Rheometrics, Inc.

Rheometric Scientific, Inc.

Ronald F Garritano

Paul G Mode

William David Richards

Joseph C Golba, Jr

John F Blanch

Gerald G Fuller

Mahesh Padmanabhan

Manuel E Papayanopulos

Michael Goncharko

John J O'Connor

On-line rheological measurements are made on a process flowing material, such as a polymer melt, utilizing a rheometer of the type in which an inlet pump delivers a relatively large volumetric flow of diverted process material from a process main stream to an inlet site located in very close proximity to the entrance of a capillary passage, and a metering pump draws a smaller portion of the volumetric flow of the diverted material from the inlet site through the capillary passage for return to the process main stream. The viscosity of the diverted material is measured as a function of the rate of flow of the material through the capillary passage and the pressure drop between spaced apart locations along the capillary passage. A parallel flow passage has a volumetric flow capacity considerably greater than the volumetric flow capacity of the capillary passage, an inlet placed at the inlet site, in very close proximity with the entrance of the capillary passage, and an outlet placed downstream of the metering pump. A parallel flow pump in the parallel flow passage moves the balance of the volumetric flow of diverted material from the inlet site for return to the process main stream to assure a continuous supply of fresh diverted material at the entrance to the capillary passage.

On-line rheological measurement for process control

Apparatus and method for the simultaneous measurement of rheological and thermal characteristics of a test specimen subjects the test specimen to stress for rheological measurements, while at the same time subjecting the same test specimen to controlled temperature changes for the measurement of temperature differentials indicative of thermal characteristics of the test specimen while the test specimen is being stressed for the rheological measurements, and a measuring cell for measuring the thermal characteristics of a specimen.

Apparatus and method for the simultaneous measurement of rheological and

A magnetic resonance analyzing apparatus includes a sampling region; a first temperature stabilization assembly for maintaining the sampling region at a predetermined temperature; a magnet for applying a base magnetic field to the sampling region; a coil for applying a first 0.degree. phase excitation pulse to the sampling region at a first time, and a second 90.degree. phase offset excitation pulse to the sampling region at a second time corresponding substantially to an end of a first time period during which an output signal emitted from the sample as a result of the first excitation pulse can not be detected; a detector for detecting the output signal in response to the excitation pulses; a computer for forming a free induction decay (FID) curve from the output signal, starting from a third time corresponding substantially to an end of a second time period during which an output signal emitted from the sample as a result of the second excitation pulse can not be detected, separating the FID curve into a Gaussian (crystallinity) curve, exponential (amorphous) curve, and intermediate (combination of crystallinity and amorphous) curve, and determining a characteristic of the sample in correspondence with y-axis intercepts of at least one of the Gaussian, exponential, intermediate and FID curves; and a second temperature stabilization assembly for controlling the temperature of the sample at the predetermined temperature prior to entering the sampling region.

Method and apparatus for analyzing samples using nuclear magnetic

Apparatus and method for measuring the shear viscosity of a fluid urges sample fluid through a gap between a sleeve having an axial passage and a pin extending axially into the passage in the sleeve to subject the sample fluid to shear while measuring the axial force tending to move the pin and the sleeve axially away from one another, the axial force being indicative of the shear viscosity of the sample fluid.

Measuring shear viscosity of fluids

On-line rheological measurements are made utilizing a rheometer of the type in which a first metering pump delivers diverted melt from a process main stream to a capillary passage and a second metering pump returns the diverted melt from the capillary passage to the process main stream and the viscosity of the diverted melt is measured by controlling the rate of flow of the melt to maintain constant the pressure drop between spaced apart locations along the capillary passage and measuring the temperature of the melt in the capillary passage. The measurements may be made while controlling the speed of the second metering pump independent of the speed of the first metering pump to maintain the pressure at the exit of the capillary passage essentially constant. The capillary passage is placed in close proximity to the process main stream for maintaining a relatively short residence time during which the diverted melt resides outside the process main stream so as to attain a relatively quick response to changes in the measured viscosity. The rheometer includes a relatively thin plate interposed between first and second blocks, the plate including a slot establishing a chamber between the first and second blocks for providing the capillary passage.

On-line rheological measurements

Impact testing apparatus in which a weighted dart is dropped from a prescribed height to penetrate a test specimen when traveling at a desired velocity and level of kinetic energy, the acceleration of the dart being assisted by a spring force in the direction of travel so that the prescribed height is maintained at a minimum for a given desired velocity and the dart being guided to the test specimen by a generally tubular guide within which the dart is loosely fitted. A force transducer is located at the tip of the dart for providing impact force information as the tip penetrates the test specimen.

Impact testing apparatus

Apparatus and method for measuring the viscous component and the elastic component of forces within a viscoelastic test specimen placed in shear, the test specimen being coupled to a platen having a rest position, the platen being displaceable from the rest position rotationally and axially relative to a fixed axis in response to rotational and axial forces exerted by the test specimen upon the platen as a result of the viscous component and the elastic component, the apparatus and method including an arrangement of component parts and a plurality of steps for establishing a rotational counterforce for balancing the rotational force on the platen and simultaneously establishing an axial counterforce for balancing the axial force on the platen to maintain the platen at the rest position, and indicating the magnitude of the counterforces necessary to maintain the platen at the rest position, whereby the viscous component and the elastic component of forces are measured at zero compliance.

Apparatus and method for measuring viscoelastic properties of materials

A rotational rheometer utilizes a rotor coupled to a test specimen and suspended in a stator by a low friction bearing suspension system, a compensation arrangement which compensates for bearing torque on the rotor throughout the full range of rotation of the rotor, and position transducers arranged for determining accurately both the angular position of the rotor throughout a full range of 360.degree. of rotation, and the longitudinal position of the rotor, relative to the stator.

Compensated rheometer

Disclosed herein is a torsion tube apparatus for making on-line measurements of the viscosity and elasticity of a fluid. The apparatus includes a housing member, an outer cylinder having one end rotatably mounted with respect to the housing member, and a motor for rotating this outer cylinder. An elongated torsion tube is mounted concentrically within and spaced from the outer cylinder and has one end fixed to the housing member, with its other end freely disposed within the cylinder for torsional movement with respect to the fixed end. Therefore, an annular void is defined between the tube and cylinder. Fluid may be introduced through a conduit into the interior of the cylinder for flow therethrough and discharge therefrom, such that rotating motion of the fluid caused by rotation of the cylinder exerts a torsional force directly on the outer surface of the tube. A torsion indicating shaft extends concentrically through the tube, having its one end fixed to the free end of the tube. An indicator is fixed to the other end of the shaft. Accordingly, torsional force on the tube provides the sole source of rotative movement of the shaft that is detected by the indicator. The assembly provides a smooth axial path for the fluid which flows through the annular void between the outer cylinder and tube.

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Flemington, NJ, United States of America

Ronald F Garritano