Preforms, processing

CaulTman. S., Brown, R.. and Bartos, A. (1994), Video monitoring of a large-scale commercial three-dimensional braider for advanced composite preform process control, Proc. of the Conf. on NDE Applied to Process Control of Composite Fabrication, Oct. 1994, pp. 127 142. 

Figure 5.6 Schematic of the direct preform process spraying two molds...

Two of the four known silica giass fiber processes are dry spinning processes. They are continuous processes, which afford either a continuous sliver or staple product, i.e., a cohesive array of discontinuous fibers, or a continuous multifilament yam, respectively. The other two processes are continuous processes yielding continuous fibers and multifilament yarns. Of these, the preform process (Chapters 4 and 6) relies on the use of silica preforms, and produces continuous, ultrapure siiica giass fibers, or quartz fibers. This process yields the strongest silica giass fibers on record. 

Najjar, W., et al., 2013. Analysis of the blank holder force effect on the preforming process using a simple discrete approach. Key Eng. Mater. 554—557,441-446. 

New glass fibre-reinforcement products for u.se in fibre-directed preform processes are another focus of development, designed specifically for liquid composite moulding applications such as resin transfer moulding with thermoset polyesters. 

Reinforcement material is provided to the process in form of one or more stacked, continuous plane textile structures. Thus, the profile s geometry must be representable with this material by shaping. Alternatively, special preforms can be used so that the geometry is limited by the performance of the preforming process. 

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