Polymer dynamic fluidity detection vibration device and detection method

Abstract

The invention discloses a polymer dynamic fluidity detection vibration device and a detection method. The detection vibration device comprises a material barrel rotating mechanism and a vibration driving mechanism. The material barrel rotating mechanism is provided with a rotary material barrel, wherein the rotary material barrel is mounted at an extrusion section and / or a plasticizing section ofan extruder. A machine head shell is arranged at the outlet end of the extruder; a mouth mould is arranged in the machine head shell; and circumferential force and displacement are applied to the rotary material barrel through the vibration driving mechanism, so that the rotary material barrel can do circumferential rotary motion with corresponding frequency and amplitude along the axis directionof a screw rod. The device and method are used for overcoming the defect that the range of materials detected by the existing polymer fluidity detection method and device is limited, adopt a local circumferential vibration mode, can provide a more complex vibration form according to test requirements, and have the advantages of small vibration energy loss, small material superposition heat, difficulty in material decomposition and vulcanization, and accurate fluidity test result.

Description

technical field [0001] The invention belongs to the technical field of polymer fluidity detection, and in particular relates to an on-line polymer dynamic fluidity detection vibration device and a detection method close to actual production. Background technique [0002] The processing of polymer is to make the polymer material change from high elastic state to viscous fluid state at a certain temperature, and become a flowing melt with a certain viscosity, so as to deform and stabilize the shape. The viscous flow state is an important stage in the polymer molding process, and the flow characteristic in the viscous flow state is fluidity. The fluidity of the rubber compound is a very complex issue, which is affected by many factors, including the internal factors of the molecular material structure and the external factors of the process parameters. The fluidity of polymers is the intrinsic cause of all behaviors during their processing. Non-Newtonian flow, extrusion swell...

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Problems solved by technology

However, due to the fixed form of the eccentric disc, grinding ring and positioning ring, it is impossible to change the flow state according to a certain frequency and amplitude

[0005] The existing vibratory extrusion technology generally introduces axial vibration on the screw, and realizes vibration through vibration device or pulse oil pressure, but there are the following disadvantages: (1) The structure of the adding device is complicated, and the adding position is limited. Difficulty (2) The length-to-diameter ratio of the screw of the rubber extruder is larger than that of the plastic extruder, and the movement of the rubber material in the barrel is long, which will cause the superimposed vibration to attenuate significantly, and the impact on the fluidity of the rubber material at the head part will be weakened

(3) The superimposed vibration of the screw part, the vibration energy is absorbed by the rubber material and converted into heat energy, which will increase the temperature of the mixed rubber to a certain extent. Excessively high rubber temperature will cause early vulcanization, which is not conducive to the softening of rubber

For some polymer materials with high hardness, due to their poor fluidity, the attenuated vibration has a weak change in the fluidity of the polymer melt, so it is impossible to measure the dynamic fluidity of such polymer materials at the die.

(2) For polymers containing vulcanizing agents in the formulation or polymers containing large heat-generating components, due to the superimposed vibration at the end of the screw, part of the vibration energy is absorbed by the polymer melt and converted into heat energy, to a certain extent It will increase the temperature of the polymer melt. Excessively high melt temperature will cause early vulcanization or decomposition of the material, resulting in partial loss of melt flow properties, and it is impossible to measure the dynamic fluidity of such polymer materials.

(3) For polymer materials with high elasticity, the superimposed vibration of the screw part will change the adhesion relationship between the melt and the metal wall of the barrel from the feeding section due to the influence of axial vibration, and the sliding speed of the surface melt relative to the wall Acceleration reduces the shearing effect of the relative movement of the screw and the barrel on the melt, which is not conducive to the transition of the polymer material from solid to melt state, is not conducive to the flow of the melt, and cannot accurately measure the properties of such polymer materials. dynamic liquidity

Therefore, the full axial vibration mode is difficult to detect the dynamic fluidity of some polymer materials, and the detection range is limited.

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