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5
Staples/Short Fibres Staples/short fibres are available from most of
the materials, such as glass fibres, carbon fibres, Kevlar fibres, etc.
Particles Particles are regular-shaped, small-sized entities. They
form a large range of materials. They are of two types: reinforcing and
non- reinforcing. The most common particles are carbon black, silicon dioxide, talc, calcium carbonate, and titanium dioxide. Mostly
particles are used for mixing in the composites as the fillers.
Whiskers Whiskers are irregular-shaped, small-sized entities. They
have high mechanical properties and specifically have a high modulus. Whiskers have reinforcing properties, but their materials are limited. The most common whiskers used are silicon carbides, aluminium
oxide (alumina), and aluminium carbides.
Natural Fibres Natural fibres are gaining importance due to environmental concerns. ‘Green composites’ are fabricated using natural
fibres (such as hemp, sisal, jute, coir, flax, wood fibre, etc.) as the reinforcement either with conventional polymeric matrices (such as
epoxy resin, polyester resin, phenolic resin, etc.) or with biodegradable polymers (such as polylactic acid (PLA), polycaprolactone (PCL),
polyglycolic acid (PGA), etc.). Natural fibres have the following
advantages:
5 Low-to-moderate density
5 Good acoustic absorbance
5 Low cost
5 No irritation to the human body
Natural fibres have the following disadvantages:
5 Hydrophilic in nature.
5 Natural fibres of plant origin are susceptible to fire.
5 Low-impact strength.
5 Environmentally dependent qualities
Natural fibres have found many applications, such as door panels,
back and front panel of car seats, etc., in the automobile sector.
5.3 Thermosetting Composites
Thermosetting matrices are the workhorses in the composite industries. Most of the high-performance polymeric composite structures are made using thermosetting matrices. The applications of
thermosetting composites range from fuselages, airframes, nose
cones, re-entry surfaces, nozzles for aerospace structures, automobiles, railway coaches, wind turbine blades, chemical storage tanks,
armoured panels, and civil structures to air conditioning ducts, furniture, and sports goods. They are fast replacing conventional structural materials [12]. The most important features of thermosetting
matrices enabling their wide uses are the following:
5 Ease of processability
5 Good fibre wetting due to low viscosities
Chapter 5 · Processability of Thermosetting Composites
5
Staples/Short Fibres Staples/short fibres are available from most of
the materials, such as glass fibres, carbon fibres, Kevlar fibres, etc.
Particles Particles are regular-shaped, small-sized entities. They
form a large range of materials. They are of two types: reinforcing and
non- reinforcing. The most common particles are carbon black, silicon dioxide, talc, calcium carbonate, and titanium dioxide. Mostly
particles are used for mixing in the composites as the fillers.
Whiskers Whiskers are irregular-shaped, small-sized entities. They
have high mechanical properties and specifically have a high modulus. Whiskers have reinforcing properties, but their materials are limited. The most common whiskers used are silicon carbides, aluminium
oxide (alumina), and aluminium carbides.
Natural Fibres Natural fibres are gaining importance due to environmental concerns. ‘Green composites’ are fabricated using natural
fibres (such as hemp, sisal, jute, coir, flax, wood fibre, etc.) as the reinforcement either with conventional polymeric matrices (such as
epoxy resin, polyester resin, phenolic resin, etc.) or with biodegradable polymers (such as polylactic acid (PLA), polycaprolactone (PCL),
polyglycolic acid (PGA), etc.). Natural fibres have the following
advantages:
5 Low-to-moderate density
5 Good acoustic absorbance
5 Low cost
5 No irritation to the human body
Natural fibres have the following disadvantages:
5 Hydrophilic in nature.
5 Natural fibres of plant origin are susceptible to fire.
5 Low-impact strength.
5 Environmentally dependent qualities
Natural fibres have found many applications, such as door panels,
back and front panel of car seats, etc., in the automobile sector.
5.3 Thermosetting Composites
Thermosetting matrices are the workhorses in the composite industries. Most of the high-performance polymeric composite structures are made using thermosetting matrices. The applications of
thermosetting composites range from fuselages, airframes, nose
cones, re-entry surfaces, nozzles for aerospace structures, automobiles, railway coaches, wind turbine blades, chemical storage tanks,
armoured panels, and civil structures to air conditioning ducts, furniture, and sports goods. They are fast replacing conventional structural materials [12]. The most important features of thermosetting
matrices enabling their wide uses are the following:
5 Ease of processability
5 Good fibre wetting due to low viscosities
Chapter 5 · Processability of Thermosetting Composites