Testing is an essential aspect of any product development process since it ensures product quality. The results reflect how effectively the product will withstand the effects of time, how the product will differ from when it was manufactured, and whether the product will be able to perform its function. But, most significantly, is the product manufactured in accordance with its specifications? This article will go over the various testing equipment and apparatus that are used to certify the quality standards of various fabrics being tested.
During a recent visit to a textile laboratory, I was astounded by the number of tests that a high-quality cloth must pass before it can be made into a garment. The various testing equipment utilised in the fabric testing laboratory is detailed below.
1. Bursting force tester
This test is used to determine the strength of any fabric in general. It is accomplished by placing the sample in a mould and applying pressure from the bottom of the cloth, which explodes once it reaches the threshold point. When the sample explodes, parameters such as speed, duration, and severity are recorded. Bursting strength is commonly expressed in kPa.
This testing apparatus is intended to determine the colour fastness of any textile material owing to rubbing. It regulates how much colour is transferred from one cloth surface to another. It is most commonly used for textile materials such as dyed, printed, or coloured fabrics. The test is performed by rubbing the sample continuously against an undyed sample. The transferred colour is then compared to a specified greyscale, and a score is assigned appropriately. This test is performed on the fabric twice, first when it is dry and again when it is wet. The outcome varies depending on the colours and fabrics used in the tests.
Fabric weather meter testing has become one of the most popular tests in the business. It operates on the premise of artificially accelerated ageing within the machine. A few minutes in the machine can simulate the fabric’s exposure to true outdoor climatic changes. Inside the machine, a mixture of artificial light (UV light), heat, particular filters, very precisely monitored radiation, regulated atmosphere (temperature and humidity), and cycled bright, dark, and rainy conditions can be formed. The modifications in the results can be compared to the original sample and evaluated accordingly.
4. Digital pill box tester
This is one of the most common tests for fabrics. It simulates pilling or snagging on materials caused by natural wear. The machine’s inside is made of cork with slight abrasion, and the samples are allowed to rub against the surface, resulting in the production of pills. Following the test, the fabric is evaluated and graded, ranging from no or very weak pill formation to severe pill formation, using prepared pilled samples or images. The quantity and timing of the cycles vary depending on the type of fabric and the order needed. It is mostly used on knitted materials.
It is a laboratory apparatus that is used to perform accelerated laundering and dyeing experiments. It can be used for washing, dry cleaning, dyeing, detergency testing, and other laboratory tasks. Temperature and mechanical agitation can be regulated and recorded inside the container for optimal testing and grading. This is very helpful because it can show the different washing conditions that different types of fabric need.
6. Spray examination
It is a piece of testing equipment used to determine the water repellency of a fabric sample. A light rain of water is sprayed over the cloth, which is held at an angle for testing. The amount of water absorbed and soaked on the cloth is then measured and compared to a specified rating table, and the fabric is graded accordingly.
Perspiration is frequently to blame for fabric colour changes. It is a piece of testing equipment used to measure the colour fastness of the dyed or printed fabric against sweat from water, seawater, and other sources, as well as sublimations during storage. It is carried out by subjecting the fabric sample, together with an undyed sample, to the action of the both acidic and alkaline medium at a controlled temperature and pressure. The fastness is then determined by comparing the sample to a shade card.
8. Tearing strength tester
Tear strength is the tensile force necessary to rupture a pre-slit woven fabric sample under controlled conditions, as measured by the work done in ripping the cloth through a defined distance. The ripping strength is expressed in newtons (N) or centinewtons (CN) (CN). The apparatus consists of a pendulum that is aligned with a fixed clamp and carries a clamp. The method begins with the pendulum being raised. When the sample cloth is raised, it is placed between both clamps. When the pendulum is released, the fabric shreds at the already slit location when the moving clamp moves away from the fixed clamp. A graduated pointer is affixed to the pendulum to directly read the tearing force.
9. GSM shears
GSM stands for Gram per Square Meter and is used to identify the weight of the fabric, which includes knit, woven, and non-woven fabrics. It is a basic piece of equipment used to cut a fabric sample in order to calculate the gsm of the cloth. The fabric sample has a cutting diameter of 11.2 cm. Following cutting, the sample is weighed and computed for GSM.
10. Crease recovery tester
A crease in a fabric after wear is highly unattractive to its aesthetic appearance. The device consists of a circular scale for measuring the recovery angle and a stand in the centre for placing the fabric. The cloth is initially crumpled for the test and then allowed to recover for one minute while the recovery angle is recorded. The greater the recovery angle, the greater the resistance to creasing. This is done in both the warp and weft directions. For different circumstances, parameters such as load (for creasing the sample), creasing time, and recuperation time can be adjusted.
11. Thickness calliper
It is a basic tool for measuring the thickness of the fabric. Most instruments nowadays are computerised, and inserting the fabric between the anvil and the pressure foot would display the thickness of the cloth on the screen. Thickness (mm) is measured in millimetres.
12. Extensometer for fabric
An extensometer is a device that measures any change in the length of a fabric sample when it is stretched or recovering from that strain. It is possible to do this with both woven and knitted fabrics. The instrument is made up of a loading frame with clamps and screws, as well as various weights that can be used to stretch the cloth sample. This tool can determine the fabric elastic, which is one of the most important qualities of the fabric at different extensions.
13. Sublimation speed tester
A sublimation tester is a device used to assess fabric ironing colour fastness, sublimation colour fastness, and dimensional stability under hot, dry circumstances. Depending on the requirements, parameters like heating plate temperature and test timings can be changed. Samples can be prepared using only fibres, yarn, or cloth. The results are then examined and rated using grey cards to determine the degree of discolouration of the original sample and staining of the white material.
14. Light fastness tester
The resistance of dyes or pigments used for colouration to tinting or colour change owing to exposure to direct sunshine or any artificial light source is referred to as light fastness or colour fastness to light. Different end uses of fabric will necessitate varying degrees of light fastness. Because artificial sunshine cannot be recreated or regulated in a laboratory setting, a xenon arc lamp that simulates UV and visible solar radiation is used. It also provides the best approach for modelling rapid light ageing of a fabric sample and tests colour fastness using a shade card.
15. Tray to catch shrinkage
Shrinkage is an unwanted feature of a fabric in which the dimensions of the fabric decrease throughout the laundering process. This is caused by the tension exerted on the strands during the weaving process. The fabric sample for the shrinkage test is cut from a template with a predetermined size and then laundered in controlled settings. The fabric is then dried, and the change in size is calculated using the formula.
Fabric length before washing)-(fabric length after washing)/fabric length after washing)*100
Testing is performed in both the warp and weft directions and the average is calculated for the most accurate result.
16. Mace snatches a tester.
The Mace snag tester is a device used to determine the fabric’s susceptibility to snag (tear yarn loops from the fabric) during normal wear. The machine is outfitted with spiked mace balls that grab onto rollers that hold fabric samples. The number of spins is determined by the fabric and the requirements. Finally, the snagged cloth is compared and assessed based on various snagged levels.
17. Chamber of cold impact.
When most fabrics are subjected to extremely cold temperatures for an extended period of time, their physical qualities alter. The changes are visible when the fabric hardens and brittles. Because the machine can reach temperatures as low as -400 C, it is used to study what happens to textile fibres when they are exposed to very cold temperatures.