Polyester-glass fibre laminates

Glass fibres are the preferred form of reinforcement for polyester resins since they provide the strongest laminates. Fabrics from other fibres may, however, be used and can in some instances provide adequate reinforcement at lower cost. Glass fibres are available in a number of forms, of which the following are the most important  

Other types of glass structures used include rovings, yams, tapes, rovings fabrics and surfacing mats. 

A number of different binder materials are in use for chopped strand mat and include starch, polyvinyl acetate and polyesters. The binder used depends on the end use of the laminate and the method of fabrication. 

Methods of producing laminates have been dealt with in detail in other publications and so details will not be given here. 

The major process today is the hand lay-up technique in which resin is stippled and rolled into the glass mat (or cloth) by hand. Moulds are easy to fabricate and large structures my be made at little cost. 

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Flexural strength of the polyester/glass fibre laminate... 

Epoxide resins reinforced with carbon and Aramid fibres have been used in small boats, where it is claimed that products of equal stiffness and more useable space may be produced with a 40% saving in weight over traditional polyester/ glass fibre composites. Aramid fibre-reinforced epoxide resins have been developed in the United States to replace steel helmets for military purposes. Printed circuit board bases also provide a substantial outlet for epoxide resins. One recent survey indicates that over one-quarter of epoxide resin production in Western Europe is used for this application. The laminates also find some use in chermical engineering plant and in tooling. 

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. 

The highest mechanical strengths are usually obtained when the fibre is used in fine fabric form but for many purposes the fibres may be used in mat form, particularly glass fibre. The chemical properties of the laminates are largely determined by the nature of the polymer but capillary attraction along the fibre-resin interface can occur when some of these interfaces are exposed at a laminate surface. In such circumstances the resistance of both reinforcement and matrix must be considered when assessing the suitability of a laminate for use in chemical plant. Glass fibres are most commonly used for chemical plant, in conjunction with phenolic resins, and the latter with furane, epoxide and, sometimes, polyester resins. 

Glass fibre reinforced polyester melamine-formaldehyde laminate with copper foil attached is used for printing circuits. 

As the submarine was too fragile to move, the only practical conservation method was to wash the vessel in situ. A tank was constructed from glass fibre - reinforced polyester resin laminate. The structure was prefabricated in sections away from the museum and assembled on site with no disturbance to... 

The flexibilized and unreinforced resin was also tested at 20°C. Moisture absorption in the unreinforced resin and in the Navy GRP was consistent with Pick s law. The Navy GRP showed the least total takeup of water. The epoxy laminates deviated from ideal Fickian behaviour. At 20°C, both the glass and polyester fibre laminates reached a peak mass and then decreased, suggesting that some material was being leached out into the water. The mechanical properties were determined by dynamic mechanical thermal analysis (DMTA). All the laminates experienced a reduction in the effec-... 

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