Inconsistent Piece Weight

A big reason food factories use machines is so that "every piece weighs the same." When weight drifts, costs can't be calculated accurately, packages fail check-weighing, and customers get different sizes. There are many causes of inconsistent weight, but the good news is that most of them can be traced to ingredients and operation.

Why One Piece Is Heavy and the Next Is Light

Ingredients

• Inconsistent firmness: Most portioning mechanisms push by volume. Soft material is easily compressed or flows back, while firm material doesn't fill completely, so the weight drifts.
• Temperature changes: Ingredients gradually warm up after coming out of the cooler, so material at the beginning and end of a run differs in firmness.
• Ongoing fermentation: Fermented dough keeps inflating in the hopper, so its density drops and the same volume weighs less. See Running Fermented Dough on Machines.
• Uneven mixing: Vegetables and meat, or oil and water, in the filling aren't mixed evenly, so the density differs from bite to bite.
• Particles too large: Whichever piece a large particle happens to land in will be noticeably heavier.

Operation

• Hopper level going up and down: High levels mean more pressure; low levels mean insufficient feeding. It's best to keep it at a steady height.
• How material is added: Dumping in a large amount of cold material at once mixes it with material that has already warmed, leaving uneven firmness.

Machine

• Residue stuck on contact surfaces or in the feed passage, or dried material that has caked, reduces the effective volume.
• Uneven feeding or air getting in.
• Worn or loose parts.

How Ingredient Temperature Affects Weight

Temperature is the most easily overlooked factor, yet it has the biggest impact. Chilled filling is firm with stable density; once it warms up, it softens and releases water and oil, slipping or flowing back as it's pushed. Dough also gets softer and stickier as its temperature rises. We recommend:

1. Run ingredients within a fixed temperature range and measure with a thermometer.
2. Replenish from the cooler in small, frequent amounts rather than taking everything out at once.
3. Pay special attention to the work area temperature in summer.

For details, see Filling Temperature: Why Chill Fillings Before Forming and Dough Temperature and Resting Time.

How to Calibrate

1. Sample weighing: Once the machine is running steadily, take a set number of consecutive pieces and weigh each one, recording the average and the spread between the heaviest and lightest. Then sample again at fixed intervals.
2. Stabilize ingredients first, then adjust settings: Once the ingredients are consistent, adjust the weight setting according to the operating manual. Change only a little at a time, and sample again after each adjustment.
3. Check wrapper and filling separately: For encrusted products, take a few pieces apart and weigh the wrapper and filling separately to see which one is drifting.
4. Keep records: Write down the ingredient temperature and settings when things are stable, and use them the next time you start up.

If sampling shows the weight gradually drifting in one direction, it's most likely related to temperature or fermentation; if it jumps between light and heavy with no pattern, suspect uneven feeding or residue.

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, remove the detachable contact parts according to the operating manual, clear residue and caked material from the feed passage and outlet, and make sure everything is reinstalled in its original position.

Dong-Yih Machinery's DY-528MS and DY-528M portioning and cutting machines handle 10g–30g per piece or heavier, at 3,000–12,000 pieces per hour.

FAQ

Q: Why does the machine make one piece heavy and the next one light?
A: Commonly it's changes in ingredient firmness and temperature, an unstable hopper level, ongoing fermentation, uneven mixing, or residue in the passages.

Q: How do I calibrate the weight?
A: Once running steadily, sample and weigh pieces one by one; after the ingredients are stable, fine-tune the settings according to the operating manual, a little at a time, and record the settings.

Q: Does ingredient temperature affect weight?
A: Yes. Ingredients that have warmed and softened are easily compressed or flow back, so run them within a fixed temperature range and replenish in small, frequent amounts.

Q: What if ingredients and settings are stable but weight still jumps around?
A: Stop the machine and cut the power, don't disassemble internal mechanisms, note the machine model, the symptoms, and your weighing records, and contact the manufacturer or a service provider. Dong-Yih Machinery: 06-257-4644.