Date of Award

8-2010

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

Advisor

Robert F. Lindyberg

Second Committee Member

Habib J. Dagher

Third Committee Member

Roberto A. Lopez-Anido

Abstract

With resin infusion increasing as a method of large composite part fabrication there is a need for an industry standard in regards to quality assurance and quality control (QA/QC) methods. In terms of part quality and consistency, resin infusion as a process bridges the gap between open molding and the autoclave/pre-preg process. The chief goal of quality control methods is to reduce incoming material variability and production variability. The primary aim of this research was to aid composite manufacturers by uncovering the major quality issues in resin infusion and identifying appropriate QA/QC practices to address these issues. To realize this aim, an investigation of the resin infusion literature was conducted to discover what key process parameters contributed most heavily to the quality of resin infused parts. Furthermore, QA/QC methods were investigated which would be suitable for controlling the most important process parameters. This was accomplished by defining the composite manufacturing QA/QC best practices contained in standards, incorporating the resin infusion specific aspects contained in the technical literature, and investigating the actual level of implementation in the manufacturing environment. Seven composite manufacturers from Maine were selected to participate in the industry investigation for the purpose of determining the actual level of benchmark QA/QC practice implementation. Manufacturers were selected to provide variety across several demographic categories (annual sales, company size, top management type, infusion operating period, product type, and level of customer quality requirements) in order to correlate these characteristics with the level of conformance to industry best practices. The industry investigation consisted of site visits during which manufacturers’ QA/QC practices were observed and ranked on a Likert scale for conformance to the industry best practices. One company was selected for further investigation because they expressed interest in aligning their QA/QC more with the industry best practices. A statistical analysis was conducted to measure the level of significance of the correlation coefficients between demographic parameters and the ratings of best practice conformance. Conformance to the industry best practices was found to vary significantly among the manufacturers, however all manufacturers had demonstrated evidence of producing quality products. Findings suggest that manufacturers with high levels of customer quality requirements conform more closely to the QA/QC best practices than manufacturers with lower levels of customer quality requirements. A cause and effect relationship between the ratings and customer quality requirements was observed in a case evaluation in which one manufacturer implemented a quality management system as a result of increased customer quality requirements.

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