Patent US4025253A successfully refreshed from Google Patents.
US4025253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the preparation of plastic articles by extrusion
Assignee: Dow Chemical Co
•
Filing: 1976-01-15
•
Granted: 1977-05-24
•
Expires: 1996-01-15
Abstract
Abstract Thin plastic tubes are prepared by extruding a heat plastified tube, stretching the tube over a gas bearing having a diameter greater than the diameter of the extruded tube, cooling the surface of the tube adjacent the gas bearing and passing the tube over a cooling mandrel having an outside diameter approximating the diameter of the gas bearing, thereby lowering the temperature of the tube below its heat plastifying temperature.
Inventors
- 👤 Carl B. Havens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:58
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/908; B29C48/03; B29C48/09; B29C48/10; B29C48/901; B29C48/902; B29C48/903; B29C48/911; B29C48/9115; B29C48/912; B29C2793/00; B29C2793/0063; B29C2948/00; B29C2948/92; B29C2948/92504; B29C2948/92609; B29C2948/92647; B29C2948/92704; B29C48/001; B29C48/0018; B29C48/0019; B29C48/0022; B29C48/885; B29C48/9135
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
177 words
An extrusion apparatus, the apparatus being particularly suited and adapted for the preparation of synthetic resinous thermoplastic extrudable tubing, the apparatus comprising in cooperative combination a source of heat plastified synthetic resinous extrudable film forming material, an extrusion die, the die having an annular extrusion orifice, the orifice being in operative communication with said source, a generally annular gas bearing in spaced relationship to the orifice and being generally coaxially disposed therewith, the bearing having an outside diameter greater than the orifice, a mandrel disposed adjacent to the bearing and remote from the orifice, the mandrel having an outer surface having the general cross-sectional configuration of the cross-sectional configuration of the bearing in a plane generally normal to an axis passing generally centrally through the die, bearing and mandrel, the bearing and the mandrel adapted to receive thereabout a tube extruded from the die, the mandrel having in operative association therewith cooling means to maintain the outer surface of the mandrel at a temperature below the heat plastification temperature of a heat plastifiable extrudable film forming material.
Claim 2
Dependent Claim
177 words
An extrusion apparatus, the apparatus being particularly suited and adapted for the preparation of synthetic resinous thermoplastic extrudable tubing, the apparatus comprising in cooperative combination a source of heat plastified synthetic resinous extrudable film forming material, an extrusion die, the die having an annular extrusion orifice, the orifice being in operative communication with said source, a generally annular gas bearing in spaced relationship to the orifice and being generally coaxially disposed therewith, the bearing having an outside diameter greater than the orifice, a mandrel disposed adjacent to the bearing and remote from the orifice, the mandrel having an outer surface having the general cross-sectional configuration of the cross-sectional configuration of the bearing in a plane generally normal to an axis passing generally centrally through the die, bearing and mandrel, the bearing and the mandrel adapted to receive thereabout a tube extruded from the die, the mandrel having in operative association therewith cooling means to maintain the outer surface of the mandrel at a temperature below the heat plastification temperature of a heat plastifiable extrudable film forming material.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein the gas bearing has a circular cross-sectional configuration in a plane normal to the axis of extrusion.
Claim 4
Dependent Claim
26 words
The apparatus of claim 1 wherein a vent is provided from a location lying between the extrusion die and the gas bearing and space external thereto.
Claim 5
Dependent Claim
27 words
The apparatus of claim 1 including means to provide a generally radially inwardly flowing planiform blast of cooling gas adjacent to and generally coaxial with the bearing.
Claim 6
Dependent Claim
23 words
The apparatus of claim 1 including a means to provide a generally planiform radially inwardly flowing gas stream adjacent the annular extrusion orifice.
Claim 7
Dependent Claim
15 words
The apparatus of claim 1 wherein the gas bearing is a generally porous metal cylinder.
Claim 8
Dependent Claim
214 words
An extrusion apparatus, the apparatus particularly suited and adapted for the preparation of synthetic resinous thermoplastic extrudable tubing, the apparatus comprising in cooperative combination a source of heat plastified synthetic resinous extrudable film forming material, an extrusion die, the die having an annular extrusion orifice, the orifice being in operative communication with said source, a generally annular gas bearing in spaced relationship to the orifice and being generally coaxially disposed therewith, the bearing having an outside diameter greater than the orifice gas bearing having a circular cross-sectional configuration in a plane normal to the axis of extrusion, a mandrel disposed adjacent to the bearing and remote from the orifice, the mandrel having an outer surface having the general cross-sectional configuration of the cross-sectional configuration of the bearing in a plane generally normal to an axis passing generally centrally through the die, bearing and mandrel, the bearing and the mandrel adapted to receive thereabout a tube extruded from the die, the mandrel having in operative association therewith cooling means to maintain the outer surface of the mandrel at a temperature below the heat plastification temperature of a heat plastifiable extrudable film forming material and means to provide a generally radially inwardly flowing planiform blast of cooling gas adjacent to and generally coaxial with the mandrel.
Claim 9
Dependent Claim
214 words
An extrusion apparatus, the apparatus particularly suited and adapted for the preparation of synthetic resinous thermoplastic extrudable tubing, the apparatus comprising in cooperative combination a source of heat plastified synthetic resinous extrudable film forming material, an extrusion die, the die having an annular extrusion orifice, the orifice being in operative communication with said source, a generally annular gas bearing in spaced relationship to the orifice and being generally coaxially disposed therewith, the bearing having an outside diameter greater than the orifice gas bearing having a circular cross-sectional configuration in a plane normal to the axis of extrusion, a mandrel disposed adjacent to the bearing and remote from the orifice, the mandrel having an outer surface having the general cross-sectional configuration of the cross-sectional configuration of the bearing in a plane generally normal to an axis passing generally centrally through the die, bearing and mandrel, the bearing and the mandrel adapted to receive thereabout a tube extruded from the die, the mandrel having in operative association therewith cooling means to maintain the outer surface of the mandrel at a temperature below the heat plastification temperature of a heat plastifiable extrudable film forming material and means to provide a generally radially inwardly flowing planiform blast of cooling gas adjacent to and generally coaxial with the mandrel.
References Cited (Backward Citations)
US2433937A
Cited
US2987767A
Cited
US3170011A
Cited
US3284552A
Cited
US3709290A
Cited
US3819790A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |