The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1977
Filed:
Sep. 01, 1976
Donald Wayne Monk, Brevard, NC (US);
Olin Corporation, Pisgah Forest, NC (US);
Abstract
An efficient process for recovering raw materials from scrap coated and uncoated cellophane, including usable cellulose, coating resin, and softener, comprising (a) shredding the scrap cellophane, (b) extracting softener and coating resin jointly by washing the shredded film with a tetrahydrofuran solution containing from 2 to 15% by weight water in an extractor, (c) removing the spent wash solution containing softener, coating resin, tetrahydrofuran, and water and rapidly evaporating tetrahydrofuran therefrom while allowing the coating resin to inherently precipitate from the softener, (d) drying the shredded cellophane after removal of the spent wash solution to recover retained tetrahydrofuran and pure cellulose, (e) recycling tetrahydrofuran obtained from the flash evaporating and drying steps to the extractor, and (f) separating the precipitated coating resin from the softener. The recovered cellulose can be used in many ways, such as recycled directly back into the process for the manufacture of cellophane. Recovered softener and coating resin are also suitable for reuse in the production of cellophane.