Impregnation of resins

Features Max. vise, reduction, min. loss of properties increases impregnation of resin systems, and level of filler loading Properties Gardner 1 max. color sp.gr. 0.92-0.94 dens. 7.7 Ih/gal vise. 1-2 cps EEW 145-155 Heloxy 68 [Resolution Pert. Prods.)... 

Stagnate for several minutes in the temperature zone of more than 200 °C. As a result, NF is degraded by heat and the strength of the fiber is reduced. Moreover, the impregnation of resin to the inside of the NF bundle of cotton yarn becomes difficult in the conventional system currendy used in the manufacture of GF, LFP, of CF. Therefore, the pellet for injection molding with the configuration of an LFP, using cotton yarn as the reinforcement fiber has not been manufactured. 

Laminates. Laminate manufacture involves the impregnation of a web with a Hquid phenoHc resin in a dip-coating operation. Solvent type, resin concentration, and viscosity determine the degree of fiber penetration. The treated web is dried in an oven and the resin cures, sometimes to the B-stage (semicured). Final resin content is between 30 and 70%. The dry sheet is cut and stacked, ready for lamination. In the curing step, multilayers of laminate are stacked or laid up in a press and cured at 150—175°C for several hours. The resins are generally low molecular weight resoles, which have been neutralized with the salt removed. Common carrier solvents for the varnish include acetone, alcohol, and toluene. Alkylated phenols such as cresols improve flexibiUty and moisture resistance in the fused products. 

Fig. 7. Schematic of a self-contained plasma processing unit designed to continuously plasma-treat and impregnate with resin, reinforcing fibers for enhanced composite strength. The unit can also be used to plasma-treat wires to be coated or treated for improved adhesion. Throughput speeds of over...

The most common supported tubes are those with membranes cast in place (Fig. 17). These porous tubes are made of resin-impregnated fiber glass, sintered polyolefins, and similar materials. Typical inside diameters are ca 25 mm. The tubes are most often shrouded to aid in permeate collection and reduce airborne contamination. 

This is a material produced from the impregnation of glass fibre-mat (fibreglass, which is in the form of dry sheet, is commonly known as chopped stranded mat (CSM)) or rovings, with a liquid and unsaturated polyester resin, which thickens chemically to a dry sheet form. The total mix is sandwiched between polyethylene films and then roller-pressed to impregnate and consolidate it. 

Until the 1970s the chemical used as the impregnating and dielectric medium for capacitor units was PCB (polychlorinated biphenyl) liquid. It was found to be toxic and unsafe for humans as well as contamination of the environment. For this reason, it is no longer used. The latest trend is to use a non-PCB, non-toxic, phenyl xylyl ethane (PXE-oil), which is a synthetic dielectric liquid of extremely low loss for insulation and impregnation of the capacitor elements or to use mixed polypropylene or allpolypropylene (PP) liquids as the dielectric. A non-oil dielectric, such as epoxy resin, is also used. 

Laminates produced by impregnation of glass and carbon fibre with polyimide resins followed by subsequent pressing have found important uses in the aircraft industry, particularly in connection with supersonic airliners. Such laminates can be used continuously at temperatures up to 250°C and intermittently to 400°C. 

Resins, usually in a partially condensed form, are used to provide a water-repellent treatment for brickwork and masonry. Methyl-phenylsilicone resins are used as coatings for eletrical equipment and in the impregnation of class H electrical equipment. Dimethylsilicone fluids are also used as water-repellent coatings for class A or class B insulation. 

Process whereby layers of resin-impregnated fabrics are built up one layer at a time onto the mold surface, forming the product. Little or no pressure is required for laminate curing. 

In another method, the liquid resin is sprayed onto wood chips. The condition for rapid and complete impregnation of the wood chips or sawdust in resins is to dilute the resins either in monomer [40] or in swelling agents [41]. Dilution of the resin with monomers of roughly 10% permits complete impregnation within a very short period. The mixed or impregnated product was subjected to press under pressure and temperature to produce a board with a natural appearance. Percent-... 

B.Gapud, M.Shoemake, E.Searcy, MF resins modified with dicyandiamide sorbitol for impregnation of substrates for post-formable decorative laminates, U.S Patent No.6,001,92 (1999). 

The dispersion of Pt(0) inside the functionalized resins was carried out by two main routes. The first is based on impregnation of the resin with a mesitylene solution of Pt nanoclusters (Solvated Pt Atoms) obtained via MVS. The second procedure, called Chemical Incorporation and Reduction (CIR), implies the immobilization of convenient molecular Pt precursors (i.e. [Pt(NH3)4]Cl2) in the pre-swollen resins, followed by chemical reduction of the metal center. Among the Pt catalysts obtained by the CIR procedure only Pt/CF3 exhibits a high conversion of the... 

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