How do you determine the extent of wear on a conveyor belt?

I. Rubber Conveyor Belts (for mining, sand/gravel, and coal; EP/NN/Steel Cord types)

Rubber belt structure: Top cover rubber (load-bearing surface) + Fabric/Steel cord core layer + Bottom cover rubber (pulley contact surface)

1. Cover rubber thickness measurement (critical assessment criterion)

Tools: Depth vernier caliper, belt thickness gauge

Assessment standards:

New standard rubber belts typically have top and bottom cover thicknesses of 3–6 mm;

Slight wear: Remaining thickness > 1/2 of original; no exposed fabric or rubber chunks missing; suitable for continued use;

Moderate wear: Remaining thickness 1/3–1/2 of original; localized thinning, fine scratches, or spot-like wear; requires more frequent inspections and periodic repairs;

Severe wear: Remaining thickness < 1/3 of original; multiple areas of localized thinning and extensive surface fraying; internal fabric/steel cords nearing exposure; replacement must be scheduled;

Scrap threshold: Fabric or steel cords exposed; moisture and material can corrode the carcass; high risk of longitudinal tearing or belt breakage; stop operation immediately for replacement.

2. Surface appearance and wear assessment

Slight wear: Uniform matte surface finish; few shallow scratches; no pits or rubber loss; edges intact;

Moderate wear: Localized indentations; scratches of varying depths; small chunks of rubber detached; slight edge wear;

Severe wear: Large-scale rubber delamination and pitting; areas thinned to paper-like consistency; deep grooves worn into sides due to prolonged mistracking;

Aging-related wear characteristics: Surface cracking, hardening, and powdering; cracking accelerated by temperature fluctuations (hot/cold conditions).

3. Edge wear assessment

Prolonged belt mistracking causes wear on one edge:

Slight: Edge becomes rounded; slight thinning;

Moderate: Groove worn into the edge; localized delamination;

Severe: Edge worn through; fabric exposed; high risk of transverse tearing. 4. Splice Wear

Wear typically occurs first at hot-vulcanized or cold-bonded splices; signs such as splice cracking, detachment of the rubber layer, or delamination indicate excessive wear and that the belt is nearing the end of its service life.

II. Lightweight PVC/PU Conveyor Belts (Food, Logistics, and Packaging Lines)

1. PU (Polyurethane) Belts

Visual Assessment

Mild: Slight surface scratches; surface layer intact; no whitening or peeling;

Moderate: Numerous deep surface scratches; localized whitening or slight peeling of the surface layer;

Severe: Large-scale peeling of the surface layer exposing the underlying fabric base; anti-slip pattern completely worn smooth;

Scrap Criteria: Exposed base fabric; through-thickness scratches; belt thinning and elongation; bulging at turns.

2. PVC Conveyor Belts

Mild: Pattern slightly worn/shallow; surface intact;

Moderate: Anti-slip pattern completely worn smooth; localized stickiness or wear-induced depressions;

Severe: PVC coating detachment; underlying fibers exposed; rapid delamination or damage upon contact with oil or water;

Anti-static PVC: Surface conductive layer worn away; resistance exceeds limits (loss of anti-static function); replace immediately.

III. Wear Assessment for Specialty Belts (Teflon, Silicone, Stainless Steel Mesh)

Teflon (PTFE) Belts

Mild: Minor fine scratches; non-stick coating intact;

Moderate: Localized coating wear (whitening); slight material adhesion;

Severe: Fiberglass substrate exposed; extensive material adhesion or coating delamination; scrap immediately;

Silicone Belts

Wear results in loss of surface elasticity, stickiness, shedding of silicone particles, and the appearance of through-cracks;

Stainless Steel Mesh Belts / Slat Chains

Mild: Slight surface scratches; minor oxidation;

Moderate: Mesh wires thinning; localized wear-induced depressions;

Severe: Mesh wires worn thin or broken; slat chain perforations; risk of breakage. 

IV. General Supplementary Indicators (Applicable to all conveyor belts)

1. Elongation-related wear (hidden wear)

Prolonged heavy loading and slippage cause permanent belt elongation:

If slippage or mistracking persists even after adjusting the tensioning screw to its limit, it indicates that the internal carcass has suffered fatigue wear and is irreparable; replacement is recommended.

2. Slippage-induced wear

Frequent pulley slippage rapidly thins the bottom cover rubber; a shiny, thinned appearance on the belt underside indicates abnormal, severe wear.

3. Damage-related hidden wear

The presence of any of the following indicates excessive wear; repair or replace as soon as possible:

Through-thickness longitudinal scratches or tears;

Holes with a diameter >10 mm or chunks of rubber missing;

Multiple localized thin spots or thickness variations exceeding 2 mm;

Delamination, blistering, or rubber separation.