More quality in textile finishing: reproducibility of processes in laboratory and production

Abstract

A trend to greater precision can be observed in production processes and technical testing procedures. Precision means that the process runs within narrow limits and that these limits are maintained with high probability. Even dyeing or printing processes in the laboratory or production plant are subject to greater or lesser fluctuations when the same processes are repeated. Quality Management according to the ISO 9000-9004 standard requires that, among other things, specifications, reproducibility levels and measurement uncertainties be defined or determined. Fundamental concepts of statistics are treated such as mean value, standard deviation, variation coefficient, confidence interval and measurement uncertainty and statistical process control (SPC). An attempt is made to reply to the question “How precisely can the colour strength of a dyestuff be determined?”. Narrower specifications can only be realistically fulfilled when the measurement uncertainty factor can be correspondingly reduced, which can often only be achieved by additional, cost-intensive measures. Value is attached to the simplest possible presentation. ©