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CN-121976305-A - Device and method for dynamically adding functional particles on line in solution spinning

CN121976305ACN 121976305 ACN121976305 ACN 121976305ACN-121976305-A

Abstract

The invention belongs to the technical field of functional nanofiber membrane preparation, and particularly relates to a device and a method for dynamically adding functional particles on line in solution blowing spinning. The invention provides a device and a method for dynamically adding functional particles on line in solution blowing spinning, which can ensure that 1, the particle injection assembly is used for injecting particles into a spinning jet flow in a discrete mode at a specific moment under the regulation and control of the control assembly by arranging a spinning assembly, a particle injection assembly, a pneumatic shearing assembly and a control assembly, and 2, the pneumatic shearing assembly is used for constructing an air flow field at the periphery of the spinning jet flow to apply transverse aerodynamic force to the spinning jet flow so as to diffuse the particles entering the spinning jet flow in the radial direction, thereby improving the spatial distribution of the particles in the fiber forming process, reducing the aggregation phenomenon of the particles in the center of a fiber film and improving the distribution uniformity of the functional particles in the fiber film.

Inventors

  • SUN GUANGWU
  • YANG JINGYI
  • YAO CHENGJIAN
  • YANG QUN

Assignees

  • 上海工程技术大学

Dates

Publication Date
20260505
Application Date
20260312

Claims (10)

  1. 1. An apparatus for dynamically adding functional particles on-line in solution blow spinning, comprising: the spinning assembly (1) comprises a spinning needle tube (11), and an airflow sleeve (12) sleeved on the outer side of the spinning needle tube (11), wherein a main airflow channel (13) is formed between the airflow sleeve (12) and the spinning needle tube (11); a particle injection assembly (2) comprising a particle delivery tube (21) in communication with the proximal outlet end of the spinning needle tube (11), a high frequency pulse valve (22) disposed on the particle delivery tube (21); A pneumatic shear assembly (3) comprising a plurality of lateral auxiliary air flow nozzles (31) circumferentially arranged around the outlet end of the spinning needle tube (11), the flow direction of the lateral auxiliary air flow nozzles (31) being directed towards the jet centre of the spinning needle tube (11); The control assembly comprises a high-frequency pressure sensor for detecting fluid pressure pulsation signals in the spinning needle tube (11) and a main control unit which is in communication connection with the high-frequency pressure sensor and the high-frequency pulse valve (22), wherein the main control unit is configured to extract jet natural disturbance main frequency f j based on the pressure pulsation signals and control the high-frequency pulse valve (22) to quantitatively inject functional particles into the spinning needle tube (11) in a pulse mode at a pulse frequency matched with the jet natural disturbance main frequency.
  2. 2. The device for dynamically adding functional particles on line in solution blowing spinning according to claim 1, wherein a frequency matching model is preset in the main control unit, and the opening pulse frequency f pulse of the high-frequency pulse valve (22) is f pulse =k·f j , wherein k is a matching coefficient, and the value range is 0.8-1.2.
  3. 3. The device for dynamically adding functional particles on line in solution spinning according to claim 1, wherein the main air flow channel (13) is sequentially provided with a contraction section (131), a throat (132) and an expansion section (133) along the air flow direction, the inlet aperture of the contraction section (131) is R1, the aperture of the throat (132) is R2, the aperture of the expansion section (133) is R3, and R1> R3 is more than or equal to R2.
  4. 4. The device for dynamically adding functional particles on line in solution blowing spinning according to claim 1, wherein the particle conveying pipe (21) is communicated with a flat slit section (23) at one end of the spinning needle tube (11), and the distance from the slit section (23) to the outlet of the spinning needle tube (11) is 5mm-30mm.
  5. 5. The device for on-line dynamic addition of functional particles in solution blown spinning according to claim 4, wherein the particle injection assembly (2) further comprises an elastic membrane (24) covering the inner wall of the slit section (23).
  6. 6. A device for on-line dynamic addition of functional particles in solution blown spinning according to claim 3, wherein 3-6 lateral auxiliary air flow nozzles (31) are provided, the included angle between the air flow direction of each lateral auxiliary air flow nozzle (31) and the central axis of the spinning needle tube (11) is 15 ° -60 °, and the control assembly further comprises a proportional control valve which is connected with the main control unit in a signal manner and is used for adjusting the flow rate and/or the switching frequency of the lateral auxiliary air flow nozzles (31).
  7. 7. An apparatus for on-line dynamic addition of functional particles in solution blown spinning according to claim 6, characterized in that said pneumatic shearing module (3) further comprises an air flow loop (32) for mounting all said lateral auxiliary air flow nozzles (31), a flow guiding branch (33) arranged on said air flow sleeve (12) and communicating the upper end of said air flow loop (32) with said constriction (131).
  8. 8. A method for on-line dynamic addition of functional particles in solution blown spinning, using the device of any one of claims 1-7, comprising the steps of: S1, introducing spinning solution into the spinning needle tube (11), introducing gas into the airflow sleeve (12), and forming spinning jet flow stretched by high-speed airflow at the outlet of the spinning needle tube (11); s2, the control component collects fluid pressure pulsation signals in the spinning needle tube (11) in real time, the main control unit performs spectrum analysis on the fluid pressure pulsation signals, and jet natural disturbance main frequency f j and peak phase of the spinning jet are extracted; S3, the main control unit generates a synchronous pulse signal to drive the high-frequency pulse valve (22) to be opened, so that functional particles are injected into the spinning needle tube (11) at the phase moment when the spinning jet flow is in a specific shearing force state, and the frequency of the synchronous pulse signal is matched with the jet flow natural disturbance main frequency f j ; S4, outputting lateral airflow by the lateral auxiliary airflow nozzle, and breaking the mechanical balance of functional particles gathered towards the center in the jet flow field, so that the functional particles are discretely distributed on the jet cross section.
  9. 9. The method according to claim 8, wherein in step S3, the main control unit locks the opening time of the high frequency pulse valve (22) at a specific phase delay Φ with respect to the jet disturbance wave by PLL algorithm, where Φ=2npi+pi/2, n is a natural number, so that the functional particles are injected at the peak time of the maximum spinning jet shear force.
  10. 10. The method for dynamically adding functional particles on line in solution blown spinning according to claim 9, wherein in step S4, the main control unit controls the lateral auxiliary air flow nozzle (31) to be alternately opened in a pulse mode which is the same as or frequency doubling of the jet natural disturbance main frequency f j , so as to induce the functional particles to generate radial diffusion.

Description

Device and method for dynamically adding functional particles on line in solution spinning Technical Field The invention belongs to the technical field of functional nanofiber membrane preparation, and particularly relates to a device and a method for dynamically adding functional particles on line in solution blowing spinning. Background The functional nano fiber membrane can endow the fiber membrane with special functions such as drug slow release, temperature regulation, fragrance release and the like by loading functional particles (such as drug microcapsules, phase change material particles, flame retardant material particles and the like) in the fibers, and can be widely applied to the fields of medical dressing, intelligent textiles, filter materials and the like. In the preparation process of the functional nanofiber membrane, uniform dispersion of functional particles in the fibers is a key to ensuring functional stability and consistency of the product. Taking microcapsule particles as an example, in order to realize long-acting combination of the microcapsule particles and a fiber membrane, a microcapsule layer is generally loaded on the surface of the spun nanofiber membrane, and stable interface interaction is constructed through a cross-linking agent, so that the microcapsule is prevented from falling off or shifting. At present, the functional particles are mainly added in a first mode of premixing, namely, the functional particles and the spinning solution are mixed in advance and then are spun, but the functional particles are easy to agglomerate in the spinning solution, especially, when van der Waals force and hydrogen bond effect exist among the particles, the agglomeration phenomenon is more serious after long-term storage, partial agglomerates are oversized and can block a spinning needle or lead to fiber breakage, and the functional particles are loaded on the surface of the fiber membrane in a second mode of post-treatment, namely, after the preparation of the nanofiber membrane is finished, the functional particles are loaded on the surface of the fiber membrane in a dipping, spraying and other modes, so that the agglomeration problem in the spinning process is avoided, but the functional particles are only adhered on the surface of the fiber membrane, are easy to fall off, have poor functional durability and are difficult to realize uniform distribution of the particles in the thickness direction of the fiber membrane. For example, chinese patent publication No. CN113430653A, publication No. 2021, month 09 and 24 discloses an electrostatic spinning preparation device and preparation process. The structure of the device comprises an injector, a propelling device, an airflow auxiliary device and an auxiliary air source. The general structural principle of the invention is that the airflow auxiliary device comprises an air pipeline and an airflow cover, the spinning needle head passes through the air pipeline along the radial direction, and the airflow cover provides high-speed airflow with the same drawing direction as the spinning so as to accelerate the drawing of the filament body. However, the preparation equipment for electrostatic spinning has at least the following defects in the actual use process, namely the technical problems to be solved by the invention are that 1 functional particles and spinning solution are premixed and conveyed, the particles are extremely easy to agglomerate in a needle tube under the van der Waals force, and 2 the functional particles can be inevitably migrated and gathered towards the central line of jet flow under the wrapping and clamping of high-speed axial air flow due to the Safmann lift force generated by the flow velocity gradient, so that the middle and edge of the finally formed nano fiber are unevenly distributed, and the functional expression is seriously influenced. In view of the foregoing, there is a need for a novel solution blow spinning device that prevents agglomeration of functional particles and uniformly distributes the particles within the fibers. Disclosure of Invention The invention provides a device and a method for dynamically adding functional particles on line in solution blowing spinning, which can ensure that 1, the particle injection assembly is used for injecting particles into a spinning jet flow in a discrete mode at a specific moment under the regulation and control of the control assembly by arranging a spinning assembly, a particle injection assembly, a pneumatic shearing assembly and a control assembly, and 2, the pneumatic shearing assembly is used for constructing an air flow field at the periphery of the spinning jet flow to apply transverse aerodynamic force to the spinning jet flow so as to diffuse the particles entering the spinning jet flow in the radial direction, thereby improving the spatial distribution of the particles in the fiber forming process, reducing the aggregation phenomenon of the particle