206
8
The flexibility in composite processing provides possibilities for
particular types of composites using different processing technologies, depending on the product requirement. The processing of
composites and the process compatibility of composites are interlinked. Process compatibility is referred to in terms of economics of
production, rate of production, processing technology, selection of
raw materials, processing parameters, and post-fabrication processes. As a matter of fact, all of these parameters govern the processability of composites discussed in 7 Chap. 4. The success of
composite product design and production lies in the process
adopted for its realization.
The processes in closed moulding are matched die moulding,
compression moulding, injection moulding, pultrusion, resin
transfer moulding (RTM), vacuum bag moulding, vacuum infusion
processing, and autoclave moulding. In closed moulding, the composite is processed in either a two-part mould set or within a vacuum bag [1, 2]. A wide range of different processes have been
developed for the moulding of composites parts, ranging from very
simple manual processes (such as hand layup) to very sophisticated
and highly industrialized processes (such as VARTM and autoclaving). Each process has its own benefits and limitations that make it
applicable to particular applications. The choice of process is important in order to achieve the required technical performance at a
reasonable cost. There are a variety of closed mould processing
methods as described next.
8.1 Closed Mould Processing Technologies
Closed moulding methods are those in which all or part of the
product is processed in a closed vessel or chamber. Liquid resin
mixtures or prepregs are used for processing. In the case of liquid
resin mixtures, they may be pumped into the mould for curing. In
closed moulding, the composite part is manufactured in a closed
mould, or it passes through a die to form the product. The heat and
pressure then may be supplied in the closed moulding process.
Some of the closed moulding processes are described here.
8.1.1 Matched Die Moulding
5 Processing Technology—This moulding process is similar to
contact layup except it uses a matched die mould that has a
matching core and cavity, as shown in . Fig. 8.1. In a matched
die moulding process, there is a possibility of the use of a
variety of resins (such as thermosets and thermoplastics) and
reinforcements. The matched die mould ensures a good surface
finish on both sides of the product due to intimate contact of
the product on the core as well as the cavity of the mould. The
matched die mould has the capabilty of heating and cooling
the mould. Also, there is no limitation of the layup time in
cases of high-temperature curing systems.
Chapter 8 · Processability in Closed Mould Processing of Polymeric Composites
8
The flexibility in composite processing provides possibilities for
particular types of composites using different processing technologies, depending on the product requirement. The processing of
composites and the process compatibility of composites are interlinked. Process compatibility is referred to in terms of economics of
production, rate of production, processing technology, selection of
raw materials, processing parameters, and post-fabrication processes. As a matter of fact, all of these parameters govern the processability of composites discussed in 7 Chap. 4. The success of
composite product design and production lies in the process
adopted for its realization.
The processes in closed moulding are matched die moulding,
compression moulding, injection moulding, pultrusion, resin
transfer moulding (RTM), vacuum bag moulding, vacuum infusion
processing, and autoclave moulding. In closed moulding, the composite is processed in either a two-part mould set or within a vacuum bag [1, 2]. A wide range of different processes have been
developed for the moulding of composites parts, ranging from very
simple manual processes (such as hand layup) to very sophisticated
and highly industrialized processes (such as VARTM and autoclaving). Each process has its own benefits and limitations that make it
applicable to particular applications. The choice of process is important in order to achieve the required technical performance at a
reasonable cost. There are a variety of closed mould processing
methods as described next.
8.1 Closed Mould Processing Technologies
Closed moulding methods are those in which all or part of the
product is processed in a closed vessel or chamber. Liquid resin
mixtures or prepregs are used for processing. In the case of liquid
resin mixtures, they may be pumped into the mould for curing. In
closed moulding, the composite part is manufactured in a closed
mould, or it passes through a die to form the product. The heat and
pressure then may be supplied in the closed moulding process.
Some of the closed moulding processes are described here.
8.1.1 Matched Die Moulding
5 Processing Technology—This moulding process is similar to
contact layup except it uses a matched die mould that has a
matching core and cavity, as shown in . Fig. 8.1. In a matched
die moulding process, there is a possibility of the use of a
variety of resins (such as thermosets and thermoplastics) and
reinforcements. The matched die mould ensures a good surface
finish on both sides of the product due to intimate contact of
the product on the core as well as the cavity of the mould. The
matched die mould has the capabilty of heating and cooling
the mould. Also, there is no limitation of the layup time in
cases of high-temperature curing systems.
Chapter 8 · Processability in Closed Mould Processing of Polymeric Composites