Advances in polymer composites: Paving the way for product innovation
The Soft Matter Group has developed a cost-effective process for manufacturing lightweight, high impact resistant polymer composites, which has been commercialised over a wide range of applications including luggage and anti-ballistic body armour.
Over many years fundamental polymer research at Leeds has, in parallel with commercial development, led to the novel idea of using a process called ‘hot compaction’ to manufacture single polymer composites. In this process highly oriented polymer fibres are heated so that the surface of each individual fibre is ‘selectively’ melted while retaining the core. Upon cooling, this skin recrystallises to form the matrix of a self-reinforced fibre composite. The resulting material offers extraordinary levels of impact resistance, is strong and very stiff, but also lightweight. Further Leeds research identified polypropylene as having the greatest commercial potential and established the best route for making commercial hot compacted polypropylene materials.
Revolutionising the luggage industry
Leeds created a spin out company to commercialise and develop the process, which was transferred to Propex Fabrics, who set up the first commercial plant for Curv®, the world’s first self-reinforced polypropylene composite. Samsonite pioneered the use of Curv®, producing a new range of lightweight, impact resistant luggage. Following initial success, the company extended the use of Curv® to the Cosmolite, a higher volume and more cost effective range, which was Samsonite’s top seller in 2009-2010 and the highest selling suitcase in Europe. Successive ranges have been based on Curv® and since its introduction Samsonite has experienced a huge growth in sales and net income.
“Samsonite's use of CURV® composite is a revolution in the industry, providing the world traveller with the best in performance."
-- Global Creative Director, Samsonite
Curv® material has been used for a wide range of diverse applications including car parts, personal protection products (e.g. helmets and safety vests) and in the loudspeaker industry (Wharfedale). Bauer uses Curv® to manufacture elite level ice hockey skates offering improved protection against impact, which were worn by 69% of USA professional National Hockey League players in 2011.
“The Curv® self reinforced PP composite which is a direct result of the hot compaction technology as applied to polypropylene developed at the University of Leeds has become a very profitable business venture for Propex Fabrics."
-- Managing Director, Propex Fabrics GmbH
Continuing development and new markets
A further Leeds breakthrough shows that incorporating an interleaved film with the hot compaction process increases the interlayer bond strength, enabling greater commercial exploitation. Following this, Leeds is part of a multi-partner research project aiming to achieve radical advances in composite materials for the cost-effective, large volume production of high performance carbon fibre reinforced parts with potential application in the automotive, aerospace, and luxury luggage sectors.
Engineering and Physical Sciences Research Council, The British Technology Group and PROPEX Fabrics GmbH
Professor I. M. Ward, Dr P. J. Hine and Mr K. Norris.