Prepregs structural applications

Epoxy resins, carbon fibre prepreg Structural components, boat hulls, chemical engineering plant, pressure vessels Aerospace applications, helicopter blades... 

A high flow, 177 C cure, modified epoxy with an equivalent temperature dry and 121 C wet, service capability. Meets all NASA s outgassing requirements and in addition to the use of 976 prepregs (tape, fabrics and rovings) for commercial and military aircraft structural applications, the material finds use for critical space structures such as the space shuttle arbiter payload bay doors. 

Flame retarded polyesters cured, as prepregs, at 135 - 163 C for vacuum-bag or low pressure press cure. Suitable for laminate or sandwich panel construction in aircraft and other secondary structural applications requiring good mechanical performance, low flammability and excellent electrical properties. 

Prepreg is the composite industry s term for continuous-fiber reinforcement preimpregnated with a polymer resin that is only partially cured. This material is delivered in tape form to the manufacturer, which then directly molds and fully cures the product without having to add any resin. It is probably the composite material form most widely used for structural applications. 

Composites used for many structural applications are commonly prepared using a layup operation (either hand or automated), in which prepreg tape plies are laid down on a tooled surface and are subsequently fully cured by the simultaneous application of heat and pressure. 

The function of the resin matrix material in filament-wound structures is to help distribute the load, maintain proper fiber position, control composite mechanical and chemical properties, and provide interlaminar shear strength. Either a thermosetting or a thermoplastic resin material may be selected. Thermosetting resins may be selected for application in a wetwinding process or as part of a prepreg resin system. 

Uniaxial compressive properties are important to the design engineer who can utilize the foams inherent high compressive strength in reinforcing other structural members. Sandwich construction is a typical example of such a use, as in submarine-hull construction. Syntactic-foam prepregs have been developed for this application (7). 

This process offers a method of producing more predictable laminated structures, for high performance applications. Prepreg tapes are mainly made of the higher performance materials, such as epoxy/carbon or PEEK/carbon. This system can also be used in filament winding. 

The application of polymer systems with an alternative curing mechanism gives the opportunity to shape concrete and the textile reinforcement in only one step. Furthermore a non-economic way of curing can be avoided and one separate process-step - the curing of the prepreg - can be canceled. ISF and ITA are developing a coated and flexible prepreg reinforcement structure for FRC. Thus, flat and poly-shaped structural FRC parts could be realized. 

Most carbon fibre reinforced plastics (CFRP) used and investigated to date are produced from preimpregnated continuous carbon fibre prepregs. Polymers reinforced with aligned short carbon fibres have certain advantages as materials for structural components, because they can easily be formed into complicated shapes with satisfactory mechanical properties. Woven fabrics produced from carbon fibres find increasing application in the aerospace and many other industries, because they are easy to handle, they have the ability to conform to complicated shapes and the in-plane properties are more isotropic than those of equivalent unidirectional materials. 

Boron/tungsten fiber applications include the use of filaments and of boron/tungsten fiber reinforced prepreg tape, aluminum matrix composites, and boron/graphite structures. The major applications for these structures are found in the aerospace market and about 25% in sporting goods markets [36]. SiC/carbon fiber reinforced products include aluminum, titanium, and ceramic matrix composites. Major applications for these structures are also found in the aerospace market, minor uses in the industrial market [37]. 

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