Quality is an issue dear to manufacturers, buyers and retailers alike and no garment can be regarded as being of good quality if the materials it is made from are not quality items to start with. Thus, whatever quality assurance schemes operate within a clothing company, additional quality control needs to be carried out on the raw materials, either within the company or by an outside testing laboratory, Niki Tait reports.

With the vast range of fabrics and finishes now available and increased requirements of textile testing, companies supplying the testing equipment are constantly updating the range and the versatility of their products. There are many tests for all stages of fabric production, from the fibre to the finished product. While the textile producer is interested in testing from raw yarn onwards, the manufacturer is more concerned with the total fabric properties.

There are many international suppliers of testing equipment with a wide range of different fabric tests. These include tear strength, resistance to abrasion and piling, fire resistance, colour fastness to light, water and wind proofing, wash ability, resistance to dry cleaning, and much else. Indeed for almost any characteristic you want to test, there is a test available.

The most important properties of yarn are tensile strength and elongation, mass unevenness and yarn count (liner density). Static tensile testers, yarn evenness testers, as well as various apparatus for yarn count testing, for example, by means of wrap reel and balance, normally serve for the assessment of these yarn properties. The use of difference testing equipments, for the purpose of conducting tests on the yarn samples by the operator, result in increased expenditure on labour and considerable financial investments on the modern automatic computer controlled testing machinery.

New Statimat DS from Textechno
combines the testing of tensiles properties, unevenness, and counts of yarn and thread in one tester, which compared to investing in three separate testing appliances, results in a very economical price. The three tests are performed in succession. An optical entanglement sensor to measure interlaces, in a multifilament yarn is available as an extra option. The operator has to present the test samples or yarn packages only to one instead of several different testers resulting in considerable time and labour savings. Results are presented in one test protocol so that the data can be easily interrelated, for example, when calculating tenacity from the measured strength and yarn-count values.

Italian company Mesdan provides a wide range of testing equipment. The Electronic Tearing Tester with interchangeable pendulums, pneumatic clamps and RS232 port enables visual checking of the single tearing value, the average tearing value, minimum and maximum tearing values, standard deviation and the range percentage to a reading accuracy of 0.2%. It is built in accordance with ASTM D 295, D 751, D1424, D 1922, UN 53862, DIN 53128, ISO 1974, EN 21974, BS ISO 13937-1 and ENISO 4674-2 and can store up to 99 test results. Built in accordance with ISO 8096 and BS 3424 and Mesdan Crumpleflex is designed to check the loss of water resistance of fabrics caused by wear and flexion during normal use. A tubular sample of fabrics is twisted at 87degrees, elongated and compressed at same time. The Vertical Flame-lab has been developed for the assessment and the measurement of the flame propagation capacity on horizontally oriented textile materials, coated and multi layer fabrics. Other properties regarding the flame propagation, such as post combustion, post combustion time, post incandescence and post incandescence time can be observed, measured and recorded. The Static-Lab checks the static electricity properties of the textiles. It is composed of an electronic control panel for the digital reading of the static electricity values in Ohms, connecting cables and measuring heads for the static electricity reading in both the surface and vertical methods.

US-based Q-Lab Corporation provides practical Xenon based quality testing equipment and services that are used to predict products’ resistance to indoor or outdoor weathering and light damage. Using full spectrum (Ultra-violet, visible light and infrared) xenon arc lamps, the Q-Sun can realistically reproduce outdoor sunlight, sunlight through window glass, or bright indoor lightning such as that found in retail or commercial environments. It can be used to test for light fastness, colour change, and strength loss to ISO 105 B02, AATCC TM 16 and AATCC TM 169 standards. Q-Lab claims Q-Sun is affordable, with a lower purchase price, lower lamp prices and lower operating costs than competitive xenon testers. A practical design makes it easy to install, easy to use, and nearly maintenance-free.

It QUV accelerated weather-ability tester tests materials by exposing them to alternating cycles of Ultra-violet light and moisture at controlled, elevated temperatures. Economical UVA-340 lamps apparently provides the most realistic laboratory simulation of short waves UV radiation (295nm to 365nm), the most damaging range of sunlight in terms of physical property changes. Since the first QUV was introduce nearly 30 years ago it has been updated regularly with technological advancements, including the patented Solar Eye Irradiance Control and AutoCaTTM Automatic Irradiance Calibration System. The QUV controller is design to store pre- programmed, commonly used test cycles. Built-in computerized data logging ensures a quick and easy connection between the QUV and a PC or LAN.

Dimensional stability or shrinkage testing is one of the most common tests performed in textile laboratories. Yet, many labs still use traditional washers and dryers to perform the test. While the testing of other quality characteristics has accelerated with the use of specially designed test instrumentation, shrinkage and related tests still take hours to perform when using standard home appliances. For years, test houses and manufacturers could only rely on washing machines for testing shrinkage of knitted and woven fabrics samples according to AATCC 135 and other international standards. The SDL Atlas Quickwash Plus, however, measures shrinkage and other quality factors in as little as fifteen minutes, a fraction of time associated with washing machine shrinkage testing. At the core of every Quickwash unit is patented technology. An on-board microcontroller provides user selectability for washing, rinsing, extraction, and dying cycles. Each Quickwash unit is pre-loaded with programs conforming to AATCC test Method 187 and other trade association test methods, including test regimens used by a variety of retailers.

Two of the latest developments from SDL Atlas are the Moisture Management Tester and Sweating Guarded Hotplate.

The M290 MMT Moisture Management Tester is a table-top unit that measures how effectively knit and woven fabrics handle moisture transport in three key areas: absorption rate of inner and outer surface, the one-way transportation from a fabric’s inner to outer surface, and moisture spreading rate. Used for both quality control and research and development, the MMT is designed to meet draft standards under consideration by AATCC, ISO, and SN.

The M259B3 Sweating Guarded Hotplate, also called the ‘skin model’, simulates the heat and vapour transfer processes which occur next to human skin, information that can be a critical concern among makers of outerwear, work and sportswear. The M259B3 unit conforms to ISO 11092 measurements of thermal and water vapor resistance under steady state conditions. Housed in a conditioned cabinet, the instrument operates with userfriendly Windows software and prints out standard test reports.

With magnification ranging from 5x- 2400x the new DMM-2000 Digital Measuring Microscope from Projectina with micro and macro optics is a versatile microscope for checking, measuring, comparing and documentation for various applications in the laboratory. Its modular and compact design is enhanced by a rotatable screen with millimeter division and angle measurement, fine height adjustment of 80mm, built-in halogen illumination of 12V/65W, a built-in high resolution digital or video camera. It has been developed to meet the specification testing requirements of the textile industry. The same device can be use to make both micro and macro enlargements while the unique combination of high-resolution digital/video camera and binoculars viewing eliminates the problem of operator’s fatigue. The sophisticated and simple to operate PIA-6000 software provides for systematic comparison, measurement, image interpretation, image processing function, establishment of data base with image search function, etc., as well as simple documentation and reproduction of examination processes with the possibility to link external data bases. For video cameras the PIA-5 software is the perfect alternative offering a variety of comparative investigation possibilities with image processing and measuring functions.

Multi-Fastest by Technorama is an analytical device designed to obtain quick response on the fastness of dyes on fabrics, yarns, knitwear, coated /resin finished products, etc. A single machine offers technical solutions capable of quickly and automatically performing all of the most important fastness and resistance tests, both dry and wet. These include water fastness (20oC), hot water fastness (40/50oC), chlorinated water fastness, sweat fastness (acid), sweat fastness (alkaline), wash fastness at 40oC, 60oC, 80oC and a rigorous home wash fastness at 95oC, resistance to hot iron at 150oC for sublimation, acid fastness, extraction with organic solvent and extraction with water to check pH, salinity, presences of sizes and starches, dry wash fastness (perchloroethylene), seawater fastness, alkali fastness, hydroclorite fastness etc.

With Multi-Fastest it is also possible to perform tests and checks on samples of dyed fabrics that are finished with synthetic resins or other chemical products that may have altered the dye’s fastness properties after such treatments, or to conduct fastness tests on resin finished, coated and/or coagulated (imitation leather) products. Multi-Fastest is designed to quickly and automatically carry out numerous tests, especially the most important dry and wet tests required by international rules on the fastness of dyes used on textile materials. If all of these tests were performed using normal recommended procedures, it would require numerous different machine and much longer processes that would not be able to satisfy the need for the speedy results. The specific software, installed on the system’s PC, makes it possible to create custom working programs to conduct tests and obtain analytical results in just a few seconds or minutes.

The WIRA Steaming Cylinder has been developed to help companies predict potential cloth shrinkage during garment pressing and stem finishing and provide a reproducible measure of ‘relaxation’ shrinkage of both woven and knitted fabrics. The WIRA steaming Cylinder subjects four cloth specimens at a time to dry saturated stem at atmospheric pressure. The specimens are given no mechanical restraint and there is no subsequent vacuum cooling. The device provides a reproducible measure of the component of shrinkage occurring in steam pressing attributable to latent strains in the cloth supplied. Any further shrinkage that may occur arises from the characteristics of the pressing process itself. The cylinder has a double-walked thermally insulated steaming chamber into which the cloth specimens are placed on the stainless steel supporting frame of low heat capacity and surface area. Steam is fed to the equipment by an integral steam generator. This is connected to water supply, thus making the operation automatic. An automatic timer is incorporated in the apparatus to give an indication of the 30-seconds cycle required for BS4323 and ISO3005. A standard shrinkage rule and coloured pens are supplied to record shrinkage.

The specimens are preconditioned in the standard atmosphere for testing textiles which ensures that in conditioning itself equilibrium is always approached from the dry side. They are marked using the measuring device and then measured. Then steamed for 30 seconds, followed by 30 seconds rest outside the cylinder, this cycle is repeated three times. After this they are preconditioned again, conditioned and re-measured. The test conforms to ISO 3005:1978, BS 4323:1979 [1995], IWTO-29-76[E] and Mark & Spencer standard test method P8.

Textest’s wide range of instruments, mainly used for technical textiles, is known for their unsurpassable accuracy. Amongst the range available, is the FX3000 Automatic Hydrostatic head tester HYDROTESTER III used for determining the resistances of coated and uncoated fabrics, and nonwpvens to water penetration by means of the dynamic, static and program test methods up to 2bar. The test specimen is placed on top of the water filled test head and is clamped in place. After starting the test, the test pressure is automatically controlled. The test result is digitally displayed. It offers automatic drop detection with optional drop detector. The alarm value reduces the operator’s attendance time by as much as 90%. It also has an automatic program that completely eliminates the operator’s attendance time for ‘pass/fail tests.

The FX3750 Elmendorf Tearing Tester is used for determining the tear strength of, among others things, wovens and nonwovens, from fine to heavy-duty materials. It offers a wide range of up to 30kgf. The instrument computes the average tearing force of a cut specimen from the energy loss of falling pendulum. The instrument digitally display the average tearing force of a single test specimen in one out of seven switch selectable units of measure, rounded to the nearest 2 digits. Instead of a slave pointer, the instrument employs a digital optical encoder for measuring the pendulum movement. It features an automatic calibration function which compensates for the pendulum friction and any leveling error in the instrument. The instrument works in accordance with standards such as EN ISO 13937-1, and ASTM D5734, among others.

James H Heal has launched TruBurst2, a brand new fully pneumatic intelligent bursting strength tester which comfortably exceeds the exacting requirements of ISO 13938-2, ASTM D3786-06 and the test principles of many other national and international standards. Combining digital microprocessor control with laser technology, there are two models in the range. With a maximum capacity of 1000kPa/145psi, Model 810 is suitable for the majority of textiles specimens including cyclic testing of elastomeric. However, there are many less resistant, more delicate materials such as nonwovens which require a lower capacity / higher resolution machine for successful and repeatable bursting strength tests. With the ability to measure values as low as 5kPa/0.7psi and a maximum capacity 100kPa/14.5psi, Model 801 is ideal for these applications.

Conventional burst testers measures the total pressure required to distend the diaphragm and to burst the specimen. TruBurst2 has an additional facility to measure the total pressure required to distend the diaphragm only to the average burst distension of the specimens under test. This value is automatically subtracted from the individual burst pressure result to achieve the TruBurst Strength. TruBurst offer a choice of five test areas, ranging from 7.3cm2 to 100cm2. TruBurst2 also utilizes optical laser photoelectric technology to measure specimen distention up to 70mm with an accuracy of 0.5%. Noncontact measurement guarantees accurate, reproducible and trouble–free distention measurement, by products of non-contact measurements are faster testing times and a significant enhancement of diaphragm life. For electrometric materials, Measuring or assessing non-recoverable extension, after a series of cycles, may be of more interest than the actual pressure to burst or the distention at burst. The instrument’s data acquisition and analysis software enables the production of test reports, which can be copied to any other windows application for further customization. It comes with a library of preprogrammed national and international standard though users may also configure up to fifty of their own test procedures.