Effects of sampling methods on detection of yarn quality

Quality control is essential to ensure product quality in the textile industry and the way of sampling can determine its effectiveness as the facts regarding the quality are derived from the inspection of the samples chosen. Such data can be used in the control charts to determine whether control is necessary at the desirable level and whether further industrial processes are required. If products or processes are not inspected carefully, these decisions cannot be made properly. Two case studies were carried out in order to investigate the effects of two sampling methods, namely, fixed sampling and random sampling, on the detection of yarn characteristics. According to the results of the yarn strength (tenacity) test, it was found that data obtained by random sampling were more revealing about the reality of a spinning process (whether it was in control or out of control) than fixed sampling. The findings also help detect the quality characteristics of different types of yarn, such as ring-spun yarn and open-end yarn.