Fibreglass fabrics

Fabric filters are widely used owing to their simplicity, reliability, efficiency and competitive capital cost. Their application is limited by both the humidity and the temperature of the gas streams. Condensation or collection of water droplets of the filter fabric wilt lead to blinding of the cloth. Normal fitter cloths can operate up to 180 °C and fibreglass fabric can operate up to 250 °C. Where the limitation of humidity or temperature is likely to be a problem, precautions must be taken (such as the use of gas to air heat exchangers, the addition of cooling air/water, or the use of auxiliary heaters), or an alternative collection system must be sought. 

In special cases that have some other requirements, fluoropolymer-coated or silicone-coated fibreglass fabrics are increasingly being used. These materials are preferred mainly for foils and coatings and topcoats of fabrics, due to their thermal and chemical stability as well as their good... 

Uncoated fibreglass fabrics are not, without special treatment, sufficiently resistant to UV radiation and the deposition of dirt. Efforts are being made to reduce these disadvantages with coatings of PTFE or silicone, which will be discussed in later sections. 

For areas with special application requirements, specifically modified polyester fabrics, as well as fabrics from aramid fibres, fluorine polymers and arylamides like Kevlar (ref. DuPont), have proved to be satisfactory. The membranes show different characteristics depending on the coatings used. Fluorine polymers such as PVDF (polyvinylidene fluoride) are used on PES fabrics (refs Mehler and Ferrari) a PTFE (polytetrafluoroethylene) coating is very suitable for fibreglass fabrics (ref Verseidag) and there is a newly developed composite membrane with THV (ret Dyneon), a polymeric blend of tetrafluoroethylene, hexafluoropropylene and vinylidenefluorine, used as a coating on PES fabrics, of which VALMEX vivax (ret Mehler) is one example. 

The US pavilion at Expo 1970 in Osaka, constructed by Birdair (Figs 8.5 and 8.6), was a 262 foot x 460 foot cable dome. Vinyl-coated fibreglass fabric was used to span between steel cables, which varied in thickness from IV2 to 214 inches (Fig. 8.7). The volume was supported by internal pressure. 

To identify ways to encourage designers to apply textiles, such as ETFE inflated foil cushions and PTFE-coated fibreglass fabric, to improve the energy efficiency of buildings in Australia. 

Attributes ETFE infiated cushions (tripie iayered) FIFE coated fibreglass fabric PTFE fabric Double glazed unit Comments... 

Opinions on PTFE-coated fibreglass fabric (typical single-skin). 

This effect may he achieved hy using fibreglass fabric bonded separately to each of the contacting faces of the members in the joint area, in directions of 45° or 90° with respect to the wood grain direction. For members with dowels or bolts loaded perpendicular to the grain, reinforcement can ensure full load carrying capacity even for very small end-distances. Local reinforcement for tension perpendicular to the grain of the timber can also be very effective for end-notched beams. 

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