Coating & Contact Mechanical

Coating Thickness When New µm

Yarn Contact Pressure kPa

Reference Pressure kPa

Pressure Exponent n

Wear Rate at Reference µm per 1000 h

Service & Thermal History

Operating Hours h

Heat-up Cycles no.

Wear per 1000 Thermal Cycles µm

Failure Thickness µm

Remaining Coating Thickness

— µm

Left after mechanical and thermal wear to date

Wear Breakdown

Mechanical Wear: — µm
Thermal Cycling Wear: — µm
Total Wear: — µm
Pressure Acceleration: — ×
Hours to Replacement: — h

Uniform wear across the cylinder is assumed and coatings do not fail uniformly — they fail at an edge, a repair, a thermal-gradient band or wherever the yarn sheet runs consistently, and one bare patch condemns the cylinder regardless of average thickness. Both rate constants must be recovered from measured coating thickness on cylinders taken out of service, since they depend on the coating system, the size recipe and how abrasive the yarn is. Sticking, scorching and size build-up are the practical end-of-life signals and generally appear before any thickness measurement is taken.

Sizing Cylinder Non-Stick Coating Degradation Predictor — free, with the formula and a worked example, at Textile School.