Factors of effect and Test Methods for the Snagging Resistance of Fabrics

In our daily life, we can observe that garments are often subjected to tear and pilling as well as another awkward situation—snagging.

The Contrast of the Snag Sweater and the Normal Sweater

What is a snag in clothing? Snagging—fiber and yarn in fabrics are snagged and drawn away from the surface of fabrics. Snagging seriously deteriorates the appearance of fabrics, not only the appearance is seriously deteriorated, the durability of the fabric is influenced, more importantly, the credit of the clothing brand is seriously affected, and the losses are difficult to measure.

So how can we avoid these serious consequences? Before the mass production of the garment, in order to select the qualified clothing raw materials, we must make an accurate assessment of the snag resistance performance of the fabric and the clothing samples in advance.

There are two steps to accurately evaluate the snag resistance properties of garment raw materials: the first step is to roughly estimate the snag resistance properties according to the original properties of fabric materials, and the second part is to accurately evaluate the fabric which meets the requirements with instruments.

What Impact of Factor of Effect on the Snagging Resistance of Fabrics on its Appearance can Make?

1 Effect of Fabric Weave

Although they are made from filament, the degree of snagging varies from fabric to fabric because of different textures. Fabric of loose texture is easier to be snagged that that of tight texture. Tighter the fabric of texture is, greater the restraint between fibers is, so is the friction between fibers, which leads to good snagging resistance. Longer the float in fabric weave is, easier the yarn is to be snagged and drawn away from the surface of fabric, which leads to worse snagging resistance. Fabrics of short float in the surface and interweaves points, generally plain woven> twill> strip> honeycomb, composites twill> messy ramie, can be greatly designed and processed, meanwhile, its aesthetic should be taken into consideration.

2 Effect of Tightness

Effect of fabric tightness on warp and weft densities reflect the tightness of fabric texture. In the circumstance of similar factors like weave, line density and tearing strength, etc., greater the fabric tightness is, tighter the fibers and yarns are; cohesion is strong enough to make fibers restricted in fiber so that fibers are not be easily snagged and drawn out despite of external force. Consequently, goog snagging resistance is possessed. Suitable tightness can be selected in accordance to style and wearing properties of products.

3 Effect of Tearing Strength

Effect of tearing strength on the snagging resistance has two sides. Fibers in fabrics having the same tightness, tend to be more difficultly snagged and drawn out in the case of less crowded lines (yarn is slenderer), and at the same time, bigger the tearing strength is, better the snagging resistance is. While fibers tend to be more easily snagged and broken in the case of more crowded lines (yarn is thicker) and the weak tearing strength, and in case of bigger tearing strength, the fiber is snagged as a loop on the surface of fabric , so that the snagging effect is more obvious, showing worse snagging resistance.

4 Effect of Elongnation Ratio

Both capabilities of elongnation and elasticity of fiber are greater, which will alleviate, to some extent, the snagging of fabric. When fabric is snagged by an external sharp object,  elasticity deformation of fiber or yarn of better elasticity will assist to alleviate the external action. After eliminating the external force, loop snagged go back the original place of weave due to recovery of elasticity deformation, so as to alleviate the snagging. When choosing raw material in production, the elongnation ratio should be taken into consideration. For types easier to be snagged, raw material of elongnation of better capability should be selected.

5 Weight and Thickness Per Unit

The warp and weft yarn density affects the weight and thickness per unit. The enlargement of line density or warp and weft yarn density will possibly make fabric heavier and thicker. The warp and weft yarn density determine the tightness of fabric and tightness are closely related to the snagging. Therefore, effect of weight and thickness per unit on the snagging resistance of fabric is, to a great extent, determined by the warp and weft yarn density of fabric.

Measuring the Snag Resistance Property of Fabric with the Snag Tester

Comparison of Test Standards

There are mainly three standards for testing the snagging resistance of fabric, including GB/T11047 Testing Method for Snagging of Fabrics, ASTM D3939  Test Method for Snagging  Resistance of Fabrics (Mace Test Method), and JIS L1058 Test Method for Snagging Resistance of Woven Fabrics and Knitted Fabrics. Related test method for the snagging resistance of fabrics are not published by ISO, EU, and the UK yet.

For Mace Test Method, the biggest difference between the three standards is that revolution employed is different in testing. Revolution of 600 is employed in both China and America, and revolution of 100 is employed in Japan. Different revolution will directly influence the test result of the snagging of specimen. The three methods have basic common in test principle, operation procedure, testing apparatus and results assessment.

It can be observed that Japanese standard includes four method for snagging, while the Mace Test Method is regarded as the main test method for snagging through the comparison of Chinese, American and Japanese standards, the three tests methods for snagging resistance. The main difference is as follows:

1 GB/ T11047 Testing Method for Snagging Resistance of Fabrics

This standard apply to testing outwear knitted fabrics and woven fabrics and other fabrics easier to be snagged, in particular synthetic filament and its textured yarn fabric. Mace Test Method is the method of this standard to test snagging degree of fabric.

2 ASTM D3939 Test Method for Snagging  Resistance of Fabrics (Mace Test Method)

This method apply to testing textured filament, non-textured filament, staple yarn, and knitted fabrics and woven fabrics mentioned above, which is made from blended yarns. Because the felt will be hooked by the pin of the hammer through the mesh of the fabric, this method doesn’t apply to fabrics with pore structure, like mesh fabric. It also doesn’t apply to the too hard or too thick fabric which is difficult to be fastened on the rotating-drum and the felt gasket. Besides, this apparatus is specially designed for knitted fabrics and woven fabrics, but not tufted fabrics and non-woven fabrics.

3 JIS L1058 Test Method for Snagging Resistance of Woven Fabrics and Knitted Fabrics

This method is used in testing woven fabric and knitted fabric in accordance with various specifications. This standard includes four test methods:

1 ICI Hammer Snagging Tester: This method is that a nail hammer suspended by a chain is placed on the surface of specimen located in rotary drum, bypassing the guide rod. When the rotary drum rotates at a constant speed, the nail hammer freely rotate and move up and down to make specimen snagged.

2 Beanbag Snagging Tester: This method is that the beanbag with spherical particles is covered and surrounded by specimen, and then placed in a rotary drum with a pin so as to make specimen snagged when the rotary drum rotates.

3Clothing Roller Snagging Tester: This method is that one end of stripe specimen is fastened on the rotary drum, and the other end is in free position. When the rotary drum rotates, specimen regularly will brush against the clothing roller having a certain rotational resistance. The specimen is touched with clothing with pins, so as to make specimen snagged.

4 ICI Fuzz and Pilling Tester: This method is that pilling box, which inside is equipped with snagging tools like scratch rod, steel pin, saw blade, and emery cloth is utilized to carry out the test.

The test methods above apply to testing the great mass of garments and home textiles. Because washing and dry cleaning will affect snagging resistance of some fabrics, specimen should be washed or dry cleaned before testing. Snagging resistance of a specified fabric will vary for different wearers and general use conditions. Therefore, during wearing, considerable difference of snagging resistance will appear on the garments made from the same material and some acceptable introduction included in the snagging resistance test should be taken into consideration when testing.

Comparison of Test Results

The revolutions specified in the three standard methods are different, which lead to that considerable difference exits between test results. For the specimen of better results of snagging resistance test, grade the test result difference as Level 0.5; however, for the specimen of some worse test results, grade the test results difference as Level 2.5. It will be seen from this that test method of China and America is stricter than that of Japan.

For fabrics of same components of fibers, test result of woven snagging testing is obviously better than that of knitted snagging testing; knitted fabrics of jacquard, mesh, terry, etc. is easier to be snagged than common fabrics.

Selected corresponding test method in accordance with the application of products and requirements of clients when carrying out the snagging resistance test. Inspector should particularly noticed that which inspection standards the target market and countries require in the trade contact, and ought to strictly conduct the test and grade according to its requirements; otherwise, it is possible to give rise to loss for clients or manufacturer. If you’d like to continually know further information about test of textiles properties, welcome to follow TESTEX Blog with interest. We devote ourselves to conduct research on every details of textiles tests.