Dynamic Textile Process and Quality Control Systems

Abstract

The paper attempts to develop a “Dynamic Process and Quality Control System (DTPQCS)” for staple spinning process that are serially connected with time lags. This new system provides process averages and control limits that are relative to the conditions of the prior processes via structural relationships that connect the factors in a given process stage to that of the next stage. By obtaining more accurate control limits, the root causes of the out of control situations will be determined precisely, and unnecessary corrective actions (false positives) that are detrimental to quality monitoring and improvement will be minimized. The major research task was to research and identify all published papers and sort out clearly defined input and output parameters that are essential for controlling process performance and product qualities. The challenge is to align and consolidate the equations to a single set at each stage in such a way that a dynamic system can be developed by combining all process steps in sequence, linking all input and outputs parameters. An approach under development attempts to consolidate the multiple structural equations obtained by different researchers into one manageable equation. In the jth process, the output Yj is expressed as a function of Yj-1 of the previous process and ‘m’ new input factors zj (zj1, zj2, …, zjm); 1 ( , ), 1, 2,3,..., j j j j Y f Y z j k − = = In any given two contiguous processes, the input (z) and output (Y) relationships are more than one in most cases. With ‘P’ structural equations with certain number of factors, each structural equation may be rewritten as a polynomial function for finite solutions or an iterative solution. Progress to this point is included here.