US3821343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacturing method of thermoplastic synthetic resin films
Assignee: Mitsubishi Chemical Corp
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Filing: 1972-06-27
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Granted: 1974-06-28
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Expires: 1992-06-27
Abstract
Abstract A hollow tube of thin thermoplastic film is extruded in downward direction and expanded to a desired cross-section. Immediately after this expansion the tube is guided into a liquid bath and along a perforate element which extends in direction of travel of the tube. The liquid in continuously circulated along the interface of the travelling tube and the perforate element and is being drawn through the latter in the direction away from this interface. This serves to cool the tube and at the same time to draw the same against the perforate element due to the suction resulting from the liquid passing through the same, so that the tube is not only cooled but also supported against and by said perforate element.
Inventors
- 👤 M Sudo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:53
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/919; B29C48/03; B29C48/09; B29C48/10; B29C48/885; B29C48/911; B29C48/9115; B29C48/912; B29C48/001; B29C48/0018; B29C48/0019
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
151 words
A method of manufacturing tubes of thermoplastic synthetic film, comprising the steps of extruding an internally unsupported hollow tube of thermoplastic synthetic film for travel in a substantially vertical direction; expanding the internally unsupported traveling tube to a desired cross section; progressively flattening the expanded internally unsupported tube while guiding it along a perforate element located in a bath of cooling liquid and which extends in said direction and has one side facing towards and another side facing away from the tube; and continuously circulating cooling liquid from said bath along the interface of the traveling tube and said one side and thereupon through said perforate element in a direction outwardly away from said tube and to said other side, whereby to cool said tube and to draw the same toward said one side of said element by the suction resulting from passage of said cooling liquid to said other side.
Claim 2
Independent Claim
151 words
A method of manufacturing tubes of thermoplastic synthetic film, comprising the steps of extruding an internally unsupported hollow tube of thermoplastic synthetic film for travel in a substantially vertical direction; expanding the internally unsupported traveling tube to a desired cross section; progressively flattening the expanded internally unsupported tube while guiding it along a perforate element located in a bath of cooling liquid and which extends in said direction and has one side facing towards and another side facing away from the tube; and continuously circulating cooling liquid from said bath along the interface of the traveling tube and said one side and thereupon through said perforate element in a direction outwardly away from said tube and to said other side, whereby to cool said tube and to draw the same toward said one side of said element by the suction resulting from passage of said cooling liquid to said other side.
Claim 3
Dependent Claim
67 words
A method as defined in claim 1, wherein an additional preforate element is provided, similar to and defining with the first-mentioned perforate element a gap which is elongated in said direction; and wherein said expanded tube is guided along both of said perforate elements, and said cooling liquid is continuously circulated through both of said perforate elements from the respective one to the respective other sides thereof.
Claim 4
Dependent Claim
89 words
A method as defined in claim 1, said element having an upper and a lower portion which are immersed in said bath of cooling liquid at a lesser and a greater depth, respectively, the combined cross-sectional area of the perforations in said upper portion being smaller than the combined cross-sectional area of the perforations in said lower portion; and wherein the step of circulating the cooling liquid through said element comprises circulating said cooling liquid through the perforations of said upper and lower portions at substantially equal liquid pressure.
Claim 5
Dependent Claim
37 words
A method as defined in claim 1, said element being hollow and said other side being the interior of said element; and further comprising the step of subdividing said interior into at least two discrete superposed chambers.
Claim 6
Dependent Claim
81 words
A method as defined in claim 2, each of said elements having a pair of lateral margins extending in said direction and laterally bounding said gap; further comprising the step of engaging and inwardly gusseting the travelling tube with at least one perforate one of said margins of at least one of said elements; aNd continuously circulating said cooling liquid along the interface of said tube and of said one perforate margin, and through the latter outwardly away from said tube.
Claim 7
Dependent Claim
39 words
A method as defined in claim 1; and further comprising the step of providing the travelling tube at longitudinally spaced locations thereof with respective transversely extending discontinuous sealed seams to thereby divide the tube into longitudinally arrayed communicating compartments.
Claim 8
Dependent Claim
38 words
A method as defined in claim 6, wherein the step of providing the tube with said transverse seams is carried out subsequent to expanding of the tube but prior to guiding of the same along said perforate element.
Claim 9
Independent Claim
177 words
A method of manufacturing tubes of thermoplastic synthetic film, comprising the steps of extruding an internally unsupported hollow tube of thermoplastic synthetic film for travel in an upright direction and path; interposing in said path a bath of cooling liquid having immersed therein a perforate element which extends in said direction and which has one side and an opposite side; expanding the traveling tube to a desired cross section upstream of said bath; guiding the expanded tube substantially vertically through said bath along said one side of said perforate element; continuously circulating liquid of said bath along the interface of the traveling tube and said one side, and thereupon through said perforate element in direction outwardly away from said tube and to said other side, whereby to cool said tube and draw the same toward and into supported engagement with said one side of said element by the suction resulting from passage of the circulating liquid to said other side; and progressively flattening the expanded tube during travel thereof along said one side of said perforate element.
Claim 10
Independent Claim
177 words
A method of manufacturing tubes of thermoplastic synthetic film, comprising the steps of extruding an internally unsupported hollow tube of thermoplastic synthetic film for travel in an upright direction and path; interposing in said path a bath of cooling liquid having immersed therein a perforate element which extends in said direction and which has one side and an opposite side; expanding the traveling tube to a desired cross section upstream of said bath; guiding the expanded tube substantially vertically through said bath along said one side of said perforate element; continuously circulating liquid of said bath along the interface of the traveling tube and said one side, and thereupon through said perforate element in direction outwardly away from said tube and to said other side, whereby to cool said tube and draw the same toward and into supported engagement with said one side of said element by the suction resulting from passage of the circulating liquid to said other side; and progressively flattening the expanded tube during travel thereof along said one side of said perforate element.
Claim 11
Dependent Claim
69 words
A method as defined in claim 8, wherein an additional perforate element is provided in said bath, similar to and defining with the first-mentioned one a gap which is elongated in said direction; and wherein said expanded tube is guided along both of said perforate elements, and said cooling liquid is continuously circulated through both of said perforate elements from the respective one to the respective other sides thereof.
Claim 12
Dependent Claim
89 words
A method as defined in claim 8, said element having an upper and a lower portion which are immersed in said bath of cooling liquid at a lesser and a greater depth, respectively, the combined cross-sectional area of the perforations in said upper portion being smaller than the combined cross-sectional area of the perforations in said lower portion; and wherein the step of circulating said cooling liquid through said element comprises circulating said cooling liquid through the perforations of said upper and lower portions at substantially equal liquid pressure.
Claim 13
Dependent Claim
37 words
A method as defined in claim 8, said element being hollow and said other side being the interior of said element; and further comprising the step of subdividing said interior into at least two discrete superposed chambers.
Claim 14
Dependent Claim
80 words
A method as defined in claim 9, each of said elements having a pair of lateral margins extending in said direction and laterally bounding said gap; further comprising the step of engaging and inwardly gusseting the travelling tube with at least one perforate one of said margins of at least one of said elements; and continuously circulating said cooling liquid along the interface of said tube and said one perforate margin and through the latter outwardly away from said tube.
Claim 15
Dependent Claim
39 words
A method as defined in claim 8; and further comprising the step of providing the travelling tube at longitudinally spaced locations thereof with respective transversely extending discontinuous sealed seams to thereby divide the tube into longitudinally arrayed communicating compartments.
Claim 16
Dependent Claim
38 words
A method as defined in claim 13, wherein the step of providing the tube with said transverse seams is carried out subsequent to expanding of the tube but prior to guiding of the same along said perfOrate element.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |