Physical Properties

  

Pilling is the formation of fuzzy balls on the surface of a fabric. Pilling occurs when loose fibers in the fabric are worked to the surface after the fabric is subjected to abrasion.
The Brush Pill Test uses nylon bristles to rub the surface of the fabric to be tested for a specified amount of time. The number of balls or pills that form of the surface of the fabric are counted and the fabric is evaluated in a 1 to 5 rating system.
Class 5 = no pilling
Class 1 = severe pilling

Breaking strength measures a fabric's ability to resist tearing or breaking when subjected to tension.
To evaluate breaking strength, the fabric to be tested is gripped by clamps at one end while weight is applied to pull it from the other end. This test is performed in both the warp and the filling directions. The number of pounds required to cause the fabric to break or tear determines the rating.
50 pounds minimum = upholstery
35 pounds minimum = panel and vertical surface fabrics
15 pounds minimum = drapery.
Seam slippage refers to the condition when fabrics pull apart at a sewn seam.
To measure a fabric's ability to resist seam slippage, a seam is sewn in the fabric to be tested. These sewn fabrics are then clamped at one end and pulled by weights at the other end. This test is performed in both the warp and filling directions. The weight is increased until the seam separates a specified distance. The number of pounds required to cause this separation determines the fabric's rating.
25 pounds minimum = upholstery
25 pounds minimum = panel and vertical surface fabrics
15 pounds minimum = drapery