Resin infusion method

The VARTM is a hquid resin infusion process and is currentiy considered by the aircraft industry to be the favoured low cost manufacmring process for the future. It is an autoclave-free process that has been identified as reducing the cost of component processing. It is reported that dimensional tolerance and mass measurements are comparable with stitched RFI autoclave panels. A conventional blade stiffened test panel (3 X 2 ft with 4-in-high blades 0.5 in thick) has been manufactured recently at NASA by using the VARTM method, achieving a reasonable quahty. 

Williams CD, Grove SM, Summerscales J. The compression response of fibre-reinforced plastic plates during manufacture by the resin infusion under flexible tooling method. Composites Part A Applied Science and Manufacturing, 1998 29(1-2) 111-114. DOI http //dx.doi.org/10.1016/S1359-835X(97)00038-9. 

Gallez, X.E. Advani, S.G. Resin infusion process simulation (RIPS) A fast method for three dimensional geometries. Proceedings of the 55th Annual Technical Conference, ANTEC, Part 2 (of 3) April-May, Toronto, Canada, Society of Plastics Engineers Brookfield, CT, USA, 1997 2454—2458. 

Typicai processing methods resin transfer molding, resin infusion molding, filament winding, prepreg consolidation ... 

The presence of stable free radicals in the final polycondensate is supported by the observation that traces of (11) have a strong inhibiting effect on the thermal polymerization of a number of vinyl monomers. Radical polymerization was inhibited to a larger extent by a furfural resin than by typical polymerization inhibitors (34). Thermal degradative methods have been used to study the stmcture of furfural resinifted to an insoluble and infusible state, leading to proposed stmctural features (35). 

Commonly accepted practice restricts the term to plastics that serve engineering purposes and can be processed and reprocessed by injection and extmsion methods. This excludes the so-called specialty plastics, eg, fluorocarbon polymers and infusible film products such as Kapton and Updex polyimide film, and thermosets including phenoHcs, epoxies, urea—formaldehydes, and sdicones, some of which have been termed engineering plastics by other authors (4) (see Elastol rs, synthetic-fluorocarbon elastol rs Eluorine compounds, organic-tdtrafluoroethylenecopolyt rs with ethylene Phenolic resins Epoxy resins Amino resins and plastics). 

A procedure based on condensation with phenol and paraform (used as formaldehyde source) was developed to convert spent UNEX solvent (CCD, PEG-400, Ph2-CMPO, and FS-13) into a solid infusible resin for disposal. The resulting material is insoluble in aqueous alkali and acidic solutions and organic solvents. Incorporation of FS-13 in the cross-linked polymer was confirmed by physicochemical methods. Resistance of the cured resin to high temperatures was proven by thermogravimetry... 

ET-AAS with graphite furnace tubes constituted the analytical support for the speciation analysis of Al and the concomitant determination of Al (III) in tea infusions, as described by Alberti and coworkers [141], Lvov platforms incorporated into the graphite furnace atomizers enabled the authors to attain an LoD of 2 xg l-1 Al. The determination was not impaired by the relatively high solid contents. Adsorption of Al on ion Chelex-100 resin was employed to estimate the free metal content and the concentration and stability constants of complexed Al species. The metal is reported to be present in total concentrations from 0.09 to 0.26 mM, but mainly linked to strong complexes. Strong complexation is demonstrated by the inability of Chelex-100 to dissociate the complexes. These results are considered by the authors as an explanation of the low toxicity of the Al associated with tea infusions. The concentration of free Al was found to be very low (at the nM level). No structural or chemical information about the ligands was obtained from the method. 

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