Quality Control

Details: Category: Quality Control

Direction of the cause and solution for common conveyor belt problems

What's the problem?	Why it happens?	The solution
1. Belt edge wear and broken excessively	1) Off centre loading	Adjust chute to place load on centre of belt and discharge material in direction of belt moving.
	2) Material Spillage and cumulation	Improve loading and conveying conditions, install cleaning devices, improve maintenance.
	3) Bowed belt	For new belt this condition should disappear soon, otherwise the belt must be straightened or replaced. In the meanwhile, should check storage and handling situation.
	4) Belt hitting structure	Install training idlers on carrying and return sides.
	5) Belt too rigid for adequate troughing	Install a more flexible belt.
2. Stripping of cover	1) Impact of materials on belt	Reduce impact by improving chute design, install impact idlers or impact bed.
2. Stripping of cover	2) Skirt board improperly adjusted or of wrong martial	Adjust Skirt Board support to minimum 25 mm between metal and belt with gap increasing in direction of belt travel. Kindly note: use skirt board rubber (not old belt).
3. Severe pulley cover wear	1) Material trapped between belt and pulley	Install scraper on return run ahead of tail pulley.
	2) Spillage on drive pulley	Increase tension, lag drive pulley, increase arc of contact.
	3) Sticking Idlers.	Free idlers and improve maintenance.
4. Cover harden or crack	1) Heat or chemical use condition	Use belt designed for specific condition.
4. Cover harden or crack	2) Improper storage or handling	Refer proper storage and handling instructions.
5. Cover softening or swells in spots	1) Contamination by spilled grease, overlubrication of idlers	Improve house-keeping, reduce quantity of grease used, check grease seals.
6. Cover bubbles	1) Cover cuts or very small punctures	Make spot repair with vulcanizer or self curing repair material.
7. Short breaks in carcass parallel to belt edge, start break in carcass	1) Impact of material on belt.	Reduce impact by improving chute design, install impact idlers or impact bed.
	2) Material trapped between belt and pulley	Install scraper on return run ahead of tail pulley.
8. Transverse breaks	1) Belt edges folding up on structure	Readjust idlers in affected area, install limit switches provide more clearance.
	2) Improper transition between troughed belt and terminal pulley	Adjust transition as recommended.
	3) Severe convex, vertical curve.	Decrease idler spacing in curve, increase curve radius
9. Lengthways carcass break with covers intact.	1) Belt running off centre and folding over	Use limit switches and determine reasons for belt running out.
10. Belt breaks at or behind fasteners, fasteners pullout	1) Wrong type of fastener, fasteners too tight or too loose	Use proper fasteners, set up schedule for regular fastener inspection.
	2)Fastener plates too long for pulley size	Replace with smaller fasteners, increase pulley size.
	3) Tension too high	Increase speed, reduce friction decrease tension by increase arc of contact.
11. Ply separation	1) Pulley too small	Use larger diameter pulleys.
	2) Heat or chemical use condition	Use belt designed for specific condition.
	3) Too many reverse bends	Use more flexible belt.
	4) Mildew or dust penetration into carcass	Prevent cuts, arrange for immediate repairs.
12. Particular section of belt runs to one side at all points on conveyor	1) Belt not joined squarely	Remove affected splice and re-splice.

What's the problem?	Why it happens?	The solution
Broken	1. Foreign object in drive 2. underdesigned drive 3. sharp band caused tensile cord damage	1. shield drive 2. redesign drive 3. follow proper storage and handling procedures
Excessive sidewall wear	1. worn of damaged sheaves 2. Misalignment or non-rigid centers 3. Bent flange	1. Replace of sheaves 2. Align drive or reinforce mounting 3. Straighten flange
Crack	1. high temperature 2. sheave diameter too small 3. slippage	1. remove heat source 2. redesign drive 3. retension drive
Cord Failure	1. high temperature 2. sheave diameter too small	1. remove heat source 2. redesign drive
Broken	1. Foreign object in drive 2. underdesigned drive 3. sharp band caused tensile cord damage	1. shield drive 2. redesign drive 3. follow proper storage and handling procedures
Wear	1. the tension force is not enough 2. Belt is too wide	1. make the belt fastened 2. Fit the belt with proper steps
Crack	1. high temperature 2. sheave diameter too small	1. remove heat source 2. redesign drive
Rob failure	Wrong Equipping Belt or Driver	Make sure that Belt is fixed well
Belt Noise	1. belt slip 2. misaligned sheaves 3. wrong belt type	1. retension 2. realign sheaves 3. replace cut edge with wrapped belt