SPE Library

Carbon fibers are widely used in the aerospace and sporting goods industry to reinforce thermoset matrix composites. Carbon fibers are also finding use within the automotive industry in thermosets and thermoplastics, due to the high specific modulus and strength. With use, comes manufacturing waste and disposal issues. Typically, carbon fiber containing composites are considered unrecyclable. Recently, carbon fiber has been reclaimed from the composite manufacturing process. This has been largely driven by the need to increase the supply of carbon fibers in the marketplace, but also the desire to reduce costs of materials made with carbon fiber. Costs of carbon fiber can range to $40/lb. Costs of engineering thermoplastics can rival and exceed the cost of carbon fiber. Thus, displacement of either of these two materials with a cheaper, physically equivalent material will make carbon fiber reinforced materials more economically tenable in the market. The disposal of manufacturing wastage from composite manufacture drives up cost of production of these engineered lightweight materials. With properly designed processes, recycled carbon fiber may be able to be produced for a fraction of the cost of virgin fiber. The economic recovery of these fibers will allow for the economic use of carbon fiber in more products than is currently feasible. Recycled fibers compounded with engineering resins were used to fabricate thermoplastic parts. This report will detail the processes used to obtain the recycled carbon fibers, the properties of the materials, products manufactured and details of economic and engineering factors in the recycling of composite materials.

Mixed Domestic Plastics will become an important source of plastic recyclate feedstock over the coming years, three streams are typically found – bottles, rigids and flexibles (films). Bottles and trays are readily sortable and recyclable back into similar articles. Film poses significant recycling problems. Recycling Mixed Domestic Post consumer film poses many challenges, this paper outlines the principal issues, both technical and commercial and provides solutions to move the process forward. Mixed Domestic film recycling poses five principal technical hurdles – 1. Handling of commingled film waste including residual paper, cans etc 2. Separation of olefinic & non-olefinic streams 3. Devolatilisation of highly printed film 4. Compatibilisation of mixed olefinic (PE/PP) stream 5. Management of residuals in recyclate Described is the front end of the process to handle commingled waste, separation techniques for the two streams, level/type of devolatilisation required to negate ink/print effects, compatibilisation methods to homogenenise PE/PP and information on final applications, including commercial examples.

Marine debris or ocean litter is a worldwide problem. In fact, 60 to 80% of the ocean litter is plastic based. 80% of the ocean debris is from land based sources. Plastic pellets from plastic manufacturers can flow into storm drains and end up in the oceans. The plastics can harm the environment in three ways: (1) plastic marine debris can cause injury and death to marine life by ingestion or entanglement; (2) plastic marine debris can release toxic chemicals in the marine environment that fish and other marine species consume and then are absorbed by humans when the animals are eaten; and (3) plastic marine debris can absorb toxins from industrial, urban, and agricultural runoff that are in the marine environment in higher concentrations than the surrounding water, and then enter our food chain through aquatic species who eat the plastic. UV light and oxygen can cause degradation of plastics in the marine environment. Biodegradation can occur for some biobased plastics. ASTM standards provide methods to test for biodegradation of biodegradable plastics. PHA and bagasse biodegradable plastics have shown biodegradation in the marine environment.