Glass fibre material

Fig. 37. Flow properties of blood on glass fibre material.

Glass Cloth—Conventionally-woven glass fibre material. 

Woven Roving (WR)—Glass fibre material made by the weaving of roving. 

People working plastic, toxic and glass fibre materials should wash their hands before eating, smoking or using the lavatory. Gloves should be well washed before they are removed. 

Assarar M, Scida D, El Mahi A, Poilane C, Ayad R (2011) Influence of water aging on mechanical properties and damage events of two reinforced composite materials flax fibres and glass fibres . Materials and Design, 32, 788-795. 

Multi-layer construction is also employed using different filter media, e.g. an inner layer of rather more open form for dust retention, an intermediate layer for fine filtration and an even closer outer layer to prevent fibre migration. Synthetic fabrics are proving to have some advantages over spun glass fibre materials although glass fibre media have proven to be very efficient. 

Figure 2. Coefficient of friction vs. velocity of spreading dX/dt after 2 s of spreading time) for POM, PA 6 and PA 6 + 25% glass fibre materials (from left to right respectively).

This includes inorganic materials such as mica, glass fibre and asbestos etc., impregnated or glued together with varnishes or compositions comprising ordinary organic substances for heat resistance such as oil-modified synthetic resins, bitumen, shellac and Bakelite. 

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. 

This comprises composite materials on mica, glass fibre and asbestos bases, impregnated or glued together with silicone resins or silicone elastomer. These materials must not contain any organic fibrous materials such as paper or cloth backing, which is covered under class B and even F insulation systems. 

This is also known as Bulk Moulding Compound (BMC). It is blended through a mix of unsaturated polyester resin, crosslinking monomer, catalyst, mineral fillers and short-length fibrous reinforcement materials such as chopped glass fibre, usually in lengths of 6-25 mm. They are all mixed in different proportions to obtain the required electromechanical properties. The mix is processed and cured for a specific time, under a prescribed pressure and temperature, to obtain the DMC. 

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. 

There are less exotic ways of increasing the strength of cement and concrete. One is to impregnate it with a polymer, which fills the pores and increases the fracture toughness a little. Another is by fibre reinforcement (Chapter 25). Steel-reinforced concrete is a sort of fibre-reinforced composite the reinforcement carries tensile loads and, if prestressed, keeps the concrete in compression. Cement can be reinforced with fine steel wire, or with glass fibres. But these refinements, though simple, greatly increase the cost and mean that they are only viable in special applications. Plain Portland cement is probably the world s cheapest and most successful material. 

A composite material for a car-repair kit consists of a random mixture of short glass fibres in a polyester matrix. Estimate the maximum toughness of the composite. You may assume that the volume fraction of glass is 30% the fibre diameter is 15 pm the fracture strength of the fibres is 1400 MPa and the shear strength of the matrix is 30 MPa. 

The above comments refer to comparisons between the two compositions at the same glass-fibre level. If, however, comparison is made between a nylon 66 composition with a glass content of x% and a nylon 6 compound with a glass content of (x + 5)%, then the differences in mechanical properties become very small. At the same time the nylon 6 material will have slightly easier processing characteristics and surface quality. 

As with the aliphatic polyamides, the heat deflection temperature (under 1.82 MPa load) of about 96°C is similar to the figure for the Tg. As a result there is little demand for unfilled polymer, and commercial polymers are normally filled. The inclusion of 30-50% glass fibre brings the heat deflection temperature under load into the range 217-231°C, which is very close to the crystalline melting point. This is in accord with the common observation that with many crystalline polymers the deflection temperature (1.82 MPa load) of unfilled material is close to the Tg and that of glass-filled material is close to the T. ... 

Several blends based on polysulphone materials have been marketed. Probably the most well known is Mindel, originally produced by Uniroyal, acquired by Union Carbide, but now marketed by Amoco. Whilst not exhibiting the heat resistance of the unblended homopolymer, Mindel materials, which are blends of polysulphone and ABS, are lower in cost, easier to process and have higher notched impact strengths. The Mindel A materials are unreinforced, the Mindel B grades contain glass fibre, and the Mindel M grades contain other mineral fillers. A related polysulphone/SAN blend has been marked as Ucardel. 

In the late 1970s several developments occurred causing renewed interest in poly(ethylene terephthalate) as a plastics material. These included the development of a new mouldable grade by ICI (Melinar) and the development of a blow moulding technique to produce biaxially oriented PET bottles. In addition there appeared a glass-fibre filled, ionomer nucleated, dibenzoate plasticised material by Du Pont (Rynite) (see Chapter 26). 

There are now commercially available a large range of laminated plastics materials. Resins used include the phenolics, the aminoplastics, polyesters, epoxies, silicones and the furane resins, whilst reinforcements may be of paper, cotton fibre, other organic fibres, asbestos, carbon fibre or glass fibre. Of these the phenolics were the first to achieve commercial significance and they are still of considerable importance. 

Industrial grade materials employ fillers such as asbestos, silica and glass fibre. These are incorporated by dry-blending methods similar to those used with woodflour-filled phenolic compositions. 

Miscellaneous uses include textile bobbins, guns for hot melt adhesives and bilge pump housings. These materials are normally found in reinforced form. In addition to glass fibres, other fillers such as glass beads, talc and mica are used in conjunction with coupling agents. 

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