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

Abstract

The invention discloses a method for measuring a non-Newtonian index of a polymer melt. The method comprises the following steps: inputting the polymer melt to be measured into a capillary channel; driving the polymer melt to enable the polymer melt to flow in the capillary channel; collecting the driving pressure and the driving rate of the polymer melt; a non-Newtonian index of the polymer melt is calculated based on the drive pressure and the drive rate. According to the non-Newtonian index measurement method and device of the polymer melt, the computer equipment and the storage medium, calculation can be carried out only by adopting the original driving pressure and driving rate, and the calculation process can be greatly simplified.

Description

Technical Field

[0001] This invention relates to the field of non-Newtonian index measurement technology for polymer melts, specifically to a method, apparatus, computer equipment, and storage medium for measuring the non-Newtonian index of polymer melts. Background Technology

[0002] Shear viscosity is one of the most important parameters for characterizing the flow behavior of polymer melts. Instruments for measuring the shear viscosity of polymer melts mainly include capillary rheometers, rotational rheometers, falling ball viscometers, and cone-plate rheometers. Among these, the capillary rheometer method involves forcing the melt through a capillary tube at a constant speed (or constant pressure) using a feed rod at a constant temperature, measuring the pressure applied by the feed rod (or the speed at which the feed rod falls), and then calculating the shear viscosity using the Hagen-Poiseuille equation and non-Newtonian fluid corrections. This method can be used in a relatively high shear rate range (10⁻⁶). 2 ~10 6 The capillary rheometer measures the shear viscosity of polymer melts within s-1. This method can also measure parameters reflecting the elastic behavior of melts, such as inlet pressure loss and extrusion swell ratio. It is suitable for simulating flow behavior in processes such as extrusion and injection molding. Therefore, the capillary rheometer has been widely used in research institutes and universities.

[0003] Polymer melts are typical non-Newtonian fluids; the relationship between shear stress and shear rate only conforms to Newtonian fluid equations at extremely low or extremely high shear rates. Over a wider range of shear rates, the relationship between shear stress and shear rate can be expressed by a power-law equation. It means that, among them Let K be the shear stress, K be the consistency coefficient, and n be the power-law exponent, also known as the non-Newtonian exponent. The non-Newtonian exponent n characterizes the extent to which a non-Newtonian fluid deviates from the properties of a Newtonian fluid. It not only directly reflects the trend of fluid shear viscosity changing with shear rate, but also reflects the breakdown and rearrangement of molecular chains within the polymer melt. Furthermore, when measuring the apparent viscosity of a polymer melt, a non-Newtonian correction is usually applied to the fluid's shear rate; therefore, correctly calculating the non-Newtonian exponent of the polymer melt is essential to obtaining its apparent shear viscosity.

[0004] In existing technologies, the main methods for calculating non-Newtonian exponents are as follows: ,in , Let be the shear rate, and have Q is the volumetric flow rate. Let R be the pressure drop across the capillary tube, n be the voltage drop across the capillary, and L be the voltage drop across the capillary tube. This calculation method uses many parameters and the calculation process is complex. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method, apparatus, computer equipment, and storage medium for measuring the non-Newtonian index of polymer melts, requiring only the original driving pressure. and drive rate It can perform calculations immediately, greatly simplifying the calculation process.

[0006] To achieve the above objectives, the specific solution adopted by the present invention is as follows: a method for measuring the non-Newtonian index of polymer melts, comprising: The polymer melt to be tested is fed into the capillary channel; Drive the polymer melt to flow in the capillary channels; Collect the driving pressure of polymer melt and drive rate ; Based on driving pressure and drive rate Calculate the non-Newtonian index of polymer melt The calculation method is as follows: ; in, For logarithmic operations, This is for differential operations.

[0007] As a further optimization of the above-mentioned method for measuring the non-Newtonian index of polymer melts, the method for inputting the polymer melt to be measured into the capillary channel includes: A heating chamber is provided at one end of the capillary channel, and the polymer is placed into the heating chamber; The polymer is heated to obtain a polymer melt, and the polymer melt is then allowed to flow into capillary channels.

[0008] As a further optimization of the aforementioned method for measuring the non-Newtonian index of polymer melts: during the process of driving the polymer melt to flow in the capillary channel, the driving rate... It is greater than the preset first threshold and less than the preset second threshold.

[0009] As a further optimization of the aforementioned method for measuring the non-Newtonian index of polymer melts: During the process of driving the polymer melt to flow in a capillary channel, a driving element is placed into the capillary channel, and the reverse force of the polymer melt on the driving element is collected to obtain the driving pressure. .

[0010] As a further optimization of the aforementioned method for measuring the non-Newtonian index of polymer melts: During the process of driving the polymer melt to flow in a capillary channel, when the polymer melt reaches the middle of the capillary channel, the driving pressure of the polymer melt is collected. and drive rate .

[0011] As a further optimization of the aforementioned method for measuring the non-Newtonian index of polymer melts: during the process of driving the polymer melt to flow in the capillary channel, based on the driving rate... Determine the position of the polymer melt in the capillary channel.

[0012] As a further optimization of the aforementioned method for measuring the non-Newtonian index of polymer melts: during the process of driving the polymer melt to flow in the capillary channel, the driving pressure is gradually increased based on a preset gradient rule. and drive rate .

[0013] A non-Newtonian index measuring device for polymer melts, used to implement the above-described method for measuring the non-Newtonian index of polymer melts, the device comprising: Capillary, the inner cavity of the capillary forms the capillary channel; The driving component can extend into the capillary channel to drive the flow of polymer melt; The acquisition module is used to acquire the driving pressure of the polymer melt. and drive rate ; Calculation module for use based on driving pressure and drive rate Calculate the non-Newtonian index of polymer melt The calculation method is as follows: ; in, For logarithmic operations, For differential operations Computer equipment, including: Memory, used to store computer programs; A processor for reading and executing the computer program to implement the above-described method for measuring the non-Newtonian index of a polymer melt.

[0014] A storage medium for storing a computer program that, when executed, implements the aforementioned method for measuring the non-Newtonian index of a polymer melt.

[0015] Beneficial effects: Compared with existing methods that first calculate the shear rate and shear stress through complex calculations and then calculate the non-Newtonian exponent, this invention only requires the original driving pressure. and drive rate This greatly simplifies the calculation process. The method of this invention does not rely on instrument parameters, is simple to calculate, and can reduce calculation errors. It not only reduces the data processing difficulty for researchers when measuring the rheological properties of non-Newtonian fluids using capillary rheometers, but also simplifies the calculation process for capillary rheometer manufacturers when designing data processing systems. Attached Figure Description

[0016] Figure 1 This is a flowchart of the method of the present invention; Figure 2 It is a non-Newtonian exponent value obtained by linear fitting after processing experimental data using existing calculation methods; Figure 3 It is the non-Newtonian exponent value obtained by linear fitting after processing the experimental data using the method of this invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, a method for measuring the non-Newtonian index of a polymer melt includes S1 to S4.

[0019] S1. The polymer melt to be tested is input into the capillary channel. In one embodiment of the present invention, a capillary rheometer can be used as the measuring device, and a capillary channel is formed using a capillary tube. Based on this, the method of inputting the polymer melt to be tested into the capillary channel includes: setting a heating chamber at one end of the capillary channel, and placing the polymer into the heating chamber; heating the polymer to obtain a polymer melt, and causing the polymer melt to flow into the capillary channel. More specifically, the heating chamber is located above the capillary channel, the capillary channel is vertically arranged and its upper end is connected to the heating chamber. After the polymer is heated to a molten state to form a polymer melt, it flows downward under the action of gravity and enters the capillary channel. The polymer melt can uniformly fill the capillary tube, ensuring the accuracy of subsequent measurements.

[0020] S2. Driving the polymer melt to flow within the capillary channel. Considering that the polymer melt is a typical non-Newtonian fluid, the relationship between shear stress and shear rate in the capillary channel only conforms to Newtonian fluid equations at extremely low or extremely high shear rates. Over a wider range of shear rates, the relationship can be expressed by a power-law equation, allowing for measurement. Therefore, during the process of driving the polymer melt to flow within the capillary channel, the driving rate... The value is greater than a preset first threshold and less than a preset second threshold to ensure that the non-Newtonian index of the polymer melt can be measured smoothly.

[0021] S3, Driving pressure for collecting polymer melt and drive rate .

[0022] Given that polymer melt is a fluid, it is not possible to add pressure sensors or other detection devices to the polymer melt to detect the driving pressure. Therefore, in the process of driving the polymer melt to flow in the capillary channel, the present invention places the driving component into the capillary channel and sets a pressure sensor at the end of the driving component facing away from the polymer melt. The driving pressure is obtained by collecting the reverse force of the polymer melt on the driving component. To address the difficulty in measuring drive pressure The problem.

[0023] Furthermore, during the process of driving the polymer melt to flow in the capillary channel, the driving pressure is gradually increased based on a preset gradient rule. and drive rate This ensures that the polymer melt remains stable in a state suitable for measuring non-Newtonian exponents, thus guaranteeing the final measurement accuracy. Based on this, when the polymer melt flows to the middle of the capillary channel, the driving pressure of the polymer melt is collected. and drive rate To avoid measuring when the polymer melt is near the end of the capillary channel, ensure the driving pressure. and drive rate The data was collected when the polymer melt was in a stable state, thus ensuring the accuracy of the measured non-Newtonian index.

[0024] Furthermore, during the process of driving the polymer melt to flow in the capillary channel, based on the driving rate... Determine the position of the polymer melt within the capillary channel. Specifically, the current position of the polymer melt can be calculated using velocity integration to ensure that the driving pressure can be sampled in the middle of the capillary channel. and drive rate The specific location calculation method is a conventional technique and will not be elaborated here.

[0025] S4, based on driving pressure and drive rate Calculate the non-Newtonian index of polymer melt The calculation method is as follows: .

[0026] in, For logarithmic operations, This is for differential operations.

[0027] Compared to existing methods that first perform complex calculations to determine the shear rate and shear stress, and then calculate the non-Newtonian exponent, this invention only requires the original driving pressure. and drive rate This greatly simplifies the calculation process.

[0028] like Figure 2 and Figure 3 It can be seen that the value of the non-Newtonian exponent calculated using this invention is accurate.

[0029] The present invention further provides a non-Newtonian index measuring device for polymer melts, used to implement the above-mentioned non-Newtonian index measuring method for polymer melts. The device includes a capillary tube, a driving component, a data acquisition module, and a calculation module.

[0030] Capillary tubes, the inner cavity of which forms capillary channels.

[0031] The driving element can extend into the capillary channel to drive the flow of polymer melt.

[0032] The acquisition module is used to acquire the driving pressure of the polymer melt. and drive rate .

[0033] Calculation module for use based on driving pressure and drive rate Calculate the non-Newtonian index of polymer melt The calculation method is as follows: .

[0034] in, For logarithmic operations, This is for differential operations.

[0035] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division; in actual implementation, there may be other division methods. Furthermore, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces; the indirect coupling or communication connection of devices or modules may be electrical, mechanical, or other forms.

[0036] The present invention also provides a computer device, including a memory and a processor.

[0037] Memory is used to store computer programs.

[0038] A processor for reading and executing computer programs to implement the aforementioned method for measuring the non-Newtonian index of a polymer melt.

[0039] Finally, the present invention provides a storage medium for storing a computer program that, when executed, implements the above-described method for measuring the non-Newtonian index of a polymer melt.

[0040] The memory, as a carrier of resources, can be a read-only memory, random access memory, disk, or optical disk, etc. The resources stored on it can include the operating system, computer programs, etc., and the storage method can be temporary or permanent storage. The operating system is used to manage and control the various hardware devices and computer programs on the electronic device, and can be Windows Server, Netware, Unix, Linux, etc. In addition to including computer programs capable of performing the adaptive emotion regulation method based on personalized reconfigurable music disclosed in any of the foregoing embodiments, the computer programs may further include computer programs capable of performing other specific tasks. The processor can be a general-purpose processor product based on architectures such as x86, IA64, RISC, MIPS, and ARM.

[0041] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for measuring the non-Newtonian index of a polymer melt, characterized in that, include: The polymer melt to be tested is fed into the capillary channel; Drive the polymer melt to flow in the capillary channels; Collect the driving pressure of polymer melt and drive rate ; Based on driving pressure and drive rate Calculate the non-Newtonian index of polymer melt The calculation method is as follows: ； in, For logarithmic operations, This is for differential operations.

2. The method for measuring the non-Newtonian index of a polymer melt as described in claim 1, characterized in that, Methods for introducing the polymer melt to be tested into a capillary channel include: A heating chamber is provided at one end of the capillary channel, and the polymer is placed into the heating chamber; The polymer is heated to obtain a polymer melt, and the polymer melt is then allowed to flow into capillary channels.

3. The method for measuring the non-Newtonian index of a polymer melt as described in claim 1, characterized in that, The driving rate during the process of driving the polymer melt to flow in the capillary channel It is greater than the preset first threshold and less than the preset second threshold.

4. The method for measuring the non-Newtonian index of a polymer melt as described in claim 1, characterized in that, During the process of driving the polymer melt to flow in a capillary channel, a driving element is placed into the capillary channel, and the driving pressure is obtained by collecting the reverse force of the polymer melt on the driving element. .

5. The method for measuring the non-Newtonian index of a polymer melt as described in claim 1, characterized in that, During the process of driving the polymer melt to flow in the capillary channel, the driving pressure of the polymer melt is collected when the polymer melt flows to the middle of the capillary channel. and drive rate .

6. The method for measuring the non-Newtonian index of a polymer melt as described in claim 5, characterized in that, During the process of driving the polymer melt to flow in the capillary channel, based on the driving rate Determine the position of the polymer melt in the capillary channel.

7. The method for measuring the non-Newtonian index of a polymer melt as described in claim 1, characterized in that, During the process of driving the polymer melt to flow in the capillary channel, the driving pressure is gradually increased based on a preset gradient rule. and drive rate .

8. A non-Newtonian index measuring device for polymer melts, characterized in that, The apparatus for implementing a method for measuring the non-Newtonian index of a polymer melt as described in any one of claims 1-7 comprises: Capillary, the inner cavity of the capillary forms the capillary channel; The driving component can extend into the capillary channel to drive the flow of polymer melt; The acquisition module is used to acquire the driving pressure of the polymer melt. and drive rate ; Calculation module for use based on driving pressure and drive rate Calculate the non-Newtonian index of polymer melt The calculation method is as follows: ； in, For logarithmic operations, For differential operations Computer equipment, characterized in that it includes: Memory, used to store computer programs; A processor for reading and executing the computer program to implement a non-Newtonian index measurement method for polymer melts as described in any one of claims 1-7.

9. A storage medium, characterized in that, Used to store a computer program, which, when executed, implements a method for measuring the non-Newtonian index of a polymer melt as described in any one of claims 1-7.

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