Double-charging barrel capillary pipe rheometer

Abstract

The invention relates to a double-charging barrel capillary pipe rheometer, and belongs to the technical field of high polymer rheological measurement. The core component double capillary pipe orifice die of the rheometer is designed into a long capillary pipe orifice die and a short capillary pipe orifice die, and the design of a zero long capillary pipe orifice die of the traditional conventional double-charging barrel capillary pipe rheometer is changed. The double-charging barrel capillary pipe rheometer drives and controls a plunger to extrude high polymer fluid in two charging barrels with the same internal diameters at the same rate through a servo motor and a screw, then the fluid enters two capillary pipes with the same internal and external diameters and different lengths, pressure is respectively measured through a pressure sensor, and after the pressure is subtracted, pressure drop of fluid flowing through inlets and outlets of the capillary pipes can be conveniently eliminated; meanwhile, compared with a zero long capillary pipe, the fluid in the short capillary pipe orifice die with certain length is provided with a completely developed flowing region with certain length, and flowing conditions of the fluid in long and short capillary pipes are more similar, so that the pressure drop measured finally is more accurate and closer to the practical situation.

Description

technical field [0001] The invention belongs to the technical field of polymer rheology testing, in particular to a double barrel capillary rheometer. Background technique [0002] Rheological properties are important properties of polymers, and the quality of rheological properties has an important impact on the processing and preparation of polymers. Therefore, it is crucial to accurately measure the rheological data of polymers. Capillary rheometer is one of the main instruments for measuring rheological properties. It measures the variation of shear viscosity with various polymer structural parameters (such as molecular weight, molecular weight distribution, branching degree) and flow field parameters (such as shear rate, temperature, pressure), establish the quantitative relationship between them, get the theoretical model and guide the actual production. Due to the large inlet pressure drop of the single-barrel capillary rheometer, cumbersome Bagley correction is requ...

AI Technical Summary

Problems solved by technology

But at present, almost all double-barrel capillary rheometers use zero-length capillary dies, and the fluid in the zero-length capillary has not fully developed the flow area. The recovery after the capillary is relatively large, and the recovery after the long capillary is small, which leads to a large difference between the outlet pressure drop of the zero-length capillary and the outlet pressure drop of the long capillary, resulting in a certain gap between the measurement results and the actual situation

Images