks moisture into the belt and holds it there, which is why belt edges turn up in environmental monitoring far more often than belt surfaces. Specify a sealed or non fraying edge, and no mechanical fasteners in the joint.
Then look underneath at the bed. A solid plate under the belt stays wet all night. Rollers or rods let it drain and let a cleaning tool through. And the belt has to lift for cleaning without a two hour strip down, because anything that takes two hours will not be done nightly, whatever the procedure says.
Points three and four: return rollers and the drive
Open ended hollow rollers fill with whatever runs into them and hold it. Ask for flat ended rollers with sealed bearings that come out for cleaning.
A motor above the belt drips lubricant and condensate onto product. Commonly cited guidance puts the motor below the product line on a drip tray with a drain pipe, or uses a drum motor with motor and gearbox sealed inside the drive drum.
While you are at that end, look at the screw tensioner. It sits in a slot, under a cover, next to the bearing, and it is the wettest and least visited place on the whole machine.
Point five: the transfer, the one everybody skips
At a transfer, product falls, crumbs collect and the frame is crowded exactly where nobody can reach. Fit a removable catch tray where debris builds up, so that lost product cannot fall into the frame and be fed back into good product. Dead plates and transfer plates should lift out without tools. And there should be no structural members over the belt, because whatever collects on them ends up in product.
A transfer that feeds lost product back into the flow is a recall waiting for a positive result, and it is usually the cheapest of the six to fix.
Point six: the frame, and what is under it
Hollow sections with drilled holes are a reservoir at product height. Water gets in and cannot get out. Specify welded closed profiles you can see along and clean along, no drilled holes, no exposed threads, and no cable ties on the rail.
Underneath, either enough clearance to clean under, with supplier guidance commonly asking for at least 200 mm fully and safely accessible, or a plinth sealed to the floor with no gap at all. The middle option, a gap of fifty or eighty millimetres, is the one that fails.
The cheaper frame costs cleaning time every night for the life of the machine, and puts a harbourage niche about three hundred millimetres from open product.
Then look up
Not a scored point, but it is where the recall comes from. Nothing flat above open product, and removable covers wherever contamination can fall from above, for example under a walkway. Electrical cabinets off the floor, with the base commonly cited at 300 mm, the roof sloped, and glands entering from underneath rather than through the top. Lighting and services shielded. Condensation traced back to where it forms rather than wiped where it lands.
What to do on Monday
Take one conveyor and score all six points, two, one or zero, with a photograph on every zero. Put the zeros into a risk register with severity, likelihood and exposure. Anything in the top band gets an interim control today. The frame and the transfer usually pay back fastest in cleaning time, so start the capital case there. Six numbers tell a supplier more than an hour of complaining ever will.
Frequently asked questions
What are the six points to inspect on a belt conveyor?
Belt edge, bed, return rollers, drive, transfer and frame. Taking them in that order every time means nothing is missed, and scoring each on its own stops a good total hiding one bad point.
Why do belt edges matter so much?
A frayed fabric edge or metal lacing wicks moisture into the belt and holds it, which makes the edge a niche rather than a surface. A sealed or non fraying edge with no mechanical fasteners in the joint removes the problem rather than managing it.
Should the drive motor be above or below the belt?
Below the product line where possible, on a drip tray with a drain pipe, or use a drum motor with the motor and gearbox sealed inside the drive drum. A motor above the belt drips lubricant and condensate onto product.
How much clearance is needed under a conveyor?
Supplier guidance commonly asks for at least 200 mm, fully and safely accessible, or a plinth sealed to the floor with no gap at all. A gap in between is too tight for a cleaning tool and too open to seal, and it is the usual finding.
Are hollow section frames ever acceptable?
Only where they are genuinely welded closed and certified as such, with no drilled holes. In practice, drilled holes appear later for cable ties, guards and sensors, which is why open, cleanable profiles are the safer specification in a wet product zone.
Score your own conveyors, point by point
Module 4 of Intermediate Hygienic Design covers frameworks and feet, belt conveyors in depth, chutes, hoppers and weighers, and drives, bearings and cabinets, with a practical application video that walks the six points with you. Nine hours, online.