JEC COMPOSITES MAGAZINE - Issue #46 - January/February 2009 - 44

FEATURE “Natural fibres” manufacture objects with complex shapes. This type of material is marketed in the form of pellets that can be used in injection or extrusion processes. The main applications for injection moulding include structural parts for the car industry, for example. Extrusion is used to produce profiles, hollow components, etc. The approaches that are in competition with the use of plant fibre/polymer composites are those using wood/polymer composites in which wood flour in ratios of up to 70% is introduced into the polymer matrices. These composites have made spectacular inroads on the US and Japanese markets in particular these last 10 years. In the building sector, the use of plant fibre/polymer composites as construction materials is still very limited, yet it stands every chance of burgeoning on account of concerns relating to the toxicity of wood preservation treatments based on chromium and copper. Products developed include window profiles, fences, shutters, gates, decking (terrace floors, outdoor profiles, etc.), siding (shingles, swimming pool railings, etc.). Other potential sectors are also being developed: public works (pipes), furnishings, materials handling (pallets), packaging, electrical and electronic goods, aerospace, boatbuilding, and consumer products. g…/… Applications for plant fibre/polymer composites in the industrial sector Propeller. New applications for flax and hemp fibres in the composites industry In addition to traditional applications, new applications are emerging, in particular in the automotive and building industries. New composite materials based on plant fibres and polymers are being increasingly used in the building industry in the United States and in car manufacturing in Europe. Plant fibres, such as flax or hemp, can be used as a reinforcement for PVC, PE or PP-type polymers in place of synthetic fibres (glass, Kevlar, carbon, etc.). This substitution offers many benefits: - economic: lower costs on account of significantly reduced cycle times, energy savings during processing, low density; - technical: mechanical properties identical to those of traditional reinforcements, reduced tool wear & tear, high geometric stability of the manufactured parts, good insulation characteristics; - environmental: renewable resource, easy to recycle, no material toxicity, reduced fossil fuels content, CO2-neutral materials. In the automotive sector, the processing technologies currently used are thermoforming/hot compression moulding, injection and extrusion. Hot compression moulding technology generally requires a nonwoven mat, consisting either partially or entirely of plant fibres that may or may not be combined with synthetic fibres. During processing, at a temperature of approximately 180°C, the synthetic fibres melt and thus constitute a matrix in which the plant fibres are embedded. These nonwovens are used as interior linings for car doors, parcel shelves, boots or pillars. The majority of European car manufacturers have at least one model equipped with these kinds of linings in their range. The processing of plant fibres by means of injection and extrusion is today on an upward growth trend, particularly in Europe. These technologies use plant fibres in combination with polypropylene, polyethylene and ABS. They can be used to Cover (car engine part) Development prospects for plant fibre/polymer composites The development of plant fibre/polymer composites is at an emerging stage since they currently represent a mere 0.1 to 0.5% market share, depending on the type of application. This market, estimated at 14,000 MT in France in 2005 by Alcimed, is set to grow rapidly on account of the increasing cost of oil and the crisis affecting the automotive sector. Indeed, some specialists believe that the widespread use of these materials could bring innovation into the sector and provide it with renewed momentum. In its prospective study carried out on behalf of ADEME in 2007, Alcimed forecasts that French production of plant fibre/polymer composites could reach 650,000 MT in 2015, rising to 1,150,000 MT in 2030. To achieve these objectives, the industry needs the support of R&D and help in its structuring. In the field of R&D, several programmes have been initiated by the public authorities and, in particular, by ADEME in order to relieve the technical sticking points that have been identified in relation to the use of these 44 jec composites magazine / No46 January-February 2009

JEC COMPOSITES MAGAZINE - Issue #46 - January/February 2009

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #46 - January/February 2009