Showing posts with label Wyzenbeek Rating. Show all posts
Showing posts with label Wyzenbeek Rating. Show all posts

Wednesday, March 7, 2012

Fabric Abrasion 101

We are asked a lot how durable certain fabrics are. Many upholstery grade fabrics will have 1 of 2 abrasion ratings listed in the description; It will either be Wyzenbeek or Martindale. These two methods of testing the durability of fabric for upholstery use are actually very different but both of them are commonly used. Let’s begin with the actual definition of abrasion. Abrasion resistance is “the ability of a fabric to resist surface wear caused by flat rubbing contact with another fabric.”

The Wyzenbeek method is a standard test used in the United States. It is often referred to as the “rub test” as people often ask how many “double rubs” a particular pattern passes. The Wyzenbeek machine tests the fabric in both the warp direction (up and down) and the fill or weft direction (right to left). A sample of the fabric is cut into two pieces and each are pulled tight in a frame where it is held stationary. A piece of cotton duck fabric is used as the abradant and is rubbed back and forth over the fabric, known as the “double rub.” The samples are checked after every 5,000 double rubs and if the fabric is still holding up, it goes through another cycle of 5,000 and so on. When wearing has become evident or two yarn breaks have occurred, the end point has been reached, and the fabric is rated by the last check point it passed. So in simple terms, this means if there isn’t any noticeable wear at the first check of 5,000 rubs but it shows noticeable wear at the next cycle it must be rated as only 5,000 double rubs. Most of the time, 15,000 double rubs is considered suitable for heavy use in a residential application.

The Martindale test method is usually performed on imported product, and uses a different method when rubbing the fabric. The sample is mounted flat and a piece of worsted wool cloth is used as the abradant. It is rubbed in an elliptical shape. Again the method is checked in 5,000 cycles and when two breaks occur or there is a sufficient change in shade or appearance, the fabric is rated by the last checkpoint it passed. A rating of 20,000 rubs is considered suitable for heavy duty residential use.

There is, however, one misconception about the two methods. There is no correlation between the two methods; you can not estimate the number of cycles on one test if you only know the test results from the other method.

The next time you are searching for upholstery fabric be sure to look for either one of these abrasion ratings. Knowing this bit of information should make your search that much easier.

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