US5784283A
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US
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System for optimizing cure assuring quality of reversion susceptible rubber articles
Assignee: PIRELLI TIRE A DELAWARE Corp LLC
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Filing: 1997-08-01
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Granted: 1998-07-21
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Expires: 2017-08-01
Abstract
Abstract A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.
Inventors
- 👤 Giovanni Rimondi
- 👤 William James Toth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:23
CPC Classifications
B; B29; B29C; B29C35/00; B29C35/02; B29C35/0288; B29C37/00; B29C2037/90; B29C2037/903; B29D; B29D30/00; B29D30/06; B29D30/0601; B29D30/0662; B29D2030/0675; B29K; B29K2021/00; B29L; B29L2030/00; G; G01; G01N; G01N2203/00; G01N2203/0058; G01N2203/0092; G01N33/00; G01N33/44
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
106 words
A method for creating a database of cure constants, which account for reversion, for later use to optimize cure of a rubber compound, comprising the steps of: providing a plurality of rubber samples, each sample having a particular rubber formulation; for at least two different temperatures, measuring a physical property which can be related to cure state of a sample of each different formulation as a function of time; calculating a set of cure constants for the rubber formulation which account for reversion from the physical property versus time profiles; and storing the set of cure constants on the database together with the corresponding rubber formulation.
Claim 2
Independent Claim
106 words
A method for creating a database of cure constants, which account for reversion, for later use to optimize cure of a rubber compound, comprising the steps of: providing a plurality of rubber samples, each sample having a particular rubber formulation; for at least two different temperatures, measuring a physical property which can be related to cure state of a sample of each different formulation as a function of time; calculating a set of cure constants for the rubber formulation which account for reversion from the physical property versus time profiles; and storing the set of cure constants on the database together with the corresponding rubber formulation.
Claim 3
Independent Claim
114 words
A method for creating a database of cure constants, which account for reversion, for later use to optimize cure of a rubber compound, comprising the steps of: providing a plurality of rubber samples, each sample having a particular rubber formulation; for at least two different temperatures, measuring a physical property which can be related to cure state of a sample of each different formulation as a function of time; calculating at least one cure constant K.sub.α o defined in the following equation, ##EQU16## for the rubber formulation which accounts for reversion from the physical property versus time profiles; and storing the cure constant K.sub.α o in the database together with the corresponding rubber formulation.
Claim 4
Independent Claim
114 words
A method for creating a database of cure constants, which account for reversion, for later use to optimize cure of a rubber compound, comprising the steps of: providing a plurality of rubber samples, each sample having a particular rubber formulation; for at least two different temperatures, measuring a physical property which can be related to cure state of a sample of each different formulation as a function of time; calculating at least one cure constant K.sub.α o defined in the following equation, ##EQU16## for the rubber formulation which accounts for reversion from the physical property versus time profiles; and storing the cure constant K.sub.α o in the database together with the corresponding rubber formulation.
Claim 5
Dependent Claim
50 words
The method of claim 2, further comprising: calculating a cure constant K.sub.β o defined in the following equation, ##EQU17## for the rubber formulation which account for reversion from the physical property versus time profiles; and storing the cure constant K.sub.β o in the database together with the corresponding rubber formulation.
Claim 6
Dependent Claim
54 words
The method of claim 3, wherein the calculating steps comprise calculating a set of isothermal cure constants at each temperature for each sample from its physical property-time profile, expressing the isothermal constants with a formula which describes their temperature dependence, and calculating the cure constants K.sub.α o and K.sub.β o for each rubber formulation.
Claim 7
Dependent Claim
15 words
The method of claim 4, wherein the measuring step comprises measuring torque with a rheometer.
Claim 8
Dependent Claim
48 words
The method of claim 4, further comprising the step of retrieving the cure constants K.sub.α o and K.sub.β o from the database for a selected rubber formulation and combining them with a temperature-time profile of a curing process to predict state of cure of the selected rubber formulation.
Claim 9
Independent Claim
90 words
A method for optimizing cure of a rubber compound, comprising the steps of: providing a database including non-isothermal cure constants K.sub.α o and K.sub.β o defined in the following equations, ##EQU18## for the rubber compound which account for reversion; providing a curing process for the rubber compound; determining a temperature-time profile of the rubber compound for the curing process; reducing the temperature-time profile and the non-isothermal cure constants with numerical analysis into a succession of isothermal cases; and determining whether the curing process will optimize cure for the rubber compound.
Claim 10
Independent Claim
90 words
A method for optimizing cure of a rubber compound, comprising the steps of: providing a database including non-isothermal cure constants K.sub.α o and K.sub.β o defined in the following equations, ##EQU18## for the rubber compound which account for reversion; providing a curing process for the rubber compound; determining a temperature-time profile of the rubber compound for the curing process; reducing the temperature-time profile and the non-isothermal cure constants with numerical analysis into a succession of isothermal cases; and determining whether the curing process will optimize cure for the rubber compound.
Claim 11
Dependent Claim
21 words
The method of claim 7, wherein the profile determining step comprises measuring the temperature-time profile during curing of the rubber compound.
Claim 12
Independent Claim
137 words
A method for assuring the quality of manufactured rubber articles, comprising the steps of: preparing a rubber sample according to a production formulation; measuring, at a given temperature, torque of the rubber sample as a function of time which can be related to cure state of the article; applying a curing model which accounts for reversion to the physical property measured as a function of time at a given temperature to generate a set of isothermal cure constants including K.sub.α and K.sub.β defined in the following equations: ##EQU19## retrieving a set of predicted cure constants for the production formulation at the given temperature from a database of predicted cure constants; and comparing the isothermal cure constants with the predicted cure constants to determine whether a rubber article produced with the production formulation will have an optimized cure.
Claim 13
Independent Claim
137 words
A method for assuring the quality of manufactured rubber articles, comprising the steps of: preparing a rubber sample according to a production formulation; measuring, at a given temperature, torque of the rubber sample as a function of time which can be related to cure state of the article; applying a curing model which accounts for reversion to the physical property measured as a function of time at a given temperature to generate a set of isothermal cure constants including K.sub.α and K.sub.β defined in the following equations: ##EQU19## retrieving a set of predicted cure constants for the production formulation at the given temperature from a database of predicted cure constants; and comparing the isothermal cure constants with the predicted cure constants to determine whether a rubber article produced with the production formulation will have an optimized cure.
Claim 14
Dependent Claim
21 words
The method of claim 9, wherein the retrieving step comprises retrieving predicted isothermal cure constants K.sub.α o and K.sub.β o .
Claim 15
Dependent Claim
47 words
The method of claim 9, wherein the retrieving step comprises the steps of: retrieving predicted non-isothermal cure constants K.sub.α o and E.sub.α o and K.sub.β o and E.sub.β o ; and calculating isothermal cure constants K.sub.α and K.sub.β from the predicted non-isothermal constants and the given temperature.
Claim 16
Dependent Claim
35 words
The method of claim 11, further comprising the step of searching the database of predicted cure constants at the given temperature with the generated isothermal cure constants to determine a formulation of the rubber sample.
Claim 17
Dependent Claim
30 words
A method of claim 11, further comprising the step of curing a portion of the rubber sample with a process determined to provide an optimized cure for the production formulation.
Claim 18
Dependent Claim
101 words
A curing press for manufacturing an article from a rubber formulation with an optimized cure, comprising: a mold having at least two segments; means for heating said mold; a transducer for generating a signal indicative of a temperature within said mold; and a computer for receiving and storing the temperature indicative signal as a function of time and for storing at least one non-isothermal cure constant K.sub.α, defined in the following equation, ##EQU20## for the rubber formulation, said computer for reducing the temperature-time profile and the cure constant to a succession of isothermal cases to determine whether the cure was optimized.
Claim 19
Dependent Claim
101 words
A curing press for manufacturing an article from a rubber formulation with an optimized cure, comprising: a mold having at least two segments; means for heating said mold; a transducer for generating a signal indicative of a temperature within said mold; and a computer for receiving and storing the temperature indicative signal as a function of time and for storing at least one non-isothermal cure constant K.sub.α, defined in the following equation, ##EQU20## for the rubber formulation, said computer for reducing the temperature-time profile and the cure constant to a succession of isothermal cases to determine whether the cure was optimized.
Claim 20
Dependent Claim
20 words
The curing press of claim 14, wherein the computer stores a non-isothermal cure constant K.sub.β defined in the equation ##EQU21##
Claim 21
Dependent Claim
30 words
The curing press of claim 15, wherein the non-isothermal cure constants are calculated by measuring a sample of the rubber formulation with a rheometer for at least two different temperatures.
Claim 22
Dependent Claim
24 words
The curing press of claim 16, wherein said transducer is located within the mold in contact with a surface of the article being cured.
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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) | 2001-07-20 | 2002-01-19 | 2002-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-07-20 | 2006-01-19 | 2006-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-07-20 | 2010-01-19 | 2010-07-21 | $7700.00 | Window Closed / Lapsed |