Pilling is one of the few fabric faults a customer notices without being told to look. It is also one of the easiest to argue about, because two labs using two different machines will not produce the same grade on the same fabric. So the first question is not which tester is better — it is which one does your buyer specify.
The ICI pilling box
The box method is the older and simpler of the two. Specimens are mounted on polyurethane tubes and tumbled inside cork-lined boxes at around 60 rpm for a set number of revolutions. Nothing presses on the fabric; pills form the way they form in a tumble dryer or a laundry bag — by the fabric rubbing against itself and against the cork.
This is the principle behind ISO 12945-1. Four boxes run at once, so a full set of fabrics is developed in one cycle and graded in one sitting under a viewing cabinet.
It suits knitted apparel, woollens, and anything where the realistic wear mechanism is loose tumbling rather than sustained surface pressure. It is also the cheaper instrument by a wide margin, needs no compressed air, and has almost nothing to go wrong.
See the ICI Pilling Tester – 4 Box.
The Martindale
The Martindale works the opposite way. The specimen is held flat and rubbed against an abradant — or against itself — under a defined load, following a Lissajous figure so the rubbing arrives from every direction in turn. That motion is the whole point: it stops the fabric developing a directional wear pattern that would not occur in real use.
In pilling mode it runs to ISO 12945-2. Swap the plates and weights and the same machine measures abrasion resistance to ISO 12947 and ASTM D4966, reported as rubs to end-point.
This is what upholstery, automotive, contract and workwear buyers ask for, because those fabrics fail by sustained surface pressure, not tumbling. It is also the instrument that gives you a second test — abrasion — from the same capital purchase.
See the Martindale Abrasion & Pilling Tester.
Choosing between them
| If your output is | Buy |
| Knitted apparel, hosiery, woollens | ICI box |
| Upholstery, automotive, contract, workwear | Martindale |
| Mixed apparel for European retail | Ask the buyer — both are specified |
| You also need abrasion resistance | Martindale, without question |
If you are equipping a lab from scratch and the budget allows only one, the Martindale is the more versatile machine because it also covers abrasion. If pilling is the only property you test and your customers are apparel buyers, the box will give you the grade they want for a fraction of the outlay.
Grading is where labs actually lose comparability
Both methods end the same way: a person compares the tested specimen against photographic standards and assigns a grade from 1 to 5. That step ruins more results than either machine does.
Grade under controlled light, not under whatever tube is above the bench. A colour matching cabinet with a D65 source gives every operator the same viewing conditions, on every shift, on every day. Without it, your grade 3 and your customer’s grade 4 are both defensible and neither is right.
Also fix the number of revolutions and stick to it. A grade only means something next to the cycle count that produced it — 125, 500, 1000, 2000 — and a report that omits it is not a report.
Practical notes
- Condition specimens before testing. Regain affects surface behaviour more than most people expect.
- Replace cork linings and polyurethane tubes on a schedule. Worn cork gives softer, slower pilling and quietly flatters your fabric.
- On the Martindale, check the abradant and felts every run. A glazed abradant under-abrades.
- Run a known control fabric periodically. If the control drifts, the machine or the consumables have drifted.
All of these instruments are built to order in India and supplied with installation and operator training. Browse the full Lab Testing Machines range, or tell us the standard you work to and we will tell you what you need.