An Investigation on Skillful Techniques and Quantified Instructional Tool on Spray-up Fabrication Method

Spray up fabrication method has been used for forming composite structures since ancient times. On the other hand, spray up work itself relies on human skills, which means that the finish differs according to the operator carrying out the work. Hence highly specialized control technique and the tradition of skill are required to ensure the consistent stability of product quality. Generally, it needs more than 10 years of training and practice, as well as relentless efforts and an instinctive sense of molding to master the art of spray up; there are in fact very few people who can be called experts of the technique in Japan. For this reason, the tradition of molding techniques needs to be carried on as quickly as possible. In this study, the authors thus conducted a motion analysis experiment using spray up experts as subjects. The experiment, seemingly a new and only attempt in Japan, quantified techniques that are not visibly apparent and considered to be tacit knowledge. For this reason, motion analysis of the spray up method process was conducted to obtain objective data on an expert applier’s skills (the default value). It was also suggested that highly specialized control techniques, the appropriate training of non-experts, and technical tradition are possible.