220
8
juncture, the outlet port is closed first, then the injection port
is closed, and finally a high vacuum is applied to evacuate any
entrapped air. The mould under the vacuum then is placed
inside the oven for curing. After the curing is complete, the
finished composite is taken out of the mould.
High-quality parts having a good surface finish on both the
sides of the product along with extremely good control over
volume fractions of reinforcement and matrix are produced by
this method. For example, composite radomes for the aircrafts
are made using VARTM process. Also, the composite annulus
filler for Rolls-Royce jet engines is made from carbon fibrereinforced composites using the VARTM process. The VARTM
process provides good control over the mechanical properties
and surface finishes that are essential for aerodynamics, as
shown in . Fig. 8.12. VARTM has improved the production
rate annulus filler along with a reduction in part weight,
resulting in lower fuel consumption and low CO 2 emission.
Advantages of the VARTM process include lower emissions
than from open mould processes; high-quality finish; dimensional tolerances within ±100 μm; complex mould shapes; and
cabling, duct, pipe, and other fittings that can be incorporated
into the product design.
Disadvantages of the RTM process are that high production
volumes are not feasible.
5 Processability Parameters—The following are the processability
parameters of VARTM technology.
5 Type of matrix resin—High-temperature curing thermosetting resins are processable by VARTM technoogy.
Thermoplastic matrices are not processable by this technolOutlet port/ vacuum port
Reinforcement
Core
Cavity
Injection port/
resin injection
. Fig. 8.11 Schematic of VARTM process [16]
Chapter 8 · Processability in Closed Mould Processing of Polymeric Composites
8
juncture, the outlet port is closed first, then the injection port
is closed, and finally a high vacuum is applied to evacuate any
entrapped air. The mould under the vacuum then is placed
inside the oven for curing. After the curing is complete, the
finished composite is taken out of the mould.
High-quality parts having a good surface finish on both the
sides of the product along with extremely good control over
volume fractions of reinforcement and matrix are produced by
this method. For example, composite radomes for the aircrafts
are made using VARTM process. Also, the composite annulus
filler for Rolls-Royce jet engines is made from carbon fibrereinforced composites using the VARTM process. The VARTM
process provides good control over the mechanical properties
and surface finishes that are essential for aerodynamics, as
shown in . Fig. 8.12. VARTM has improved the production
rate annulus filler along with a reduction in part weight,
resulting in lower fuel consumption and low CO 2 emission.
Advantages of the VARTM process include lower emissions
than from open mould processes; high-quality finish; dimensional tolerances within ±100 μm; complex mould shapes; and
cabling, duct, pipe, and other fittings that can be incorporated
into the product design.
Disadvantages of the RTM process are that high production
volumes are not feasible.
5 Processability Parameters—The following are the processability
parameters of VARTM technology.
5 Type of matrix resin—High-temperature curing thermosetting resins are processable by VARTM technoogy.
Thermoplastic matrices are not processable by this technolOutlet port/ vacuum port
Reinforcement
Core
Cavity
Injection port/
resin injection
. Fig. 8.11 Schematic of VARTM process [16]
Chapter 8 · Processability in Closed Mould Processing of Polymeric Composites