Recycled carpet

In both the materials used and the construction process, sustainability and efficiency will become standard. Improvements mjob site management and building design will reduce waste and cost of construction. Materials such as engineered wood, recycled carpeting, and cellulose insulation, which have lower environmental impact, will become cheaper and more widely available. Not only are buildings constructed with such material friendlier to the environment, they also provide higher-quality, lower-cost solutions. 

Important solvolysis reactions for nylons are hydrolysis, methanolysis, glycolysis, aminolysis, ammonolysis, transamidation, and acidolysis.17 Hydrolysis of nylon-6 with steam in the presence of an acid catalyst to form caprolactam is tlie preferred depolymerization approach. However, when recycling carpet face fibers, file fillers in the polymer may react with file acid catalyst and lower the efficiency of the catalyst. 

Schut, J.H., Big German Plant May Relieve U.S. Bottleneck in Recycling Carpet Nylon,... 

Tullo, A. 2000. DtiPont, Evergreen to recycle carpet forever. Chemical and Engineering News, January 24 23-24. 

Cost is another concern associated with the use of recycled carpet waste fibers in concrete. Currently a vast amount of carpet waste is disposed of each year and therefore the cost of raw material for the recycled fibers is negligible. The disassemble process to convert the waste into fibers suitable for concrete reinforcement requires only simple, inexpensive shredding operation. Therefore the cost of the recycled fibers will remain very competitive with virgin fibers for FRC. 

FRC using recycled carpet waste fibers has also been used in the construction project of a 11,000 m2 building. Conventional equipment and procedures were used in the construction. The project consumed about 20 tons of carpet waste as concrete additives. The waste fibers were directly added into concrete mixing trucks. The mixing, pouring and finishing went smoothly the compressive and flexural strengths exceeded specifications and improved ductility and shatter resistance of the material were evident. This project has demonstrated that low-cost carpet waste... 

Residential carpets are continuing to be more visible in MSW. Carpets are quite complex with polyamide/PP/PET face libers, PP backing, latex adhesive, and calcium carbonate as tiller. In addition, the recycled carpet will have a higher amount of dust particles. There have been efforts in the United States to collect residential carpet. As it is very difficult to separate the different components of the carpet, the reasonable way is to shred the carpets and pelletize it so that the pellets can be used in products such as plastic lumber. Only a small percentage of the face materials (nylonb and nylon 66) are recovered and recycled. 

YoujiangW (1993) Fiber reinforced concrete using recycled carpet industrial waste and its potential use in highway construction. Symp Proc on Recovery and effective reuse of discarded materials and by-products for construction of highway facdities, October 1993, Denver, CO... 

Products from recycled carpet waste. [Data from Riccirdelli, X E King, M H ... 

United Recycling Inc. (URI), which was in operation from the early 1990s to 1999, introduced two extruded blends (URI 20-(X)l and URI 10-(X)1) from postconsumer carpet waste for injection molding in 1993 [61]. These were the first commercial recycled carpet compounds. The process used both polypropylene and nylon carpet. Their products were described as proprietary blends containing polypropylene. The composition and properties of the two compoimds are listed in Table 16.5. The molding compounds developed by URI were used to extrude carpet tack strip. 

Figure 16.4. Extrusion process developed by Monsanto for recycling carpet waste [63],...

In a study on concrete reinforcement with carpet waste fibers [78, 79], recycled carpet waste fibers about 12-25 mm in length and fiber volume fractions of 1 and 2% were used. FiberMesh, a virgin polypropylene (PP) fiber (19 mm long), at 0.5 and 1% volume fractions was included for comparison. 

A recyclable carpet based on polypropylene fibers also has been developed [98, 99]. Unlike polyester fiber, polypropylene fiber is pigmented during the fiberforming stage. The tufted polypropylene fiber is manufactured by the use of a needle-bonding method to interlock the primary and secondary backings. The polypropylene face yams were tufted into the primary backing first. Then the... 

Invista, based in Calhoun, GA, has been recycling carpet since 1991. It will collect and reclaim any used carpet, as well as installation scraps, from any manufacturer, and guarantees that no material will be sent to landfill. Recycled materials are used in manufacture of new carpet, carpet cushions, filtration devices, automotive parts, packaging materials, and furniture. Users must pay for the service. ... 

Tullo, A., DuPont, Evergreen to Recycle Carpet Forever, Chemical Engineering News, Jan. 24,2000, pp. 23-24. 

In this chapter we have tried to give an overview of the considerations and cost structure for the planning of systems for recycling carpet. One conclusion is that the volume of material that the system handles has a very pronounced effect on the overall economics. A failure to reach the capacity of the system, or creating mismatches in the capacity to process and sort, the capacity to collect and the market volume, can lead to system failure despite the apparent viability of each component. A second conclusion is that the material that cannot be put into value-added products can be a severe drag on the system economics the extra handling cost and then the cost of the disposal of this fraction can be significant. 

Sharer P. C. (1996), Method of recycling carpet forming components from waste carpet , US Patent 5 518188. 

Chen T. (1996), Recycling Carpet Waste hy Reactive Extrusion , M. S. Thesis, School of Textile and Fiber Engineering, Georgia Institute of Technology, March. 

Utilization of recycled carpet waste fibers for reinforcement of concrete and soil... 

The restrained shrinkage cracking behavior was measured by the total crack width of each ring specimen with respect to time. The crack widths were significantly reduced in the fiber composites, including all recycled fibers except those with rubber strips. In the recycled carpet fiber composites, the crack width and spacing were evenly distributed. The crack widths were much larger than those with steel fibers, and about one half of those with FiberMesh. 

Test curves for the triaxial compression test with a 34.5 kPa confinement pressure (a) reinforced with recycled carpet fibers, (b) reinforced with fibrillated polypropylene fibers. 

Wang Y. (1999), Utilization of Recycled Carpet Waste Fibers for Reinforcement of Concrete and Soil , Journal of Polymer-Plastics Technology Engineering, Vol. 38, No. 3, 533-546. 

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