US3786221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for heat treating a polar, dielectric parison
Assignee: Primerica Inc
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Filing: 1973-03-29
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Granted: 1974-01-15
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Expires: 1993-03-29
Abstract
Abstract A method of heat treating an axial zone of a polar, dielectrically lossy, thermoplastic, polymeric parison with a high frequency energy source to produce a temperature gradient across the thickness of the sidewall in said zone prior to blow molding the parison into a bottle, whereby the temperature is higher on the inner surface of the parison sidewall than on the outer surface of the parison sidewall.
Inventors
- 👤 A Silverman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:19
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/46; H05B6/62; B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C49/6436; B29C49/6445; B29C49/6454; B29C2949/00; B29C2949/07; B29C2949/0715; B29C35/00; B29C35/02; B29C35/12; B29C49/02; B29C49/06
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
89 words
A method of heat treating an axial zone of a polar, dielectrically lossy, thermoplastic, polymeric parison and producing a temperature gradient across the thickness of the sidewall in said zone prior to blow molding the parison into a bottle, comprising: locating said parison between concentrically arranged electrodes; and dielectrically heating the parison with a high frequency energy source to thereby produce said temperature gradient in said zone wherein the temperature is higher on the inner surface of the parison sidewall than on the outer surface of the parison sidewall.
Claim 2
Independent Claim
89 words
A method of heat treating an axial zone of a polar, dielectrically lossy, thermoplastic, polymeric parison and producing a temperature gradient across the thickness of the sidewall in said zone prior to blow molding the parison into a bottle, comprising: locating said parison between concentrically arranged electrodes; and dielectrically heating the parison with a high frequency energy source to thereby produce said temperature gradient in said zone wherein the temperature is higher on the inner surface of the parison sidewall than on the outer surface of the parison sidewall.
Claim 3
Dependent Claim
88 words
The method of claim 1 wherein the temperature gradient in Fahrenheit degrees in said axial zone is in the range from about 25((SR(i)/SR(o)) - 1) to about 150((SR(i)/SR(o)) - 1) where SR(i) is the ratio of the inner diameter of the bottle in said zone to the inner diameter of that portion of the parison from which said zone of the bottle was formed, and where SR(o) is the ratio of the outer diameter of the bottle in said zone to the corresponding outer diameter of the parison.
Claim 4
Dependent Claim
88 words
The method of claim 1 wherein the temperature gradient in Fahrenheit degrees in said axial zone is in the range from about 75((SR(i)/SR(o)) - 1) to about 125((SR(i)/SR(o)) - 1) where SR(i) is the ratio of the inner diameter of the bottle in said zone to the inner diameter of that portion of the parison from which said zone of the bottle was formed, and where SR(o) is the ratio of the outer diameter of the bottle in said zone to the corresponding outer diameter of the parison.
Claim 5
Dependent Claim
25 words
The method of claim 3 wherein the temperature gradient in Fahrenheit degrees in said axial zone is determined according to the formula: 100((SR(i)/SR(o)) - 1).
Claim 6
Dependent Claim
15 words
The method of claim 3 wherein the concentrically arranged electrodes are circular in cross section.
Claim 7
Dependent Claim
21 words
The method of claim 3 wherein the thickness of the sidewall in said axial zone is between 100 and 250 mils.
Claim 8
Dependent Claim
15 words
The method of claim 3 wherein the temperature gradient is between 10* and 250* Fahrenheit.
Claim 9
Dependent Claim
17 words
The method of claim 3 wherein there is an air gap between the parison and the elctrodes.
Claim 10
Dependent Claim
23 words
The method of claim 8 wherein the air gap is filled or partially filled with one or more dielectric materials other than air.
Claim 11
Dependent Claim
149 words
The method of claim 1 wherein the polymer is derived from (A) about 60 to 90 parts by weight of an alpha,beta-olefinically unsaturated mononitrile having the structure CH2 = C(-R1)-CN where R1 is selected from the group consisting of hydrogen, halogen, and lower alkyl groups, (B) about 40 to 10 parts by weight of an ester of an olefinically unsaturated carboxylic acid having the structure CH2 = C(-R1)-C(O)O-R2 where -R1 is as defined above and -R2 is an alkyl group having from 1 to 6 carbon atoms, (A) and (B) together comprising 100 parts by weight, polymerized in the presence of (C) about 1 to 20 parts by weight of a nitrile rubber containing about 60 to 80 percent by weight of moieties derived from a conjugated diene monomer and about 40 to 20 percent by weight of moieties derived from a mononitrile having said CH2 = C(-R1)-CN structure.
Claim 12
Dependent Claim
37 words
The method of claim 10 wherein the mononitrile is acrylonitrile or methacrylonitrile, the ester is selected from the group consisting of methyl acrylate, ethyl acrylate and methyl methacrylate, and the conjugated diene monomer is butadiene or isoprene.
Claim 13
Dependent Claim
60 words
The method of claim 11, wherein the polymer is derived from 73 to 77 parts by weight acrylonitrile and 27 to 23 parts by weight of methyl acrylate, polymerized in the presence of 8 to 10 additional parts by weight of a nitrile rubber containing about 70 percent by weight butadiene moieties and about 30 percent by weight acrylonitrile moieties.
Claim 14
Dependent Claim
16 words
The method of claim 1 wherein the temperature gradient is between about 40* and 150* F.
Claim 15
Dependent Claim
11 words
The method of claim 1 wherein the parison is injection molded.
Claim 16
Dependent Claim
11 words
The method of claim 1 wherein the frequency is radio frequency.
Claim 17
Dependent Claim
16 words
The method of claim 15 wherein the frequency is between 107 and 108 cycles per second.
Claim 18
Dependent Claim
25 words
The method of claim 1 wherein the polymer has a dielectric loss tangent greater than 0.02 at room temperature measured at 30 megacycles per second.
Claim 19
Dependent Claim
11 words
The method of claim 17 wherein the electrodes are half-hard brass.
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) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |