Factors Influencing Quality Control
The wrinkling or SA test method has several additional that are designed to aid in assuring consistency in evaluation of fabrics and, hence, in quality control. Suppose that you and your classmates are asked to use a set of AATCC standard SA replicas to evaluate the specimen of laundered fabric and to assign an SA rating to the fabric. Would everyone in the class assign the same rating? Even though the same set of standard fabric replicas is used by each evaluator, individual ratings will depend on several other factors. Students sitting in the front of the classroom may see more wrinkles than those farther away from the fabric and replicas. In addition to the distance from the specimen, ratings may be influenced by lighting, angle of the specimen and replicas, color of the background on which they are placed, as well as the size of the specimen. All standard test methods specify the various conditions in test methods is examined further in Chapter 2.Even in the simple case of evaluating the appearance of a laundered fabric specimen, the standard test method specifies the specimen size, viewing angle, distance, lighting, and background material, all in order to further assure consistency among evaluators, which is part of the precision of the test, a topic that is discussed in Chapter 3.