Parallel plate clamp for rotational rheometer

Abstract

The invention relates to a parallel plate clamp for a rotational rheometer. The parallel plate clamp comprises an upper plate and a lower plate which are parallel to each other, a rotating shaft whichrotates clockwise is fixed at the center of the lower plate, the upper part of the rotating shaft traverses through the center of the fixed upper plate, the rotating shaft is in clearance fit with the upper plate, and the revolution shaft of the rheometer drives the rotating shaft to rotate in order to drive the lower plate to rotate. The upper plate is coaxial with the lower plate, and the coaxiality between the two plates is high, so compared with traditional rotational rheometers, the rotational rheometer has the following advantages: the parallelism between the upper plate and the lower plate is easily guaranteed, and the precision of the parallelism is high; and the shallow thread of the rotating shaft can partially offset the Weissenberg effect caused by a normal stress difference during test, so the test shearing efficiency is well improved, the test range is enlarged, and the test result is optimized.

Description

technical field [0001] The invention relates to the technical field of rheological testing, in particular to a parallel plate fixture of a rotational rheometer. Background technique [0002] The parallel plate fixture of a traditional rotational rheometer is usually divided into an upper plate and a lower plate, and the shear rate of the material between the two plates = Rω / H, where R is the radius of the rotating plate, and H is the distance between the two plates , ω is the angular velocity of the rotating plate. The upper plate and the lower plate of the traditional rotational rheometer are separated, so when the distance between the two plates is large, such as H=1mm, the parallelism error δ=10μm=0.01mm, δ is smaller than H, δ=0.01 H, this error is negligible and has little effect on the test. If you want to get a larger shear rate, you need to set the H value to be very small, such as H=0.1mm, but due to the large parallelism error between the two plates, δ=10μm=0.01m...

AI Technical Summary

Problems solved by technology

If you want to get a larger shear rate, you need to set the H value to be very small, such as H=0.1mm, but due to the large parallelism error between the two plates, δ=10μm=0.01mm, then δ=0.1H, such a large Parallelism errors will affect the test results

This limits the increase of the shear rate, that is, the traditional rotational rheometer can only test the rheological parameters at low shear rates

Images