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US4602046A Expired / Lapsed US ⏱️ 0.0 years remaining

Recovery of polyester from scrap by high shear conditions

Assignee: EIDP Inc
•
Filing: 1985-01-22
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Granted: 1986-07-22
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Expires: 2005-01-22
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Abstract

Abstract A method for the recovery of plastic material such as polyester from scrap material such as photographic film having a polyester base and at least one layer of a macromolecular organic polymer. The process includes mixing small pieces of the scrap material in a solution having a scrap solids concentration level of at least 25 percent by volume. The mixture is subjected to conditions of high shear to remove and comminute the polymer layer to particles of a maximum size particle dimension substantially smaller than the minimum size in the longest dimension of the scrap pieces. The polymer particles are then separated from the remaining pure polyester.

Inventors

  • 👤 Kenneth R. Buser
  • 👤 Thomas A. Rettig

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 22:07
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; C08J2367/00; C08J2367/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 117 words
A process for the recovery of plastic material from articles having a plastic base material and at least one layer of a macromolecular organic polymer having different tensile properties which comprises: mixing pieces of the plastic article ranging in size from about 2 to about 20 millimeters in the longest dimension, with a caustic alkali solution wherein the resulting mixture has a solids concentration level of at least 25 percent by volume, subjecting the mixture to conditions of high shear unitl the polymer layer is removed from the pieces and to comminute the polymer layer to particles having maximum size of about 150 microns, and separating the polymer particles to recover pieces of essentially pure plastic material.
Claim 2
Dependent Claim 117 words
A process for the recovery of plastic material from articles having a plastic base material and at least one layer of a macromolecular organic polymer having different tensile properties which comprises: mixing pieces of the plastic article ranging in size from about 2 to about 20 millimeters in the longest dimension, with a caustic alkali solution wherein the resulting mixture has a solids concentration level of at least 25 percent by volume, subjecting the mixture to conditions of high shear unitl the polymer layer is removed from the pieces and to comminute the polymer layer to particles having maximum size of about 150 microns, and separating the polymer particles to recover pieces of essentially pure plastic material.
Claim 3
Dependent Claim 13 words
A process according to claim 1 wherein the plastic material is polyethylene terephthalate.
Claim 4
Dependent Claim 12 words
A process according to claim 2 wherein the polymer is polyvinylidene chloride.
Claim 5
Dependent Claim 29 words
A process according to claim 1 wherein the polymer particles are separated by filtration means that passes only particles no larger than the maximum size of the polymer particles.
Claim 6
Dependent Claim 15 words
A process according to claim 3 wherein the solution has an alkalinity of about 1.0N.
Claim 7
Dependent Claim 27 words
A process according to claim 1 wherein the mixture is subjected to the high shear conditions by a multi-bladed rotor drivn at about 1300 revolutions per minute.
Claim 8
Dependent Claim 17 words
A process according to claim 1 wherein the solids concentration level is above 30 percent by volume.
Claim 9
Dependent Claim 118 words
A process for the recovery of polyester from photographic film having a polyester base and at least one coating of a macromolecular organic polymer of different tensile properties which comprises: mixing pieces of the coated film ranging in size from about 2 to about 20 millimeters in the longest dimension with a caustic alkali solution at a solids concentration level of at least 25 percent by volume, subjecting the mixture to conditions of high shear so that the polymer layer is removed from the pieces and is comminuted to particles of no greater than about 150 microns within a period of less than about 20 minutes, and separating the polymer particles to recover pieces of essentially pure polyester.
Claim 10
Dependent Claim 118 words
A process for the recovery of polyester from photographic film having a polyester base and at least one coating of a macromolecular organic polymer of different tensile properties which comprises: mixing pieces of the coated film ranging in size from about 2 to about 20 millimeters in the longest dimension with a caustic alkali solution at a solids concentration level of at least 25 percent by volume, subjecting the mixture to conditions of high shear so that the polymer layer is removed from the pieces and is comminuted to particles of no greater than about 150 microns within a period of less than about 20 minutes, and separating the polymer particles to recover pieces of essentially pure polyester.
Claim 11
Dependent Claim 12 words
A process according to claim 8 wherein the polymer is polyvinylidene chloride.
Claim 12
Dependent Claim 27 words
A process according to claim 8 wherein the mixture is subjected to the high shear conditions by a multi-bladed rotor driven at about 1300 revolutions per minute.
Claim 13
Dependent Claim 35 words
A process according to claim 8 wherein the longest dimension of each of the film pieces is not reduced appreciably by the high shear conditions, the minimum longest dimension being substantially greater than 150 microns.

References Cited (Backward Citations)

GB870639A Cited
US3098046A Cited
US3503904A Cited
US3652466A Cited
US3928253A Cited
US3873314A Cited
US4324705A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-07-21 1990-01-20 1990-07-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-07-21 1994-01-20 1994-07-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-07-21 1998-01-20 1998-07-22 $7700.00 Window Closed / Lapsed

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