Method and machine for recycling discarded carpets
US5704104A · kind A · utility
Inventors
Key dates
| Filing date | Dec 27, 1995 |
| Grant date | Jan 6, 1998 |
| Priority date | — |
| Expiry date | Dec 27, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/913
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and machine are disclosed for using a cold dry abrasion step for separating segments of discarded carpet into pile material (usually nylon) and backing layers (usually polypropylene) for recycling. A preferred method of abrasion uses dry ice pellets (made of frozen carbon dioxide) which are ejected at high speed from a set of nozzles that shoot the pellets directly into an abrasion zone, as a segment of discarded carpet on a conveyor system is being stripped apart and disassembled. The dry ice pellets "freeze" the binder material (usually latex) by lowering it to a temperature that makes the binder brittle and easy to break apart. The pellets also serve as abrasive agents, in a manner comparable to sand-blasting; however, unlike sandblasting or liquid (steam or chemical) systems, the dry ice pellets evaporate (sublimate) directly into gas without going through a liquid phase, and without leaving any liquid or gritty residue. This eliminates the need for a drying operation, which saves time and energy and avoids a potential air pollution problem; it also renders the recyclable output material free of unwanted liquid residues, grit, or other materials that would decrease the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.