CN-122016557-A - Method and device for measuring non-Newtonian index of polymer melt, computer equipment and storage medium

Abstract

A method for measuring the non-Newtonian index of a polymer melt includes inputting the polymer melt to be measured into a capillary channel, driving the polymer melt to flow in the capillary channel, collecting the driving pressure and the driving rate of the polymer melt, and calculating the non-Newtonian index of the polymer melt based on the driving pressure and the driving rate. The invention provides a non-Newtonian index measurement method, a device, computer equipment and a storage medium for polymer melt, which can calculate by adopting original driving pressure and driving speed, and can greatly simplify the calculation process.

Inventors

• FAN JICHANG
• YIN GUOJIE
• ZHU XINJUN
• XU YANKAI
• LI YINGYING
• PENG QI
• WAN LIN
• HU PENGFEI

Assignees

• 洛阳理工学院

Dates

Publication Date

20260512

Application Date

20260115

Claims (9)

1. 1. A method for measuring the non-newtonian index of a polymer melt comprising: inputting a polymer melt to be measured into the capillary channel; Driving the polymer melt to flow in the capillary channel; Collecting driving pressure of polymer melt And drive rate ; Based on driving pressure And drive rate Calculating the non-Newtonian index of a polymer melt The calculation method comprises the following steps: ; Wherein, the In the case of a logarithmic operation, Is a differential operation.
2. 2. A method of measuring the non-newtonian index of a polymer melt according to claim 1, wherein the method of inputting the polymer melt to be measured into the capillary channel comprises: A heating cavity is arranged at one end of the capillary channel, and a polymer is placed in the heating cavity; the polymer is heated to obtain a polymer melt and the polymer melt is flowed into the capillary channel.
3. 3. The method of measuring a non-Newtonian index of a polymer melt according to claim 1, wherein the driving rate is a driving rate in driving the polymer melt to flow in the capillary channel Is greater than a preset first threshold and less than a preset second threshold.
4. 4. The method of measuring a non-Newtonian index of a polymer melt according to claim 1, wherein the driving member is placed in the capillary channel during driving the polymer melt to flow in the capillary channel, and a driving pressure is obtained by collecting a reverse force of the polymer melt to the driving member 。
5. 5. The method for measuring a non-Newtonian index of a polymer melt according to claim 1, wherein the driving pressure of the polymer melt is collected while the polymer melt is flowing to the middle of the capillary channel in the process of driving the polymer melt to flow in the capillary channel And drive rate 。
6. 6. A method for measuring a non-Newtonian index of a polymer melt as defined in claim 5, wherein the driving of the polymer melt to flow the polymer melt in the capillary channel is based on the driving rate The location of the polymer melt in the capillary channel is determined.
7. 7. The method for measuring a non-Newtonian index of a polymer melt according to claim 1, wherein the driving pressure is gradually increased based on a predetermined gradient rule during driving the polymer melt to flow in the capillary channel And drive rate 。
8. 8. A device for measuring the non-newtonian index of a polymer melt, characterized in that it is intended to implement a method for measuring the non-newtonian index of a polymer melt according to any of claims 1-7, said device comprising: the inner cavity of the capillary channel forms the capillary channel; A driver capable of extending into the capillary channel to drive the polymer melt flow; a collecting module for collecting driving pressure of polymer melt And drive rate ; A calculation module for based on the driving pressure And drive rate Calculating the non-Newtonian index of a polymer melt The calculation method comprises the following steps: ; Wherein, the In the case of a logarithmic operation, Is differential operation A computer device, comprising: A memory for storing a computer program; a processor for reading and executing the computer program to implement a method for measuring the non-newtonian index of a polymer melt according to any of claims 1-7.
9. 9. Storage medium, characterized in that it is used for storing a computer program which, when executed, implements a method for measuring the non-newtonian index of a polymer melt according to any one of claims 1-7.

Description

Method and device for measuring non-Newtonian index of polymer melt, computer equipment and storage medium Technical Field The invention relates to the technical field of polymer melt non-Newtonian index measurement, in particular to a method, a device, computer equipment and a storage medium for measuring a non-Newtonian index of a polymer melt. Background Shear viscosity is one of the most important parameters in characterizing the melt flow behavior of polymers. The measuring instrument of polymer melt shear viscosity mainly comprises a capillary rheometer, a rotary rheometer, a falling ball viscometer, a cone plate rheometer and the like. The method for measuring the shear viscosity of the liquid crystal material comprises the steps of extruding a melt through a capillary tube at a constant temperature through a material rod at a constant speed (or constant pressure), measuring the pressure applied by the material rod (or the falling speed of the material rod), and calculating the shear viscosity by combining a Hagen-Poiseuille equation and non-Newtonian fluid correction. The method can measure the shear viscosity of the polymer melt in a higher shear rate range (10 2~106 s-1), can measure parameters reflecting the elastic behavior of the melt such as inlet pressure loss, extrusion expansion ratio and the like, and is suitable for simulating the flow behavior in the processing processes such as extrusion, injection molding and the like, so that the capillary rheometer is widely applied to scientific research institutions and universities. Polymer melts are typically non-newtonian fluids whose shear stress versus shear rate only satisfy newtonian fluid formulas at very low or very high shear rates. The relationship between the shear stress and the shear rate can be obtained by using a power law equation in the rest wider shear rate rangeRepresentation of whereinFor shear stress, K is the consistency coefficient and n is the power law index, also known as the non-Newtonian index. The non-Newtonian index n represents the deviation of the non-Newtonian fluid from the Newtonian fluid, can intuitively reflect the change trend of the shear viscosity of the fluid along with the shear rate, and can also reflect the damage and rearrangement of the molecular chains in the polymer melt. In addition, when measuring the apparent viscosity of a polymer melt, non-newtonian correction is typically performed on the shear rate of the fluid, so that the apparent shear viscosity can be obtained by correctly calculating the non-newtonian index of the polymer melt. In the prior art, the main calculation method of the non-Newton index is as followsWherein,Is at a shear rate and hasQ is the volume flow rate,Is the pressure drop across the capillary, R is n and L is. The calculation method has the advantages of multiple parameters and complex calculation process. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a method, a device, a computer device and a storage medium for measuring the non-Newtonian index of a polymer melt, which only need to adopt the original driving pressureAnd drive rateThe calculation can be performed, and the calculation process can be greatly simplified. In order to achieve the aim, the invention adopts the specific scheme that the method for measuring the non-Newtonian index of the polymer melt comprises the following steps: inputting a polymer melt to be measured into the capillary channel; Driving the polymer melt to flow in the capillary channel; Collecting driving pressure of polymer melt And drive rate; Based on driving pressureAnd drive rateCalculating the non-Newtonian index of a polymer meltThe calculation method comprises the following steps: ; Wherein, the In the case of a logarithmic operation,Is a differential operation. As a further optimization of the above-described method for measuring the non-Newtonian index of a polymer melt, the method for inputting a polymer melt to be measured into a capillary channel comprises: A heating cavity is arranged at one end of the capillary channel, and a polymer is placed in the heating cavity; the polymer is heated to obtain a polymer melt and the polymer melt is flowed into the capillary channel. As a further optimization of the non-Newtonian index measurement method of a polymer melt described above, the rate of driving the polymer melt during its flow in the capillary channelIs greater than a preset first threshold and less than a preset second threshold. As a further optimization of the method for measuring the non-Newtonian index of the polymer melt, the method comprises the steps of placing a driving member into a capillary channel in the process of driving the polymer melt to flow in the capillary channel, and collecting the reverse acting force of the polymer melt on the driving member to obtain driving pressure。 As a further optimization of the above-mentioned method for measuring non-Newtonian ind