US4216253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Molding process for the fabrication of hollow shaped articles
Assignee: Rhone Poulenc Industries SA
•
Filing: 1977-12-07
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Granted: 1980-08-05
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Expires: 1997-12-07
Abstract
Abstract Hollow shaped articles are extruded, advantageously continuously extruded, from molten thermoplastics by controlled cooling of the molten charge prior to entry into an extrusion die.
Inventors
- 👤 Claude Bonnebat
- 👤 Gerard Halna du Fretay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:04
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/78; B29C48/86; B29C48/87; B29C48/03; B29C48/09; B29C48/10; B29C48/30; B29C48/32; B29C48/36; B29C48/362; B29C48/395; B29C48/865; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1397
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
86 words
In a process for the manufacture of hollow-shaped thermoplastic articles comprising forming a molten mass of thermoplastic polymer, extruding said mass and subsequently forming the extruded thermoplastic into a hollow-shaped article, the improvement comprising cooling the molten thermoplastic mass from its original temperature T 0 , which is above its temperature of complete fusion T FF , to a temperature T 1 which is between temperature T FF and the temperature of the beginning of crystallization T DC , prior to entry into the extrusion die.
Claim 2
Dependent Claim
86 words
In a process for the manufacture of hollow-shaped thermoplastic articles comprising forming a molten mass of thermoplastic polymer, extruding said mass and subsequently forming the extruded thermoplastic into a hollow-shaped article, the improvement comprising cooling the molten thermoplastic mass from its original temperature T 0 , which is above its temperature of complete fusion T FF , to a temperature T 1 which is between temperature T FF and the temperature of the beginning of crystallization T DC , prior to entry into the extrusion die.
Claim 3
Dependent Claim
17 words
The process as defined by claim 1, wherein the temperature of the thermoplastic mass is changed homogeneously.
Claim 4
Dependent Claim
23 words
The process as defined by claim 1, wherein said extrusion is performed by passing the molten thermoplastic mass through a calibrated, extrusion die.
Claim 5
Dependent Claim
25 words
The process as defined in claim 3, wherein said hollow-shaped article is formed from said extruded thermoplastic mass by a conformation and/or blow molding device.
Claim 6
Dependent Claim
20 words
The process as defined by claim 1, wherein said molten thermoplastic mass has a viscosity lower than about 30,000 poise.
Claim 7
Dependent Claim
21 words
The process as defined by claim 5, wherein said molten thermoplastic mass has a viscosity between about 1,500 and 15,000 poise.
Claim 8
Dependent Claim
18 words
The process as defined by claim 1, wherein said thermoplastic polymer comprises homopolymers and copolymers of polyethylene terephthalate.
Claim 9
Dependent Claim
52 words
The process as defined by claim 7, wherein said thermoplastic polymer is melted at said temperature T 0 which is at least 5° C. above the temperature of complete fusion T FF of said thermoplastic polymer and subsequently, homogeneously cooled to said temperature T 1 prior to entry into the extrusion die.
Claim 10
Dependent Claim
23 words
The process as defined by claim 8, wherein said temperature T 1 is not more than 50° C. below temperature T FF .
Claim 11
Dependent Claim
24 words
The process as defined by claim 9, wherein said temperature T 1 is between about 25° and 5° C. below temperature T FF .
Claim 12
Dependent Claim
46 words
The process as defined by claim 8, wherein said thermoplastic is polyethylene terephthalate having a molten viscosity between about 1500 and 15,000 poise and wherein temperature T 0 is between about 270° and 285° C. and temperature T 1 is between about 220° and 250° C.
Claim 13
Dependent Claim
31 words
The process as defined by claim 4, wherein said cooling is accomplished by a heat exchange means located between the source of the molten thermoplastic mass and the calibrated extrusion die.
Claim 14
Dependent Claim
32 words
The process as defined by claim 1, wherein the molten thermoplastic polymer is selected from the group consisting of a crystalline thermoplastic polymer, a semi-crystalline thermoplastic polymer and an amorphous thermoplastic polymer.
Claim 15
Dependent Claim
14 words
The process as defined by claim 13, wherein the molten thermoplastic polymer is crystalline.
Claim 16
Dependent Claim
14 words
The process as defined by claim 13, wherein the molten thermoplastic polymer is sem-crystalline.
Claim 17
Dependent Claim
14 words
The process as defined by claim 13, wherein the molten thermoplastic polymer is amorphous.
Claim 18
Dependent Claim
12 words
The process as defined by claim 1, the same being conducted continuously.
Claim 19
Dependent Claim
11 words
Hollow-shaped amorphous thermoplastic articles prepared by the process of claim 1.
Claim 20
Dependent Claim
11 words
Hollow-shaped crystalline thermoplastic articles prepared by the process of claim 1.
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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) | 1983-08-05 | 1984-02-04 | 1984-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-05 | 1988-02-04 | 1988-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-05 | 1992-02-04 | 1992-08-05 | $7700.00 | Window Closed / Lapsed |