Glass fibre types

Table 6.4 displays examples of the mechanical and physical properties of the three most important glass fibre types. 

Crocidolite, tremolite, 11 vitrous fibre dusts, 5 insulation wools, granular SiC Intraperitoneal injection in Wistar rats. Tumours in the abdominal cavity 2 mesotheliomas were found in a total 395 rats treated with saline or granular SiC (250 and 1000 mg). Dose-dependently, 11 fibre dusts induced mesothehomas at rates up to 97 %. UICC-like crocidolite ranked at the top, the glass fibres type B-01 with its low biopersistance and type B-09 with a low diameter at the end of the carcinogenicity scale life tremohte, rock wool MMVF-21 took a front place. Roller et al. (1996) ... 

The glass-fibre-filled types can be obtained in two ways. 

The first commercial grades were introduced by Phillips Petroleum in 1968 under the trade name Ryton. These were of two types, a thermoplastic branched polymer of very high viscosity which was processed by PTFE-type processes and an initially linear polymer which could be processed by compression moulding, including laminating with glass fibre, and which was subsequently oxidatively cross-linked. 

Polyesters. The main application of this material is as a matrix for glass fibre reinforcement. This can take many forms and is probably most commonly known as a DIY type material used for the manufacture of small boats, chemical containers, tanks and repair kits for cars, etc. 

Tanks may be constructed of mild steel coated with rubber or plastics, lead, glass-fibre resin or stainless steel (316 or 317 type). Capacity is typically 100-1 5001 or 21 per amp passed. 

In pipelining, the trend is towards all-welded steel for long lines, and since the wall thickness is less than that of cast iron, protection is the more important. Many types of coating are used, from thick concrete to thin paint films, and each has its own particular suitability, but the majority of pipelines throughout the world today are coated with hot-applied coal tar or petroleum asphalt-base-filled pipeline enamels, into which reinforcing wraps, such as glass fibre are applied. 

Heterogeneous liquid membrane electrodes. This type, which has become of considerable practical importance, consists of a liquid ion-exchange layer or a complex-forming layer within a hydrophobic porous membrane of plastic (PTFE, PVC, etc.), sintered glass or filtering textile (glass-fibre, etc.). The construction of such an electrode is depicted in Fig. 2.12. 

For plastics, ISO 3451 Plastics — Determination of Ash describes various methods for determination of the ash content of different types of plastics including those containing glass fibres and/or flame-retardants. 

Conveyor systems are applied in a number of areas in the rubber industry. The types used can range from simple canvas belt conveyors used for haul-off from conventional extruders, to systems used for transport and cooling of profile products, both in and emerging from continuous vulcanisation units. The latter types have to be resistant to the temperatures used in such systems and are variously constructed from glass fibre-reinforced polytetrafluoroethylene or a silicone rubber covered belt. 

Table 63 Average composition and main property examples of the three main types of glass fibres used in polymer reinforcement...

Table 6.9 shows the enhancement ratios for aramid fibres versus glass fibres used in the same composite type. The enhancement ratios are the ratios of a property for an aramid fibre reinforced composite versus the same property for the glass fibre reinforced composite. 

In all cases, carbon fibres lead to the highest mechanical performances compared to glass and aramid fibres. Nevertheless, their impact behaviour and price restrict their consumption. Glass fibres yield the cheapest composites but performances are more limited. Table 6.10 compares the properties of the main fibre types and shows some examples of properties for a nylon matrix reinforced with short fibres of the three types. 

While organo-silane treatments are extensively used in both thermoset and elastomer applications, their use in thermoplastics has so far been somewhat restricted. This is because they do not react with the surface of calcium carbonate, one of the principal fillers used in this type of polymer and because of the lack of a suitable reactive functionality for most of the thermoplastic polymers. Today they are principally used in conjunction with glass fibres, calcined clays, aluminium and magnesium hydroxides, micas and wollastonite. The main thermo-... 

In the industrial field, modified silica assists the development of advanced materials. Modified silica powders are used as a filler in rubbers and in new-type gas sensors. Most industrial applications involve the use of strongly related materials such as glass fibres or thin Si02 layers. We wish to restrict ourselves to a discussion of the application of powdered silica and a short indication of related compounds. 

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