Composites Prepreg

Trujillo, R. E., Engler, B. P. Chemical Characterization of Composite Prepreg Resins, Part 1, Sandia Laboratory Report, SAND 78-1504 (1978)... 

Morgan, R. J., Walkup, C. M., Hoheisel, T. H. Differential Scanning Calorimetry Studies of the Cure of Carbon Fiber-Epoxy Composite Prepregs, J. Appl. Polym. Sci., 30, 289 (1985)... 

In Table 15.3 are shown the chemical structures and Tg and of some representative thermoplastic polymers for use at high temperature (3,9). These matrices have high continuous service temperatures (120-200° C) even under wet environmental conditions. Advantages of thermoplastic over thermoset matrices are their shorter fabrication cycle (generally controlled environment storage is not required) and the possibility to be reprocessed and reconsolidated after manufacture. Poly(ether ether ketone) is a strong contender with epoxy resins for use as a matrix in composite prepregs with carbon fibers to be utilized in structural aircraft components. 

Hou (1986) presented a resin-flow model for long-fibre-reinforced-composite prepreg lamination processing. The model includes the following chemorheological model ... 

Thermid . [Nat l. Starch ft Chem.] Polyimides thermosetting resin for laminating, composite prepregs, molding, coatings, adhesives (strucu and etetronic). 

In a majority of cases, the thermoset/thermoset blends are actually formulated by the fabricator or the end user during the fabrication and processing of such materials as composite prepregs, printed circuit boards, laminates and adhesives. The formulations and compositions are often kept proprietary and are designed to meet their own individual requirements. 

Grunenfelder LK, Nutt SR. Void formation in composite prepregs — effect of dissolved moisture. Compos Sci Technol 2010 70 2304-9. 

Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of NOx Uses Accelerator for epoxy resins, adhesives, composites, prepregs herbicide weed and brush killer... 

Cape Composites Inc., San Diego CA, USA—produce composite prepreg products. Acquired by Zoltek in November 1999 and renamed SP Systems (USA). 

Commercial bismaleimide thermoset resins are based on aromatic bismaleimides such as 4,4 -bismaleimidodiphenylmethane (Compimid MDAB, Evraiik). Compimid MDAB, also known in literature as MDA-BMT is derived from the condensation reaction between 4,4 -methylene dianiline (MDA) and maleic anhydride, both relatively low-cost monomers. The MDA-BMI is often used as a eutectic mixture with other BMIs such as TDA-BMI, to reduce its melting point for improved impregnation and tackiness in the glass and carbon-fiber-based composite prepregs. 

Figure 7. Raman spectrvm from carbon fibres in PEEK before and after straining the composite prepreg to the level indicated.

Hubert, P. and Poursartip, A., A method for the direct measurement of the fibre bed compaction curve of composite prepregs . Composites Part A Applied Science and Manufacturing, 32, 2001, 179-187. 

Of course the high variable cost is also something to look at, which is by and large driven by the physics of the process. To heat up a large quantity of inert gas and transfer heat to a massive tool to cure a composite prepreg laminate, the smallest portion of the whole setup, is obviously time consuming and therefore quite inefficient. 

Gruenenfelder, L. K. and Nutt, S. R., Void formation in composite prepregs Effect of... 

Kaufmaim M, Zenkert D, Akermo M (2010), Cost/weight optimization of composite prepreg structures for best draping strategy . Composites A, 41, 464-A72... 

DISCO n An epoxy-based composite prepreg containing discontinuous but oriented fibers, nearly as strong as unidirectional composites of the same fiber content, and formable into complex shapes and over corners. 

When the textile fabric reinforcement is combined with the matrix to form the composite prepregs, a set of deformation modes are introduced, which may be referred to as top-level deformation modes since they involve the movements of the reinforcement (macro- and micro-level fabric deformation mechanisms) and the matrix. They are in fact the conformation modes of the composite prepreg sheet or group of sheets, as is usually the case, during the forming process. The hierarchy of the top-level deformation modes consist of transverse flow, resin percolation, interply shear and intraply shear, as summarized by Cogswell and revisited by Martin et... 

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