ASTM D5034 Grab Testing for Textile Fabrics

0 1
ASTM D5034 Grab Testing for Textile Fabrics

Textile fabrics such as woven, nonwoven, and felted fabrics can be quality tested using ASTM D5034. ASTM D5034 uses grab and modified grab testing procedures to measure the strength and elongation of textile fabric.

What is ASTM D5034?

ASTM D5034 grab test procedures apply to woven, nonwoven, and felted fabrics, while the modified grab test procedure is used primarily for woven fabrics. The grab test determines the effective strength of the fabric: the strength of the yarns in a specified width with fabric assistance from the adjacent yarns. It doesn’t reflect yarn strength actually gripped between clamps. The modified grab test determines the breaking force of fabrics with constructions in which the application of tensile stress on ravel strip specimens produces further unraveling. This process applies to high-strength fabrics.

How is ASTM D5034 performed?

A grab test is a tensile strength test where the center of the specimen width is gripped between mechanical clamps. The modified grab test is similar - lateral slits are made mid-length of the textile, severing all yarns bordering that portion of the specimen held between the two clamps.

In the grab test, front grip faces should measure 1 inch by 1 or 2 inches, with the longer dimension along the vertical side. The rear grip faces should be 2 inches wide. For the modified grab test the front grip face should measure 1 inch by 2 inches, with the longer dimension along the vertical side once again.

8 specimens should be tested in the warp (machine) direction; and 8 specimens from the waft (cross or filling) direction.

For grab testing textile fabrics, you should select a versatile universal testing machine where load cells can generate sample breaks at 10 to 90% of the load cell range. Make sure you choose the correct grips for the job, with either rubber coated or smooth surfaces. We have determined that for denim material it is wise to use rubber coated jaws to avoid tearing at the upper corners of the jaws, which invalidates the test. This denim material did not slip in rubber lined jaws. If you do encounter slippage in the jaws, section 11.7.1 in the standard describes a way to wind the specimen around a mandrel above the upper jaw set and below the lower jaw set to avoid this slippage. The control test should run at 12 inches per minute.