US 5,650,722 AGranted

Using resin age factor to obtain measurements of improved accuracy of one or more polymer properties with an on-line NMR system

AssigneeAuburn International, Inc.

InventorsThomas B. Smith, Ajoy K. Roy, Christian I. Tanzer

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Abstract

A real-time, on-line nuclear magnetic resonance (NMR) system, and related method, can predict various properties of interest of a sample of polymer material. A regression or neural network technique is used to develop a model based upon manipulated NMR output and a resin age factor which compensates for time dependent aging phenomena and enhance predictive accuracy of the model. In a preferred embodiment, the resin age factor is a function of elapsed cycle time prior to sample measurement, sample temperature at time of measurement, and/or sample form. The polymer can be a plastic such as polyethylene, polypropylene, or polystyrene, or a rubber such as ethylene propylene rubber.

Claims22

Dependent claims

A method for predicting a value of a property of a polymer sample in real time from an on-line production process, said method comprising:

storing a model useful for predicting a value of a property of interest of a production polymer sample, said model generated by:
a) acquiring free induction decay curves for polymer samples having known values of said property of interest;
b) applying an iterative technique to derive respective component curve equations from each of said free induction decay curves;
c) calculating respective component curve equation constants;
d) acquiring process data for said known samples;
and
e) generating said model using said constants, said process data, and said known values;
providing a production sample having an unknown value of said property of interest;
applying a base magnetic field to the production sample to effect precession of nuclei of the production sample;
modifying the precession;
receiving a resulting relaxation signal representative of a free induction decay of nuclei of the production sample;
digitizing said relaxation signal;
applying an iterative technique to derive respective component curve equations from said relaxation signal;
calculating respective component curve equation constants;
acquiring process data for said production sample;
and
applying said constants and said process data to said model to predict the value of the property of interest, wherein said process data comprises a resin age factor.

14 more elements

Apparatus for predicting a value of a property of a polymer sample in real time from an on-line production process, said apparatus comprising:

means for storing a model useful for predicting a value of a property of interest of a production polymer sample;
means for generating said model comprising means for:
a) acquiring free induction decay curves for polymer samples having known values of said property of interest,
b) applying an iterative technique to derive respective component curve equations from each of said free induction decay curves,
c) calculating respective component curve equation constants,
d) acquiring process data for said known samples, and
e) generating said model using said constants, said process data, and said known values;
means for providing a production sample having an unknown value of said property of interest;
means for applying a base magnetic field to the production sample to effect precession of nuclei of the production sample;
means for modifying the precession;
means for receiving a resulting relaxation signal representative of a free induction decay of nuclei of the production sample;
means for digitizing said relaxation signal;
means for applying an iterative technique to derive respective component curve equations from said relaxation signal;
means for calculating respective component curve equation constants;
means for acquiring process data for said production sample;
and
means for applying said constants and said process data to said model to predict the value of the property of interest, wherein said process data comprises a resin age factor.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/646,084Filed 7 May 1996 · continuation in part
Priority: 20 Nov 1991
Granted: 22 Jul 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01R 33/4625
NMR spectroscopy: processing of acquired signals, e.g. elimination of phase errors, baseline fitting, chemometric analysis
G01N 24/085
By using nuclear magnetic resonance: analysis of materials for the purpose of controlling industrial production systems
G01R 33/389
Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field: field stabilisation , e.g. by field measurements…
G01N 24/082
By using nuclear magnetic resonance: measurement of solid, liquid or gas content

Family

Serial794,931Parent of this continuation · filed 20 Nov 1991
Serial885,633Parent of this continuation · filed 19 May 1992
Serial226,024Parent of this continuation-in-part · filed 11 Apr 1994
Serial226,061Parent of this continuation-in-part · filed 11 Apr 1994
US 5,302,897 AParent of this continuation · filed 12 Apr 1994
US 5,302,896 AParent of this continuation · filed 12 Apr 1994
Serial370,862Parent of this continuation-in-part · filed 10 Jan 1995
Serial371,091Parent of this continuation-in-part · filed 10 Jan 1995
Serial491,632Parent of this continuation-in-part · filed 19 Jun 1995
Serial586,559Parent of this continuation-in-part · filed 12 Jan 1996
US 5,519,319 AParent of this continuation-in-part
US 5,530,350 AParent of this continuation-in-part
US 5,650,722 AThis patent

From the US filing history. Foreign family members aren’t listed.