171
6
5 Flow of a Matrix—Short fibres/whiskers/particle reinforcements increase the viscosity of the mixture of matrix and
reinforcement. The flow of a matrix is essential for the resin to
percolate throughout the reinforcement so that complete
wettability of the reinforcement by resin is achieved.
5 Production Rate—Injection moulding supports high production
rates. Other production methods are batch-forming processes;
therefore, the production rates are comparatively lower.
5 Cost of Production—The cost of production is directly linked
with the rate of production and cost of raw materials. The
selection of the right kind of reinforcement for a required
service and the service life of the composite is the key.
6.8 Methods to Improve Processability
in Thermoplastic Composites
The methods and mechanisms to improve the processability in
thermoplastic composites are adsorption and wetting, chemical
bonding, mechanical adhesion, interdiffusion, and electrostatic
attraction. These have been described in detail in 7 Chap. 5. Apart
from these methods and mechanisms to improve the processability,
crystallization of the matrix on the fibre is also carried out. Moderate
crystallization creates an inherently strong interphase region
because of the intimacy of the crystal growth pattern on the fibre
surface. This is shown schematically in . Fig. 6.5. Therefore, crystallization can either decrease or increase adhesion depending on
the relative effects of interdiffusion and crystalline intimacy.
. Fig. 6.4 Rear housing of Motorola made out of Kevlar reinforced PC/PET
composite [20]
6.8 · Methods to Improve Processability in Thermoplastic Composites
6
5 Flow of a Matrix—Short fibres/whiskers/particle reinforcements increase the viscosity of the mixture of matrix and
reinforcement. The flow of a matrix is essential for the resin to
percolate throughout the reinforcement so that complete
wettability of the reinforcement by resin is achieved.
5 Production Rate—Injection moulding supports high production
rates. Other production methods are batch-forming processes;
therefore, the production rates are comparatively lower.
5 Cost of Production—The cost of production is directly linked
with the rate of production and cost of raw materials. The
selection of the right kind of reinforcement for a required
service and the service life of the composite is the key.
6.8 Methods to Improve Processability
in Thermoplastic Composites
The methods and mechanisms to improve the processability in
thermoplastic composites are adsorption and wetting, chemical
bonding, mechanical adhesion, interdiffusion, and electrostatic
attraction. These have been described in detail in 7 Chap. 5. Apart
from these methods and mechanisms to improve the processability,
crystallization of the matrix on the fibre is also carried out. Moderate
crystallization creates an inherently strong interphase region
because of the intimacy of the crystal growth pattern on the fibre
surface. This is shown schematically in . Fig. 6.5. Therefore, crystallization can either decrease or increase adhesion depending on
the relative effects of interdiffusion and crystalline intimacy.
. Fig. 6.4 Rear housing of Motorola made out of Kevlar reinforced PC/PET
composite [20]
6.8 · Methods to Improve Processability in Thermoplastic Composites