An apparatus and method for analyzing the swellability and dispersion uniformity of ultra-high molecular weight polyethylene

Abstract

An apparatus for analyzing the swelling property and dispersion uniformity of ultra-high molecular weight polyethylene, comprising: a solvent tank, a feed pump, a swelling tank, a feed pump and a pipeline mixer connected in sequence; wherein the swelling tank is provided with an online swelling monitoring device at the upper, middle and lower positions; the pipeline mixer is provided with an online swelling monitoring device at the discharge port; a solid feeder connected to the discharge port and the feed port of the swelling tank; and a granular raw material tank connected to the discharge port and the feed port of the solid feeder. The apparatus can obtain the swelling starting temperature and starting time, the minimum swelling temperature, the swelling rate at different temperatures and time periods, the swelling equilibrium point, the swelling and dissolution demarcation point and the particle agglomeration condition by monitoring the particle size and distribution of the ultra-high molecular weight polyethylene before and after feeding, thereby monitoring the swelling process and obtaining analysis data quickly, directly monitoring the particle size distribution of the ultra-high molecular weight polyethylene during the swelling process and monitoring the swelling property and dispersion uniformity online.

Description

Technical Field

[0001] This invention relates to the field of performance testing technology for ultra-high molecular weight polyethylene (UHMWPE), and more specifically, to an apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of UHMWPE. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) is a non-polar crystalline polymer, comprising both crystalline and amorphous regions. At room temperature, UHMWPE is insoluble; it can only be heated to near its melting point. Once the crystalline regions melt, small-molecule solvents can penetrate into the polymer's crystalline regions, gradually swelling and dissolving. After sufficient swelling, reaching a swelling equilibrium, solvent molecules fully penetrate into the center of the polymer particles. This allows the macromolecular chains to fully extend and expand within the solvent, resulting in a solution with high viscosity (molecular weight). For UHMWPE, if the swelling time is short and the swelling degree is insufficient, microscopic clumps of UHMWPE polymers will form after dissolution. In addition to the swelling properties of individual molecules, the dispersibility of UHMWPE also significantly affects the performance of UHMWPE fibers. Insufficient dispersion uniformity can lead to a decrease in the mechanical properties of the gel filaments, thus affecting the fineness of the finished fibers.

[0003] Currently, the methods for characterizing swelling properties include: (1) Hot-stage microscopy. Hot-stage microscopy is a traditional microscope with a heating stage added. In addition to observing the original microstructure of the sample, it also allows observation of the changes in the microstructure of the sample under different atmospheres during a certain heating process. It is widely used in polymer melting, recrystallization and other changes. Hot-stage microscopy can directly observe the relationship between the swelling process and the heating rate. However, since hot-stage microscopy cannot simulate the swelling-dissolution process in the production process by simultaneously stirring and heating, it has certain limitations. (2) Gravimetric method for measuring swelling ratio. The ratio of the mass of ultra-high molecular weight polyethylene particles after being fully swollen by the solvent to the mass of ultra-high molecular weight polyethylene contained in them. Determination Procedure: The swollen ultra-high molecular weight polyethylene resin and white oil were separated by vacuum filtration using a Buchner funnel and qualitative analytical filter paper. The mass of the swollen product (m1) was weighed. The swollen product was then thoroughly washed twice with xylene in an ultrasonic bath for 1 minute each time. After the above filtration and aspiration treatment, it was placed in a vacuum oven at 70℃ for 4 hours and its mass (m2) was weighed. α was calculated as α = m1 / m2. This process was repeated until the total mass of the sample remained constant, reaching swelling equilibrium. The swelling ratio at this point reflects the swelling equilibrium. The advantage of this method is that it does not require expensive equipment. However, the manual testing operation is cumbersome. Furthermore, the time required to reach constant weight is long, and the sample needs to be collected for testing. The experimental environment of the collected sample differs from the production environment, making it impossible to truly replicate the reaction environment of the sample in the solvent. Therefore, it has no reference value.

[0004] Currently, methods for characterizing uniformity include CN103411987A by Luo Zhiqiang et al., who used scanning electron microscopy coupled with X-ray energy dispersive spectroscopy to determine the uniformity and dispersibility of titanium dioxide surface coatings; and CN102338747A by Yang Yi et al., who selected no fewer than three sample regions from synthesized polymer samples containing nanomaterials, and used appropriate chemical titration reactions and colorimetric reactions to perform chemical titration of the characteristic elements of the nanomaterials, calculated the content of the nanomaterials, and characterized the dispersibility of the nanomaterials by the relative standard deviation of the technical content, and provided corresponding quantitative evaluation standards. However, there is currently no analytical characterization method for the dispersibility of ultra-high molecular weight polyethylene in solvents. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE), which can quickly obtain analytical data, directly monitor the particle size distribution of UHMWPE during the swelling process, and monitor the swelling and dispersion uniformity of UHMWPE online.

[0006] This invention provides an apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene, comprising:

[0007] The solvent tank, feed pump, swelling tank, feed pump, and pipeline mixer are connected in sequence; an online swelling monitoring device is installed at the top, middle, and bottom of the swelling tank; an online swelling monitoring device is installed at the outlet of the pipeline mixer;

[0008] A solid feeder whose outlet is connected to the inlet of the swelling tank;

[0009] A granular raw material tank whose discharge port is connected to the feed port of a solid feeder.

[0010] Preferably, the swelling tank is a kettle-type, column-type, or square-type vessel, and is equipped with a stirring device inside. The stirring device is one or more combinations of propeller-type, ribbon-type, screw-type, anchor-type, frame-type, and folding-blade-type.

[0011] Preferably, the pipeline mixer is a dynamic mixer or a static mixer.

[0012] Preferably, the online swelling monitoring device can detect the particle size of solid particles and can count the changes in the number of solid particles; the online swelling monitoring device is a laser focusing reflectance measuring instrument, a laser reconstruction imaging particle size analyzer, or an ultrasonic particle size analyzer.

[0013] Preferably, the upper, middle, and lower positions of the swelling tank are 60%–80%, 30%–50%, and 10%–20% of the tank height, respectively.

[0014] This invention also provides a method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene, comprising the following steps:

[0015] The apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) using the above-described technical solution first heats the solvent in the solvent tank to a first temperature, then pumps it into the swelling tank. Simultaneously, the granular raw material in the granular raw material tank is heated to a second temperature and then fed into the swelling tank using a solid feeder. The swelling tank is then heated to a third temperature, and three online swelling monitoring devices located at the top, middle, and bottom of the swelling tank are used to monitor the particle size distribution of the UHMWPE raw material within the tank. The mixture is then pumped to a pipeline mixer, and finally, an online swelling monitoring device at the outlet of the pipeline mixer is used to monitor the particle size distribution of the UHMWPE raw material. After swelling equilibrium is reached, the mixture is fed into the dissolution unit.

[0016] Preferably, the solvent is No. 48 white oil or No. 68 white oil; the particulate raw material is ultra-high molecular weight polyethylene with a median diameter of 178μm to 192μm and an ideal maximum swelling median diameter of 238μm to 249μm.

[0017] Preferably, the first temperature is 50℃~70℃; the second temperature is 50℃~70℃; the heating rate to the third temperature is 1℃ / min~2℃ / min; the third temperature is 110℃~120℃; and the holding time at the third temperature is 1h~2h.

[0018] Preferably, the mass ratio of the solvent to the particulate raw material is (6-10):100; the flow rate of the mixture is 0.1 m³ / s. 3 / h~1m 3 / h.

[0019] Preferably, the particle size swelling rate at each time period is expressed as follows:

[0020]

[0021] Among them, D t D0 is the median diameter of the particle at a certain moment to be measured, and D0 is the median diameter of the particulate material. T The ideal maximum swelling median diameter;

[0022] When E Dt When the RSD is greater than 80%, the swelling requirement is met; after swelling occurs, when the RSD... D50 When the concentration is between 2% and 5%, swelling equilibrium is reached;

[0023] when When n0 is the point where swelling and dissolution begin, nt is the number of particles at the initial swelling point and nt is the number of particles at any point after swelling occurs.

[0024] Dispersion uniformity is expressed as:

[0025]

[0026] Among them, D 90 D represents the particle size at which the cumulative particle size distribution percentage of a sample reaches 90%. 10 D represents the particle size at which the cumulative particle size distribution percentage of a sample reaches 10%. 50 This refers to the particle size at which the cumulative particle size distribution percentage of a sample reaches 50%.

[0027] When η Dt A concentration of 2% to 5% indicates that the material is uniform.

[0028] This invention provides an apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE). The apparatus includes: a solvent tank, a feed pump, a swelling tank, a feed pump, and a pipeline mixer connected in sequence. An online swelling monitoring device is installed at the upper, middle, and lower positions of the swelling tank; an online swelling monitoring device is installed at the outlet of the pipeline mixer; a solid feeder is connected to the outlet of the swelling tank and the inlet of the swelling tank; and a granular raw material tank is connected to the outlet of the solid feeder and the inlet of the solid feeder. Compared with the prior art, the apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of UHMWPE provided by this invention can obtain the swelling initiation temperature and initiation time, the minimum swelling temperature, the swelling rate at different temperatures and time periods, the swelling equilibrium point, the swelling and dissolution boundary point, and the particle agglomeration status by monitoring the particle size and distribution of UHMWPE before and after feeding into the swelling reaction device. This allows for monitoring of the swelling process, enabling rapid acquisition of analytical data, direct monitoring of the UHMWPE particle size distribution during the swelling process, and online monitoring of the swelling and dispersion uniformity of UHMWPE. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the apparatus provided in an embodiment of the present invention for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides an apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene, comprising:

[0032] The solvent tank, feed pump, swelling tank, feed pump, and pipeline mixer are connected in sequence; an online swelling monitoring device is installed at the top, middle, and bottom of the swelling tank; an online swelling monitoring device is installed at the outlet of the pipeline mixer;

[0033] A solid feeder whose outlet is connected to the inlet of the swelling tank;

[0034] A granular raw material tank whose discharge port is connected to the feed port of a solid feeder.

[0035] Please see Figure 1 , Figure 1A schematic diagram of the apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene provided in an embodiment of the present invention; wherein, 1 is a solvent tank; 2 is a feed pump; 3 is a granular raw material tank; 4 is a solid feeder; 5 is an online swelling monitoring device; 6 is a swelling tank; 7 is a feed pump; and 8 is a pipeline mixer.

[0036] In this invention, the solvent tank is used for storing, stirring, and heating the solvent; the solvent tank is preferably a kettle-type, column-type, or square-type, more preferably a kettle-type, with a volume of 100mL to 200mL. 3 All are acceptable; the solvent tank is equipped with a stirring device, which is preferably one or more of the following: propeller type, ribbon type, screw type, anchor type, frame type, and folding blade type, more preferably a combination of anchor type and propeller type, or a combination of frame type and propeller type.

[0037] In this invention, the feed pump is located between the solvent tank and the swelling tank, and is used to transport the solvent in the solvent tank to the swelling tank.

[0038] In this invention, the swelling tank is used for mixing solvent and particulate raw materials and for swelling ultra-high molecular weight polyethylene raw materials. It can be stirred and heated. The swelling tank is preferably a kettle-type, column-type, or square-type tank, more preferably a kettle-type tank, with a volume of 100mL to 200mL. 3 All are acceptable; the swelling tank is equipped with a stirring device, which is preferably one or more of the following: propeller type, ribbon type, screw type, anchor type, frame type, and folding blade type, more preferably a combination of anchor type and propeller type, or a combination of frame type and propeller type.

[0039] In this invention, the feed pump is located between the swelling tank and the pipeline mixer, and is used to transport the mixture in the swelling tank to the pipeline mixer.

[0040] In this invention, the pipeline mixer is preferably a dynamic mixer or a static mixer; the outlet of the pipeline mixer is connected to the dissolving unit.

[0041] In this invention, an online swelling monitoring device is provided at the upper, middle, and lower positions of the swelling tank; an online swelling monitoring device is provided at the outlet of the pipeline mixer; the online swelling monitoring device can detect the particle size of solid particles and can count the changes in the number of solid particles, and can also be called an online particle size distribution monitoring device; the online swelling monitoring device is preferably a laser focusing reflection measuring instrument, a laser reconstruction imaging particle size analyzer, or an ultrasonic particle size analyzer, and more preferably a laser focusing reflection measuring instrument or a laser reconstruction imaging particle size analyzer.

[0042] In this invention, the upper, middle, and lower positions of the swelling tank are 60%–80%, 30%–50%, and 10%–20% of the tank height, respectively. Specifically, the probes of the online swelling monitoring device are installed on the side wall of the swelling tank. As described above, one probe is installed at each of the upper, middle, and lower positions inside the swelling tank. The probes are connected to the host and display device, etc., through a connecting circuit.

[0043] In this invention, each online swelling monitoring device monitors the uniformity of ultra-high molecular weight polyethylene in the swelling tank and pipeline mixer. Once swelling equilibrium is reached, it can be transported to the subsequent dissolution unit.

[0044] In this invention, the outlet of the solid feeder is connected to the inlet of the swelling tank, and the outlet of the granular raw material tank is connected to the inlet of the solid feeder, thereby enabling the ultra-high molecular weight polyethylene solid granular raw material in the granular raw material tank to be transported to the swelling tank via the solid feeder.

[0045] In this invention, the various structures are connected by connecting pipelines, which are preferably equipped with heating devices and heat preservation devices according to the specific material properties, thereby improving the fluidity of the mixture in the pipeline.

[0046] This invention also provides a method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene, comprising the following steps:

[0047] The apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) using the above-described technical solution first heats the solvent in the solvent tank to a first temperature, then pumps it into the swelling tank. Simultaneously, the granular raw material in the granular raw material tank is heated to a second temperature and then fed into the swelling tank using a solid feeder. The swelling tank is then heated to a third temperature, and three online swelling monitoring devices located at the top, middle, and bottom of the swelling tank are used to monitor the particle size distribution of the UHMWPE raw material within the tank. The mixture is then pumped to a pipeline mixer, and finally, an online swelling monitoring device at the outlet of the pipeline mixer is used to monitor the particle size distribution of the UHMWPE raw material. After swelling equilibrium is reached, the mixture is fed into the dissolution unit.

[0048] In this invention, the solvent is preferably No. 48 white oil or No. 68 white oil; the particulate raw material is preferably ultra-high molecular weight polyethylene, with a median diameter (D0) preferably between 178 μm and 192 μm, and an ideal maximum swelling median diameter (D0) of [missing value]. T The preferred particulate size is 238 μm to 249 μm. This invention does not impose any special restrictions on the source of the solvent and particulate raw materials; commercially available products well-known to those skilled in the art can be used.

[0049] In this invention, the first temperature is preferably 50℃~70℃, more preferably 60℃; the second temperature is preferably 50℃~70℃, more preferably 60℃; the heating rate to the third temperature is preferably 1℃ / min~2℃ / min; the third temperature is preferably 110℃~120℃; and the holding time at the third temperature is preferably 1h~2h.

[0050] In this invention, the preferred mass ratio of the solvent to the particulate raw material is (6-10):100; the preferred flow rate of the mixture is 0.1 m³ / s. 3 / h~1m 3 / h.

[0051] This invention provides a method for characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) in a solvent during the production of UHMWPE fibers via gel spinning. The method allows for online monitoring of the UHMWPE swelling process. Specifically:

[0052] (1) The initial particle size distribution and median diameter (D0) of the initial ultra-high molecular weight polyethylene were analyzed using an online particle size distribution monitoring device.

[0053] (2) Add ultra-high molecular weight polyethylene and solvent in proportion;

[0054] (3) Adjusting the temperature inside the swelling tank can achieve a constant heating rate or a constant final temperature.

[0055] (4) Monitor the particle size distribution change curve, minimum swelling temperature T (swelling rate of 10% within 1 hour), D T The ideal maximum swelling median diameter is obtained by allowing the material to swell for an extended period (24h–48h) at this temperature until equilibrium is reached; the initial particle size (D0) is equal to the initial median particle size (D...). 50 ), D t Let be the median diameter of the particles at a certain moment to be measured. Then, the particle swelling rate at each time interval can be expressed as:

[0056]

[0057] When E Dt When the RSD is greater than 80%, the swelling requirement is met; after swelling occurs, when the RSD... D50 When (t=11)=2%~5%, swelling equilibrium is reached;

[0058] when When n0 is the point where swelling and dissolution begin, nt is the number of particles at the initial swelling point and nt is the number of particles at any point after swelling occurs.

[0059] (5) Dispersion uniformity is expressed as:

[0060]

[0061] Among them, D 90 This refers to the particle size at which the cumulative particle size distribution percentage of a sample reaches 90%. Physically, it means that 90% of the particles are smaller than this value. 10 This refers to the particle size at which the cumulative particle size distribution percentage of a sample reaches 10%. Physically, it means that 10% of the particles are smaller (or larger) than this value. 50 It is the particle size that corresponds to a cumulative particle size distribution percentage of 50% for a sample. Its physical meaning is that 50% of the particles are smaller than it.

[0062] When η Dt A concentration of 2% to 5% indicates that the material is uniform.

[0063] (6) The monitoring location can be selected inside the swelling tank or in the swelling circulation pipeline. There are at least 3 monitoring points, located at different positions in the upper, middle and lower parts of the swelling tank.

[0064] (7) When the swelling rate reaches the specified value, the mixture of ultra-high molecular weight polyethylene and solvent can be dissolved. The reaction temperature is increased, and the uniformity of the solution is monitored by an online monitor (the solution droplets are uniform in size, the particle size distribution curve is smooth, and there are no solid particles).

[0065] The apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene provided by this invention have the following beneficial effects:

[0066] (1) It can perform online analysis or in-situ online analysis, and the analysis results are close to the actual experimental or production conditions;

[0067] (2) The data analysis is intuitive and fast, and can provide rapid guidance for experiments and production;

[0068] (3) No sampling and analysis is required, which can save product materials and reduce the risks caused by high temperature or high pressure conditions during the swelling process;

[0069] (4) It takes less time to analyze than conventional methods and requires less human intervention;

[0070] (5) This method can analyze and characterize both solid-liquid dispersion in containers and solid-liquid dispersion in pipelines.

[0071] This invention provides an apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE). The apparatus includes: a solvent tank, a feed pump, a swelling tank, a feed pump, and a pipeline mixer connected in sequence. An online swelling monitoring device is installed at the upper, middle, and lower positions of the swelling tank; an online swelling monitoring device is installed at the outlet of the pipeline mixer; a solid feeder is connected to the outlet of the swelling tank and the inlet of the swelling tank; and a granular raw material tank is connected to the outlet of the solid feeder and the inlet of the solid feeder. Compared with the prior art, the apparatus and method for analyzing and characterizing the swelling and dispersion uniformity of UHMWPE provided by this invention can obtain the swelling initiation temperature and initiation time, the minimum swelling temperature, the swelling rate at different temperatures and time periods, the swelling equilibrium point, the swelling and dissolution boundary point, and the particle agglomeration status by monitoring the particle size and distribution of UHMWPE before and after feeding into the swelling reaction device. This allows for monitoring of the swelling process, enabling rapid acquisition of analytical data, direct monitoring of the UHMWPE particle size distribution during the swelling process, and online monitoring of the swelling and dispersion uniformity of UHMWPE.

[0072] To further illustrate the present invention, detailed descriptions are provided below through the following embodiments. Unless otherwise stated, the reagents, materials, and devices involved in the following embodiments are all commercially available and conventionally applicable in the art; the conventional operations involved in the following embodiments can be found in patents, patent applications, and publications disclosed in the art.

[0073] Example 1

[0074] Please see Figure 1 , Figure 1 The diagram below shows the structure of the apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene provided in the embodiments of the present invention. In the diagram, 1 is a solvent tank; 2 is a feed pump; 3 is a granular raw material tank; 4 is a solid feeder; 5 is an online swelling monitoring device; 6 is a swelling tank; 7 is a feed pump; and 8 is a pipeline mixer.

[0075] The working process of the apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene provided in this embodiment of the invention (method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene) is as follows:

[0076] First, the solvent tank 1 containing solvent is stirred at a suitable speed (20-100 r / min) and heated to a certain temperature. Then, it is transported to the swelling tank 6 using the feed pump 2. The granular raw material tank 3 is heated to a suitable temperature and transported to the swelling tank 6 using the solid feeder 4. The particle size distribution of the ultra-high molecular weight polyethylene raw material is monitored in the swelling tank using the online swelling monitoring device 5. The raw material is then transported to the pipeline mixer 8 via the feed pump 7. The particle size distribution of the ultra-high molecular weight polyethylene raw material is monitored at the outlet of the pipeline mixer using the online swelling monitoring device 5. After swelling equilibrium is reached, the raw material is transported to the dissolution unit.

[0077] In this embodiment, the solvent is No. 68 white oil, the median diameter (D0) of the solid particulate raw material is 185 μm, and the ideal maximum swelling median diameter (D... T The particle size is 249 μm, the dosage-to-material ratio is 6%, and the flow rate is 1 m³ / min. 3 The initial solvent temperature and raw material feeding temperature are both 60℃, the heating rate is 1℃ / min, and the temperature is raised to 110℃. A static mixer is used, the swelling tank is a kettle type, and the stirring method is a combination of anchor and propeller.

[0078] Table 1 below shows the data after the temperature was raised to 110℃ and held at that temperature for 2 hours.

[0079] Table 1

[0080]

[0081] Example 2

[0082] The apparatus and method for characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) as described in Example 1 are used, with the difference being that: in this example, the solvent is No. 68 white oil, the median diameter (D0) of the solid particulate raw material is 185 μm, and the ideal maximum swelling median diameter (D... T The particle size is 245 μm, the dosage-to-material ratio is 6%, and the flow rate is 1 m³ / min. 3 The initial solvent temperature and raw material feeding temperature are both 60℃, the heating rate is 2℃ / min, and the temperature is raised to 110℃. A static mixer is used, the swelling tank is a kettle type, and the stirring method is a combination of anchor and propeller.

[0083] Table 2 below shows the data after heating to 110℃ and holding at that temperature for 2 hours.

[0084] Table 2

[0085]

[0086] Example 3

[0087] The apparatus and method for characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) as described in Example 1 are used, with the difference being that: in this example, the solvent is No. 68 white oil, the median diameter (D0) of the solid particulate raw material is 185 μm, and the ideal maximum swelling median diameter (D... T The particle size is 245 μm, the dosage-to-material ratio is 6%, and the flow rate is 1 m³ / min. 3 The initial solvent temperature and raw material feeding temperature are both 60℃, the heating rate is 2℃ / min, and the temperature is raised to 110℃. A static mixer is used, the swelling tank is a kettle type, and the stirring method is a combination of anchor and propeller.

[0088] Table 3 below shows the data after heating to 110℃ and holding at that temperature for 2 hours.

[0089] Table 3

[0090]

[0091] Comparative Example 1

[0092] The apparatus and method for characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) as described in Example 1 are used, with the difference being that: the solvent in this comparative example is No. 48 white oil, the median diameter (D0) of the solid particulate raw material is 178 μm, and the ideal maximum swelling median diameter (D... T The particle size is 238 μm, the dosage-to-material ratio is 6%, and the flow rate is 1 m³ / min. 3 The initial solvent temperature and raw material feeding temperature are both 60℃, the heating rate is 1℃ / min, and the temperature is raised to 110℃. A static mixer is used, the swelling tank is a kettle type, and the stirring method is a combination of anchor and propeller.

[0093] Table 4 below shows the data after heating to 110℃ and holding at that temperature for 2 hours.

[0094] Table 4

[0095]

[0096] Comparing Comparative Example 1 and Example 1, the swelling test of ultra-high molecular weight polyethylene (UHMWPE) was verified using different solvents, specifically No. 48 white oil and No. 68 white oil. The test results verified the analytical characterization method and implementation system for the swelling and dispersion uniformity of UHMWPE. Swelling occurred in both solvent tests. When No. 68 white oil was used as the solvent, η... Dt Smaller size indicates higher uniformity.

[0097] Comparative Example 2

[0098] The apparatus and method for characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) as described in Example 1 are used, with the difference being that: the solvent in this comparative example is No. 68 white oil, the median diameter (D0) of the solid particulate raw material is 192 μm, and the ideal maximum swelling median diameter (D... T The particle size is 248 μm, the dosage-to-material ratio is 10%, and the flow rate is 1 m³ / s. 3 The initial solvent temperature and raw material feeding temperature are both 60℃, the heating rate is 2℃ / min, and the temperature is raised to 110℃. A dynamic mixer is used, the swelling tank is a kettle type, and the stirring method is a combination of frame and propeller type.

[0099] Table 5 below shows the data after heating to 110℃ and holding at that temperature for 2 hours.

[0100] Table 5

[0101]

[0102] Comparing Comparative Example 2 and Example 2, it was verified that swelling occurred during the tests at different dosage ratios (10% and 6%). At a dosage ratio of 6%, η... Dt Smaller size indicates higher uniformity.

[0103] Comparative Example 3

[0104] The apparatus and method for characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene (UHMWPE) in Example 1 are used, with the difference being that: the solvent in this comparative example is No. 68 white oil, the median diameter (D0) of the solid particulate raw material is 185 μm, and the ideal maximum swelling median diameter (D... T The particle size is 245 μm, the dosage-to-material ratio is 6%, and the flow rate is 1 m³ / min. 3 The initial solvent temperature and raw material feeding temperature are both 60℃, the heating rate is 2℃ / min, and the temperature is raised to 110℃. A dynamic mixer is used, the swelling tank is a kettle type, and the stirring method is a combination of frame and propeller type.

[0105] Table 6 below shows the data after heating to 110℃ and holding at that temperature for 2 hours.

[0106] Table 6

[0107]

[0108] Comparing Comparative Example 3 and Example 3, it was verified that different stirring methods all achieved swelling equilibrium. Furthermore, the static mixer and swelling tank were both of the same type, and the stirring method combined anchor and propeller stirring. η Dt Smaller size indicates higher uniformity.

[0109] 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. An apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene, characterized in that, include: The solvent tank, feed pump, swelling tank, feed pump, and pipeline mixer are connected in sequence; an online swelling monitoring device is installed at the top, middle, and bottom of the swelling tank; an online swelling monitoring device is installed at the outlet of the pipeline mixer; A solid feeder whose outlet is connected to the inlet of the swelling tank; A granular raw material tank whose outlet is connected to the inlet of a solid feeder; The swelling tank is of the kettle type, column type or square type, and is equipped with a stirring device inside. The stirring device is one or more combinations of propeller type, ribbon type, screw type, anchor type, frame type and folding blade type. The pipeline mixer can be a dynamic mixer or a static mixer; The online swelling monitoring device can detect the particle size of solid particles and count the changes in the number of solid particles; the online swelling monitoring device is a laser focusing reflectance measuring instrument, a laser reconstruction imaging particle size analyzer, or an ultrasonic particle size analyzer. The upper, middle, and lower positions of the swelling tank are 60%~80%, 30%~50%, and 10%~20% of the tank height, respectively.

2. A method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene, characterized in that, Includes the following steps: The apparatus for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene as described in claim 1 first heats the solvent in the solvent tank to a first temperature and then pumps it into the swelling tank. Simultaneously, the granular raw material in the granular raw material tank is heated to a second temperature and then pumped into the swelling tank using a solid feeder. The swelling tank is then heated to a third temperature, and the particle size distribution of the ultra-high molecular weight polyethylene raw material in the swelling tank is monitored using three online swelling monitoring devices installed at the top, middle, and bottom of the swelling tank. The mixture is then pumped to a pipeline mixer via a feed pump. Finally, the particle size distribution of the ultra-high molecular weight polyethylene raw material is monitored using an online swelling monitoring device installed at the outlet of the pipeline mixer. After swelling equilibrium is reached, the mixture is pumped to the dissolution unit. The particle size swelling rate for each time period is expressed as follows: ； Among them, D t D0 is the median diameter of the particle at a certain moment to be measured, and D0 is the median diameter of the particulate material. T The ideal maximum swelling median diameter; When E Dt When the RSD is greater than 80%, the swelling requirement is met; after swelling occurs, when the RSD... D50 When the concentration is 2%~5%, swelling equilibrium is reached; When 0.8 < When <1, it is the boundary between swelling and dissolution; where n0 is the number of particles at the initial swelling, and nt is the number of particles at any time after swelling occurs; Dispersion uniformity is expressed as: ； Among them, D 90 D represents the particle size at which the cumulative particle size distribution percentage of a sample reaches 90%. 10 D represents the particle size at which the cumulative particle size distribution percentage of a sample reaches 10%. 50 This refers to the particle size at which the cumulative particle size distribution percentage of a sample reaches 50%. when When the concentration is 2% to 5%, it indicates that the material is uniform.

3. The method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene according to claim 2, characterized in that, The solvent is No. 48 white oil or No. 68 white oil; the particulate raw material is ultra-high molecular weight polyethylene with a median diameter of 178μm~192μm and an ideal maximum swelling median diameter of 238μm~249μm.

4. The method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene according to claim 2, characterized in that, The first temperature is 50℃~70℃; the second temperature is 50℃~70℃; the heating rate to the third temperature is 1℃ / min~2℃ / min; the third temperature is 110℃~120℃; and the holding time at the third temperature is 1h~2h.

5. The method for analyzing and characterizing the swelling and dispersion uniformity of ultra-high molecular weight polyethylene according to claim 2, characterized in that, The mass ratio of the solvent to the particulate raw material is (6~10):100; the flow rate of the mixture is 0.1 m³. 3 / h~1m 3 / h.

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