US2917418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermolytic process for cleaning apparatus used in processing polyethylene terephthalate
Assignee: Eastman Kodak Co
•
Filing: 1958-03-13
•
Granted: 1959-12-15
•
Expires: 1978-03-13
Abstract
No abstract record available.
Inventors
- 👤 John A Catheart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:08
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/785; B; B08; B08B; B08B7/00; B08B7/0064; B08B7/0071; B08B7/0085; B08B2220/00; B08B2220/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
151 words
A THERMOLYTIC METHOD FOR REMOVING UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE FROM APPARATUS WHICH HAS BEEN USED IN PROCESSING POLYETHYLENE TEREPHTHALATE WHICH COMPRISES (A) INTERNALLY CONTACTING SAID APPARATUS WITH A GAS HEATED AT FROM ABOUT 275*C. TO ABOUT 350* C. UNTIL THAT PORTION OF THE UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE WHICH WILL MELT AND FLOW INTO A REMOVABLE LOCATION HAS BEEN MELTED AND REMOVED FROM SAID APPARATUS, AND THEN (B) INTERNALLY CONTACTING SAID APPARATUS WITH A GAS HEATED AT FROM ABOUT 325* TO ABOUT 525*C. UNTIL THE REMAINING UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE HAVE BEEN VAPORIZED, WHERIN DURING SAID INTERNAL CONTACT WITH THE HEATED GAS SAID APPARATUS IS ALSO EXTERNALLY HEATED AT AN APPARATUS TEMPERATURE NOT SUBSTANTIALLY GREATER THAN 325*C. DURING STEP (A) AND NOT SUBSTANTIALLY GREATER THAN 525*C. DURING STEP (B), SAID APPARATUS TEMPERATURES BEING ACHIEVED AT ALL POINTS ABOVE 300*C. AT A GRADUAL RATE NOT TO EXCEED 50*C. PER HOUR.
Claim 2
Dependent Claim
151 words
A THERMOLYTIC METHOD FOR REMOVING UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE FROM APPARATUS WHICH HAS BEEN USED IN PROCESSING POLYETHYLENE TEREPHTHALATE WHICH COMPRISES (A) INTERNALLY CONTACTING SAID APPARATUS WITH A GAS HEATED AT FROM ABOUT 275*C. TO ABOUT 350* C. UNTIL THAT PORTION OF THE UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE WHICH WILL MELT AND FLOW INTO A REMOVABLE LOCATION HAS BEEN MELTED AND REMOVED FROM SAID APPARATUS, AND THEN (B) INTERNALLY CONTACTING SAID APPARATUS WITH A GAS HEATED AT FROM ABOUT 325* TO ABOUT 525*C. UNTIL THE REMAINING UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE HAVE BEEN VAPORIZED, WHERIN DURING SAID INTERNAL CONTACT WITH THE HEATED GAS SAID APPARATUS IS ALSO EXTERNALLY HEATED AT AN APPARATUS TEMPERATURE NOT SUBSTANTIALLY GREATER THAN 325*C. DURING STEP (A) AND NOT SUBSTANTIALLY GREATER THAN 525*C. DURING STEP (B), SAID APPARATUS TEMPERATURES BEING ACHIEVED AT ALL POINTS ABOVE 300*C. AT A GRADUAL RATE NOT TO EXCEED 50*C. PER HOUR.
References Cited (Backward Citations)
US2563085A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-12-14 | 1963-06-15 | 1963-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-12-14 | 1967-06-15 | 1967-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-12-14 | 1971-06-15 | 1971-12-15 | $7700.00 | Window Closed / Lapsed |