33 results about "Rheometry" patented technology

The invention relates to a method and system for monitoring and adjusting both air content and rheology (e.g., slump, slump flow) properties of a hydratable concrete mix contained within a concrete mixer. The system simultaneously tracks dosage of both rheology-modifying admixture (e.g., polycarboxylate polymer cement dispersant) and air control agent or “ACA” (e.g., air entraining agent) by reference to at least four nominal dose response (“NDR”) curves or profiles, which at least four NDR profiles are based on the respective behaviors of each of the ACA and rheology-modifying agent on air content and rheology.

Resin blends useful for pipe and blow-molded articles are disclosed. The blends comprise a low-molecular-weight, high-density polyethylene and a high-molecular-weight, low-density ethylene copolymer. The high-molecular-weight component is made with a bridged indenoindolyl Group 4 metal complex having open architecture. Blends of the invention uniquely have high molecular weight (M_w>200,000) and low levels of long-chain branching. A quick, convenient approach for estimating levels of long-chain branching in polyethylenes from gel permeation chromatography and dynamic oscillatory rheometry (“viscosity enhancement factor”) is disclosed.

An apparatus and method for performing rheological measurements of interfaces located at the top of fluid sub-phases. In one configuration, a rotating rheometer is provided with a chamber wall whose inner surface defines an outer chamber radius and an inner cylinder disposed within the cylindrical chamber and having an inner chamber radius. The rotating rheometer is configured to hold a liquid sub-phase and interface layer that can be probed using a circular ribbon that is concentric with and suspended between the inner cylinder and chamber wall. The ratio of the ribbon radius, inner chamber radius, and outer chamber radius is designed to yield an average shear rate in the inner region that is the same as an average shear rate in the outer region. In one configuration, an interface-pinning feature is provided on at least one of the inner cylinder and the chamber wall.

A sensor for making rheological measurements takes the form of a ferromagnetic bob alternately driven through a sample fluid in opposite directions by magnetic force from two alternately driven coils. The bob's position affects the mutual inductance between the coils, so it can be inferred by sensing the signal that current flowing in one coil induces in the other, and rheological properties are determined from the relationships among the bob's motion, the coil current, and the sensor geometry. Some such measurements' accuracies are enhanced by computing bob acceleration and suppressing inertial effects thereby detected.

The invention provides a system for the preshearing based control of the flow and deformation behavior, i.e., the setting kinetics, and the time dependent shear viscosity, elasticity of aqueous cementitious suspensions that can be used for bone repair and regeneration. The dynamic cement microstructure is tailored to the demands of the surgical tasks (faster/slower setting) or additive manufacturing tasks (lower/higher viscosity) by application of various preshearing conditions. The relationships between the preshearing and pressurization conditions and the setting kinetics and the time dependent changes in elasticity and viscosity are complex and characterization of viscoelastic properties using advanced rheological characterization techniques including small-amplitude oscillatory and steady torsional rheometry is needed a priori to enable such tailoring. The preshearing system is intended to give control on the injectability and setting time of any calcium phosphate cement formulation to the surgeon during an orthopedic surgery where a batch of bone cement is processed. Other possible utilizations of the system include controlling the setting kinetics, shear viscosity and facilitating the resultant flow stability of cementitious ceramic suspensions processed in direct ink writing assemblies for additive manufacturing of cement constructs, in injection systems for restoration and fracking.

The invention relates to the technical field of rheological measurement and particularly relates to a rotational rheometer capable of testing normal stress. The rotational rheometer disclosed by the invention is improved on the basis of a traditional rotational rheometer, and a spring is increased, so that an upper plate can make a small-amplitude axial movement during test, the axial displacement is tested, the normal force is calculated, and a testing principle of the traditional rotational rheology parameters is still applicable to the rotational rheometer disclosed by the invention. A torque sensor is arranged on a rotating shaft of the rheometer. The rheometer is controlled by software, and experimental data and curves can be recorded and processed by computer software.

A rheometer is disclosed that includes rheometry logic that is responsive to a material selection control, to an objective selection control, to material property storage, and to process parameter storage, and is operative to assist the user with a measurement using the rheometer. In another general aspect, a rheometer includes sample history storage operative to store a history that spans a plurality of different operations performed by the rheometer on a same sample.

The invention discloses a tensile shear rheometer and a method for testing rheological properties of an alloy solid-liquid two-phase region by using the tensile shear rheometer, and relates to the tensile shear rheometer and the method for testing the rheological properties of the alloy solid-liquid two-phase region by using the tensile shear rheometer. The invention aims at improving the accuracy and efficiency of a conventional method for testing rheological properties of an alloy solid-liquid two-phase region. The tensile shear rheometer is composed of a pull bar, a positioning pin, an upper end cover, a crucible, a high-aluminum fiber, and a lower end cover. Then, a molten metal liquid flows into the rheometer and is cooled to prepare a rheological test specimen; finally, creep properties of the alloy melt are tested on a high-temperature creepmeter, and the rheological properties of the alloy in the solid-liquid two-phase region are obtained. The method can more accurately measure the rheological properties of the alloy in the solid-liquid two-phase region, the specimen only needs to be prepared in the method, and a used loading device and heating device are both realized in the high-temperature creepmeter; the method is simple and easy to control, and easy to popularize.

Rheometry apparatus comprises a block of substantially rigid material having an external surface and at least a first internal flow channel, the first internal flow channel being arranged inside the block and substantially in a plane and the block further comprising a plurality of holes, each hole communicating with the first internal flow channel at a respective position along the first internal flow channel and extending from the respective position to said external surface so as to provide access to the first internal flow channel from the external surface, the plurality of holes comprising a first hole communicating with a first said position, for connection to pumping means to drive fluid flow along said first internal flow channel, a second hole communicating with a second position and in which a sensor may be located to measure a property of fluid at the second position, and a third hole communicating with a third position and in which a sensor may be located to measure a property of fluid at the third position.

A system for improving processing of polyethylene resins, comprising a processor; a memory; an output device; and an analysis component stored in the memory, that when executed on the processor, configures the processor to receive a shear stress as a function of shear rate for a plurality of multimodal metallocene-catalyzed polyethylene samples, wherein the determination of the shear stress as a function of the shear rate comprises using capillary rheometry; determine values for a magnitude of slip-stick, a stress for smooth to matte transition, and a shear rate for smooth to matte transition for each of the plurality of multimodal metallocene-catalyzed polyethylene samples based on the shear stress and the shear rate measured from capillary rheometry; identify individual multimodal metallocene-catalyzed polyethylene resins from the plurality of multimodal metallocene-catalyzed polyethylene samples having a reduced tendency to melt fracture characterized by a magnitude of slip-stick greater than about 300 psi, a stress for smooth to matte transition greater than about 90 kPa, and a shear rate for smooth to matte transition greater than about 10 s-1; and output an identification of the individual multimodal metallocene-catalyzed polyethylene resins to the output device.

A method of selecting a commercially viable chewing gum including testing a chewing gum using nonlinear rheology, compiling rheological data from the nonlinear rheology, and then comparing the rheological data obtained to rheological data ranges of commercially acceptable chewing gum. The nonlinear rheology can include large amplitude oscillatory shear test, start-up of steady uniaxial extension test, and uniaxial compression test (lubricated or unlubricated) and relaxation.