Pilling Resistance Testing: Martindale, ICI Box and Random Tumble
Three standard pilling methods simulate three different wear conditions, and choosing the wrong one gives misleading confidence.
This article sets out what the requirement involves, how to specify it and how to verify it before bulk production.
How pilling develops
Loosened fibres migrate to the surface, entangle into pills and remain attached until abrasion removes them.
It is one of the few areas where a modest investment in development removes a large volume of after-sales work.
Martindale method
Fabric rubs against itself or a standard abradant in a Lissajous pattern, suited to flat abrasion conditions.
Keep the specification on one page with a diagram for measurement points, so it cannot be interpreted in two ways.
- Ask for a separate price line for the requirement
- Confirm minimum quantities before committing the colourway
- Build one extra approval round into the calendar
ICI pilling box
Samples tumble against a cork-lined box, reproducing the random contact typical of knitwear in wear.
Set an in-process check at the point where the parameter is created, not at final inspection where correction is expensive.
Random tumble method
Used mainly for US programmes and closer to domestic washing and drying action.
Verify with an accredited test on production fabric rather than a development sample, and repeat the test after laundering.
- Confirm the numeric range and the test method in the specification
- Keep an approved physical standard at the machine
- Retest after the agreed care regime before shipping
Grading and acceptance
Results are graded against photographic standards, with grade 4 or better as a common requirement after the agreed cycle.
Ask for the cost of the requirement to be shown separately, so it can be weighed against the benefit it delivers.
Summary
A clear specification, a trained operator and a documented test together remove most of the risk from this part of the programme.
