US4033907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reclaiming waste plastics
Assignee: Monsanto Co
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Filing: 1975-07-07
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Granted: 1977-07-05
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Expires: 1995-07-07
Abstract
Abstract In reclaiming thermoplastic materials, process improvements wherein ground particles having molecular orientation are heated sufficiently to relieve orientation stresses and reduce surface area, thereby facilitating subsequent washing, separating and melt processing steps. When refabrication into other articles is intended, the materials can be exposed to a hot caustic solution to eliminate bacteria and mold growth.
Inventors
- 👤 William D. Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:43
CPC Classifications
B; B29; B29B; B29B17/00; B29B17/0026; B29B17/0042; B29B17/02; C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; B29B2017/0213; B29B2017/0217; B29B2017/0237; B29B2017/0244; B29K; B29K2023/00; B29K2023/10; B29K2023/12; B29K2033/00; B29K2033/04; B29K2033/12; B29K2067/00; B29K2105/00; B29K2105/06; B29K2105/065; B29K2705/00; B29K2705/02; B29L; B29L2007/00; B29L2007/008; B29L2031/00; B29L2031/712; B29L2031/7158; B29L2031/744; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y02W30/62
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
94 words
In a process for recycling non-cellular molecularly oriented thermoplastic material which includes the steps of: reducing the material to the form of platelets; and melt processing such material via a rotating screw during refabrication of articles therefrom; the improvement in said process comprising, in combination, the step of: heating the molecularly oriented platelets to within the molecular orientation temperature range of the thermoplastic material prior to such melt processing to relieve stresses in the platelets without causing substantial fusing of adjacent platelets whereby the surface area is decreased to improve the screw feeding characteristics.
Claim 2
Dependent Claim
94 words
In a process for recycling non-cellular molecularly oriented thermoplastic material which includes the steps of: reducing the material to the form of platelets; and melt processing such material via a rotating screw during refabrication of articles therefrom; the improvement in said process comprising, in combination, the step of: heating the molecularly oriented platelets to within the molecular orientation temperature range of the thermoplastic material prior to such melt processing to relieve stresses in the platelets without causing substantial fusing of adjacent platelets whereby the surface area is decreased to improve the screw feeding characteristics.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein: said platelets are exposed to infra-red radiation while being conveyed forwardly in a layer on a moving surface to accomplish said heating.
Claim 4
Dependent Claim
41 words
The process of claim 1 including the step subsequent to said heating of: exposing the products of said heating step to a caustic solution at a temperature of from about 130° to 200° F. for a time sufficient to sterilize same.
Claim 5
Dependent Claim
19 words
The process of claim 3 including the step of: neutralizing said products subsequent to exposure to said caustic solution.
Claim 6
Dependent Claim
19 words
The process of claim 4 wherein said neutralization is such that the thermoplastic material remains basic after completion thereof.
Claim 7
Dependent Claim
108 words
In a process for recycling non-cellular thermoplastic containers which includes the steps of: grinding the containers to reduce the bulk thereof; exposing the ground material to one or more liquid separating or washing media; drying the material; and thereafter melt processing said dried material via a rotating screw; the improvements in said process wherein said containers have molecular orientation and comprising, in combination, the step of: heating the molecularly oriented material after said grinding step and before said step of exposure to a liquid media to within the molecular orientation temperature range of the material to substantially relieve orientation stresses therein without causing substantial fusion of the material.
Claim 8
Dependent Claim
108 words
In a process for recycling non-cellular thermoplastic containers which includes the steps of: grinding the containers to reduce the bulk thereof; exposing the ground material to one or more liquid separating or washing media; drying the material; and thereafter melt processing said dried material via a rotating screw; the improvements in said process wherein said containers have molecular orientation and comprising, in combination, the step of: heating the molecularly oriented material after said grinding step and before said step of exposure to a liquid media to within the molecular orientation temperature range of the material to substantially relieve orientation stresses therein without causing substantial fusion of the material.
Claim 9
Dependent Claim
14 words
The process of claim 6 wherein the thermoplastic material is a high barrier polymer.
Claim 10
Dependent Claim
17 words
The process of claim 6 wherein the thermoplastic material contains a major proportion of a polymerized olefin.
Claim 11
Dependent Claim
29 words
The process of claim 7 wherein the high barrier polymer contains a major proportion of a polymerized monomer selected from the group consisting of acrylonitrile, methacrylonitrile and mixtures thereof.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |