Indian Journal of Fibre & Textile Research Vol. 33, September 2008, pp. 333-338 Robotic approach to textile preforming for composites P Potluri a , T Sharif & D Jetavat Textile Composites Group, School of Materials, Textiles and Paper, University of Manchester, Manchester M60 1QD, UK Technical textiles offer high-value engineering applications for the traditional textile sector which is generally viewed as a low-cost and high-volume commodity industry. This paper reviews the application of textiles in fibre-reinforced composites and identifies key challenges to the textile industry in order to serve this market. While traditional textile machinery may be adopted for producing 2D broadcloth reinforcements, novel machines/machine modifications are necessary for producing 3D textile preforms. In this paper, a robotic approach to 3D textile preforming has also been proposed. Keywords: 3D weaving, Automation, Fibre-reinforced composites, Robotics, Textile composites 1 Introduction Fibre-reinforced composites (FRC) are popular in a wind-range of applications including airframes, rocket casings, ballistic armour, racing cars, high-end passenger cars, wind turbines, racing & luxury yachts, bridge decking and sporting equipment as replacement for conventional engineering materials such as steel, aluminium and concrete. For example, Boeing 787 Dreamliner will have 50% by weight of composites. Composites offer the advantages of high specific stiffness and strength, improved fatigue life and freedom from corrosion; they typically consist of 30-55% by volume of fibres such as carbon, glass & kevlar and rest the matrix (typically an engineering polymer such as epoxy). Aerospace composites are traditionally manufactured using expensive prepreg systems (fibres pre-impregnated with resin); individual prepreg plies are cut to shape, stacked in preferred orientations and subsequently cured in autoclaves. This is an expensive and relatively slow production process. In recent years, dry fibre preforms in conjunction with liquid infusion techniques (vacuum infusion, resin transfer moulding) are becoming popular as a means of improving productivity and reducing process costs. Reinforcing fibres, in the form of yarn or roving, are arranged in the required shape of the component (preform) prior to infusion with a matrix material. Textile processes, such as weaving, braiding, stitching, knitting and embroidery, are employed in the manufacture of the fibre preforms, and the resulting preforms are generally referred to as ‘textile preforms’. The present paper reviews the application of textiles in fibre- reinforced composites and identifies challenges to textile industries. A robotic approach to 3D textile preforming has also been proposed. 1.1 Textile Preforms Weaving, braiding and stitch-bonding are three preferred methods for preforming as shown in Fig. 1. These structures exhibit relatively small fibre waviness. Weaving and stitch-bonding are commonly used for manufacturing broadcloth (referred to as 2D fabrics) while braiding is used for relatively narrow seamless tubes. Knitting is less frequently used as the resulting loops greatly reduce the strength and stiffness. 2D broadcloth is subsequently converted into a preform using a variety of manual or semi- automated processes. 1 Individual fabric panels are cut in the preferred orientations using an automated cutting table. Then these plies are stacked and simultaneously draped on a mould surface. Thermoplastic binders or stitching may be employed to hold the layers together so that the preform can be easily handled. Preforming is the most expensive and labour intensive step in the composites manufacturing process. Efforts have been made in the past to automate the preforming process. Buckingham and Newell 2 , and Zhang and Sarhadi 3 developed automated preforming processes. However, these systems are not widely used. Recently, 3D weaving has received a lot of attention as a means of reducing the preforming costs. 3D weaving process produces a multi-layer preform consisting of several warp and weft layers held together by ‘binding yarns.’ This ____________ a To whom all the correspondence should be addressed. E-mail: [email protected]
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Indian Journal of Fibre & Textile Research
Vol. 33, September 2008, pp. 333-338
Robotic approach to textile preforming for composites
P Potluri a, T Sharif & D Jetavat
Textile Composites Group, School of Materials, Textiles and Paper, University of Manchester, Manchester M60 1QD, UK
Technical textiles offer high-value engineering applications for the traditional textile sector which is generally viewed
as a low-cost and high-volume commodity industry. This paper reviews the application of textiles in fibre-reinforced
composites and identifies key challenges to the textile industry in order to serve this market. While traditional textile
machinery may be adopted for producing 2D broadcloth reinforcements, novel machines/machine modifications are
necessary for producing 3D textile preforms. In this paper, a robotic approach to 3D textile preforming has also been
proposed.
Keywords: 3D weaving, Automation, Fibre-reinforced composites, Robotics, Textile composites
1 Introduction Fibre-reinforced composites (FRC) are popular in a
wind-range of applications including airframes, rocket
casings, ballistic armour, racing cars, high-end
passenger cars, wind turbines, racing & luxury yachts,
bridge decking and sporting equipment as
replacement for conventional engineering materials
such as steel, aluminium and concrete. For example,
Boeing 787 Dreamliner will have 50% by weight of
composites. Composites offer the advantages of high
specific stiffness and strength, improved fatigue life
and freedom from corrosion; they typically consist of
30-55% by volume of fibres such as carbon, glass &
kevlar and rest the matrix (typically an engineering
polymer such as epoxy). Aerospace composites are
traditionally manufactured using expensive prepreg
systems (fibres pre-impregnated with resin);
individual prepreg plies are cut to shape, stacked in
preferred orientations and subsequently cured in
autoclaves. This is an expensive and relatively slow
production process. In recent years, dry fibre
preforms in conjunction with liquid infusion
techniques (vacuum infusion, resin transfer moulding)
are becoming popular as a means of improving
productivity and reducing process costs. Reinforcing
fibres, in the form of yarn or roving, are arranged in
the required shape of the component (preform) prior
to infusion with a matrix material. Textile processes,
such as weaving, braiding, stitching, knitting and
embroidery, are employed in the manufacture of the
fibre preforms, and the resulting preforms are
generally referred to as ‘textile preforms’. The present
paper reviews the application of textiles in fibre-
reinforced composites and identifies challenges to
textile industries. A robotic approach to 3D textile
preforming has also been proposed.
1.1 Textile Preforms
Weaving, braiding and stitch-bonding are three
preferred methods for preforming as shown in Fig. 1.
These structures exhibit relatively small fibre
waviness. Weaving and stitch-bonding are commonly
used for manufacturing broadcloth (referred to as 2D
fabrics) while braiding is used for relatively narrow
seamless tubes. Knitting is less frequently used as the
resulting loops greatly reduce the strength and
stiffness. 2D broadcloth is subsequently converted
into a preform using a variety of manual or semi-
automated processes.1 Individual fabric panels are cut
in the preferred orientations using an automated
cutting table. Then these plies are stacked and
simultaneously draped on a mould surface.
Thermoplastic binders or stitching may be employed
to hold the layers together so that the preform can be
easily handled. Preforming is the most expensive and
labour intensive step in the composites manufacturing
process. Efforts have been made in the past to
automate the preforming process. Buckingham and
Newell2, and Zhang and Sarhadi
3 developed
automated preforming processes. However, these
systems are not widely used. Recently, 3D weaving
has received a lot of attention as a means of reducing
the preforming costs. 3D weaving process produces a
multi-layer preform consisting of several warp and
weft layers held together by ‘binding yarns.’ This
____________ aTo whom all the correspondence should be addressed.