Determining Maximum Force Using the Grab Method
scope
The grab method test is a tensile test in which the center of the specimen in the width direction is clamped with a jig. The scope of application, test equipment, gauge length, and maximum force are the same as those in ISO 13934-1.
Sampling and Sample Preparation
sampling
A full width of at least 1 m was randomly cut from each pile of the lot as a laboratory sample. Make sure the sample is free of creases and obvious blemishes.
specimen preparation
Cut a group of samples from each sample in the warp direction and weft direction, and each group should include at least 5 samples. If the accuracy is high, the number of samples should be increased. The sample should be representative, avoiding wrinkling, and the wrinkling should be at least 150mm away from the edge of the selvage. The warp yarn sample group should not be sampled on the same warp yarn, and the weft yarn sample group should not be sampled on the same weft yarn.
The effective width of each sample should be (100±2) mm, and its length should meet the gauge length of 100 mm. A marking line is drawn on each sample along the yarn parallel to the length of the sample, 38 mm from the long side of the sample and running the entire length of the sample.
test program
Set the gauge length of the Tensile Testing Machine to 100mm, or 75mm as agreed by the relevant parties, with an accuracy of ±1mm.
Set the tensile speed of the Tensile Testing Machine to 50 mm/min.
Clamp the sample. Make sure that the longitudinal centerline of the specimen passes through the centerline of the grips and is perpendicular to the line of the jaws so that the marked line on the specimen is aligned with the side of the grips. After the upper jaw is clamped, the other end is laid flat in the lower jaw by its own mass, and the lower jaw is closed.
Start the Tensile Testing Machine, stretch the sample until it breaks, record the maximum force, and at least 5 samples in each direction.
Wet sample test: take the sample out of the aqueous solution, put it on absorbent paper to absorb excess water, and immediately carry out the test according to the above test procedure.
The calculation results are modified in the same way as ISO 13934-1.
