Foam pulse rheometer
US4905504A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1989 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Mar 15, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N11/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A foam pulse rheometer measures the total integrated stress response of a foaming polymer to a short duration strain pulse applied to the polymer, from which can be calculated the equilibrium modulus and the zero shear viscosity of the foaming polymer during the foaming reaction. A shear plate mounted to a load cell above a jacket extends downwardly into a foaming polymer within the jacket. Under the application of a vertical square wave strain pulse to the jacket, the load cell senses the shear force exerted upon the shear plate by the foaming polymer. Simultaneously, a video camera and recorder monitors the surface area of the plate acted upon by the jacket. For each pulse, simultaneously occurring discrete sensed force values and discrete monitored surface area values can be used to compute the total integrated stress response, from which can be calculated the equilibrium modulus and the zero shear viscosity. By applying successive strain pulses during the foaming process, until the polymer tears away from the plate, the evolution of the equilibrium modulus can be studied throughout the course of the foaming reaction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.