US3892828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making plastic articles having easily severable flash
Assignee: Continental Can Co Inc
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Filing: 1973-06-07
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Granted: 1975-07-01
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Expires: 1993-06-07
Abstract
Abstract A method of making an article which comprises introducing a parison laminate having a high strength inner lamina and a low strength outer lamina into an open mold and closing the mold to enclose the laminate and pinching the laminate at the parting areas of the mold sufficiently to squeeze out the high strength lamina leaving a flash-connecting, easily severable, low strength lamina and producing an article having a high gloss exterior with a tough and strong body portion. Either lamina may incorporate a coloring pigment.
Inventors
- 👤 Arden R Weatherly
- 👤 Carson F Buckman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:25
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/22; B29C48/00; B29C48/03; B29C48/09; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/32; B29C48/335; B29C48/336; B29C49/02; B29C49/04; B29C49/42; B29C49/48; B29C49/4802; B29C2049/4805; B29C49/482; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0608; B29K2023/0633; B29K2023/065; B29L; B29L2031/00; B29L2031/46; B29L2031/463; B29L2031/712; B29L2031/7158; Y; Y10; Y10S; Y10S425/00; Y10S425/806
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
112 words
A method of making a thermoplastic article having easily severable flash comprising the steps of coextruding into open mold sections a laminae of plastic in the form of a parison having a high density inner lamina and a low density external lamina, then closing the mold sections to enclose the parison and in closing the mold sections squeezing the laminae at the parting line of the mold sections to an extent sufficient to squeeze out the high density lamina at the parting line leaving thereat a thin easily severable weak web of low density lamina connecting the flash with the parison, and expanding the parison to form the article within the mold.
Claim 2
Independent Claim
112 words
A method of making a thermoplastic article having easily severable flash comprising the steps of coextruding into open mold sections a laminae of plastic in the form of a parison having a high density inner lamina and a low density external lamina, then closing the mold sections to enclose the parison and in closing the mold sections squeezing the laminae at the parting line of the mold sections to an extent sufficient to squeeze out the high density lamina at the parting line leaving thereat a thin easily severable weak web of low density lamina connecting the flash with the parison, and expanding the parison to form the article within the mold.
Claim 3
Dependent Claim
22 words
The invention according to claim 1 wherein said high density lamina is high density polyethylene and low density lamina is low polyethylene.
Claim 4
Dependent Claim
45 words
The invention according to claim 1 wherein said parison is formed as a tube and partially inflated after being introduced into the mold and said partially inflated tube is indented by portions of the mold and then pinched to squeeze out the high density lamina.
Claim 5
Dependent Claim
114 words
In a method of making a plastic container formed of an expansible laminae of material having an inner core of high density and a material of low density forming an outer sheath integral with the inner core, the steps of introducing the laminae into open mold, sections then while in a plastic state, closing the mold sections against the laminae at a pressure sufficient to exude the high density material from between sections of the mold at the parting line thereof and leaving a web of said low density material therebetween and thereby forming an easily severable connection between the flash and the container formed upon subsequent expansion of said laminae within the mold.
Claim 6
Dependent Claim
114 words
In a method of making a plastic container formed of an expansible laminae of material having an inner core of high density and a material of low density forming an outer sheath integral with the inner core, the steps of introducing the laminae into open mold, sections then while in a plastic state, closing the mold sections against the laminae at a pressure sufficient to exude the high density material from between sections of the mold at the parting line thereof and leaving a web of said low density material therebetween and thereby forming an easily severable connection between the flash and the container formed upon subsequent expansion of said laminae within the mold.
Claim 7
Dependent Claim
28 words
The method according to claim 4 and said material of high density comprising a high density polyethylene and the material of low density comprising a low density polyethylene.
Claim 8
Dependent Claim
15 words
The invention according to claim 4 and dispersing a pigment between said core and sheath.
Claim 9
Dependent Claim
21 words
The invention according to claim 4 and introducing an opague pigment into the core material prior to said step of introducing.
Claim 10
Independent Claim
85 words
A METHOD OF MAKING AN ARTICLE FROM A LAMINATE COMPRISING AN INNER LAYER THERMOPLASTIC MATERIAL AND AN OUTER LAYER OF MATERIAL DIFFERENT THAN THE INNER LAYER AND COMPRISED OF LOW DENSITY POLYTHYLENE COMPRISING INTRODUCING SUCH LAMINATE INTO ARTICLE FORMING MOLD SECTIONS HAVING A CONFIGURATION WHEREIN ISLANDS OF FLASH ARE DEVELOPED, THEN CLOSING THE MOLD SECTIONS AN EXTENT SUFFICIENT TO PINCH THE MATERIAL AND SQUEEZE OUT THE INNER LAYER OF MATERIAL FROM BETWEEN THE PARTING AREAS OF THE MOLD SECTIONS LEAVING ONLY AN EASILY SEVERABLE MATERIAL
Claim 11
Independent Claim
85 words
A METHOD OF MAKING AN ARTICLE FROM A LAMINATE COMPRISING AN INNER LAYER THERMOPLASTIC MATERIAL AND AN OUTER LAYER OF MATERIAL DIFFERENT THAN THE INNER LAYER AND COMPRISED OF LOW DENSITY POLYTHYLENE COMPRISING INTRODUCING SUCH LAMINATE INTO ARTICLE FORMING MOLD SECTIONS HAVING A CONFIGURATION WHEREIN ISLANDS OF FLASH ARE DEVELOPED, THEN CLOSING THE MOLD SECTIONS AN EXTENT SUFFICIENT TO PINCH THE MATERIAL AND SQUEEZE OUT THE INNER LAYER OF MATERIAL FROM BETWEEN THE PARTING AREAS OF THE MOLD SECTIONS LEAVING ONLY AN EASILY SEVERABLE MATERIAL
Claim 12
Dependent Claim
14 words
The invention according to claim 8 wherein the inner layer of material is polypropylene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |