Stretch Recoverability of Fabric

Fabric stretch recovery is calculated as the percentage of the fabric growth recovered with respect to the fabric growth determined after tension or after a specified extension obtained at the various intervals. Fabric with good tensile or elastic properties will shrink itself after spreading and will be difficult to deal with in cutting, sewing, ironing, and other operations. Because of the product drawing, the size changed and the stitching part of the corrugated shape, if the stitching direction of the tension is too large, the sewing is easy to break or shrink the thread. Therefore, when operating for the above-mentioned fabric, we should choose the suitable elastic sutures for tensile properties.

What is a Woven Fabric Stretch Recovery Tester?

Woven Fabric Stretch Recovery Tester covers the determination of the amount of fabric stretch, fabric growth, and fabric recovery of fabrics woven in whole or in part from stretch yarns after a specified tension and extension.

Woven Fabric Stretch Recovery Tester is intended for use with woven fabrics exhibiting high stretch (greater than 12 percent) and good recovery properties from the low tension of fabric width. When agreed upon, this test method can be used for fabrics woven in whole or in part from non-stretch yarns that exhibit limits within the stretch characteristics shown above.

Test Principle

Fabric Growth after Stretching to a Specified Extension—Bench marks of a known distance are made on a fabric specimen. A specimen, paired to one used in the fabric stretch test, is held at a specified extension for a prescribed period of time. The tension is then removed from the specimen and the distance between the bench marks is measured after the specimen has been allowed to relax for various time intervals. The fabric growth at each time interval is calculated from the distance between the bench marks of the specimen prior to stretching and the length after each relaxation period at zero tension.

Nominal Definition

Fabric stretch under a specified tension-calculated from the length difference between bench marks prior to application of the tension ad while under the tension.

Fabric growth after a specified tension-calculated from the length difference between the bench marks prior to application of the tension and after relaxation.

Fabric growth after stretching to a specified extension-a specimen is held at a specified extension for a pre-scribed period of time. Calculated from the distance between the bench marks of the specimen prior to stretching and the length after each relaxation period at zero tension.

Fabric recovery-calculated as the percentage of the fabric growth recovered with respect to the fabric growth determined after tension or after a specified extension.

Test Procedure

1 Cut a certain number of samples of 65mm*560mm size as required. Ensure the specimens are free of folds, creases, or wrinkles. Avoid getting oil, water, grease, etc. on the specimens when handling.

2 Clamp the end of one specimen in the top clamp of the stretch tester such that the folded and sewn loop end hangs freely.

3 Measure and record the distance between the bench marks to the nearest 1 % or 1 mm (0.05 in.) and record as Distance O1 (original before tension is applied).

4 Insert a dowel pin, or equivalent, through the loop and place the tension weight hook through the slit in the fold and over the dowel pin, thereby providing the specified tension to the specimen.

5 Pre-stress the specimen slowly by cycling 3 times between 0 and the total tension specified. A complete cycle should take approximately 5 s of which the specimen is under the specified tension for approximately 3s. Following the third cycle, apply the specified tension for a fourth time and measure the fabric stretch.