Composites recycling

Advanced Materials Newsletter 18, No.20, Iss.411, 21st Oct.1996, p.2 TITAN TECHNOLOGIES, ADHERENT TECHNOLOGIES RESEARCH COMPOSITES RECYCLING VIA SBIRS... 

Thermoplastics and thermoplastic composite recyclates mechanical and calorific properties... 

Getting pure ethanol will be difficult. Ethanol is in the third distillation region, and no obvious means exist to cross the relevant distillation boundaries. A new entrainer might be added, as was the case for the previous example. However, since the ethanol is only going to be recycled to the reactor, the required purity specification might be questioned. What is the effect of small amounts of contaminants DEM and water in the recycled ethanol The acetal formation reaction is equilibrium-controlled, so there may be some deleterious effect of including products with a reactant. However, additional analysis indicated that the effect is small, and so the ethanol composition requirement was relaxed and the overhead composition recycled to the reactor directly as produced. 

By mid-1996, ERCOM Composite Recycling GmbH had mechanically recycled over 1 million SMC parts. Production scrap accounted for 750,000 parts and post consumer scraps 250,000 (from the Mercedes Recycling System MeRSy, BMW repair shops and Deutsche Telekom dismantling plants). As a result, over 2 million parts containing recyclate were put back into service in automobiles, including spare wheel well (Audi 320,000), noise barrier shield (VW 250,000), truck bumpers and front end panels (Mercedes Benz 600,000), sunroof frames (350,000), and other components (450,000). 

Zia KM, Bhatti HN, Bhatti lA. Methods for polynrethane and polyurethane composites, recycling and recovery a review. React Funct Polym 2007 67 (8) 675-692. 

DuPont, DuPont Composite Recycle Technology Makes Like-New Nylon from Scrapped Car parts, Helps Meet ELV Regulations, news release, June 24, 2003. 

DuPont, Toyota, DuPont Engineering Polymers Show Value of Composite Recycle Technology in Automotive Air Intake Manifolds, news release, March 8, 2004. 

Parameter Virgin Recycled Composite Recycled Virgin Composite... 

Conroy A, Halliwell S and Reynolds T (2006), Composite recycling in the construction industry . Compos Appl Sci Manuf, 37, 1216-1222. 

Parameter Virgin Recycled (Composite Recycled Virgin Cbmposite... 

In the manufacturing of composites a certain amount of a waste is generated. Such a waste consists of a crosslinked resin and glass fibers. ORTECH has developed composite recycling process for one of its clients. Fig 7, shows a schematic of this process. Waste composite material is fed into a low speed, high torque shredder where it is shredded into elongated pieces approximately 8cm by 8cm. The shredded material is deposited on a vibrating non-perforated screen where free fibres are separated, picked up an airlift and further... 

Processes that do not rely on the melting of plastic recyclate relate to large scale predominantly tertiary and quaternary recycling. Thermoset matrix composites recycling also falls within this description, and the principal recycling routes for thermoset matrix composites are outlined below. 

To tackle these technical challenges a series of companies and trade associations were set up across the globe to develop recycling methods for these materials. These groups are ERCOM Composite Recycling GmbH (Germany), VALOR (France), SMC Alliance (USA) and the FRP Forum (Japan). 

Interfaces represent the most critical factor of the design of multiphase systems both from synthetic and bio-based polymers and this importance grows with the increase of the specific surface area of the components exponentially. This contribution compares the aims, design and technology of multicomponent polymer systems of modified interfaces within a range covering the reinforced composites, recycled, fire retarded materials and pharmaceutical systems. 

In currently evolved compositions, recycling and disposal present no special difficulties because thermally degradable binders are used. Ideally, the binders undergo controlled thermal degradation so that the material can be easily removed from explosive casings for the purpose of efficient recycling of the base explosive or low pollution disposal of the entire item. 

Composites are inherently difficult to recycle because they are multiphase. The two or more phases/materials that constitute the composite are normally intermixed on a very fine scale, and trying to separate them complicates the recycling process. However, some techniques have been developed, with modest success, for reoyoUng polymer-matrix composites. Recycling technologies differ only slightly for thermoset-matrix and thermoplastic-matrix composite materials. 

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