Adhesive bonding and miscellaneous chemical manufacture – Differential fluid etching apparatus – With microwave gas energizing means
Reexamination Certificate
1997-03-27
2002-04-30
Osele, Mark A. (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Differential fluid etching apparatus
With microwave gas energizing means
C156S583200, C241S021000, C241S039000, C264S037280
Reexamination Certificate
active
06379489
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to an improved process for carpet reclamation and more particularly, the process is directed to the use of an agent for chemically softening or swelling binder material conventionally associated with carpet in order to expedite and simplify the reclamation process.
2. Description of the Prior Art
Carpet reclamation processes have been previously proposed in the art and are exemplified by the process disclosed in U.S. Pat. No. 5,230,473, issued to Hagguist et al., Jul. 27, 1993.
In the Hagguist et al. method, apart from introductory steps which involve screening the carpet, and preliminary loop cutting and other processing, the removal of the secondary backing involves a whole series of steps. This additionally is the situation when the binder material is to be removed from the primary backing.
In greater detail and with respect to the removal of the secondary backing from the carpet, the carpet must be initially exposed to fluids under pressure for loosening and debonding the latex binder from the secondary backing. The next step includes passing the remaining material onto a further processing stage where the secondary backing is mechanically treated with rotating mechanical impingement devices on both sides of the carpet. It is the mechanical arrangement that results in the removal of the secondary backing. At this time, the binder system is still substantially intact.
In order to remove the binder material, the remaining carpet structure must be passed to yet another stage where there is included a plurality of rotating brushes as well as rotating high pressure nozzle heads. This, as indicated by the patentees, results in the gradual loosening and removal of the binder system from the primary backing.
In view of the teachings of this reference, it is clear that the method is dependent on the use of mechanical means for the removal of not only the secondary backing, but further the removal of the latex binder conventionally positioned between the secondary backing and the primary backing.
The Hagguist et al. process also suffers the drawbacks common to all multiple step processes, including increased production time and cost, the use of a greater number of moving parts, the potential requirement for a larger labor force and difficulty in efficiently operating at a commercial level wherein, for example, millions of square meters of carpet may be processed.
In view of what has been proposed in the prior art set forth above, there clearly exists a need for a high efficiency method of reclaiming base components of a carpet quickly and without the use of toxic contaminants or complex, multiple stage processes.
BRIEF SUMMARY OF THE INVENTION
The present invention satisfies the above needs and achieves the results and benefits set forth below by providing a process for reclaiming carpet components, the carpet including backing material, binder material and carpet pile. In a first embodiment, the process includes the steps of: contacting the carpet with a composition including a chemical softening agent (as defined below) for the binder and separating the pile from the backing.
The amount of chemical softening agent in the composition and the conditions for the contacting step, for example temperature and time, may be selected to either substantially dissolve the binder or soften the binder.
In a second embodiment, the process includes reducing the size of the carpet to form a reduced carpet sample; combining at least a portion of the reduced carpet sample with a composition including a chemical softening agent for the binder to form a carpet/composition mixture; and applying to the mixture shear forces under turbulent conditions in an amount sufficient to promote detachment of the binder from the remaining materials (e.g., pile material and/or backing material).
The process and device of the present invention permits the reuse and recycle of the pile or backing material into critical end uses requiring a high degree of product purity such as, for example, carpet fibers, plastic pellets and other materials. Once the contacting step is complete, the various materials may be further separated from each other by making use of mechanical means, fluid means including air and liquid flow, vacuum means or by manual means.
According to yet another aspect of one embodiment of the present invention there is provided a system for reclaiming carpet components, the carpet including backing material, binding material and carpet pile, the system including: advancing means for advancing the carpet to a solvent application means; solvent application means for applying solvent to the carpet to dissolve the binder material; and collection means for collecting separated backing material and carpet pile.
It will be readily appreciated that the process as set forth herein is clearly applicable to all carpet types including, for example, standard carpet with styrene butadiene rubber latex binders and primary and secondary backings, and those with foam layers, including urethanes.
REFERENCES:
patent: 4028159 (1977-06-01), Norris
patent: 5169870 (1992-12-01), Corbin et al.
patent: 5227085 (1993-07-01), Motsenbocker
patent: 5230473 (1993-07-01), Hagguist et al.
patent: 5518188 (1996-05-01), Sharer
patent: 5535945 (1996-07-01), Sferrazza et al.
patent: 5598980 (1997-02-01), Dilly-Louis et al.
patent: 5719198 (1998-02-01), Young et al.
patent: 5722603 (1998-03-01), Costello et al.
Dickerson Jerauld Lee
Goulet Roger Joseph
Ramsden Peter Michael
Williams Susan Ramilo
Howrey Simon Arnold & White , LLP
Monsanto Company
Osele Mark A.
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