Analysis and optimization of properties of paint materials for reduction of paint defects in agro products

Abstract

To satisfy the customer needs and to fulfil the competitive market requirement it becomes essential for manufacturing enterprises to reduce the rejection. The present work is focused on reduction of various painting defects like uncover, paint rundown, peel-off, orange peel by optimizing the properties of paint materials and different pre-treatment paint processes. These paint defects arises due to different reasons such as viscosity of the paint material, pH of paint material and paint material to thinner ratio. The pre-treatment of material before painting like Phosphating, Degreasing, Derusting and Passivation of the material also affect the quality of painted products. The properties of paint materials and pre-treatment processes are optimised using Lean Six Sigma (LSS) and Robust Taguchi Design (RTD). The define phase uses the tools like pareto charts, project charter and voice of business that shows the critical stage involves paint material properties and pre-treatment in the spray-painting process. In analysing phase, main factors that cause defects are spotted as viscosity, cleaning temperature, air pressure by using fishbone diagram. The improve phase focuses on refining the main factors responsible for rejection by using Robust Taguchi design methodology. In control phase, the procured results are implemented. This case study deals with selection of paint material properties in the organization manufacturing the agro products facing the rejection (about 12% monthly) problem dominantly due to paint defects. The data collected from the company is investigated deeply for analysing and observing the rejection causes. The implementation of adopted methodology disclosed a fall in rejection rate from 12% to 5% by optimizing the paint material properties. The implemented methodologies improve the sigma level from 2.8 to 4.1. The improved paint material properties and optimized process parameters result in better quality of agro products and good market share of agriculture equipment manufacturing organization.