US4229970A
Expired / Lapsed
US
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Method and apparatus for measuring the rheological properties of an extrudable material
Assignee: Alpha Technologies Us Lp
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Filing: 1979-01-05
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Granted: 1980-10-28
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Expires: 1999-01-05
Abstract
Abstract The rheological properties of an extrudable material can be measured by extruding a strand of the material, measuring its diameter continuously, to give a series of diameter values, interpreting the variations in the strand diameter so as to characterize the surface of the strand, and deriving rheological data from the surface characteristics of the strand. The variations in the strand diameter can be interpreted as to peak-to-peak amplitude, average diameter value, the frequency of significant extreme values, standard deviations from a mean value, and the like. By means of these mathematical characterizations, the rheological behavior of the extrudable material can then be derived. The scorch behavior of a curable elastomer can be measured. The heterogeneity of a rubber compound can be described, or the macromolecular properties of a polymer can be measured (such as "gel", or degree of cross-linking.
Inventors
- 👤 Robert I. Barker
- 👤 David P. King
- 👤 Patrick F. Rice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:46
CPC Classifications
G; G01; G01N; G01N11/00; G01N11/02; G01N33/00; G01N33/44; G01N33/445; G01N2203/00; G01N2203/0058; G01N2203/0092
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
101 words
The method of measuring the rheological properties of an extrudable material comprising the steps of (a) extruding a continuous strand of the material under controlled conditions of temperature and shear rate or shear stress, (b) measuring the diameter of the strand periodically to provide a plurality of instantaneous diameter values, (c) averaging the instantaneous diameter values over a finite number of such values to obtain an average diameter figure, (d) measuring the frequency of those instantaneous values which depart from the average diameter figure by more than a given amount, and (e) comparing the frequency thus obtained with a predetermined standard.
Claim 2
Independent Claim
101 words
The method of measuring the rheological properties of an extrudable material comprising the steps of (a) extruding a continuous strand of the material under controlled conditions of temperature and shear rate or shear stress, (b) measuring the diameter of the strand periodically to provide a plurality of instantaneous diameter values, (c) averaging the instantaneous diameter values over a finite number of such values to obtain an average diameter figure, (d) measuring the frequency of those instantaneous values which depart from the average diameter figure by more than a given amount, and (e) comparing the frequency thus obtained with a predetermined standard.
Claim 3
Dependent Claim
14 words
The method of claim 1, wherein the diameter of the strand is measured optically.
Claim 4
Dependent Claim
15 words
The method of claim 1, wherein the diameter values are expressed in an analogue signal.
Claim 5
Independent Claim
72 words
The method of measuring the rheological properties of an extrudable material comprising the steps of (a) extruding a continuous strand of the material under controlled conditions of temperature and shear rate or shear stress, (b) measuring the diameter of the strand periodically to provide a plurality of instantaneous diameter values, (c) calculating the magnitudes of the peak-to-peak differences in diameter values, and (d) comparing the magnitudes thus calculated to a predetermined standard.
Claim 6
Independent Claim
72 words
The method of measuring the rheological properties of an extrudable material comprising the steps of (a) extruding a continuous strand of the material under controlled conditions of temperature and shear rate or shear stress, (b) measuring the diameter of the strand periodically to provide a plurality of instantaneous diameter values, (c) calculating the magnitudes of the peak-to-peak differences in diameter values, and (d) comparing the magnitudes thus calculated to a predetermined standard.
Claim 7
Dependent Claim
14 words
The method of claim 4, wherein the diameter of the strand is measured optically.
Claim 8
Dependent Claim
15 words
The method of claim 4, wherein the diameter values are expressed in an analogue signal.
Claim 9
Independent Claim
94 words
The method of measuring the scorch time of an extrudable vulcanizable rubber compound comprising the steps of (a) extruding a continuous strand of the compound under controlled conditions of temperature and shear rate or shear stress, (b) measuring the diameter of the strand from time to time to provide a plurality of diameter values, (c) characterizing the diameter values as to the magnitudes of the peak-to-peak differences therein, (d) comparing the magnitude of the peak-to-peak differences with a predetermined standard, and (e) determining the time at which the said magnitude exceeds the predetermined standard.
Claim 10
Independent Claim
94 words
The method of measuring the scorch time of an extrudable vulcanizable rubber compound comprising the steps of (a) extruding a continuous strand of the compound under controlled conditions of temperature and shear rate or shear stress, (b) measuring the diameter of the strand from time to time to provide a plurality of diameter values, (c) characterizing the diameter values as to the magnitudes of the peak-to-peak differences therein, (d) comparing the magnitude of the peak-to-peak differences with a predetermined standard, and (e) determining the time at which the said magnitude exceeds the predetermined standard.
Claim 11
Dependent Claim
14 words
The method of claim 7, wherein the diameter of the strand is measured optically.
Claim 12
Dependent Claim
15 words
The method of claim 7, wherein the diameter values are expressed in an analogue signal.
Claim 13
Dependent Claim
63 words
Apparatus for measuring rheological properties of an extrudable material, comprising in combination: (a) an extruder capable of extruding a strand of the material at controlled temperature and shear rate, (b) means to measure the diameter of the strand thus formed, (c) means to average diameter readings over a plurality of diameter measurements, and (d) means to record maximum excursions from the average diameter.
Claim 14
Dependent Claim
63 words
Apparatus for measuring rheological properties of an extrudable material, comprising in combination: (a) an extruder capable of extruding a strand of the material at controlled temperature and shear rate, (b) means to measure the diameter of the strand thus formed, (c) means to average diameter readings over a plurality of diameter measurements, and (d) means to record maximum excursions from the average diameter.
Claim 15
Dependent Claim
18 words
Apparatus according to claim 10, wherein the means to measure the diameter of the strand is optical means.
Claim 16
Dependent Claim
13 words
Apparatus according to claim 11, wherein the optical means includes a laser beam.
Claim 17
Dependent Claim
73 words
Apparatus for measuring rheological properties of an extrudable material, comprising in combination: (a) an extruder capable of extruding a strand of the material at controlled temperature and shear rate, (b) means to measure the diameter of the strand thus formed, (c) means to average diameter readings over a plurality of diameter measurements, and (d) means to record the frequency of diameter reading excursions having a given value above or below the average diameter.
Claim 18
Dependent Claim
73 words
Apparatus for measuring rheological properties of an extrudable material, comprising in combination: (a) an extruder capable of extruding a strand of the material at controlled temperature and shear rate, (b) means to measure the diameter of the strand thus formed, (c) means to average diameter readings over a plurality of diameter measurements, and (d) means to record the frequency of diameter reading excursions having a given value above or below the average diameter.
Claim 19
Dependent Claim
18 words
Apparatus according to claim 13, wherein the means to measure the diameter of the strand is optical means.
Claim 20
Dependent Claim
13 words
Apparatus according to claim 14, wherein the optical means includes a laser beam.
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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) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |