Controle de processos no benefeciamento primário de uma indústria têxtil: estudo da interferência das concentrações de peróxido de hidrogênio e soda cáustica no processo de desengomagem oxidativa

Abstract

Process control within a textile industry is of paramount importance in the search for continuous improvement of its processes and products. Every year, companies certified by NBR ISO 9001 undergo audits that validate the consistency of the company's Quality Management System (SGQ) so that it can continue with its certification. However, when it comes to textile processing operations, especially primary processing, it becomes difficult to exercise control over parameters that do not have all the information on how they affect the process, thus generating high rates of non-conformities and, consequently, inconsistencies in the SGQ. Given this context, the present work aimed to develop an improvement proposal for the oxidative desizing process of the textile industry in Natal - RN, to reduce non-conformities in the concentration differentials of caustic soda and hydrogen peroxide in the bath of desizing. To this end, a study was carried out on the influence of these differentials on the physicochemical properties and on the whiteness of the fabrics obtained after this process, seeking to evaluate the adequacy of the current tolerance range of these differentials to the real needs of the process. For the analysis of each question raised, quality tools such as Pareto Diagrams and scatter plots were used, which made it possible to diagnose that the degree of whiteness of the bleached fabrics in the oxidative desizing does not correlate with the NaOH and H2O2 differentials of the machine bath, to conditions specified in the current process recipe. In short, with the application of the improvement suggestion, structured through a Kaizen Cycle and which proposes a change in the current tolerance interval, it becomes possible to reduce the number of non-conformities and reach rates above 90% of conforming analyzes for bath differences.