Polyurethane/glass fibre

This includes inorganic materials such as glass fibre and mica impregnated or glued together with epoxy, polyesterimide, polyurethane or other resins having superior thermal stability. 

In the special case of pipelines operating at relatively high temperatures such as for the transmission of heavy fuel oil at up to 85°C, heat insulation and electrical insulation are provided by up to 50 mm of foam-expanded polyurethane. As a further insurance against penetration of water, and to prevent mechanical damage, outer coatings of polyethylene (5 mm), butyl laminate tape (0-8 mm) or coal-tar enamel reinforced with glass fibre (2-5 mm) have been used. 

The glass fibre, PPG 3540, is a polyurethane-sized glass fibre manufactured by PPG Industries, Inc. The surface treatment on the glass fibre promotes good adhesion between the fibre and the polymer. b Note montmorillonite is surface treated with octadecylammonium or dioctadecyldimethylammo-nium ions. 

Certain incinerator chimneys are in hybrid stainless steel with an inner lining in sandwich resin/glass fibres with a core in foamed polyurethane. 

Flexible plastics and rubbers can, as a matter of fact, only be treated with rubber-elastic lacquers, mainly on the basis of polyurethane, which, moreover, should be resistant to oxidation, oils, fuel and UV light. Besides, polyurethane lacquers are often used for several other plastics, such as PVC, polyamides, ABS and glass-fibre reinforced resins. 

The PFM films may also be backed with a glass fibre reinforced polyurethane foam. This technology is already being used in thermoplastic roof modules and gives rise to parts having low weight, high stiffness and excellent thermal insulation. 

Fillers. Fillers mentioned for epoxy systems (subsection 2.2.6.4) are used in polyurethanes too. Ground calcium carbonate (coated as well as uncoated) is commonly used. Barium sulphate, silica fumes, wood flour and milled glass fibres are also used. 

Polyurethane (PU) materials have been formed by RIM using a commercial isocyanate reacting with either various compatible or incompatible polyol blends, or with slurries containing polyol blends and glass fibres. 

Formulations for producing polyurethanes (PUs) by reaction injection moulding (RIM) usually contain mixtures of polyols and diols in order to achieve the desired properties in the moulded part. The present work forms part (1) of a systematic investigation into the effects of polyol blends and glass fibres on the physical properties of unfilled and filled PUs formed by RIM. In the case of unfilled PUs, by using a multi-component polyol mixture, it is possible to investigate the effects on properties of (a) polyol structure, molar mass and functionality, (b) the relative proportions of diol-based hard blocks and triol-based soft blocks and (c) polyol blend compatibility. The... 

A typical layered structure consists of two thin, glass-fibre-reinforced polymer skins bonded to a thick, lightweight honeycomb core (Fig. 4.5a). Such sandwich panels are used in railway carriages and aircraft there are similar structures inside many skins. Other examples are less obvious the space between the outer container and the toughened polystyrene liner of a refrigerator is filled with rigid polyurethane foam. 

Polyurethane foam is used with facings such as paper, glass fibre, plasterboard or glass fibre reinforced concrete. The facings and foam are layers connected in series, so the temperature drop across each layer is added for the steady-state heat flow. If layer i has thickness Lj and conductivity ki then the overall U-value of the product is given by... 

Plastics and rubbers occur most frequently as conveyor belts and straps as well as in cables and pipes. Ventilating conduits and chutes are made of glass-fibre-reinforced polyester. In addition, in-situ expanded rigid polyurethanes have recently been gaining ground as thermal insulating materials. 

A study of glass fibre reinforced soybean oil-based polyurethane indicates that the mechanical properties such as tensile strength (259 c 270 MPa), flexural strength (418 cf. 444 MPa), tensile modulus (17 ct 18.6 GPa) and flexural modulus (18 cf. 27 GPa) of the soybean-based composites, were comparable with those of composites based on petrochemical (Jeffol) polyurethane. Since this soybean oil-based polyurethane composite offers better thermal, oxidative and hydrolytic stability than those based on petrochemicals, vegetable oil-based polyurethane composites could offer a viable alternative to petrochemical-based composites. 

Continuous glass fibre (roving) is chopped in the chopper unit of the spray gun by the action of a rotating blade against a polyurethane roller. The resulting chopped strands are blown from the gun by the exhaust from the air motor which drives the chopper. Concurrently resin is sprayed from the gun and the streams of resin and chopped glass fibre meet approximately at the mould surface. 

Thermoset plastics are undamaged by the liquid adhesive, and these include Glass fibre polyester composite. Epoxies, Polyurethanes, and Bakelite materials based on phenolic resins. 

RRIM polyurethanes are an extension to Reaction Injection Moulding (RIM) which is a relatively recent, but now established, plastics processing technique. Simplified, RRIM is the inclusion of a reinforcement - short glass fibres - into one of the components used in the RIM process. However, the inclusion of glass reinforcement into one of the reactive components, usually the polyol, has meant that certain processing equipment modifications were necessary in order to handle the... 

Another novel pultruded panel has been developed by Mastercore System Ltd., Canada. This could be used in applications such as truck walls, roofs, floors and doors, boat decks, freight containers and sound barriers. The mastercore panel consists of an outer shell of a polyurethane-impregnated fibre carbon/glass fibre hybrid composites with an inner core of a structural foam (Jacob, 2006). 

Prolonged exposure to a number of the controlled substances (and, of course, other toxic materials) may occur in the laboratory, workshop or elsewhere. Styrene, glass fibre, isocyanates and chlorinated solvents are amongst the substances most frequently used in conservation workshops. Exposures to levels above the control limit can occur where there is insufficient containment. In the laboratory or workshop the use of local exhaust ventilation or a fume cupboard will reduce the risk, but outside the laboratory, however, the use of polyurethane foam, epoxies, styrene and fibreglass may lead to problems. 

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