Tailored Reinforcement for Liquid Composite Molding Processes

Manufacturing of Tailored Reinforcement for Liquid Composite Molding Processes 

Institute for Composite Materials Ltd., University of Kaiserslautern, Kaiserslautern, Germany 

Structural seams. The purpose of this seam type is to stitch the elements, which transmit the forces between various semi-finished goods or layers via tailored reinforcements e.g., ribs on support structures). These seams can also be used for positioning inserts or to enhance connections of inserts to the entire structure. Joining seams penetrate through the complete preform and are stitched by using threads made of carbon or glass fibers. 

Assembly seam. Seams of this type are especially important for tool loading and the injection process. The sub-preforms can be assembled by using suitable types of threads, which again assist the sewing operation. The preform assembly can either be two-dimensional or three-dimensional and the respective stitching parameters can be chosen to be different. 

The requirements to the seams and preform structures define the usage of various stitch types. In general, chain stitches and lock stitches are well known in the garment as well as in the composite industry. Also, one-sided stitches (OSS ), blind stitches, and tufting can be helpful in 3D preform assembling. The modified lock stitch is advantageous in most of the stitching operations. 

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