IN-MOLD COATING VIA TRANSFER FOIL FOR FIBER REINFORCED THERMOSETS IN AEROSPACE APPLICATION

摘要

In the aviation industry most of fiber reinforced plastics are coated with an extra process step after curing the matrix and removing release agent residuals from the part. In-mold coatings allow for the direct application to the mold, but also carry disadvantages regarding safety precautions, cleanliness requirements, and the tool occupancy time. A transfer foil with an integrated in-mold coating can reduce or even eliminate these disadvantages. To manufacture such a coated transfer foil with a uniform coating the adhesion between transfer foil and primer needs to be sufficient. The cured but still flexible in-mold coating is bonded to the fiber composite utilizing the properties of the reactive resin (e.g. epoxy resin). The transfer foil can be peeled off after curing. Research focuses on the following: Determination of tensile properties: The flexibility of the coated release film depends primarily on the type of primer and its thickness. Integrated coating during curing of the matrix: Deep drawing the coated release film on double-curved molds affords elongations of more than 10%. Adhesion of the coating: All cross-cut tests show excellent adhesion between the primer and the cured matrix without the need for activation of the primer.