US4572811A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing polyester containers
Assignee: Yoshino Kogyosho Co Ltd
•
Filing: 1984-01-11
•
Granted: 1986-02-25
•
Expires: 2004-01-11
Abstract
Abstract Spherulites are grown in such sections as neck, neck end, bottom center and/or bottom periphery of a hollow bottle-shaped container of biaxially oriented-blow molded polyethylene terephthalate (PET) resin where the resin is not substantially subjected to orientation, thereby to improve the thermal resistance, stiffness and content resistance of such sections to almost the same extent as the biaxially oriented sections of the container such as the shoulder and cylindrical sections thereof. The aforesaid non-oriented sections of the preformed piece before being blow-molded or of the blow-molded container are first heated at or above the glass transition temperature of the resin for about 2-8 minutes and are then annealed at room temperature, with the result that such sections have a spherulite texture of an increased density and are rendered opaque.
Inventors
- 👤 Akiho Ota
- 👤 Fumio Negishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:12
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/02; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0811; B29C49/48; B29C49/4823; B29C2049/4838; B29C49/6436; B29C49/6445; B29C49/6452; B29C49/6604; B29C49/6605; B29C71/0063; B29K; B29K2067/00; B29K2995/00; B29K2995/0037; B29K2995/004; B29K2995/0041; B29K2995/0043; Y; Y10; Y10S; Y10S264/00; Y10S264/907; Y10S264/908
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
145 words
A method for producing a hollow bottle-shaped container of biaxially oriented polyethylene terephthalate having a non-biaxially oriented neck section, a bottom section, and a biaxially oriented body section extending between said neck section and bottom section from a preform having a prefinished neck section, said method comprising the steps of: biaxially orienting in a mold only the regions of the preform below said neck section, including those immediately therebelow, to form the hollow bottle-shaped container, heating only the prefinished neck section of said container to a heating temperature of at least the glass transition temperature of the polyethylene terephthalate for a heating time at least long enough to begin formation of crystal nuclei, and thereafter cooling the neck section to increase the density of the spherulite texture only in the neck section to produce a container having a crystallized area only in the neck section.
Claim 2
Independent Claim
145 words
A method for producing a hollow bottle-shaped container of biaxially oriented polyethylene terephthalate having a non-biaxially oriented neck section, a bottom section, and a biaxially oriented body section extending between said neck section and bottom section from a preform having a prefinished neck section, said method comprising the steps of: biaxially orienting in a mold only the regions of the preform below said neck section, including those immediately therebelow, to form the hollow bottle-shaped container, heating only the prefinished neck section of said container to a heating temperature of at least the glass transition temperature of the polyethylene terephthalate for a heating time at least long enough to begin formation of crystal nuclei, and thereafter cooling the neck section to increase the density of the spherulite texture only in the neck section to produce a container having a crystallized area only in the neck section.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said heating temperature is at least 70° C.
Claim 4
Dependent Claim
18 words
A method according to claim 2, wherein said heating temperature is in the range of about 120°-180° C.
Claim 5
Dependent Claim
18 words
A method according to claim 3, wherein said heating temperature is in the range of about 140°-170° C.
Claim 6
Dependent Claim
13 words
A method according to claim 1, wherein said heating time is 3-8 minutes.
Claim 7
Dependent Claim
13 words
A method according to claim 3, wherein said heating time is 3-8 minutes.
Claim 8
Dependent Claim
13 words
A method according to claim 4, wherein said heating time is 3-5 minutes.
Claim 9
Dependent Claim
23 words
A method according to claim 1, wherein the entire neck section is heated and cooled so that said entire neck section is crystallized.
Claim 10
Dependent Claim
34 words
A method according to claim 1, wherein only an upper end portion of said prefinished neck section is heated and cooled so that only said upper end portion of said neck section is crystallized.
Claim 11
Dependent Claim
13 words
A method according to claim 1, wherein said prefinished neck section is threaded.
Claim 12
Dependent Claim
36 words
A method according to claim 1, wherein said heating element comprises an electromagnetic induction heating device, and a metal ring is fitted onto the outside of said neck section of the container as a heating medium.
Claim 13
Dependent Claim
27 words
A method according to claim 9, wherein said upper end portion of said prefinished neck section is heated by means of a far infrared ray bar heater.
Claim 14
Dependent Claim
49 words
A method according to claim 8, wherein said entire neck section is heated by means of a radiant heater surrounding said neck section, and a portion of said container immediately adjacent said neck section is shielded from thermal influence of said radiant heater by means of a shielding plate.
References Cited (Backward Citations)
US3562273A
Cited
US3544673A
Cited
US3555135A
Cited
US3733309A
Cited
US3733309B1
Cited
US4264558A
Cited
DE2540930A1
Cited
US3948404A
Cited
US4039641A
Cited
US4108937A
Cited
US4025594A
Cited
US4179488A
Cited
US4385089A
Cited
US4150079A
Cited
US4358491A
Cited
JPS5468384A
Cited
US4151249A
Cited
US4320083A
Cited
GB2074932A
Cited
US4233022A
Cited
JPS5468385A
Cited
JPS574741A
Cited
US4476084A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |