US4874657A
Expired / Lapsed
US
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Methods of producing biaxially-oriented polymer product, and the product produced thereby
Assignee: Alcoa Corp
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Filing: 1986-11-24
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Granted: 1989-10-17
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Expires: 2006-11-24
Abstract
Abstract In accordance with the instant invention, biaxially-oriented polymer sheet is produced by continuously forging polymer feedstock between pairs of converging opposed surfaces. After it is biaxially-oriented, the sheet product is either cooled or heated while being restrained and advanced. The sheet produced by the process and apparatus has substantially uniform strain distribution over the width and length thereof as well as through the thickness thereof.
Inventors
- 👤 Ying-Cheng Lo
- 👤 Darral V. Humphries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:48
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/18; B29C43/00; B29C43/02; B29C43/22; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/09; B29C48/25; B29C48/30; B29C48/305; B29C55/10; B29C55/12; B29C67/00; B29C67/0029; B29K; B29K2995/00; B29K2995/0037; B29K2995/0041; B29K2995/005; B29K2995/0053; Y; Y10; Y10S; Y10S428/00; Y10S428/91
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
158 words
A method of producing biaxially-oriented polymer product from solid feedstock of solid polymer material comprising the steps of: introducing feedstock of solid polymer material in an axial direction between at least a pair of moving opposed surfaces, which surfaces converge in a downstream direction to compress the solid material while advancing the solid material; biaxially-orienting the solid material by simultaneously elongating the solid material in a longitudinal direction; spreading the solid material in a lateral direction, and reducing the thickness of the solid material, all by advancing the solid material between and with the moving opposed surfaces; maintaining the temperature of the solid material of the feedstock and the moving opposed surfaces between the glass transition temperature and the viscous flow temperature of the polymer thereof as the feedstock is being biaxially-oriented and restraining the polymer product after it has been formed from the feedstock for a period of time sufficient to stabilize the morphology and configuration thereof.
Claim 2
Independent Claim
158 words
A method of producing biaxially-oriented polymer product from solid feedstock of solid polymer material comprising the steps of: introducing feedstock of solid polymer material in an axial direction between at least a pair of moving opposed surfaces, which surfaces converge in a downstream direction to compress the solid material while advancing the solid material; biaxially-orienting the solid material by simultaneously elongating the solid material in a longitudinal direction; spreading the solid material in a lateral direction, and reducing the thickness of the solid material, all by advancing the solid material between and with the moving opposed surfaces; maintaining the temperature of the solid material of the feedstock and the moving opposed surfaces between the glass transition temperature and the viscous flow temperature of the polymer thereof as the feedstock is being biaxially-oriented and restraining the polymer product after it has been formed from the feedstock for a period of time sufficient to stabilize the morphology and configuration thereof.
Claim 3
Dependent Claim
33 words
The method of claim 1, wherein the moving surfaces converge towards one another at an angle, the angle being in the approximate range of greater than zero degrees and less than six degrees.
Claim 4
Dependent Claim
33 words
The method of claim 1, wherein both the material is heated to a temperature level between the glass transition temperature and the viscous flow temperature of the polymer prior to initiating the process.
Claim 5
Dependent Claim
33 words
The method of claim 2, wherein the moving surfaces are heated to a temperature level between the glass transition temperature and the viscous flow temperature of the polymer prior to initiating the process.
Claim 6
Dependent Claim
14 words
The method of claim 1, wherein the material is cooled during the restraining step.
Claim 7
Dependent Claim
14 words
The method of claim 1, wherein the material is heated during the restraining step.
Claim 8
Dependent Claim
12 words
The method of claim 1, wherein the polymer is a semicrystalline polymer.
Claim 9
Dependent Claim
27 words
The method of claim 7, wherein the polymer is selected from the group consisting of polypropylene, polyethylene, ultrahigh-molecular weight polyethylene, polyacetal, polyamide, polyethylene terephthalate and polybutylene terephthalate.
Claim 10
Dependent Claim
12 words
The method of claim 1, wherein the polymer is an amorphous material.
Claim 11
Dependent Claim
23 words
The method of claim 9, wherein the amorphous material is selected from the group consisting of polyvinyl chloride, polymethylmethacrylate, polycarbonate and polyethylene terephthalate.
Claim 12
Dependent Claim
26 words
The method of claim 1, wherein the steps are continuous with the step of restraining the feedstock occurring immediately after the step of deforming the material.
Claim 13
Independent Claim
141 words
A method of producing geometrically stable, biaxially-oriented polymer sheet from solid unoriented feedstock, the method comprising the steps of: biaxially orienting the solid unoriented feedstock to form the biaxially oriented sheet by inserting the unoriented feedstock between converging belt surfaces moving in a longitudinal direction to apply compressive pressure against the feedstock in order to reduce the thickness of the feedstock while spreading the feedstock laterally with respect to the direction of movement; maintaining the temperature of the feedstock between the glass transition temperature and the viscous flow temperature of the material thereof while the feedstock is being biaxially oriented, and restraining the biaxially oriented sheet between longitudinally moving, parallel belt surfaces as the sheet emerges from the conveying belt surfaces to stabilize the biaxially oriented sheet, whereby the sheet remains flat upon emerging from between the opposed parallel belt surfaces.
Claim 14
Independent Claim
141 words
A method of producing geometrically stable, biaxially-oriented polymer sheet from solid unoriented feedstock, the method comprising the steps of: biaxially orienting the solid unoriented feedstock to form the biaxially oriented sheet by inserting the unoriented feedstock between converging belt surfaces moving in a longitudinal direction to apply compressive pressure against the feedstock in order to reduce the thickness of the feedstock while spreading the feedstock laterally with respect to the direction of movement; maintaining the temperature of the feedstock between the glass transition temperature and the viscous flow temperature of the material thereof while the feedstock is being biaxially oriented, and restraining the biaxially oriented sheet between longitudinally moving, parallel belt surfaces as the sheet emerges from the conveying belt surfaces to stabilize the biaxially oriented sheet, whereby the sheet remains flat upon emerging from between the opposed parallel belt surfaces.
Claim 15
Dependent Claim
30 words
The method of claim 12 wherein the belt surfaces are continuously wedged into abutment with the feedstock and sheet by platens engaging belts on which the belt surfaces are disposed.
Claim 16
Dependent Claim
20 words
The method of claim 13 wherein the sheet is cooled while being restrained by the longitudinally moving, parallel belt surfaces.
Claim 17
Dependent Claim
20 words
The method of claim 13 wherein the sheet is heated while being restrained by the longitudinally moving, parallel belt surfaces.
Claim 18
Dependent Claim
31 words
The method of claim 13 wherein the converging belt surfaces converge toward one another at an angle in the approximate range of greater than zero degrees and less than six degrees.
Claim 19
Dependent Claim
38 words
The method of claim 13 wherein the feedstock is rectangular in cross section and the belt surfaces engaging the feedstock and sheet are planar and flat resulting in biaxially oriented sheet having continuously parallel upper and lower surfaces.
Claim 20
Independent Claim
125 words
A method of producing biaxially-oriented polymer sheet from feedstock of solid polymer comprising the steps of: reducing the thickness of the feedstock between a pair of opposed, continuous belts which converge in at least one zone to biaxially orient the material of the feedstock while reducing the thickness of the feedstock to that of the sheet; maintaining the temperature of the feedstock between the glass transition temperature and the viscous flow temperature of the material thereof during the step of reducing the thickness of the feedstock; and restraining the sheet produced by reducing the thickness of the feedstock to the thickness of the sheet so that the sheet stabilizes, whereby the sheet emerges from the restraining step as a sheet having a stable, planar configuration.
Claim 21
Independent Claim
125 words
A method of producing biaxially-oriented polymer sheet from feedstock of solid polymer comprising the steps of: reducing the thickness of the feedstock between a pair of opposed, continuous belts which converge in at least one zone to biaxially orient the material of the feedstock while reducing the thickness of the feedstock to that of the sheet; maintaining the temperature of the feedstock between the glass transition temperature and the viscous flow temperature of the material thereof during the step of reducing the thickness of the feedstock; and restraining the sheet produced by reducing the thickness of the feedstock to the thickness of the sheet so that the sheet stabilizes, whereby the sheet emerges from the restraining step as a sheet having a stable, planar configuration.
Claim 22
Dependent Claim
29 words
The method of claim 18, wherein the feedstock and belts are heated to a temperature above the glass transition temperature and below the viscous flow temperature of the feedstock.
Claim 23
Dependent Claim
13 words
The method of claim 19, wherein the sheet is cooled while being restrained.
Claim 24
Dependent Claim
13 words
The method of claim 19, wherein the sheet is heated while being restrained.
Claim 25
Dependent Claim
13 words
The method of claim 19, wherein the polymer feedstock is a semi-crystalline material.
Claim 26
Dependent Claim
28 words
The method of claim 22, wherein the polycrystalline material is selected from the group consisting of polypropylene, polyethylene, ultrahigh-molecular weight polyethylene, polyacetal, polyamide, polyethylene terephthalate, and polybutylene terephthalate.
Claim 27
Dependent Claim
12 words
The method of claim 19, wherein the polymer is an amorphous material.
Claim 28
Dependent Claim
23 words
The method of claim 24, wherein the amorphous material is selected from the group consisting of polyvinyl chloride, polymethylmethacrylate, polycarbonate and polyethylene terephthalate.
Claim 29
Dependent Claim
42 words
The method of claim 18, further including the step of controlling the temperature of the feedstock and the belts during advancement of the feedstock to equalize surface friction between the feedstock and the belts with the compressive deformation resistance of the feedstock.
Claim 30
Dependent Claim
27 words
The method of claim 18, wherein the belts are supported uniformly over those portions in engagement with the feedstock and sheet during advancement of the feedstock sheet.
Claim 31
Dependent Claim
103 words
The sheet produced continuously by the process of claim 18, wherein the sheet is rectangular in cross-section and in the direction of sheet extent formed of a semi-crystalline thermoplastic polymer which is biaxially-oriented; the sheet having a density which is equal to or greater than the density of the unoriented polymer and having a microstructure substantially devoid of process-induced microvoids and microfibrils; the sheet being comprised of compressed, platelet-like, crystalline aggregates, which are biaxially-oriented in the direction of the sheet extent, the sheet having a substantially uniform distribution of deformed crystalline aggregates over the length and width thereof and through the thickness thereof.
Claim 32
Dependent Claim
38 words
The sheet of claim 28, wherein the sheet has a thickness greater than approximately 0.03 inches and less than approximately 0.5 inches with a thickness-to-width ratio less than approximately 0.04 and a length of at least 20 feet.
Claim 33
Dependent Claim
21 words
The sheet of claim 29, having a filler material included therein which comprises up to 60% by weight of the sheet.
Claim 34
Dependent Claim
71 words
The sheet continuously produced by the method of claim 18, wherein the sheet is made of a thermoplastic amorphous polymer, is rectangular, biaxially-oriented and has a density which is at least equal to the density of the unoriented amorphous thermoplastic polymer; the sheet having a substantially uniform distribution of strain over the length and width thereof and through the thickness thereof and substantially constant mechanical and physical properties in all planes.
Claim 35
Dependent Claim
38 words
The sheet of claim 31, wherein the sheet has a thickness greater than approximately 0.03 inches and less than approximately 0.5 inches with a thickness-to-width ratio less than approximate 0.04 and a length of at least 20 feet.
Claim 36
Dependent Claim
21 words
The sheet of claim 31, having a filler material included therein which comprises up to 60% by weight of the sheet.
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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) | 1992-10-16 | 1993-04-17 | 1993-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-16 | 1997-04-17 | 1997-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-16 | 2001-04-17 | 2001-10-17 | $7700.00 | Window Closed / Lapsed |