Composites application

We have also looked at the lap shear strength of selected EB-ciirable epoxy adhesives. Because the adhesives being developed were being used for both aluminum-to-aluminum and composite-to-composite applications the lap shear strengths for both adherends was measured. Aluminum adherends were T2024 phosphoric acid anodized according to ASTM 3933. The composite adherends... 

Stnjcturai Design Guide for Advanced Composite Applications, Vol. 1, Material Characterization, 2nd edition. Advanced Composites Division, Air Force Materials Laboratory, January 1971. 

The purpose of this subsection is to familiarize the reader with some of the basic characteristics and problems of composite laminate joints. The specific design of a joint is much too complex for an introductory textbook such as this. The published state-of-the-art of laminate joint design is summarized in the Structural Design Guide for Advanced Composite Applications [7-5] and Military Handbook 17A, Plastics for Aerospace Vehicles, Part 1, Reinforced Plastics [7-6]. Further developments can be found in the technical literature and revisions of the two preceding references. 

The Vinyloop process is based on the selective dissolution of PVC used in composites applications like cable insulation, flooring, tarpaulins, blisters, etc. After removal of insoluble parts like metals, rubber or other polymers, the PVC is reprecipitated with all additives by introduction of a non-solvent component whieh will form with the seleetive solvent an azeotropie mixture. By using typical conditions, the process is able to reeover a pure PVC eompound powder ready for use without any additional treatment like melt filtration or a new pelletisation (speeific characteristics of the powder are average diameter of 400 microns and bulk density above 600 kg/ eub.m). All the solvents used are eompletely reeyeled and reused. PVC compounds recovered in the Vinyloop process can be reused in a closed-loop recycling scheme... 

Details are given of the development of energy and material recycling processes for thermosetting polymer composites. Applications in the cement industry and in coal fired fluidised bed combustion plants are discussed. 3 refs. 

Table 2.9 Market shares for the nine main composite application...

Figure 2.8. Market shares of the nine major composite application sectors...

As the laser beam can be focused to a small diameter, the Raman technique can be used to analyze materials as small as one micron in diameter. This technique has been often used with high performance fibers for composite applications in recent years. This technique is proven to be a powerful tool to probe the deformation behavior of high molecular polymer fibers (e.g. aramid and polyphenylene benzobisthiazole (PBT) fibers) at the molecular level (Robinson et al., 1986 Day et al., 1987). This work stems from the principle established earlier by Tuinstra and Koenig (1970) that the peak frequencies of the Raman-active bands of certain fibers are sensitive to the level of applied stress or strain. The rate of frequency shift is found to be proportional to the fiber modulus, which is a direct reflection of the high degree of stress experienced by the longitudinally oriented polymer chains in the stiff fibers. 

Figure 5.107 Variation in toughness and shear strength for various surface treatments of continuous carbon fiber-reinforced composites. Reprinted, by permission, from T. L. Vigo and B. J. Kinzig, ed.. Composite Applications, p. 224. Copyright 1992 by VCH Publishing, Inc.

Economic Benefits. The traditional costs of a product include raw materials, processing, overhead, and so forth. Designers and engineers considering potential composite applications cannot compare material costs only. Polymer composites, except for inexpensive fillers and small amounts of additives, consist mostly of resin and reinforcement, whose materials costs are usually higher than traditional materials. 

Ziegler E, Ziegler H (1998) Elavourings production, composition, applications, regulations. Wiley-VCH, New York... 

As illustrated in Figure 10.2, many composite applications utilize a caul plate or pressure intensifier. Caul plates result in a greatly improved part surface finish compared with a bag surface, improved dimensional control, and improved radius quality. Caul plates are also used to reduce ply movement during processing of honeycomb reinforced parts. Caul plates may be semi-rigid or rigid in nature. Semi-rigid caul plates, which are the most common type, are typically constructed of thin metal, composite, or rubber materials so they are flexible in... 

Virtually any reinforcement-matrix combination feasible in any other composites application also may be used in pultrusion however, glass heavily dominates as reinforcement with 95 percent in the United States and 98 percent in Europe (see Table 11.1), whereas polyester resin dominates as matrix material with 79 percent in the United States and 66 percent in Europe [2]. 

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