Dough Sticking to the Machine and Conveyor Belt

Sticking is something everyone who has used food machinery has run into. Mild sticking means the operator has to keep stopping to scrape off material; severe sticking tears products, deforms them, makes the weight jump around, and slows down the whole line.

Why Does It Stick?

Ingredients too soft or too wet
Dough with too much water, fillings that release water, and glutinous rice wrappers are all very sticky by nature and stick as soon as they touch a contact surface. See How Wrapper Moisture Affects Machine Running and Characteristics of Glutinous Rice Wrappers on Machines.

Temperature too high
Dough, glutinous rice dough, and oily fillings become soft and sticky as soon as they warm up. Continuous machine operation and a hot summer work area both gradually raise the temperature of the ingredients. See Dough Temperature and Resting Time.

Over-fermentation
Over-proofed dough has a damp, sticky surface and tends to stick to the belt.

Contact surface condition

• If residue from the previous batch isn't cleaned off, new material sticks to the old material and builds up.
• Starting the machine without wiping or air-drying it after washing leaves moisture that makes the dough stick.
• Scratches, fraying, or wear on the belt or contact surfaces let material lodge in the recesses.

How Much Dusting Flour?

Dusting (bench flour, anti-stick powder) is the most common remedy, and the rule is just enough to stop sticking:

• Too little: it still sticks.
• Too much: the product surface is powdery and the texture suffers; flour on the seal of dumplings and buns keeps it from sticking, causing seals that won't hold. Lots of dust also makes the work area less hygienic, and powder that falls into gaps in the mechanism cakes up.

Dough products commonly use wheat flour or cornstarch, glutinous rice products commonly use pre-cooked (toasted) flour or potato starch, and sweet potato and taro balls commonly use tapioca starch. It's best to standardize how you dust, for example with a fixed sieve at a fixed position, rather than leaving it to each person's feel.

For the N208 model RHEON launched in Japan in 1986, the company says it was equipped with a non-stick encrusting mechanism that could handle sticky products such as ohagi without dusting flour. This shows that besides the ingredients, mechanism design has a lot to do with sticking; the same product may need very different amounts of dusting on different models.

Surface Care and Cleaning

1. Clean thoroughly after every production run: Remove the detachable parts and wash them according to the operating manual. Soak dried residue to soften it before cleaning, and don't scrape contact surfaces with sharp, hard objects.
2. Dry after washing: Wipe dry or air-dry before reassembling and starting the machine.
3. Inspect contact surfaces regularly: Check the belt for fraying, cracks, and edge wear, and metal contact surfaces for scratches and dents.
4. Don't apply non-food-grade substances to contact surfaces yourself: Any coating or lubricant on parts that directly contact food must comply with food-contact regulations, so ask the manufacturer first.

Self-Checks After Stopping

Before checking anything by hand, press stop, turn off the power, and unplug the machine or cut the main switch, and make sure the machine has come to a complete stop. In factories with multiple workers, lock the switch and hang a "Under maintenance, do not energize" tag. Article 57 of Taiwan's Occupational Safety and Health Facilities Rules (職業安全衛生設施規則) requires that when machinery is being cleaned, oiled, inspected, repaired, or adjusted, operation and feeding must be stopped, and measures such as locking out and posting signs must be taken to prevent accidental start-up.

Once the power is confirmed off, clear residue from contact surfaces and the conveyor belt and check the surface condition. If the belt needs tension adjustment, realignment, or replacement, or contact surfaces have obvious damage, leave it to professional service.

FAQ

Q: Why does my dough keep sticking to the machine?
A: Commonly the dough is too soft or wet, too warm, or over-fermented, or there is residue on contact surfaces or they weren't dried after washing.

Q: How much dusting flour should I use?
A: Just enough to stop sticking. Too much affects texture, keeps seals from sticking, and lets dust accumulate in the machine.

Q: What should I do if the conveyor belt surface is frayed or scratched?
A: Surface damage lets material catch and stick. Stop the machine, cut the power, and contact the manufacturer or a service provider to assess whether it needs replacing.

Q: What if it still sticks after cleaning?
A: First check ingredient firmness and temperature. If the ingredients are fine and it still sticks, note the machine model and the symptoms and contact the manufacturer or a service provider. Dong-Yih Machinery: 06-257-4644.