GeneralTextile Test Methods
Textile products are among the most widely used materials in the world. There is hardly a daily function we perform that doesn’t involve some type of textile product. Each of these products has performance and serviceability requirements. For each requirement, a test method must be developed and maintained.
ASTM International’s Committee D13 on Textiles is responsible for developing and maintaining the test methods and standards associated with all types of textile products. These include the testing of raw fiber, yarns, and fabrics as well as performance standards for end-use products.
The variables for length, diameter, color, strength and elongation, as well as dyeability of natural and synthetic raw fiber, must be tested before it is processed into yarn or nonwoven fabric. Once processed, the yarns are tested for mechanical properties that may include linear density, the amount of twist inserted, strength and elongation, and friction properties. These are determined before the yarns are used in applications as varied as sewing thread, hand-knitting products, tea bag attachments, or fabrics.
The yarns are processed into woven or knitted fabrics that are then tested for end-use performance. These tests may assess the number of yarns per inch, thickness, weight, strength and elongation, tear resistance, breathability (air permeability), burst strength, stretch recovery, abrasion resistance and many other variables, depending on the end use and consumer requirements.
As you may have guessed, the test methods maintained by Committee D13 are very diverse and complex. Each end-use for a textile product brings with it a testing protocol for specific consumer requirements. This requires that current methods must be maintained and kept current, and that new methods are developed based on evolving technologies and requirements.
New Standards Under Development
Several subcommittees under D13’s jurisdiction have new standards under development.
The task groups of Subcommittees D13.58 on Yarn Test Methods and D13.59 on Fabric Test Methods General have been revising the test methods and definitions for stretch yarns and fabrics. These projects have attracted not only yarn and fabric manufacturers but participation from marketing, merchandising and fashion designers.
Subcommittees D13.59 and D13.60 on Fabric Test Methods Specific are actively involved with fabric test methods. As the technologies for stretch yarns and stretch fabrics have evolved, so have performance requirements. The original materials were elastic bands covered with fiber and woven into flat materials. The new generations of yarns are generic synthetic material produced with stretch and recovery characteristics. This allows the development of flat woven or knitted fabrics that have new applications in high performance fashion apparel and some end-use industrial fabrics.
There has been increased consumer interest in sheeting fabrics that have higher construction counts. The commonly accepted term for the number of yarns per inch is thread count. These fabrics are woven with derivatives from the original plain weave and allow for more yarns per inch in the construction. Some of these yarns are constructed from multiple single yarns twisted or plied together. Subcommittee D13.63 on Home Furnishings has added definitions and interpretations to the standards. This clarifies the terminology for thread count that is used by the industry and by consumers and will harmonize terminology used by the U.S. Federal Trade Commission.
Subcommittee D13.60 has been involved with the revision of the method for tearing strength. With the use of high strength filament yarns, combined with spun yarns into high performance safety applications and heavy duty technical fabrics, the existing terminology and understanding of tear strength or resistance to a tearing force needed to be modified. The methods for tear strength are undergoing changes in definitions, sample size and testing configuration. This type of method evolution is particularly applicable to high performance types of apparel and industrial fabric.
There is a large and active group within D13.94 on Government Interface that has been involved with the transition of federal test methods to consensus documents. The National Technology Transfer and Advancment Act of 1995 dictates that all federal agencies must use technical standards that are developed or adopted by voluntary consensus standards developing organizations. Groups such as Committee D13 have resources and expertise that cannot be matched by an agency of the government alone.
Proficiency Testing and Training
Subcommittee D13.93 on Statistics has developed a proficiency testing program for textile laboratories. With the introduction of laboratory quality systems came a requirement for the performance of interlaboratory proficiency testing. This program provides participating laboratories with a statistical quality assurance tool, enabling them to compare their performance against other laboratories. Currently there are seven fabric test methods that are performed biannually on three different materials and distributed to more than 100 laboratories worldwide. The test data is returned to ASTM and a statistical analysis is performed. The results are published in a report to the laboratories on a strictly confidential basis with no disclosure of lab identity except for one’s own laboratory. This is the only textile proficiency program offered in the world.
Committee D13 has also developed two professional training programs for textiles. One of the programs deals exclusively with training technologists in the understanding and use of flammability test methods. This is particularly important with domestic producers, consumers and government regulators; it is also very important to the import industry. The products must meet the flammability requirements of the government and American consumers.
The other program instructs technicians in the proper selection and use of general yarn and fabric test methods. While the original program was designed for specific methods, it has been tailored for presentation to specific producing groups with specialized requirements. Both of these training programs have been presented internationally and have trainers stationed in other countries.
Global Use of ASTM Standards
The textile products supplier base and market areas are truly global. Committee D13 test methods and practices are used extensively for international trade. With the United States being the largest consumer of textile products in the world, producers must test and report material characteristics that are acceptable and understood by American consumers. American textile producers have always used D13 methods to test and describe product performance and serviceability. In order to achieve and maintain product acceptability, international producers must do likewise.
Subcommittee D13.20 on Inflatable Restraints (automotive airbags) has taken the lead in translating test methods and practices into German and Spanish. With the global expansion of the airbag industry, there is a growing manufacturing base in Mexico and Europe that needs specific methods to test airbags. In 1990, D13.20 began to write specific test methods and aging practices that are germane to airbag performance. These methods are cited in automotive material specifications from many countries and describe the testing for specific performance requirements such as air permeability on deployment, seam strength, fabric stability during stress, the ability to hold inflation pressure, packability, and durability after stringent accelerated aging protocols. Several testing instruments were invented and manufactured to be used with these methods. There are no equivalent test methods described by other international standards development bodies specific to airbag fabric and cushion performance.
The production of natural fibers primarily cotton, flax, wool, mohair and cashmere require many tests to assess the quality of the fiber and its suitability for processing. These methods are developed and maintained by Subcommittees D13.11 on Cotton Fibers and D13.13 on Wool and Felt and are used extensively in international trade. These groups are working with other international bodies to utilize electronic instrumentation for classifying and grading natural fibers.
Subcommittee D13.62 on Care Labeling is very active with other international groups that determine and confirm the appropriate care label instructions. These care label instructions appear in many languages and all have the standardized symbols that describe practices to refurbish the products.
Committee D13’s membership roster reflects the number of members and company representatives from around the world who contribute to the development and maintenance of its methods and practices. In addition, subcommittee chairs receive numerous calls and e-mails from interested parties with specific questions, recommendations and clarifications from all parts of the world. By offering open membership, ASTM and Committee D13 encourage active participation by everyone.
ASTM Committee D13 is quite busy and proactive with the development and maintenance of the standards and methods under its jurisdiction. We encourage anyone with an interest in textile products to join and become active. //