Investigation of the Laminating Characteristics of CFRP Plates with a Thin and Wide Configuration in Production for an Effective Inspection Process

Carbon fiber-reinforced plastic (CFRP) products have a relatively high number of thickness irregularities. Such irregularities can be a critical problem in the production process. It requires strict production management, including quality assurance, which results in an increase in production costs. Hence, understanding factors affecting the laminating characteristics is necessary to enhance the inspection efficiency. This study investigated the laminating characteristics of the CFRP plate, which has a wide configuration and is composed of various layers. Fabrication parameters and plate configuration were selected as factors affecting CFRP thickness. The Taguchi method was employed to analyze the effect of fabrication parameters, and the configuration effect was verified by comparing an asymmetric plate with an axisymmetric plate in terms of thickness per ply (TPP). The results showed that the TPP of the thick layers tended to be higher than those of the thin layers in both the plates and the TPP of the asymmetric plate was lower than that of the axisymmetric plate. Among various fabrication parameters, the humidity of the lay-up process and the 1st heat-up time were identified as significant factors in TPP variance. In addition, an improved inspection process based on the verified laminating characteristics is suggested and discussed. The efficiency of inspection according to the confidence level of the objective CFRP products can be improved by applying the proposed inspection process.