US6217818B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making preform and container with crystallized neck finish
Assignee: Graham Packaging Pet Technologies Inc
•
Filing: 1995-09-26
•
Granted: 2001-04-17
•
Expires: 2015-09-26
Abstract
Abstract A preform and container each having a crystallized neck finish and method of making the same, wherein the method involves introducing a first thermoplastic material into a first mold section to form a substantially crystallized neck portion of a preform, and introducing a second thermoplastic material into a second mold section to form a substantially amorphous body-forming portion of a preform. The first material may have a substantially higher crystallization rate than the second material, and/or the first mold section may be at a higher temperature than the second mold section. In one embodiment, an indexer carrying two core sets is movable between first and second cavity sets for sequentially molding the neck portions on the first core set in the first cavity set, and then transferring the cores and neck portions to the second cavity set for molding the body-forming portions. The method enables cost-effective manufacture of preforms with crystallized neck finishes and enables production of a thermal resistant finish within a close dimensional tolerance.
Inventors
- 👤 Wayne N. Collette
- 👤 Suppayan M. Krishnakumar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:19
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/16; B29C45/1615; B29C45/1625; B29C45/1657; B29C45/1684; B29C49/00; B29C49/0005; B29C49/071; B29C49/42; B29C49/64; B29C49/6409; B29C49/6436; B29C49/6454; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0822; B29C2035/0855; B29C2035/0861; B29C2045/1659; B29C49/22; B29C2049/222; B29C49/78; B29C2049/7879; B29C2949/00; B29C2949/07; B29C2949/0715; B29C2949/072; B29C2949/0724; B29C2949/0725; B29C2949/073; B29C2949/0733; B29C2949/076; B29C2949/0768; B29C2949/0769; B29C2949/077; B29C2949/0772; B29C2949/0773; B29C2949/0777; B29C2949/079; B29C2949/08; B29C2949/081; B29C2949/0811; B29C2949/0817; B29C2949/0819; B29C2949/082; B29C2949/0826; B29C2949/0829; B29C2949/0835; B29C2949/0861; B29C2949/0862; B29C2949/0863; B29C2949/0865; B29C2949/20; B29C2949/22; B29C2949/24; B29C2949/26; B29C2949/28; B29C2949/30; B29C2949/3008; B29C2949/3009; B29C2949/3012; B29C2949/3016; B29C2949/3018; B29C2949/302; B29C2949/3024; B29C2949/3026; B29C2949/3028; B29C2949/303; B29C2949/3032; B29C2949/3034; B29C2949/3036; B29C2949/3038; B29C45/03; B29C45/04; B29C45/0408; B29C45/0416; B29C45/0441; B29C45/045; B29C49/02; B29C49/06; B29C49/08; B29C49/087; B29C49/4273; B29C49/4283; B29C49/42832; B29C49/6604; B29C49/6605; B29K; B29K2067/00; B29K2105/00; B29K2105/25; B29K2105/253; B29K2105/26; B29K2667/00; B29K2995/00; B29K2995/0018; B29K2995/0025; B29K2995/0037; B29K2995/0039; B29K2995/004; B29K2995/0041; B29K2995/0043; Y; Y10; Y10S; Y10S264/00; Y10S264/907; Y10S264/908
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
273 words
A method of making a preform by molding, the molding steps comprising: introducing at least one first thermoplastic material into a first mold to form during a first molding step while under first molding conditions a substantially crystallized and opaque first portion of a preform, the first portion being substantially a neck finish of the preform, the first molding conditions including a first melt temperature and a first mold temperature selected to achieve the substantially crystallized and opaque first portion; transferring the first portion of the preform to a second mold; and introducing at least one second thermoplastic material into the second mold to form by a second molding step while under second molding conditions different from the first molding conditions a substantially amorphous and transparent second portion of the preform, the second portion being substantially a body-forming portion of the preform, the second material having a relatively low crystallization rate compared to the first material, and the second molding conditions including a second melt temperature and a second mold temperature selected to achieve the substantially amorphous and transparent second portion, the second molding conditions further allowing maintenance of compressive forces to bond the first and second portions; wherein during the first molding step a first molding core is positioned in the first mold for forming the first preform portion on the first core, and during the second molding step the first core and first preform portion are transferred to the second mold for forming the second preform portion over the first core; and cooling the second mold to enable solidification and removal of the first and second preform portions from the molds.
Claim 2
Independent Claim
273 words
A method of making a preform by molding, the molding steps comprising: introducing at least one first thermoplastic material into a first mold to form during a first molding step while under first molding conditions a substantially crystallized and opaque first portion of a preform, the first portion being substantially a neck finish of the preform, the first molding conditions including a first melt temperature and a first mold temperature selected to achieve the substantially crystallized and opaque first portion; transferring the first portion of the preform to a second mold; and introducing at least one second thermoplastic material into the second mold to form by a second molding step while under second molding conditions different from the first molding conditions a substantially amorphous and transparent second portion of the preform, the second portion being substantially a body-forming portion of the preform, the second material having a relatively low crystallization rate compared to the first material, and the second molding conditions including a second melt temperature and a second mold temperature selected to achieve the substantially amorphous and transparent second portion, the second molding conditions further allowing maintenance of compressive forces to bond the first and second portions; wherein during the first molding step a first molding core is positioned in the first mold for forming the first preform portion on the first core, and during the second molding step the first core and first preform portion are transferred to the second mold for forming the second preform portion over the first core; and cooling the second mold to enable solidification and removal of the first and second preform portions from the molds.
Claim 3
Dependent Claim
19 words
The method of claim 1 , wherein the first mold is at a higher temperature than the second mold.
Claim 4
Dependent Claim
37 words
The method of claim 1 , wherein during the first molding step a second core with a first preform portion is positioned in the second mold for simultaneously molding a second preform portion on the second core.
Claim 5
Dependent Claim
58 words
The method of claim 1 , wherein during the first molding step a plurality of first preform portions are molded on a plurality of first cores in a plurality of first molds, and during the second molding step a plurality of second preform portions are molded on the plurality of first cores in a plurality of second molds.
Claim 6
Dependent Claim
40 words
The method of claim 4 , wherein during the first molding step a plurality of second cores with first preform portions are positioned in the second molds for simultaneously molding a plurality of second preform portions on the second cores.
Claim 7
Dependent Claim
35 words
The method of claim 1 , wherein a flow-adjusting element is provided in at least one of the first and second molds to increase the flow rate of the second material adjacent the first material.
Claim 8
Dependent Claim
32 words
The method of claim 1 , wherein the second material comprises a predetermined polymer composition and the first material comprises the predetermined polymer composition with nucleating agents to increase the crystallization rate.
Claim 9
Dependent Claim
15 words
The method of claim 7 , wherein the predetermined polymer composition is a polyester composition.
Claim 10
Dependent Claim
15 words
The method of claim 8 , wherein the polyester composition is substantially polyethylene terephthalate (PET).
Claim 11
Dependent Claim
34 words
The method of claim 1 , wherein the first material is selected from the group consisting of polyester, polyester with nucleating agents, arylate polymers, polyethylene naphthalate (PEN), polycarbonate, polypropylene, polyimide, polysulfone, and acrylonitrile styrene.
Claim 12
Dependent Claim
36 words
The method of claim 1 , wherein the second material is selected from the group consisting of homopolymers, copolymers or blends of any one or more of: polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and post-consumer PET.
Claim 13
Dependent Claim
38 words
The method of claim 1 , further comprising introducing a nonthermoplastic material into at least one of the first and second molds to form a nonthermoplastic layer in at least one of the first and second preform portions.
Claim 14
Dependent Claim
27 words
The method of claim 1 , further comprising expanding the body-forming portion to form a container having a substantially transparent body portion and the crystallized neck portion.
Claim 15
Dependent Claim
35 words
The method of claim 1 , wherein one or more differences in temperature and pressure are used in the first and second molds to obtain the different molding conditions in the first and second molds.
Claim 16
Dependent Claim
26 words
The method of claim 1 , wherein the second molding step includes maintaining compressive forces to form a composite preform from the first and second portions.
Claim 17
Dependent Claim
30 words
The method of claim 15 , wherein differences in pressure are used in the first and second molds to obtain the different molding conditions in the first and second molds.
Claim 18
Dependent Claim
24 words
The method of claim 1 , wherein the average percent crystallinity of the first preform portion in the first mold is at least 30%.
Claim 19
Dependent Claim
20 words
The method of claim 16 , wherein the average percent crystallinity of the first preform portion is at least 35%.
Claim 20
Dependent Claim
20 words
The method of claim 17 , wherein the average percent crystallinity of the first preform portion is at least 40%.
Claim 21
Dependent Claim
22 words
The method of claim 1 , wherein the first portion is still warm when transferred on the core to the second mold.
Claim 22
Dependent Claim
26 words
The method of claim 1 , wherein the first and second portions are bonded by any one of melt, diffusion, chemical, chain entanglement and hydrogen bonding.
Claim 23
Dependent Claim
12 words
The method of claim 21 , wherein the bonding is melt bonding.
Claim 24
Dependent Claim
13 words
The method of claim 1 , wherein the first material is substantially polyester.
Claim 25
Dependent Claim
13 words
The method of claim 23 , wherein the second material is substantially polyester.
Claim 26
Dependent Claim
19 words
The method of claim 23 , wherein the first portion is substantially a monolayer of PET with nucleating agents.
Claim 27
Dependent Claim
20 words
The method of claim 25 , wherein the second portion is a multilayer including one or more layers of PET.
Claim 28
Independent Claim
278 words
A method of making a preform by molding, the molding steps comprising: introducing at least one first thermoplastic material into a first mold to form during a first molding step while under first molding conditions a substantially crystallized and opaque first portion of a preform, the first portion being substantially a neck finish of the preform, the first molding conditions including a first melt temperature and a first mold temperature, the first melt temperature being selected to achieve crystallization of the first thermoplastic material in the first mold, and the first mold temperature being selected to achieve the substantially crystallized and opaque first portion; transferring the first portion of the preform to a second mold; and introducing at least one second thermoplastic material into the second mold to form by a second molding step while under second molding conditions different from the first molding conditions a substantially amorphous and transparent second portion of the preform, the second portion being substantially a body-forming portion of the preform, the second material having a relatively low crystallization rate compared to the first material, and the second molding conditions including a second melt temperature and a second mold temperature selected to achieve the substantially amorphous and transparent second portion, the second molding conditions further allowing maintenance of compressive forces to bond the first and second portions; and wherein during the first molding step a first molding core is positioned in the first mold for forming the first preform portion on the first core, and during the second molding step the first core and first preform portion are transferred to the second mold for forming the second preform portion over the first core.
Claim 29
Independent Claim
278 words
A method of making a preform by molding, the molding steps comprising: introducing at least one first thermoplastic material into a first mold to form during a first molding step while under first molding conditions a substantially crystallized and opaque first portion of a preform, the first portion being substantially a neck finish of the preform, the first molding conditions including a first melt temperature and a first mold temperature, the first melt temperature being selected to achieve crystallization of the first thermoplastic material in the first mold, and the first mold temperature being selected to achieve the substantially crystallized and opaque first portion; transferring the first portion of the preform to a second mold; and introducing at least one second thermoplastic material into the second mold to form by a second molding step while under second molding conditions different from the first molding conditions a substantially amorphous and transparent second portion of the preform, the second portion being substantially a body-forming portion of the preform, the second material having a relatively low crystallization rate compared to the first material, and the second molding conditions including a second melt temperature and a second mold temperature selected to achieve the substantially amorphous and transparent second portion, the second molding conditions further allowing maintenance of compressive forces to bond the first and second portions; and wherein during the first molding step a first molding core is positioned in the first mold for forming the first preform portion on the first core, and during the second molding step the first core and first preform portion are transferred to the second mold for forming the second preform portion over the first core.
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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) | 2004-04-16 | 2004-10-16 | 2005-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-04-16 | 2008-10-16 | 2009-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-04-16 | 2012-10-16 | 2013-04-17 | $7700.00 | Window Closed / Lapsed |