Test methods are developed for textiles and textile products by several different organizations. They are typically developed in response to a need expressed by an individual manufacturer, a product user, or occasionally by a consumer group. The example of the test for SA after laundering began as a widely perceived need to precisely define the degree of fabric wrinkling, at a time when there was a large research and development effort in the area of durable press (DP) finishes. A similar situation paralleled the more recent introduction of inflatable restraints, or automotive air bags, resulting in the current development of tests for this product. Another recent example is the urgent development of test methods for penetration of fabrics by blood-borne pathogens, largely a result of concern over transmission of the AIDS virus. Test methods for blood-borne pathogens are addressed.
As explained in the section on Research and development, the initial development of a test method sometimes occurs within an individual lab or company, and the method is later adopted – perhaps in a modified form – by the industry-wide organization as a standard test method. An example is the wrinkle recovery angel test, which was originally developed by the Monsanto Company, but later modified and adopted by AATCC.
Whether the idea for a test method begins within an industry-wide organization or within an individual company, once the idea is adopted by the industry-wide organization, test method development typically takes place through committees composed of individuals representing companies or organizations that either will eventually use the test method or who have an interest in the objectives of the test method. Committee members suggest approaches and laboratory trials are conducted within the various groups represented by the committee members. Basically, through a process of trial and error, combined with committee members’ expertise in understanding the properties to be evaluated by the test method, the proposed test procedure is refined and the written, proposed method revised until it is acceptable to the working group actively involved in its development.
During this process, committee members are concerned with the validity of the test method, and the practically of following the test method in everyday use. In this case, validity means whether the proposed method actually addresses the problem. For example, if the purpose of the proposed test method were to evaluate the effects of abrasion on upholstery, then the questions of validity would center around whether the abrasion machine employed in the test provides the same forces that the upholstery would be subjected to in actual use as people repeatedly sit on the upholstered furniture. The other concern that of the practically of conducting the test on a routine basis, involves considering the skill and training of the personnel who will perform the test, the cost of conducting the test, including the cost of time, equipment, supplies, and personnel, and the usefulness of the test results. These are difficult consideration and often compromises and trade-offs must be made between validity and practicality.
In most organizations that develop standard test methods, once the test procedure is clearly defined, the proposed method then undergoes inter-laboratory trials. Inter-laboratory testing can reveal problems with procedures that must be corrected, and they can also be used to determine whether the test method is applicable to a particular type of product; for example, does the method work only on woven fabrics, or can it also be sued for knits? The primary purpose of the inter-laboratory test is to determine the precision of the test. Precision indicates whether the test will repeatedly produce the same results on the same fabric specimen. Inter-laboratory test determine the reproducibility of the test from one lab to another and from one operator to another. A test which has a high level of precision has good inter-laboratory reproducibility and good between-operation reproducibility.
Following inter-laboratory testing and refinement of the method, the proposed test method is submitted to committee vote. When approved by the committee, the method must undergo balloting by other committees. For example, in AATCC, after a proposed test method on weathering is approved by the weathering research committee, it must be approved by the Editorial Committee, and then by the Technical Committee on Research, which is composed of the chairs from many different research committees. At each level of balloting, input from committee members is sought and is used to improve the test method. At each level, attempts are made to resolve negative votes through written correspondence and conferences.
Finally, once a test method is approved as a standard test method for the organization (such as AATCC or ASTM), the method must undergo periodic reconsideration and re-approval in order to be retained as a standard test method. This extensive development and review process is intended to assure that standard test methods meet the needs of users. Test method development and revision are ongoing processes. New test methods are introduced every year and older methods are dropped in response to the changing needs of the textile, apparel, and home furnishings industries and their consumers.
