Estudo de melhoria da qualidade de um componente de copolímero moldado por injeção

Abstract

This work aims to identify the source of dimensional variations in an injection-molded component, specifically a housing that accommodates an electronic sensor for a planting monitor. This component is essential to Terris Tecnologia's technological solutions for the agricultural sector. The case is manufactured from styrene-acrylonitrile copolymer (SAN), which is required to ensure transparency and mechanical strength for the sensor. During inspection of the case samples, a dimensional variation was observed in the thicknesses of the bottom and top walls, suggesting possible compensation of the injected material, which may be linked to the deflection of the insert that forms the part's internal cavity. To investigate the root cause of these inconsistencies, a Cause-and-Effect Diagram, also known as an Ishikawa Diagram, was initially used to structure the analysis and categorize possible causes. The investigation continued with the collection of experimental data, including dimensional inspection of samples from different production batches and analysis of variation patterns among the four mold cavities over time. Computer simulations were also performed using Autodesk Moldflow Adviser and ANSYS to analyze the mechanical stresses acting on the denture and the polymer's behavior during injection. Analysis of the problem and simulation results enabled tracing the source of the deformation, identifying critical regions of stress and deformation, and quantifying the deflection experienced by the insert. Based on these analyses, improvements were proposed for the mold design or the insert itself, to ensure the dimensional stability of the case and the reliability of the sensor. This study contributed to the optimization of the manufacturing process for injection-molded components, with applications focused on precision devices for precision agriculture.