Carbon fibres grades

Commercial grades of polymer may contain, in addition to glass fibre, fire retardants, impact modifiers and particulate reinforcing fillers. Carbon fibre may be used as an alternative to glass fibre. 

Methods of preparation of the laminates depend on the partieular grade of polyimide resin used but in one process the polyimide precursor is dissolved in acetone and this solution is used to impregnate the glass or carbon fibre and thus produce a pre-preg . The pre-preg is dried and then pre-cured at about 200°C for about 3 hours. This operation reduces the volatile content and also modifies the flow properties to make them more suitable for the subsequent... 

A large number of grades is available, one supplier alone offering about 40, including unreinforced, glass- and carbon-fibre reinforced, mineral filler reinforced, impact modified, elastomer modified, flame retardant and various combinations of the foregoing. 

Carbon-fibre-filled grades exhibit interesting tribological properties and useful antistatic behaviour. 

Table 1.8 indicates the service temperatures which can be used with a range of plastics. It may be seen that there are now commercial grades of uiweinforced plastics rated for continuous use at temperatures in excess of 200°C. When glass or carbon fibres are used the service temperatures can approach 300°C. 

Most significantly, the price per litre varies from about 1 to more than 100 according to the nature of the polymer itself, the formulation of the grades and the inclusion of high-cost reinforcements including carbon fibres and so on. 

For the global advanced composites market, the average cost of high-performance fibre reinforcements (carbon, aramid, high modulus polyethylene, boron, R/S/T-glass and some E-glass) is estimated from 5.5 to 6 per kg. This moderate price is due to the decrease in the carbon fibre price. Some grades could fall to less than 10/kg in the short or medium term. 

Framework of load compensator on plane wings injection moulding of carbon fibre reinforced PEEK replaces the aluminium alloy previously used. This part plays a critical role in plane safety and must resist the static and dynamic stresses and hydraulic fluids. The grade selected after many tests has a high fluidity allowing the manufacture of parts with dimensions of 200 mm by 400 mm. With 30% carbon fibre reinforcement, this PEEK grade ... 

Specific grades of carbon and steel fibres are especially marketed as additives for conductive plastics allowing resistivities of roughly 10 ohm.cm to be obtained. The other properties of the final material - colour, modulus, impact strength. .. are modified. Carbon fibres have a large reinforcing effect. 

Some self-lubricating grades of polycarbonate are marketed, containing specific additives and reinforced with glass or carbon fibres. The coefficients of friction are in a good range, from 0.1 up to 0.21. Wear resistance is not as good as for PA 66. 

Some self-lubricating grades of polyarylketones containing specific additives, and possibly reinforced with glass or carbon fibres, are marketed. The coefficients of friction are good, for example 0.1 at room temperature, and remain unchanged at high temperature 0.12 at... 

For three given grades of neat and glass or carbon fibre reinforced PEEK, Figure 4.107 displays examples of SN or Wohler s curves. 

Use a reinforced grade to reduce the wall thickness and consequently the material weight. In ascending order of performance but also of cost, the most-used reinforcements are natural fibres, glass fibres, aramid fibres, carbon fibres. Carbon fibres, if their development leads to a substantial lowering of their cost, could solve many cost problems. 

One of the first applications for the adhesive grade of PES is as a structural adhesive to upgrade the temperature performance of epoxy resins (17). Mixtures of PES with epoxy resin are used to stick the aluminium outer skin on to aluminium honeycomb and such structures are designed for a 10,000 hr lifetime at 300°F whioh is typical of idle performance requirements of some supersonic aircraft. This adhesive grade can also be used as a matrix for making carbon fibre composites which show hi ... 

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