EN
Yarn breaks, unstable fabric density, and frequent loom stops are the hidden profit killers in PP woven bag production. Many plants focus on speed and output, but from a maintenance manager’s viewpoint, the best way to increase effective capacity is to reduce unplanned downtime—especially downtime caused by warp/weft breakage, poor tension control, and insufficient lubrication.
This article provides a practical preventive maintenance schedule for a woven bag making machine (including circular looms and conversion sections) and highlights three high-impact areas: tensioners, roller frames, and cam lubrication. If you’re comparing a pp woven bag machine or evaluating woven bag machine price, use this checklist to estimate real running cost and reliability—not just purchase price.
1) Why Preventive Maintenance Matters More Than “Max Speed”
A loom rated at high RPM still won’t deliver output if it stops every 10–20 minutes due to yarn breaks. In real factories, effective production depends on:
- fewer stops per shift
- faster restart after stops
- stable fabric quality (less rework and rejection)
Preventive maintenance improves OEE by stabilizing:
- yarn tension (warp/weft)
- motion accuracy (cams, gears, bearings)
- alignment (rollers and guides)
2) The 3 Most Common Reasons for Yarn Breaks
A) Tensioner drift and contamination
Dust, PP fibrillation, and oil contamination change friction and tension response, leading to breakage.
Checks
- tensioner spring condition
- pad wear and alignment
- dirt buildup and sticky residue
B) Roller frame misalignment
If guide rollers are not aligned or bearings are worn, yarn rubs and heats, then breaks.
Checks
- roller bearing play
- roller parallelism
- edge guide condition
C) Cam and drive lubrication failure
Dry cams cause higher friction, heat, and unstable motion—often showing up as random breaks across multiple positions.
Checks
- lubricant level and type
- oil distribution lines (blockage/leaks)
- cam surface scoring
3) Preventive Maintenance Schedule (Shift / Weekly / Monthly)
Shift (10–15 minutes per loom)
- Clean yarn path: remove lint, dust, and fibrillation
- Confirm tensioner readings are within standard band
- Quick lubrication check for key points (per machine manual)
- Listen for abnormal noise at bearings/cams (early failure signal)
- Record: break count, stop reason, and loom position
Weekly
- Deep clean tensioner assemblies (do not over-oil)
- Inspect rollers: rotate manually, check bearing smoothness
- Check cam surfaces for scratches, overheating marks
- Verify belts/chains tension and alignment
- Check sensors/stop motion devices (false triggers waste time)
Monthly
- Replace worn tension pads and high-wear guides
- Inspect gearbox oil condition and metal debris
- Verify loom frame leveling and vibration
- Calibrate tension settings using a standard test method
- Audit spare parts stock: bearings, pads, cams, stop-motion parts
4) Standardizing Tension = Standardizing Quality
To improve woven quality (GSM consistency, fabric density, bag strength):
- create tension “recipes” by fabric spec (denier, tape width, weave density)
- train operators to adjust only within limits
- lock in preventive replacement intervals for tension pads and key bearings
5) How Maintenance Impacts Woven Bag Machine Price (TCO)
A lower woven bag machine price can become expensive if:
- it requires frequent cam replacement
- bearings fail early
- lubrication system is hard to maintain
- tension system is unstable and causes scrap
When comparing sack making machine price or woven sack machine quotes, ask for:
- lubrication design details
- recommended preventive parts list
- typical yarn break rate at stable production
- reference factories running similar denier and output