Mechanical separation of carpet components

Mechanical methods have been utilized to separate carpet components. One or more segregated components then are recycled into products that generally compete with products produced from virgin polymers. 

In a process developed by DuPont, - nylon 6,6 carpet first is passed through dry processes consisting of a series of size reduction and separation steps. This provides a dry mix of 50-70% nylon, 15-25% polypropylene and 15-20% latex, fillers and dirt. Water is added in the second step, where the shredded fiber is washed and separated using the density differences between fillers, nylon and polypropylene. Two product streams are obtained one 98% pme nylon and the other 98% pure polypropylene. The recycled nylon is compounded with virgin nylon at a ratio of 1 3 for making automotive parts. 

A centrifuge system has been developed to separate ground nylon carpet into nylon, polypropylene and adhesive (latex and fillers). The systan employs a drum rotated at a speed to generate a centrifugal acceleration KXX) to 15(X) times that of the gravitational acceleration. In the first stage, a liquid with a 1.15 g/cm density is used to separate the fibers (nylon and polypropylene) from the adhesive. 

The second stage, using a liquid with a 1.0 g/cm density (e.g. water), further separates the nylon from the polypropylene. 

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