US5336464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion blow molding of thermotropic liquid crystalline polymers
Assignee: CNA Holdings LLC
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Filing: 1992-11-20
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Granted: 1994-08-09
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Expires: 2012-11-20
Abstract
Abstract An extrusion blow molding process for a heat-treated, liquid crystalline polymer is provided. By the process, molten polymer having improved melt strength, is vertically extruded downward into space through a parison-forming, annular gap. Sag resistant parisons are formed. Beneficially, the parisons may be formed periodically. Advantageously, large-sized parts or structures may be produced.
Inventors
- 👤 Cheryl F. Corallo
- 👤 Robert B. Sandor
- 👤 Ralph S. Blake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:28
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/0005; B29C49/02; B29C49/04; B29C49/0411; B29C49/04112; B29C35/00; B29C49/041; B29K; B29K2105/00; B29K2105/0079; B29K2105/06; B29K2105/12; B29K2995/00; B29K2995/0037; B29K2995/0065
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
93 words
A method for extrusion blow molding a liquid crystalline polymer, said method comprising the steps of; heat-treating a liquid crystalline polymer so to enhance the melt strength of said polymer, said heat-treatment being conducted at a temperature near said polymer's melt temperature; melting said heat-treated liquid crystalline polymer at a suitable parison-forming temperature; forming a parison by vertically extruding the polymer melt generally downward into space; clamping a forming mold around said parison; blowing gas into the clamped parison to form a molded part; and opening said mold to provide the formed part.
Claim 2
Independent Claim
93 words
A method for extrusion blow molding a liquid crystalline polymer, said method comprising the steps of; heat-treating a liquid crystalline polymer so to enhance the melt strength of said polymer, said heat-treatment being conducted at a temperature near said polymer's melt temperature; melting said heat-treated liquid crystalline polymer at a suitable parison-forming temperature; forming a parison by vertically extruding the polymer melt generally downward into space; clamping a forming mold around said parison; blowing gas into the clamped parison to form a molded part; and opening said mold to provide the formed part.
Claim 3
Dependent Claim
16 words
The extrusion blow molding method of claim 1, wherein said liquid crystalline polymer is a polyester.
Claim 4
Dependent Claim
18 words
The extrusion blow molding method of claim 1, wherein said liquid crystalline polymer is a wholly aromatic polyester.
Claim 5
Dependent Claim
26 words
The extrusion blow molding method of claim 1, wherein said liquid crystalline polymer is a wholly aromatic polyester made from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid monomers.
Claim 6
Dependent Claim
19 words
The extrusion blow molding method of claim 1, wherein said liquid crystalline polymer is a thermotropic liquid crystalline polymer.
Claim 7
Dependent Claim
14 words
The extrusion blow molding method of claim 1, wherein said forming mold is heated.
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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) | 1997-08-08 | 1998-02-07 | 1998-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-08 | 2002-02-07 | 2002-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-08 | 2006-02-07 | 2006-08-09 | $7700.00 | Window Closed / Lapsed |