fiberglass reinforced plastic
Glass fiber reinforced plastic , short GRP ( English GFRP - glass-fiber reinforced plastic ), a Fiber-reinforced plastic from a plastic and glass fibers . Both thermosetting plastics (e.g. polyester resin [UP] or epoxy resin ) and thermoplastics (e.g. polyamide ) can be used as the basis.
Continuous glass fibers were first produced industrially in the USA in 1935 as reinforcement fibers. Mass production was developed in the 1930s by Games Slayter (Owens Corning) and others - at that time the material was mainly used to insulate houses. The first aircraft made of GRP was the Fs 24 Phönix from Akaflieg Stuttgart from 1957.
GRP is also known colloquially as fiberglass . The word fiberglass is an Anglicism that was formed from fiberglass ( AE ) or fiberglass ( BE ), the English word for glass fiber. In the non-specialist world, they often only speak of fibers when they talk about GRP or carbon fiber reinforced plastic (CFRP). However, the fiber-reinforced plastics are always meant, because without the plastic matrix that gives shape and surface, the components would not be able to be manufactured.
Properties and areas of application
|Basic elasticity quantities|
|44,500 N / mm²|
|13,000 N / mm²|
|5,600 N / mm²|
|5 100 N / mm²|
|2.0 g / cm³|
|1,000 N / mm²|
|900 N / mm²|
|50 N / mm²|
|120 N / mm²|
|70 N / mm²|
|Coefficient of thermal expansion|
|7 · 10 −6 1 / K|
|27 · 10 −6 1 / K|
Glass fiber reinforced plastics are an inexpensive, yet very high-quality fiber-plastic composite . In mechanically highly stressed applications, glass fiber reinforced plastic is found exclusively as continuous fibers in fabrics or in UD tapes.
Compared with fiber-plastic composites made from other reinforcing fibers, the glass-fiber reinforced plastic combined with a suitable plastic matrix has high elongation at break, high elastic energy absorption, but a relatively low modulus of elasticity . Even in the direction of the fibers, it is below that of aluminum. It is therefore not suitable for components with high rigidity requirements, but is good for leaf springs and similar components.
Glass fiber reinforced plastic has excellent corrosion behavior even in an aggressive environment. This makes it a suitable material for tanks in plant construction or for boat hulls. Since these hulls are also non-magnetic , the material was used to build minesweepers as early as 1966 .
With a suitable matrix, glass fiber reinforced plastic has a good electrical insulation effect, which makes it a very useful material in electrical engineering. Especially insulators that have to transmit high mechanical loads are made of glass fiber reinforced plastic. Switch cabinets for outdoor use are often made of GRP due to the durability and stability of the material.
In 2015, around 1,069,000 tons of GRP were produced in Europe. The most important customer was the transport industry with 35% of the total, followed by the construction industry (including for rotor blades for wind turbines) and the electronics and sports equipment industry with 30%.
In 2014, the following quantities of glass fiber reinforced plastic were processed in Europe:
- Containers and pipes, mainly in the filament winding and centrifugal process: 145e6 kg
- GMT and LFT (see fiber matrix semi-finished products ): 121e6 kg
- Continuous processes such as B. Pultrusion : 132e6 kg
- RTM procedure: 132e6 kg
- Pressing SMC and BMC : 264e6 kg
- Open form processes such as B. Hand lamination or fiber spraying: 232e6 kg
- other procedures: 17e6 kg
A total of 1,043 kt of glass fiber reinforced plastic was processed in Europe in 2014.
Some typical types of glass fiber reinforced plastics are:
|EN 60893-3||NEMA LI 1-1998||Mil|
|Epoxy resin laminate||EP GC 202||FR-4||MIL-I-24768/27 (GEE-F)|
|Epoxy resin laminate||EP GC 204||FR-5||MIL-I-24768/28 (GEB-F)|
|Epoxy resin laminate||EP GC 201||G-10||MIL-I-24768/2 (GEE)|
|Epoxy resin laminate||EP GC 203||G-11||MIL-I-24768/3 (GEB)|
|Melamine resin laminate||MF GC 201||G-5||MIL-I-24768/8 (GMG)|
|Melamine resin laminate||MF GC 201||G-9||MIL-I-24768/1 (GME)|
|Phenol-formaldehyde resin - laminate||PF GC 301||G-3||MIL-I-24768/18 (GPG)|
|Polyester resin laminate||UP GM 201||GPO-1||MIL-I-24768/4 (GPO-N-1)|
|Polyester resin laminate||UP GM 202||GPO-2||MIL-I-24768/5 (GPO-N-2)|
|Polyester resin laminate||UP GM 203||GPO-3||MIL-I-24768/6 (GPO-N-3)|
|Polyester resin laminate||GPO-1P||MIL-I-24768/31 (GPO-N-1P)|
|Polyester resin laminate||GPO-2P||MIL-I-24768/32 (GPO-N-2P)|
|Polyester resin laminate||GPO-3P||MIL-I-24768/33 (GPO-N-3P)|
|PTFE laminate||MIL-I-24768/7 (GTE)|
|Silicone resin laminate||SI GC 201||G-7||MIL-I-24768/17 (GSG)|
Short and long fiber reinforced components
Short fiber reinforced components are mainly used as cladding or are manufactured because of their good malleability and great design freedom. Components reinforced with short fibers usually have a quasi-isotropic behavior because the short fibers are randomly distributed. A weakly pronounced orthotropy can arise during the injection molding of short-fiber reinforced thermoplastics. The fibers are oriented along the flow lines. The addition of short glass fibers to thermoplastics improves their stiffness, strength and especially their behavior at high temperatures. The creep of short fiber reinforced thermoplastics is less than that of the base material.
Continuous fiber reinforced components
Continuous fiber reinforced components are manufactured with defined material properties. They are used more and more frequently in lightweight construction .
- GRP made from fabrics or scrims
- GRP made from rovings or unidirectional fabrics / scrims (manufactured using the strand drawing process )
- Mixed forms from the types mentioned above
- Reinforcement in concrete construction
- Leaf springs
- Shower trays and bathtubs
- Vehicle parts (e.g. hoods, fenders)
- Sleeves and envelopes
- Small molded parts
- Climbing aids for greening facades with climbing plants
- Profiles and reinforcements
- Rotor blades for wind turbines and helicopters
- Hulls and wings of sailplanes or high-performance powered aircraft
- Hulls of boats and yachts
- Vehicle fairings in automobile racing
- Playground slides / slides
- Batons and violin bows
- Cladding and facades
- Limbs for crossbows
- Fishing components
- Bracket for overhead tram lines
- Hangar and industrial doors
- Printed circuit boards
- Cooling towers
- Protective cover for UHF transmitting antennas
- Tanks for the food and chemical industry
Manufacturing and processing problems
When using polyester resins, styrene vapors are released. These irritate the mucous membranes and the respiratory tract. Therefore the GefStoffV prescribes a maximum occupational exposure limit (AGW) of 86 mg / m³. In certain concentrations, an explosive mixture can even arise. During the further processing of GRP components (grinding, cutting, sawing) fine dusts and chips with glassy filaments as well as sticky dusts arise in considerable quantities. These affect human health and the functionality of machines and systems. The installation of effective extraction and filter systems is necessary so that occupational safety regulations can be complied with and economic efficiency can be guaranteed in the long term .
Disposal / recycling
GRP can be added to cement production as a substitute fuel, with the plastic component supplying energy and the glass component becoming part of the cement raw material. Neocomp GmbH has developed this process and is currently using it (as of September 2019).
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