- Email: [email protected]
Hands Off GRP III Coventry, UK, 25 October 1989
reported two techniques which have been employed to characterize the process. The first involved the use of heat transfer calculations and reaction kinetics data to simulate the temperature and cure distributions within the pultrusion die. The other approach utilizes an instrumented pultrusion machine to monitor the temperature. pull force and shear stresses in the process. A useful table of process faults that can affect pultrusion was shown but not included in the printed papers. The pultrusion of thermoplastic composites is limited by the heat transfer processes. The third paper was a joint presentation on the pultruded structural panels used on the A19 Tees viaduct, by Head and Churchman (Maunsell Structural Plastics). Five different pultrusions are assembled to produce 3 m x 11 m panels which are assembled to form a 16 000 rn’ floor suspended under the road bridge. The project used 24 km of the main pultruded section. The pultruded section approach was 30% cheaper than aluminium. Anticipated life is 30-40 years (in an industrial areaj, and hence an equivalent of BS5750 Part 2 was in place for the project. It is ironic that the two papers in the original programme which would have addressed the use of quality systems in the manufacture of mass production composites were both withdrawn: ‘Synchronised manufacture of composites knowledge study’- Oliver (EITB)/Strickland (PPITB), and ‘Quality by intelligence’ - Fletcher ( DevTech). With a few notable exceptlons, the composites industry in the United Kingdom has been lamentabij slow in the adoption of modern quality philosophies. Wednesday morning opened with Steptoe (Hoechst Celanese) describing a range of thermoplastic materials produced by pulling continuous fibres through the die (but not through the extruder) in an extrusion process. The material is subsequently chopped into pellets of lo-50 mm length for use in the injection moulding of high performance components. Boyce (PERA) reported the use of robots for the ‘fibre arranging’ process: peg winding or placement into a channel. Fibres are wetted at up to 160 m min- l by pultrusion with pulsed feed and vacuum zones in the die. A four-axis Cartesian robot receives bar-coded tools on a specialized feed system with a recognition capability for flexible manufacture. The system can produce steering wheel frame preforms for compression moulding or the glass/epoxy walkway frames described by Jongh at one-minute per component. Clegg (Sheffield City Polytechnic) reported investigations into the mechanical properties and forming behaviour of composite materials produced by the reconstitution of off-cuts derived from carbon fibre/ PEEK manufacturing processes. Remnants were cut to squares of varying sizes (6-25 mm) and consolidated in a compression mould with careful control of the fibre orientation. The properties of the recycled plaques are superior to material recycled by injection moulding because orientation and fibre length are more controlled. The final session was opened by Phillips (DuPont, USA) presenting a systems approach for the manufacture of economic complex automotive parts from thermoplastic composite materials. The system integrates materials selection, design and engineering, preforming and largescale parts manufacturing. A motor car door was used as a case study. Timms (Courtaulds Research) used case studies (jet engine cowling outlet, wind turbine spoiler flap lever, balance tube for a multiblade aircraft propellor) to illustrate the benefits to be gained by the
50
intelligent use of the injection moulding process for composite materials. The composites producer has the ability to cost effectively replace metal parts (even over relatively small numbers of parts) achieving weight reduction, parts consolidation and improved corrosion resistance. Shaw-Stewart (Pultrex) presented the final paper, on pullwinding. The process combines filament winding with pultrusion for the continuous production of pultrusions with improved hoop strength. In general pullwound tubes will be used as mechanical tubing rather than for fluid transport, because there is no resin-rich internal layer. Typical applications include tent-frames, high jump poles, golf umbrellas. shooting sticks, canoe paddles and stunt kites. The system is not limited to round tubes, although greater process control will be necessary for complex profiles. The symposium brought together fifteen rather disparate papers within a common theme. In the opening paper Kijster made a distinction between ‘reinforced plastics’ (essentially short fibre materials) and ‘advanced composites’ (continuous fibres). Only two-thirds of the papers addressed mass production with continuous fibre materials, the essential manufacturing technology for the acceptance of structural composites by the automotive industry. The papers on short fibre materials, particularly those by raw materials suppliers with ‘yet another material form’, were of limited relevance for the structural composites industry. It would perhaps have been more useful to hear what the textiles industry is capable of in terms of translating fibre properties into useful preforms. Hopefully if the Symposium is repeated in a few years it will be possible to provide a complete programme of continuous fibre composites manufacturing papers. John Summerscales Advanced Composites Manufacturing Centre Polytechnic South West, UK Some refereed papers-from this symposium will be published in a forthcoming Special Issue of Composites Manufacturing
Hands Off GRP III Coventry, UK, 25 October 1989
Organized by: The Plastics and Rubber Institute, UK Congratulations to the Chairman, Mr Gotch (BREL) and his organizing committee for producing a well structured and managed programme and for the speakers who provoked, stimulated and often amused the 90 or so delegates who attended Hands Off GRP III. The opening speaker, Mrs Tina Starr (Technolex), reminded the audience that the once largely hand-crafted GRP industry was beginning to consider and slowly adopt low investment equipment fabrication techniques. Like all innovation the outcome has two faces that of prosperity or bankruptcy and the decision making pathway to innovation is as always against a background of known fact and ignorance. As the day proceeded known fact replaced ignorance in quite a few minds.
Composites
Manufacturing
March
1990
Mr Evans (International Paint Ltd) followed reminding the industry that in the immediate future, change in manufacturing procedures would be accelerated by the requirements of Health and Safety. A convincing case was produced by Mr Riley (Fletcher International Speedboats Ltd.) for the spray deposition of sportsboat hulls. It was, however, clear from his presentation that this had been achieved by sound engineering, dedicated plant design, thorough training and good management. The next paper moved on to consider cold press moulding and Mr Kinley (Ex-Press Plastics Ltd) produced a concise guide to the pros and cons for the process. He indicated that the process had the ability to produce GRP products with through colour, automotive ‘A class’ surface and good structural performance. He predicted that low pressure press moulding would be a market leader before long. The ‘after coffee’ session was devoted to Resin Transfer Moulding (RTM). Mr Harper (Plastech Ltd.) demonstrated the important advances in RTM technology with examples that extended the illustrations in his written paper; whilst Mr Clarke (Polymer Engineering Ltd) outlined the evolutionary processes that were involved when his company decided to expand the business from hand lay-up to RTM. To conclude this session Mr Harris (Southampton Plastic Moulding Ltd) _ identified and discussed his experiences of the engineering required to set up and run an RTM shop from ‘square one’ to a reliable quality system for the production of components by RTM. Mr Lees (Permabond Adhesives Ltd) gave an interesting paper on Adhesive Bonding, and presented a convincing case that no composite component manufacturer should be without a sound knowledge of bonding. This was followed by two papers on tooling. Mr Brown (Ex-Press Plastics Ltd) outlined the initial approach to ‘which sort of tool material to choose’? and then presented a more detailed appraisal of metal moulds. Mr Brain (Ciba-Geigy) outlined the philosophy of design and gave practical details on the manufacture of soft tooling. There is obviously a need for more detailed study of mould design at the component design stage. The last two papers addressed the subject of the reinforcement. Mr Taylor (Carr Reinforcements) outlined the engineering considerations of textile fibre geometries and the possibilities of producing special purpose fabrics and shapes by the textile route. Finally Mr Thornburrow (Vetrotex (UK) Ltd) described the technical and economic advantages of using preforms in the manufacture of medium volume GRP components by RTM. Most of those who attended agreed with the chairmans summing up ‘that the day had been intense, interesting and exhausting, and that it was encouraging to see so many moulders attending. Approximately 50% of the delegates were from moulding companies. He also asked the question should there be another ‘Hands Off GRP’?’ The answer should be an unqualified ‘yes’ if the standard of the days format and presentations can be reproduced, ’ with the possible inclusion of some of the other ‘hands off’ techniques. David Short Advanced Composites Manufacturing Centre Polytechnic South West, UK
Composites Manufacturing March 1990
POI,l’TECHNIC
SOUTH
LL’EST
Plymouth * Exeter * Exmouth * Jvewton Abbot The Advanced Composites Xfanufacturing Centre at Polytechnic South \Vest (Plymouth) runs regular short courses and workshops on the design, manufacture and testing of libre-reinforced
plastics.
RESIS TRANSFER MOULDING 30th April - 3rd May 1990 This Short Course offers a systematic introduction to the theoty and practice of RT.\I. through presentation and discussion of the underlying scientific principles governing resin flow through fibres, and the detailed examination of case study material. As with most xC~IC courses, a significant proportion of the time is devoted to practical laborator): demonstrations. and much of the course material will be given by visiting speakers from industry. PULTRUSIOS ‘1st - 24th May 1990 Pultrusion is an automated process for the continuous manufacture of composite materials with constant cross-section profiles. This Short Course aims to make a detailed study of pultrusion and the associated processes, from basic principles through to the latest technological developments in hardware and software. It will be of interest to managers, engineers and technicians who are familiar with composites yet have little or no previous experience of pultrusion.
PRACTICAL COMPOSITE TOOLING 4th - 8th June 1990 This course provides a unique opportunity to gain practical expertise in the production of composite tooling for use in vacuum bag and autoclave processes. The course will be run under the supervision of Norman Brain (Tooltex) and will cover the complete manufacture of small formed tools using both prepeg and we lay-up systems.
RESIN TRASSFER MOULDING WORKSHOP 18th - 20th June 1990 Resin Transfer Youlding continuesto attract widespread attention asa process suitable for high duty compositecomponents as well as volume manufacture. This Workshop offers an informal atmosphere for an in-depth review and discussion of the technology. Industrial experts will lead sessions which will include raw materials, tooling design and construction, process control and automation.
For further details, please telephone Plymouth (0752) 232653
Department of Mcchantial Engineering, Polytechnic South West, Drake Circus, Plymouth, Devon PL.4 8AA
51
50
intelligent use of the injection moulding process for composite materials. The composites producer has the ability to cost effectively replace metal parts (even over relatively small numbers of parts) achieving weight reduction, parts consolidation and improved corrosion resistance. Shaw-Stewart (Pultrex) presented the final paper, on pullwinding. The process combines filament winding with pultrusion for the continuous production of pultrusions with improved hoop strength. In general pullwound tubes will be used as mechanical tubing rather than for fluid transport, because there is no resin-rich internal layer. Typical applications include tent-frames, high jump poles, golf umbrellas. shooting sticks, canoe paddles and stunt kites. The system is not limited to round tubes, although greater process control will be necessary for complex profiles. The symposium brought together fifteen rather disparate papers within a common theme. In the opening paper Kijster made a distinction between ‘reinforced plastics’ (essentially short fibre materials) and ‘advanced composites’ (continuous fibres). Only two-thirds of the papers addressed mass production with continuous fibre materials, the essential manufacturing technology for the acceptance of structural composites by the automotive industry. The papers on short fibre materials, particularly those by raw materials suppliers with ‘yet another material form’, were of limited relevance for the structural composites industry. It would perhaps have been more useful to hear what the textiles industry is capable of in terms of translating fibre properties into useful preforms. Hopefully if the Symposium is repeated in a few years it will be possible to provide a complete programme of continuous fibre composites manufacturing papers. John Summerscales Advanced Composites Manufacturing Centre Polytechnic South West, UK Some refereed papers-from this symposium will be published in a forthcoming Special Issue of Composites Manufacturing
Hands Off GRP III Coventry, UK, 25 October 1989
Organized by: The Plastics and Rubber Institute, UK Congratulations to the Chairman, Mr Gotch (BREL) and his organizing committee for producing a well structured and managed programme and for the speakers who provoked, stimulated and often amused the 90 or so delegates who attended Hands Off GRP III. The opening speaker, Mrs Tina Starr (Technolex), reminded the audience that the once largely hand-crafted GRP industry was beginning to consider and slowly adopt low investment equipment fabrication techniques. Like all innovation the outcome has two faces that of prosperity or bankruptcy and the decision making pathway to innovation is as always against a background of known fact and ignorance. As the day proceeded known fact replaced ignorance in quite a few minds.
Composites
Manufacturing
March
1990
Mr Evans (International Paint Ltd) followed reminding the industry that in the immediate future, change in manufacturing procedures would be accelerated by the requirements of Health and Safety. A convincing case was produced by Mr Riley (Fletcher International Speedboats Ltd.) for the spray deposition of sportsboat hulls. It was, however, clear from his presentation that this had been achieved by sound engineering, dedicated plant design, thorough training and good management. The next paper moved on to consider cold press moulding and Mr Kinley (Ex-Press Plastics Ltd) produced a concise guide to the pros and cons for the process. He indicated that the process had the ability to produce GRP products with through colour, automotive ‘A class’ surface and good structural performance. He predicted that low pressure press moulding would be a market leader before long. The ‘after coffee’ session was devoted to Resin Transfer Moulding (RTM). Mr Harper (Plastech Ltd.) demonstrated the important advances in RTM technology with examples that extended the illustrations in his written paper; whilst Mr Clarke (Polymer Engineering Ltd) outlined the evolutionary processes that were involved when his company decided to expand the business from hand lay-up to RTM. To conclude this session Mr Harris (Southampton Plastic Moulding Ltd) _ identified and discussed his experiences of the engineering required to set up and run an RTM shop from ‘square one’ to a reliable quality system for the production of components by RTM. Mr Lees (Permabond Adhesives Ltd) gave an interesting paper on Adhesive Bonding, and presented a convincing case that no composite component manufacturer should be without a sound knowledge of bonding. This was followed by two papers on tooling. Mr Brown (Ex-Press Plastics Ltd) outlined the initial approach to ‘which sort of tool material to choose’? and then presented a more detailed appraisal of metal moulds. Mr Brain (Ciba-Geigy) outlined the philosophy of design and gave practical details on the manufacture of soft tooling. There is obviously a need for more detailed study of mould design at the component design stage. The last two papers addressed the subject of the reinforcement. Mr Taylor (Carr Reinforcements) outlined the engineering considerations of textile fibre geometries and the possibilities of producing special purpose fabrics and shapes by the textile route. Finally Mr Thornburrow (Vetrotex (UK) Ltd) described the technical and economic advantages of using preforms in the manufacture of medium volume GRP components by RTM. Most of those who attended agreed with the chairmans summing up ‘that the day had been intense, interesting and exhausting, and that it was encouraging to see so many moulders attending. Approximately 50% of the delegates were from moulding companies. He also asked the question should there be another ‘Hands Off GRP’?’ The answer should be an unqualified ‘yes’ if the standard of the days format and presentations can be reproduced, ’ with the possible inclusion of some of the other ‘hands off’ techniques. David Short Advanced Composites Manufacturing Centre Polytechnic South West, UK
Composites Manufacturing March 1990
POI,l’TECHNIC
SOUTH
LL’EST
Plymouth * Exeter * Exmouth * Jvewton Abbot The Advanced Composites Xfanufacturing Centre at Polytechnic South \Vest (Plymouth) runs regular short courses and workshops on the design, manufacture and testing of libre-reinforced
plastics.
RESIS TRANSFER MOULDING 30th April - 3rd May 1990 This Short Course offers a systematic introduction to the theoty and practice of RT.\I. through presentation and discussion of the underlying scientific principles governing resin flow through fibres, and the detailed examination of case study material. As with most xC~IC courses, a significant proportion of the time is devoted to practical laborator): demonstrations. and much of the course material will be given by visiting speakers from industry. PULTRUSIOS ‘1st - 24th May 1990 Pultrusion is an automated process for the continuous manufacture of composite materials with constant cross-section profiles. This Short Course aims to make a detailed study of pultrusion and the associated processes, from basic principles through to the latest technological developments in hardware and software. It will be of interest to managers, engineers and technicians who are familiar with composites yet have little or no previous experience of pultrusion.
PRACTICAL COMPOSITE TOOLING 4th - 8th June 1990 This course provides a unique opportunity to gain practical expertise in the production of composite tooling for use in vacuum bag and autoclave processes. The course will be run under the supervision of Norman Brain (Tooltex) and will cover the complete manufacture of small formed tools using both prepeg and we lay-up systems.
RESIN TRASSFER MOULDING WORKSHOP 18th - 20th June 1990 Resin Transfer Youlding continuesto attract widespread attention asa process suitable for high duty compositecomponents as well as volume manufacture. This Workshop offers an informal atmosphere for an in-depth review and discussion of the technology. Industrial experts will lead sessions which will include raw materials, tooling design and construction, process control and automation.
For further details, please telephone Plymouth (0752) 232653
Department of Mcchantial Engineering, Polytechnic South West, Drake Circus, Plymouth, Devon PL.4 8AA
51