Why use Composite Fibre?
A composite is a combination of two or more different materials which together make a unique and superior material. Perhaps the most significant benefit of composite materials is that they can be custom designed to achieve project specific material properties.
Structural fibres embedded in a polymer matrix make up Fibre Reinforced Plastics (FRP). Glass Reinforced Plastic (GRP) are the most common form of FRP however there are many other types of structural fibres used. Some common types of fibres used in FRP are shown in the table below. There are also several polymer resins that can be chosen to form a laminate, each having different advantages. Some common resins include:
Strength to Weight Ratio:
The following table provides a comparison between the mechanical properties of common fibre reinforcements and metals such as aluminium, titanium and steel. FRP laminates can be designed to achieve a similar strength to steel with 3-5 times less weight.
Sandwich construction using light weight cores can further reduce the weight of FRP structural components. FRP sandwich panels are used in the automotive, marine and aeronautical industries where weight savings are critical.
Resin can be chosen to meet a wide range of chemical resistance requirements meaning that FRP can be used in applications where only Stainless Steel could be used otherwise. Composite fibre does not require the regular maintenance that is needed to maintain metals such as Stainless and Galvanised Steel and has proven to perform extremely well in areas such as chemical storage, processing, salt water environments and fuel storage.
Form & Function
Fibre composites can be manufactured to almost any shape or size with the use of purpose built moulds. This largely eliminates the need for post machining and means a single FRP part can be used in lieu of complicated multiple part metal assemblies. This can reduce manufacturing times and costs significantly. In the case of fibre composite bridges, BAC’s modular design has reduced on site installation times down to less than one day. Click here for more details on BAC’s CNC, plug and mould capabilities.
Low Thermal Conductivity:
Composites are great insulators, and when manufactured as sandwich panels make an excellent choice for floors, roofs, doors, walls and containers.
Composites have the ability to maintain their shape under varying temperature and humidity. This is particularly important where a tight fit between components is important, such as in an aircraft that regularly endures the effect of varying altitudes.
Fibre composites are inherently non-conductive warranting their use in markets where electrical safety and insulation is of paramount importance. Conversely, where conductivity is required, additives can be mixed with the resin to give selective conductivity.
Non-magnetic and EMI Transparent:
Fibre composites are non-magnetic and electromagnetically transparent. This means that their use is ideal applications where sensitive electrical and computer equipment is needed, e.g. radar covers in aircraft and ships.
Fire retardant additives in resins and coatings allow fibre composites to be custom designed to specific fire resistance requirements.
The history of Fibre Composite Construction:
The ancient Pheonicians and Egyptians were two civilizations that made glass, and both of them made glass into fibres, or made fibreglass. Many other civilizations had access to glass fibres. Of these, most made a small amount of the glass fibre at a time, and the fibre that they did make was very coarse. They used this fibre for decoration, unaware of the potential that lay within it.
In 1870, a man named John Player developed a process of mass producing glass strands with a steam jet process to make what was called mineral wool. This material was used as an effective insulation.
In 1880 Herman Hammesfahr was awarded a patent for a type of fibreglass cloth. This fibreglass cloth had silk interwoven with it. It was both durable and flame retardent.
The first glass fibres of the type that we know today as fibreglass were made through an accident, as many advancements in science have been. Dale Kleist, a young researcher for Corning Glass had been attempting to weld two glass blocks together to form an airtight seal. Unexpectedly, a jet of compressed air hit a stream of the molten glass and created a shower of glass fibres, showing Dale an easy method to create fibreglass.
In 1935, Corning Glass joined with Owens-Illinois, another company that had been experimenting with fibreglass, to develop the product further. In 1936, they patented the product "Fibreglass", with only 1 's', and then in 1938 the two companies merged to become Owens-Corning, which is still in existence today.
In the late 1930's to early 1940's they researched the idea of spinning the fibres into a cloth like material. In 1941, experiments progressed with heat cleaning and treating Fibreglass cloth. The heat treatment gave the cloth more flexibility, and proved to be key in making Fibreglass fibres suitable for use as reinforcements in plastic laminates.
In 1936, Carlton Ellis of DuPont was awarded a patent for polyester resin. Polyester resin is something that can be combined with Fibreglass to produce a composite.
The Germans furthered the manufacturing process of polyester resin by refining its curing process. During World War II British intelligence agents stole secrets for the resin from the Germans and turned them over to American firms. American Cyanamid produced the direct forerunner of todays polyester resin in 1942.
As early as 1942, Owens-Corning was producing fibreglass and polyester airplane parts for the war effort. These were low pressure plastic laminates made from the patented Fibreglass cloth impregnated with the resin.
The earliest reference to a composite boat having been made was around 1937, made by Ray Greene. Ray had been working with Owens Corning on fibreglass composites. While he did make a composite sailboat, he did not attempt to capitalize upon the idea, because he was looking for just the right plastic for the resin of the composite. In 1942, he produced a daysailer made with a polyester resin/fibreglass composite.
And, today, almost every family in the developed world has some sort of fibreglass item. Perhaps it is a water faucet, or a shower stall, or a bathtub. Perhaps it is a car, or a boat. Or perhaps there is fibreglass insulation in the walls. The list of uses for fibreglass composites may go on nearly forever.