The use of fiberglass started during the Second World War. Polyester resin was invented in 1935. Its potential was recognized, but finding a suitable reinforcing material proved elusive – even palm fronds were tried. Then, glass fibers which had been invented in the early 1930’s by Russel Games Slaytor and used for glass wool home insulation, were successfully combined with the resin to make a durable composite. Although it was not the first modern composite material (Bakelite - cloth reinforced phenolic resin was the first), glass reinforced plastic (‘GRP’) quickly grew into a worldwide industry.
By the early 1940s, fibreglass laminates were being produced. The first amateur use – the building of a small dinghy was in Ohio was in 1942.
Early wartime use of Glass Fiber
As a new technology, resin and glass production volumes were relatively low and as a composite, its engineering characteristics were not well understood. Nevertheless, its advantages over other materials, for specific uses, were apparent. Wartime metal supply difficulties focused on GRP as an alternative.
Initial applications were to protect radar equipment (Radomes), and as ducting, for example airplane engine nacelles. In 1945, the material was used for the aft fuselage skin of the US Vultee B-15 trainer. Its first use of fiberglass in main airframe construction was that of a Spitfire in England, though it never went into production.
Almost 2 million tons a year of the unsaturated polyester resin (‘UPR’) component are produced worldwide, and its widespread use is based on a number of features besides its relatively low cost:
- low technology fabrication
- high flexing tolerance
- moderate/high strength/weight ratio
- corrosion resistance
- impact resistance
Aviation and Aerospace
GRP is used extensively in aviation and aerospace though it is not widely used for primary airframe construction, as there are alternative materials which better suit the applications. Typical GRP applications are: engine cowlings, luggage racks, instrument enclosures, bulkheads, ducting, storage bins and antenna enclosures. It is also widely used in ground-handling equipment.
For those who love automobiles, the 1953 model Chevrolet Corvette was the first production car to have a fibreglass body. As a body material, GRP has never succeeded against metal for large production volumes. (yet...)
However, fiberglass has a big presence in the replacement body parts, custom and kit auto markets. Tooling costs are relatively low as compared with metal press assemblies, and ideally suit smaller markets.
Boats and Marine
Since that first dinghy in 1942, this is an area where fibreglass is supreme. Its properties are ideally suited to boat building. Although there were problems with water absorption, modern resins are more resilient, and the composites continues to dominate the marine industry. In fact, without GRP, boat ownership would never have reached the levels it has today, as other construction methods are simply too expensive for volume production and not amenable to automation.
GRP is widely used for circuit board manufacture (PCB's) – there is probably one within six feet of you now. TVs, radios, computers, cellphones – GRP holds our electronic world together.
Almost every home has GRP somewhere – whether in a bathtub or a shower tray. Other applications include furniture, and spa tubs.
How much GRP do you think there is in Disneyland? The cars on the rides, the towers, the castles – so much of it is based on fiberglass. Even your local fun park probably has water slides made from the composite. And then the health club – do you ever sit in a Jacuzzi? That’s probably GRP as well.
Because of its low porosity, non-staining and hard wearing finish, GRP is ideally suited to medical applications, from instrument enclosures to X-ray beds (where X-ray transparency is important).
Most people who tackle DIY projects have used fibreglass at one time or another. It is readily available in hardware stores, easy to use (with a few health precautions to be taken), and can provide a really practical and professional looking finish.
Building 100’ wind turbine blades is a major growth area for this versatile composite, and with wind energy a massive factor in the energy supply equation, its use is certain to continue to grow.
GRP is all around us, and its unique characteristics will ensure that it remains one of the most versatile and easy to use composites for many years to come.