The drive to manufacture large, homogeneous products that exhibit uniform characteristics, continues to challenge designers and manufacturers working across a vast spectrum of industry sectors and with a broad range of materials.
Not only must the material lend itself to being manufactured and processed in large pieces, but the production equipment available must be suitable for creating and handling large single units without compromising manufacturing quality.
Yet it is a challenge which has to be met in order to comply with both the performance and aesthetic demands of modern customers. Any area where two components have to be bonded together is a potential source of weakness – any bond is only as good as the surface pre-treatment and the bonding medium used – while aerodynamic and aesthetic demands in sectors such as automotive and aerospace mean that the use of multi-piece components often cannot be countenanced.
One recent high-profile project where this was amply illustrated related to the development of a Personal Rapid Transit (PRT) vehicle for use at South Korea's Suncheon Bay, a coastal wetland that needs a tourist transportation system with minimal environmental impact.
The design for the composite pod for the system by specialist manufacturer Vectus contained a door surround with a 9-metre circumference. The challenge given to the Commercial Composites engineering team at Morgan Advanced Materials was to come up with a way of manufacturing the structural frame in a single piece which would be rigid and lightweight yet flexible enough to meet the required performance parameters.
Morgan designs and manufactures products in a variety of composite materials in highly demanding applications in sectors ranging from defence to medical. Core to its thinking on each project is the need to marry the demands of performance and appearance while minimising component weight.
One of the team’s key areas of experience is in the manufacture of large blown tube structures. For this project the team recommended a carbon fibre core which was both woven – structured in two directions for flexibility and ease of surface finishing – and unidirectional, allowing the design to be optimised on a structure for different load cases. The laying-up process would be undertaken ‘dry’ with the part created in an autoclave. The part would then be finished using a phenolic resin system, which offers enhanced fire resistance compared with epoxy-based products.
Chris Davies of Morgan explained: “The alternative to the process we recommended would have been to split the moulding into two or three parts and employ traditional composite manufacturing process with wet lay-up. However, this would have been much less structurally efficient, as well as creating bond lines and material overlaps which would have potentially compromised the smooth, sleek appearance required.”
The door surround is now fully operational on the PRT unit, which conveys an estimated three million tourists annually around the Suncheon Bay reserve.
Write a comment
No comments