| Title: CONTINUOUS ULTRASONIC DEVULCANIZATION OF VULCANIZED
ELASTOMERS Inventor(s): A. Isayev, J. Chen
Disclosure 171 U.S. Patent 5,258,413
Disclosure 171-CIP U.S. Patent 5,284,625
This invention relates to a continuous ultrasonic method for selectively breaking the
carbon-sulfur (C-S), sulfur-sulfur (S-S), and if desired, carbon-carbon (C-C) bonds in a
vulcanized elastomer.
It is well known that vulcanized elastomers having a three-dimensional chemical
network, cannot flow under the effect of heat and/or pressure. This creates a hugh problem
in the recycling of used tires and other elastomeric products. Through the application of
certain levels of ultrasonic amplitudes in the presence of pressure and optionally heat,
the three-dimensional network of vulcanized elastomer can be broken down. As a most
desirable consequence, ultrasonically treated cured rubber becomes soft, thereby enabling
this material to be reprocessed and shaped in a manner similar to that employed with
uncured elastomers.
To date the following materials have been processed using this technology: Ground Tire
Rubber (GTR), tire buffings, EPDM, Nitrile, Butyl, SBR, Ethylene Vinyl Acetate (EVA),
fluoroelastomers, and silicon. Other materials will continually be added to the list in
the future.
Experimental processing of your in-house elastomer waste stream (sample) is available
upon request for a small fee. This experimental processing permits requestor to evaluate
the chemical, physical, and mechanical properties after ultrasonic treating. Experimental
processing information is held confidential and requestor is not required to disclose
recipe details.
This technology is broken down into three segments: (1) equipment, (2) processing
tires, and (3) processing non-tire materials. The equipment and processing tire segments
have been licensed on a limited exclusive basis to National Feedscrew & Machining,
Inc. (NFM) of Massillon, OH. NFM is an equipment manufacturer and refurbisher with a
precision machine shop, and in the Summer of 1995 has set-up a pilot plant to recycle
tire. Equipment can be either fixed or on a mobile station to move from site to site.
All interested parties in recycling tires should contact NFM. For those interested in
processing non-tire material, or in-house waste streams, can secure license rights
directly from The University of Akron, and NFM will sell the equipment to meet your
particular specifications. |
