Prepreg processing manufacturing processes

Thornel 300 carbon-fiber-reinforced Fiberite 934 epoxy laminates (ca. 60% fiber and 40% resin by volume) were fabricated from prepreg tapes manufactured by Fiberite Corporation. The details of this fabrication process have been disclosed elsewhere ni). Panels of suitable lamination sequence were prepared from prepreg types. These panels were cured in an autoclave held for 0.5 hour at 135 °C and 2.0 hour at 180 °C, under 6.8 atm of pressure. 

The cost limitations of prepreg processing have led to the development of alternative techniques in which dry fabric is infused with resin as part of the manufacturing... 

Many prepregs are manufactured by a process called solution impregnation. This process is depicted in Fig. 6.3. First, the fibre material is introduced to the manufacturing line. For UD prepregs, this usually happens in the form of several bobbins of individual endless rovings (yarns). A roving itself... 

Phenolic novolacs, 18 760-761 Phenolic resin adhesives, 18 783-784 Phenolic resin can coatings, 18 38 Phenolic resin composites, 18 792-794 Phenolic resin drying-oil varnishes, 18 783 Phenolic resin fibers, 18 797-798 mechanical properties of, 18 798 Phenolic resin foam, 18 795-796 Phenolic resin manufacturers, U.S., 18 774 Phenolic resin polymerization, 18 760-765 alkaline catalysts in, 18 762-765 neutral catalysts in, 18 761-762 strong-acid catalysts in, 18 760-761 Phenolic resin prepregs, 18 793 Phenolic resin production unit, 18 766 Phenolic resins, 10 409 18 754-755, 756-802 22 10 26 763 in abrasive materials, 18 786-787 in air and oil filters, 18 790 additional reactants in, 18 759 analytical methods for, 18 774-779 applications of, 18 781-798 batch processes for, 18 766 from biomass and biochemical processes, 18 769-770... 

Solution prepregging, 20 284-285 Solution processing, 14 80 Solution process, of ethylene-propylene polymer manufacture, 10 708-710 Solution properties of lignin, 15 13 of polyampholytes, 20 479 ofVDC copolymers, 25 703-706 Solution spectrophotometry, 9 232 Solution spinning... 

The chapter is divided into a section on development of process cycles or plans and a section on in-process control. The tools to be discussed include design of experiments, expert systems, models, neural networks, and a variety of combinations of these techniques. The processes to be discussed include injection molding, resin transfer molding, autoclave curing, and prepreg manufacturing. The relative cost and difficulty of developing tools for these applications will be discussed where data is available. 

The purpose of this study is to develop a simple model which retains some of the features of the above complex process to predict the lay-up thickness as a function of time during the squeeze-flow lamination of circular prepreg lay-ups. The prepreg of interest is of the type commonly adopted in the board manufacturing industry. It is composed of two outer resin layers and a fabric core constructed of interlaced yarns oriented in two directions perpendicular to each other (Figure 1). The fabric core is treated as a porous slab characterized by a constant Darcy permeability coefficient (see k in Darcy s law% i.e.. Equation 2 below) which can be estimated from fabric parameters such as the yarn diameter and the pitch distances. The lay-up thickness predictions provided by this model have been found to be in reasonable agreement with experiment for the lamination of up to five epo.xy prepreg layers. 

A model has been developed for the prediction of the lay-up consolidation process during the lamination of prepreg lay-ups for the manufacture of printed circuit boards. This model can be used advantageously in prepreg material screening and in the optimization of lamination schedules for high-performance structural composites. 

Vacuum bag and autoclave processing are the two main methods for the manufacture of final parts from prepregs. Consolidation involves the cutting and stacking of prepreg... 

Being a readily formulated material, prepreg minimizes the material s knowledge required by a component manufacturer. The cumbersome process of stocking various resins, hardeners, and reinforcements is avoided. 

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