Tuesday, July 6, 2010

Which rub is the right rub?

We all know we want our fabric to be durable, but do you know how to gauge a fabric's durability just by reading a few numbers?

In the textile world, there are two main indicators for fabric durability. One is the Wyzenbeek Method and the other is a Martindale Cycle. While both tests are abrasion tests, they are not alike. A Wyzenbeek rating of 30,000 double rubs doesn't necessarily equate to a Martindale rating of 30,000 double rubs and vice versa.

The Wyzenbeek Method entails pulling a piece of fabric taut in a frame and subsequently rubbing it back and forth with an abradant (different fabrics may require different levels of abradant, from cotton duck to steel wire) until two yarn breaks occur or noticeable wear is observed. The number of double rubs is recorded as the fabric’s abrasion rating.

A Martindale Cycle is what is referred to as an oscillating test. In the Martindale test protocol, a fabric is mounted flat and rubbed in a figure eight like motion using a piece of worsted wool cloth as the agitator. The number of cycles achieved prior to a marked change in appearance (yarn breaks, pilling, holes) is the durability rating.

While both tests are a good indicator of how a fabric will perform, there are many other factors that will predict the durability of your fabric, such as fiber content, weaves, finishes, furniture design, maintenance, cleaning, and usage.

Both methods are recognized by the American Society of Testing and Materials (ASTM). The way to compare Wyzenbeek vs Martindale ratings is with a 4:3 ratio.
For example:
40,000 Martindale = 30,000 Wyzenbeek
20,000 Martindale = 15,000 Wyzenbeek

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