US4251585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Product and process for stretching a tubularly formed sheet of orientable thermoplastic material
Assignee: Biax Fiberfilm Corp
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Filing: 1978-05-01
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Granted: 1981-02-17
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Expires: 1998-05-01
Abstract
Abstract There is described a process for bi-axially stretching a tubularly-formed sheet of thermoplastic material in first and second stations wherein the first and second stations are provided with sets of rolls having generally sinosoidally-shaped grooves perpendicular and parallel, respectively, to the axis of each set of rolls to produce bags of improved strip tensile breaking strength.
Inventors
- 👤 Eckhard C. A. Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:07
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/18; B29C55/023; B29C55/10; B29C55/12; B29C55/14; B29C55/143; B29L; B29L2023/00; B29L2023/001; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24025; Y10T428/24744
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
155 words
A process for manufacturing tubularly-shaped thermoplastic products of improved strip tensile breaking strength from an orientable thermoplastic material, which comprises: (a) forming said thermoplastic material into a tubularly-shaped film; (b) forming said tubularly-shaped film into a sheet; (c) heat sealing said sheet at preselect intervals substantially perpendicularly to the movement of said sheet; (d) introducing said sheet on step c into a nip of interdigitating rollers having grooves substantially parallel to the axis of said rollers; (e) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent slipping of said film and thereby longitudinally stretch incremental portions of said sheets by a deflection of said sheet into the shape of said grooves: (f) withdrawing said sheet from said rollers at a velocity greater than the rotational velocity of said roller; and (g) collecting the thus stretched sheet.
Claim 2
Dependent Claim
155 words
A process for manufacturing tubularly-shaped thermoplastic products of improved strip tensile breaking strength from an orientable thermoplastic material, which comprises: (a) forming said thermoplastic material into a tubularly-shaped film; (b) forming said tubularly-shaped film into a sheet; (c) heat sealing said sheet at preselect intervals substantially perpendicularly to the movement of said sheet; (d) introducing said sheet on step c into a nip of interdigitating rollers having grooves substantially parallel to the axis of said rollers; (e) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent slipping of said film and thereby longitudinally stretch incremental portions of said sheets by a deflection of said sheet into the shape of said grooves: (f) withdrawing said sheet from said rollers at a velocity greater than the rotational velocity of said roller; and (g) collecting the thus stretched sheet.
Claim 3
Dependent Claim
31 words
The process as defined in claim 1 wherein the withdrawal velocity of step f) is not greater than a factor of the draw ration of said nip of said interdigitating rollers.
Claim 4
Dependent Claim
9 words
The product produced by the process of claim 1.
Claim 5
Dependent Claim
159 words
A process for manufacturing tubularly-shaped thermoplastic products of improved strip tensile breaking strength from an orientable thermoplastic material, which comprises: (a) forming said thermoplastic material into a tubularly-shaped film; (b) forming said tubularly-shaped film into a sheet; (c) heat sealing said sheet at preselect intervals substantially perpendicularly to the movement of said sheet; (d) introducing said sheet of step c) into a nip of interdigitating rollers having grooves substantially perpendicular to the axis of said rollers; (e) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent narrowing of said film prior to introduction thereby to laterally stretch incremental portions of said sheet by deflection of said sheet into the shape of said grooves; (f) laterally elongating and withdrawing said sheet from said rollers at a velocity substantially corresponding to the velocity of introduction; and (g) collecting the thus stretched sheet.
Claim 6
Dependent Claim
159 words
A process for manufacturing tubularly-shaped thermoplastic products of improved strip tensile breaking strength from an orientable thermoplastic material, which comprises: (a) forming said thermoplastic material into a tubularly-shaped film; (b) forming said tubularly-shaped film into a sheet; (c) heat sealing said sheet at preselect intervals substantially perpendicularly to the movement of said sheet; (d) introducing said sheet of step c) into a nip of interdigitating rollers having grooves substantially perpendicular to the axis of said rollers; (e) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent narrowing of said film prior to introduction thereby to laterally stretch incremental portions of said sheet by deflection of said sheet into the shape of said grooves; (f) laterally elongating and withdrawing said sheet from said rollers at a velocity substantially corresponding to the velocity of introduction; and (g) collecting the thus stretched sheet.
Claim 7
Dependent Claim
9 words
The product produced by the process of claim 4.
Claim 8
Dependent Claim
253 words
A process for manufacturing tubularly-shaped thermoplastic products of improved strip tensile breaking strength from an orientable thermoplastic material, which comprises: (a) forming said thermoplastic material into a tubularly-shaped film; (b) forming said tubularly-shaped film into a sheet; (c) heat sealing said sheet at preselect intervals substantially perpendicularly to the movement of said sheet; (d) introducing said sheet of step c) into a nip of interdigitating rollers having grooves substantially parallel to the axis of said rollers; (e) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent slipping of said film and thereby longitudinally stretch incremental portions of said sheet by a deflection of said sheet into the shape of said grooves: (f) withdrawing said sheet from said rollers at a velocity greater than the rotational velocity of said rollers; (g) introducing said longitudinally stretched sheet into a nip of interdigitating rollers having grooves substantially perpendicular to the axis of said rollers; (h) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent narrowing of said film prior to introduction thereby to laterally stretch incremental portions of said sheet by deflection of said sheet into the shape of said grooves; (i) laterally elongating and withdrawing said sheet from said rollers at a velocity substantially corresponding to the velocity of introduction; and (j) collecting the bi-axially stretched sheet.
Claim 9
Dependent Claim
253 words
A process for manufacturing tubularly-shaped thermoplastic products of improved strip tensile breaking strength from an orientable thermoplastic material, which comprises: (a) forming said thermoplastic material into a tubularly-shaped film; (b) forming said tubularly-shaped film into a sheet; (c) heat sealing said sheet at preselect intervals substantially perpendicularly to the movement of said sheet; (d) introducing said sheet of step c) into a nip of interdigitating rollers having grooves substantially parallel to the axis of said rollers; (e) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent slipping of said film and thereby longitudinally stretch incremental portions of said sheet by a deflection of said sheet into the shape of said grooves: (f) withdrawing said sheet from said rollers at a velocity greater than the rotational velocity of said rollers; (g) introducing said longitudinally stretched sheet into a nip of interdigitating rollers having grooves substantially perpendicular to the axis of said rollers; (h) controlling the velocity of introduction of said sheet into said nip to assume and maintain the velocity substantially identical to the surface velocity of said rollers to prevent narrowing of said film prior to introduction thereby to laterally stretch incremental portions of said sheet by deflection of said sheet into the shape of said grooves; (i) laterally elongating and withdrawing said sheet from said rollers at a velocity substantially corresponding to the velocity of introduction; and (j) collecting the bi-axially stretched sheet.
Claim 10
Dependent Claim
18 words
The process as defined in claim 6 wherein steps d) to i) are again repeated prior to j).
Claim 11
Dependent Claim
18 words
The process as defined in claim 6 wherein steps g) to i) are twice repeated to step j).
Claim 12
Dependent Claim
9 words
The product produced by the process of claim 6.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-17 | 1984-08-18 | 1985-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-17 | 1988-08-18 | 1989-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-17 | 1992-08-18 | 1993-02-17 | $7700.00 | Window Closed / Lapsed |