When clothes are worn for a long time, due to friction the yarn thinning, the…
In our daily life, we often find that small holes appear in newly-purchased clothes after several laundries or wearing. Worst, our clothes even become worn as long as we fall for the first time. However, some clothes can still keep good in wearability although they have been used for a long time with faded color. So what is the secret? It has to do with the abrasion resistance of textiles.
The abrasion resistance has a direct influence on durability and the using effect of textile products. Additionally, the usage efficiency of textiles, a crucial indicator used to assess the quality of fabric products, can be improved with the help of the test for abrasion resistance. Manufacturers of textiles or brand entrepreneurs will undoubtedly be motivated to boost their businesses by making durable and consumer-satisfying products. Therefore, the test for textile abrasion resistance must be conducted prior to the shipment of the textiles.
The textile abrasion resistance test is to determine and assess the degree of abrasion and wear of the textiles subject to repeated mechanical friction. And the wear is mainly manifested in the following aspects: breakage, quality reduction, color fading, pilling, and so on. There are many kinds of instruments for testing textile abrasion resistance, among which the Martindale Abrasion Tester is the most commonly used in factories and laboratories.
Table of Contents
What is the Martindale Abrasion Tester?
The Martindale Abrasion Tester is a testing instrument that is designed following the principle of J.G. Martindale and the specifications of the Wool Industry Research Association. Besides, it is used to test the degree of the textile abrasion or pilling resistance by taking standard wool felt as the rubber to rub the test sample such as cloth. And we can also change the rubber, such as sandpaper, to respond to various test methods and requirements. Driven by vertical and horizontal eccentric wheels, the testing sample is mounted on a cylinder with a standard weight, pressed on the rubber, and moves on the trajectory of Lissajous to complete the multi-directional abrasion test.
How to measure textile abrasion by the Martindale Abrasion Tester?
Abrasion shows up as a change in the shape of textiles, mostly as breakage, a loss of quality, and visual modifications such as discoloration and pilling. Three factors are typically considered when measuring the fabric’s abrasion resistance: appearance changes, sample breaking, and mass loss.
Evaluation of appearance changes: under a certain load, the specimen in the jig is rubbed against the grinding material complying with the trajectory of Lissajous curve plane movement, and the abrasion resistance of the fabric is determined by appearance changes of the specimen before and after rubbing.
Assessment of specimen breakage: under a certain load, the specimen is rubbed against the grinding material in the fixture according to the trajectory of the Lissajous curve plane movement. Finally, judging from the overall amount of friction when it becomes worn, we can determine the abrasion resistance of textiles.
Determination of mass loss: under a certain load, the specimen in the jig is rubbed against the grinding material following the trajectory of the Lissajous curve plane movement. And finally, the abrasion resistance is determined by the difference in mass before and after rubbing when the specimen is rubbed a specific number of times.
Among them, the first test method is more commonly used as it provides intuitive data and convincing references. The common testing equipment is often used to calculate the number of wear cycles (in Martindale) that makes the material worn to a specific degree by taking 5000 times as a cycle. For example, the German National Textile Association specifies the minimum requirements for various applications, and the followings are requirements for abrasion resistance of mats.
|Utilization||Specified numbers of soft pad||Specific numbers of the hard pad|
|Family||10，000 times||15，000 times|
|Office||25，000 times||35，000 times|
|Public transportation||30，000 times||40，000 times|
Besides, we score the abrasion resistance of textiles: the higher the score is, the more durable textiles are. The scores below are found online but are not available in specific countries and regions of application. However, according to the points on the table, we can figure out various usages of textiles.
Make cushions or decorative items. Not suitable for general household or furniture decorations.
lightweight household products, such as furniture made of upholstery fabrics that are only dry cleaned and are usually made from delicate yarns.
|20,000 – 25,000|| |
General household products used in daily life; Not suitable for furniture items which are extremely heavy, such as reclining chairs
25,000 – 30,000
Heavy household products with high quality; applicable to lightweight household products for commerce, such as reclining chairs and other sports furniture
Commercial use; Suitable for heavy household products
The structure of the Martindale Abrasion Tester
The structure includes a power cord, footing, clamping table, operation panel, emergency stop button, fixed fixture, test fixture, test weight, and mobile tray, as shown in the following figure.
Test process of the Martindale Abrasion Tester
Step 1 The way to be positioned. The specimen is required to be placed in a standard atmosphere and kept flat-laid for a certain time without stretching based on different standards, such as 24 h (G B /T 4 80 2 .2 a 19 97) and 16h (EN ISO 12947-4:1998).
Step 2 Find out proper grinding materials. The diverse characteristics of the specimen call for different standard grinding materials. The woven plain wool fabric should be used to rub non-coated fabric while No.600 water sandpaper is for non-coated fabric. Grinding materials and grinding table are separated by the wool felt. After the test, check the surface of the wool felt to see if there is a stain or wear. If so, it should be replaced promptly.
Step 3 Sampling method. At least 3 pieces of woven fabrics should contain various warp and weft yarns. Jacquard fabric or fancy texture is required to contain parts of a stitch repeat. When a stitch repeat or pattern is relatively large in size, every part of them can be sampled respectively.
Step 4 Choose fixtures and pads of the specimen. When testing the quality of the unit area of the specimen, if the unit area of the specimen should be equal to or larger than 500g/m2, there is no need for the foam liner. If the unit area of the specimen is less than 500g/m2, foam liner should be extra installed in the specimen fixture and replaced for each test.
Step 5 Select the total effective mass of friction load. The total effective mass of the friction load is the sum of the mass of the gripper, the stainless steel disc, and the specimen weight. For example, some testing instrument companies supply clamps with a mass of 199 or 201 grams, stainless steel discs with a mass of 259 or 261 grams, and sample counterweight of 393, 397, 592, or 596 grams. There are three options to figure out the corresponding total effective mass of friction load according to the characteristics of fabrics and the usage of samples.
1) 788 or 802 grams: workwear, furniture upholsteries, bed linens, and industrial fabrics
2) 588 or 602 grams: coated fabrics for non-clothing, textiles for clothing, and home textiles such as furniture upholstery and bed linen
3) 196 or 200 grams: coated fabrics for clothing
Step 6 Take the load and load shafts from the tester
Step 7 Remove the top plate and the test fixture
Step 8 Loosen the retaining ring on the test fixture, then remove the specimen press, and place the specimen into the test fixture base. The specimens on each clamp shall be subjected to the same tensile strength.
Step 9 Put the wool felt and grinding materials with heavy weight on the grinding table, then place them on the chuck ring and tighten the nut so that grinding materials can be fixed on the grinding table.
Step 10 Increase pressure by placing the grinding head on grinding materials.
Place the test fixture with the sample face down on the base fixture, and adjust the circular groove of the test fixture to align with the load shaft. As a result, the load shaft is inserted into the circular groove of the test fixture.
Step 11 Place the test fixture with the sample face down on the base fixture, and adjust the circular groove of the test fixture to align with the load shaft. As a result, the load shaft is inserted into the circular groove of the test fixture.
Step 12 Set the number of testing times according to the standard and establish an appropriate inspection interval before the experiment based on the estimation of the times of friction that is needed to make textiles worn. Then turn on the switch and carry out the test. The interval is taken as an indicator to measure the wear state of the worn surface of the sample during the wear resistance test.
Step 13 Finally display the test result. Measure the total number of friction when each sample has become worn, and take the accumulated friction times before the sample is damaged as the wear resistance times.
Precautions of the Martindale Resistance Test :
1 Remove the cloth from the insole first and then carry out the Martindale abrasion test.
2 The abradant cloth cannot be used repeatedly and needs to be exchanged after the completion of a test.
3 The wool felt can be used repeatedly. But if its surface is worn or stained, it needs to be exchanged or used with both sides.
4 The operation must be carried out under the guidance of strict standards and within the guarantee of personnel safety.
5 When making samples, we should ensure that there is no change in furs on the cutting edge to avoid unnecessary quality loss and changes in appearance.
Maintenance of the Martindale Abrasion Tester
1 Turn off the power supply when the instrument is not operating.
2 Please remove the test pressure plate, spray anti-rust oil and add lubricant to the gear parts every month if you will not use it for a long time.
3 It is a must to clean the external part of the instrument regularly and wipe the cylindrical axis under test before and after the experiment to keep the instrument clean.
4 Inspect the test instrument regularly to see if there are any abnormalities in operation. Generally speaking, the friction head will draw the trajectory of the Lissajous curve. The distortion of the guide plate, guide shaft of the friction head, and friction head all affect the friction movement trajectory, resulting in adverse effects on the test. Therefore, we need to protect the integrity of accessories.
5 For protecting the life span of the instrument, users are required to operate it in a correct way instead of infringed way. If you can not find out the reasons why the instrument encounters malfunctions by yourself, you should immediately contact manufacturers and repair it under the guidance of professional engineers.
Purchase recommendations of the Martindale Abrasion Tester
1 Identify the terms of service and the type of service that the manufacturer can provide and figure out whether there is a professional after-sales team.
2 Take a comprehensive consideration of the capability of the manufacturer including the brand recognition, qualification, establishment time, and sales scale.
3 Observe the sales staff’s professionalism to inspect whether they have a complete awareness of the needs of clients and whether they are knowledgeable about the specifics of the instrument.
4 Learn about the functions, features, and operation situation of the instrument in a full way. For example, we need to see whether there is thorough persuasive evidence proving the instrument can still run stably for a long time while with a low possibility of malfunction.