215
8
over the entire assembly. Applying the vacuum inside the bag
causes an atmospheric pressure that eliminates voids and
provides compaction to the laminate.
Vacuum bag processing produces laminates with a uniform
quality. The removal of entrapped air inside the laminate
reduces the void content. Structures fabricated with traditional
hand layup techniques may result in composites that are resin
rich, but vacuum bagging eliminates this problem. Additionally, complete fibre wet-out can be accomplished if the process
is done correctly. The final results of improved compaction and
core bonding are possible with vacuum bag processing.
5 Processability Parameters—The processability parameters are
similar to those explained in vacuum infiltration technology.
The difference in vacuum bag technology is that it supports
using a high-temperature resin as matrices. This processing
technology also supports the processability of thermoplastic
prepregs using pressure bag technology.
The disadvantage of autoclaving and vacuum moulding is
the use of excessive consumables that are quite costly and make
the product cost also very high. The long time for processing
also makes the production slow.
Prepeg layers
Mbuld treated with
release agent
Seal
Peel Ply
Release film
Air/resin bleed layer
Vacuum bag
To vacuum
pump
. Fig. 8.7 Vacuum bag process [13]
Tubular mould
Vacuum
Vacuum
Composite
Sealant putty
Pressure
Pressure bag
. Fig. 8.8 Pressure bag technology
8.1 · Closed Mould Processing Technologies
8
over the entire assembly. Applying the vacuum inside the bag
causes an atmospheric pressure that eliminates voids and
provides compaction to the laminate.
Vacuum bag processing produces laminates with a uniform
quality. The removal of entrapped air inside the laminate
reduces the void content. Structures fabricated with traditional
hand layup techniques may result in composites that are resin
rich, but vacuum bagging eliminates this problem. Additionally, complete fibre wet-out can be accomplished if the process
is done correctly. The final results of improved compaction and
core bonding are possible with vacuum bag processing.
5 Processability Parameters—The processability parameters are
similar to those explained in vacuum infiltration technology.
The difference in vacuum bag technology is that it supports
using a high-temperature resin as matrices. This processing
technology also supports the processability of thermoplastic
prepregs using pressure bag technology.
The disadvantage of autoclaving and vacuum moulding is
the use of excessive consumables that are quite costly and make
the product cost also very high. The long time for processing
also makes the production slow.
Prepeg layers
Mbuld treated with
release agent
Seal
Peel Ply
Release film
Air/resin bleed layer
Vacuum bag
To vacuum
pump
. Fig. 8.7 Vacuum bag process [13]
Tubular mould
Vacuum
Vacuum
Composite
Sealant putty
Pressure
Pressure bag
. Fig. 8.8 Pressure bag technology
8.1 · Closed Mould Processing Technologies