Pulse ultrahigh-pressure dispersing and mixing device for high-solid-content composite material

Abstract

The invention discloses a pulse ultrahigh-pressure dispersing and mixing device for a high-solid-content composite material. The pulse ultrahigh-pressure dispersing and mixing device comprises a stator and a rotor arranged in the stator, one end of the stator is provided with a feed port, and the other end of the stator is provided with a discharge port; a plurality of working cavities with different volume characteristics are sequentially constructed between the rotor and the stator in the conveying direction, and the working cavities are used for enabling materials to be subjected to volume compression and volume release in the working cavities in the conveying process, so that periodic volume pulse deformation is formed under the continuous conveying condition. The device overcomes the defects that when existing mixing equipment is used for treating a high-solid-content system, the existing mixing equipment mainly depends on steady-state shearing and conventional stirring effects, and a high-strength pulse power field is difficult to apply to materials in the continuous operation process; therefore, the problems of non-uniform dispersion of the filler, difficulty in breaking of an agglomerated structure, deterioration of system fluidity and unstable performance of the final composite material are solved, and the mixing and dispersing effects of the high-solid-content composite material are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of composite material processing and extrusion molding technology, specifically to a pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials. Background Technology

[0002] Composite materials are multiphase systems composed of two or more materials with significant differences in physical or chemical properties. Through rational component combination and structural design, they can achieve comprehensive performance superior to single-component materials, thus finding wide application in packaging, construction, automotive, electronics, and functional materials. In the continuous processing of composite materials, especially in plasticizing and mixing processes represented by extrusion, the plasticizing efficiency of the material, the uniformity of component dispersion, and the degree of contact and rearrangement between different components directly determine the macroscopic properties and stability of the final composite material.

[0003] As composite materials develop towards higher filler content, higher solids content, multi-component structures, and functionalization, they generally exhibit characteristics such as high system viscosity, poor flowability, easy agglomeration, and difficulty in uniform dispersion during processing. In particular, in high-solids-content composite systems, a large number of solid components exist in the form of powders, particles, or fibers, and their uniform dispersion and effective mixing in the matrix have become key technical challenges in continuous processing.

[0004] Currently, continuous plasticizing and mixing of composite materials still mainly relies on single-screw or twin-screw extruders. Traditional screw extruders primarily use screw rotation to generate shearing action and axial conveying pressure within the working chamber, gradually plasticizing the material and transporting it axially. While this type of equipment can meet basic plasticizing and conveying requirements in the processing of low-filler or well-compatible composite materials, its shortcomings are becoming increasingly apparent in the processing of high-solids-content composite materials, mainly in the following aspects: Under high solids content conditions, the overall flowability of the material decreases significantly, and the flow field pattern dominated by continuous shear in traditional screw extruders is difficult to form a sufficiently effective dispersion effect in local areas. Solid components are prone to forming stable agglomerates, and the lack of forced volume compression and release processes during the transfer of material between screw channels or adjacent working spaces results in limited spatial rearrangement and uniform mixing effects between components.

[0005] In summary, existing continuous plasticizing and mixing devices for composite materials struggle to achieve efficient and uniform dispersion and mixing while maintaining processing stability in the processing of high-solids-content composite materials. In particular, they are ill-equipped to effectively break down agglomerated structures and promote the full exchange and rearrangement of components without relying on continuous high shear. Therefore, there is a need to develop a novel continuous mixing device that can introduce pulsed ultra-high pressure and volumetric deformation during material transport, enhancing component dispersion and mixing through periodic compression and release processes, in order to meet the dispersion efficiency requirements of high-solids-content composite materials. Summary of the Invention

[0006] The purpose of this invention is to provide a pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials. This device overcomes the problems of existing mixing equipment, which mainly rely on steady-state shearing and conventional stirring when processing high solids content systems. It is difficult to apply a high-intensity pulsed dynamic field to the material during continuous operation, resulting in uneven dispersion of fillers, difficulty in breaking agglomerates, deterioration of system fluidity, and instability of the final composite material performance. This device significantly improves the mixing and dispersion effect of high solids content composite materials.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials, wherein the high solids content composite material is a plastic material in the form of powder, granules or fibers, the device includes a stator and a rotor disposed within the stator; one end of the stator is provided with a feed inlet and the other end with a discharge outlet; multiple working chambers with different volume characteristics are sequentially constructed between the rotor and the stator along the transport direction, the working chambers are used to cause volume compression and volume release of the material during transport, thereby forming periodic volume pulse deformation under continuous transport conditions.

[0008] The rotor rotates around its own axis under the action of the drive mechanism, and the rotor and stator form a working chamber for material transport, mixing, and plasticization. By constructing multiple working chambers with different volume characteristics and arranged sequentially along the material transport direction between the rotor and stator, the material undergoes volume compression and release between adjacent working chambers during continuous transport, thereby forming a periodic volume pulse deformation under overall continuous transport conditions. Under this volume pulse deformation, the solid phase components in the high-solids-content composite material are repeatedly compacted, rearranged, and exchanged, achieving mixing, dispersion, plasticization, and transport of the material.

[0009] As a preferred embodiment, the working chamber includes a feeding section, a compaction section, and a plasticizing section arranged sequentially along the material transport direction. The feeding port is connected to the feeding section, and the discharging port is connected to the plasticizing section. The feeding section, compaction section, and plasticizing section have different volume characteristics. Specifically, the feeding section is used for continuous introduction and initial transport of materials; the compaction section is used to apply pulsed ultra-high pressure compaction to the materials under volume-constrained conditions; and the plasticizing section is used to enhance the mixing, dispersion, and plasticizing processes of the materials within a not completely enclosed working chamber.

[0010] As a preferred embodiment, the rotor at the feed inlet is a single-screw feed structure. This allows for the continuous introduction of powdered, granular, or fibrous high-solids-content composite materials and ensures stable transport of the material to the subsequent working chamber.

[0011] As a preferred embodiment, the rotors of both the compaction and plasticizing sections are cyclic lead combination structures. Each cyclic lead combination structure consists of a large-lead pusher screw and two small-lead pusher screws forming a cyclic unit, with multiple cyclic units connected sequentially along the axial direction. The rotor structure of the compaction section employs a cyclically arranged configuration of a large-lead pusher screw connected to two small-lead pusher screws. This causes a significant volumetric abrupt change in the material as it transfers from a large-volume working chamber to a small-volume working chamber, thereby creating periodic pulse compaction in localized areas. This is beneficial for breaking up agglomerated structures in high-solids-content composite materials and improving the contact between the components.

[0012] Preferably, in the compaction section, the gap between the rotor and stator is less than 0.05 mm, so that this section forms a nearly closed cavity unit; in the compaction section, there is essentially no structural gap between the rotor and stator, and the cavity unit within the working cavity is in a nearly closed state. In the plasticizing section, the gap between the rotor and stator is 0.2–0.5 mm, so that this section forms a partially closed cavity unit. In the plasticizing section, a structural gap is provided between the rotor and stator, so that the cavity unit within the working cavity is in a partially closed state within a single cavity. Under the action of rotor rotation, the material undergoes volume pulsation and local exchange movement within the structural gaps in the plasticizing section, thereby enhancing the mixing, dispersion, and plasticizing process of the material while maintaining continuous transport.

[0013] As a preferred embodiment, in the compaction section, the equivalent spatial boundary of the cavity unit between the stator and rotor can be described by the following function: ; In the formula, The eccentricity between the center of the rotor cross-section and the center of the shaft. t is the rotor lead; x is the axial coordinate of the helical advance; t is the rotor pulsation time; T is the rotor's motion period.

[0014] As a preferred embodiment, the geometric space enclosed by the equivalent spatial boundary corresponds to different effective volumes at different axial positions. By integrating this volume, the geometric cavity volume at the corresponding position can be obtained. This forms cavity units with significantly different volumes at adjacent axial positions, for a specific lead interval. ,have: ; In the formula, V is the local volume corresponding to the cavity unit; h is the height parameter perpendicular to the cross section, used to characterize the scale of the cavity unit in the third-dimensional direction; xa is the starting position of the lead interval; and γa is the length of the lead interval.

[0015] The significantly larger and significantly smaller cavity elements represent the maxima of the local volume for different leads. and minimum value This results in a sudden change in volume between adjacent cavity units.

[0016] As a preferred embodiment, the volume abrupt change between the significantly larger cavity unit and the significantly smaller cavity unit can be characterized by the volume ratio R between adjacent cavity units, defined as: ; In the formula, This represents the maximum local volume corresponding to a cavity unit with a significantly larger volume; The significantly smaller cavity unit corresponds to the local volume minimum, which is obtained by integrating the equivalent spatial boundary function; the volume ratio R can be obtained from the rotor eccentricity. and rotor lead It is jointly determined that the volume ratio R is used to reflect the device's ability to apply forced compaction to materials and generate ultra-high pressure.

[0017] Preferably, the ultra-high pressure provided by the device in the compaction section can be characterized by equivalent pressure. In the equivalent description, this equivalent pressure satisfies the following relationship with the structural parameters of the device and the material state parameters: ; In the formula, This refers to the density of a solid material under ultimate compaction. The density of the material in its initial loose state. The return coefficient is caused by the structural clearance between the stator and rotor. and These are the rotor eccentricities for the feeding section and the pressure section, respectively. and The rotor leads for the feed section and the pressure section are respectively. It is an equivalent coefficient related to the compressibility properties of the material.

[0018] As a preferred option, the rotors of the compaction section and the plasticizing section can adopt any one of the following structures: single-head structure, double-head structure, triple-head structure, or quadruple-head structure, depending on the processing requirements, in order to adjust the frequency of occurrence of volume pulse deformation and the mixing and dispersion intensity within a unit length.

[0019] As a preferred embodiment, the stator is provided with a visualization window for observing the state of the material being conveyed to the compaction section.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The present invention generates volume pulse deformation by constructing the volume characteristics of the working cavity between the rotor and the stator, which can effectively break up the agglomeration structure formed by solid components under high solid content conditions, promote the rearrangement and uniform dispersion of each component in the local area, and thus significantly improve the mixing and dispersion effect of high solid content composite materials.

[0021] 2. This invention employs a segmented working chamber structure combining a compaction section and a plasticizing section, achieving dispersion, mixing, plasticizing, and transport of high-solids-content composite materials without relying on continuous high shear. Through the synergistic effect of pulsed ultra-high pressure compaction and pulsating mixing, the risk of excessive shearing and damage to the polymer matrix molecular chains and functional filler structure caused by traditional continuous shear flow fields is effectively reduced. This helps to inhibit thermo-mechanical degradation of the material and maintain the inherent properties of the composite material.

[0022] 3. This invention, through the organic combination of volumetric pulse deformation and continuous transport processes, maintains stable operation even during the processing of high-solids-content, high-viscosity composite materials. Compared to traditional methods that rely on increasing rotational speed or extending the mixing section to enhance mixing, this invention helps reduce equipment torque load and energy consumption, shortens the mechanical and thermal history of materials, and improves dispersion and mixing efficiency while also ensuring processing stability and energy efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to the present invention.

[0024] Figure 2 This is a schematic diagram of the equivalent spatial boundary of the cavity unit.

[0025] Figure 3 The image shows a cross-sectional view of the stator and rotor, where the rotor is a single-head rotor and the gap between the rotor and stator is less than 0.05 mm.

[0026] Figure 4 The image shows a cross-sectional view of the stator and rotor, where the rotor is a single-head rotor and the gap between the rotor and stator is 0.2–0.5 mm.

[0027] Figure 5 The pressure result of the melt material measured by the melt pressure sensor when processing high solids content composite materials according to the method described above.

[0028] Figure 6 This is a cross-sectional view of the stator and rotor of a double-headed rotor.

[0029] Figure 7 This is a cross-sectional view of the stator and rotor of a three-head rotor.

[0030] Figure 8 This is a cross-sectional view of the stator and rotor of a four-head rotor.

[0031] Wherein, 1 is the stator; 2 is the rotor; 3 is the working chamber; 4 is the visualization window; 5 is the feed inlet; and 6 is the discharge outlet. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0033] like Figure 1As shown, this embodiment provides a pulsed ultra-high pressure dispersion and mixing device for high-solids-content composite materials. The high-solids-content composite material is a plastic material in the form of powder, granules, or fibers. The device includes a stator 1 and a rotor 2, with the rotor 2 disposed within the stator 1. The stator and rotor form a working chamber 3 for material conveying, compaction, and plasticization. The working chamber mainly includes a feeding section, a compaction section, and a plasticization section along the material conveying direction, with different volume characteristics for each section. Specifically, the feeding section is used for continuous introduction and initial conveying of the material; the compaction section is used to apply pulsed ultra-high pressure compaction to the material under volume-constrained conditions; and the plasticization section is used to enhance the mixing, dispersion, and plasticization processes of the material within a not completely closed working chamber. In the compaction section, the gap between the rotor and the stator is less than 0.05 mm, and the cavity unit within the working chamber is in a nearly closed state. The rotor structure in the compaction section employs a cyclical lead combination structure connecting a large-lead pusher screw and a small-lead pusher screw. Specifically, a large-lead pusher screw and two small-lead pusher screws form a cyclic unit, with multiple cyclic units connected sequentially along the axial direction to form a multi-stage shear-intensification structure. This causes a significant volumetric abrupt change in the material as it transfers from a large-volume working chamber to a small-volume working chamber, resulting in periodic pulsed ultra-high pressure compaction in localized areas. This is beneficial for breaking up agglomerated structures in high-solids-content composite materials and improving the contact degree between components. In the plasticizing section, the gap between the rotor and stator is 0.2–0.5 mm, ensuring that the working chamber is not completely closed within a single cavity. Under the action of rotor rotation, the material undergoes volumetric pulsation within the gap of this structure, accompanied by localized exchange motion, thereby enhancing the mixing, dispersion, and plasticizing process of the material while maintaining continuous transport. The rotor in the plasticizing section also adopts the same cyclic lead combination structure as the compaction section to accommodate the continuous occurrence of volume pulse deformation.

[0034] The equivalent spatial boundary of the cavity unit between the stator and rotor can be described by the following function: ; in, This is the eccentricity between the center of the rotor cross-section and the center of the shaft. t is the rotor lead; x is the axial coordinate of the helical advance; t is the rotor pulsation time; T is the rotor's motion period.

[0035] The geometric space enclosed by the equivalent spatial boundary corresponds to different effective volumes at different axial positions. By integrating it, the geometric cavity volume at the corresponding position can be obtained. This forms cavity units with significantly different volumes at adjacent axial positions, for a specific lead interval. ,have: ; Where V is the local volume corresponding to the cavity element; h is the height parameter perpendicular to the cross section, used to characterize the scale of the cavity element in the third-dimensional direction; xa is the starting position of the lead interval; and γa is the length of the lead interval.

[0036] The significantly larger and significantly smaller cavity elements represent the maxima of the local volume for different leads. and minimum value The abrupt change in volume can be characterized by the volume ratio R between adjacent cavity units, defined as: ; In the formula, This represents the maximum local volume corresponding to a cavity unit with a significantly larger volume; This represents the local minimum value corresponding to a cavity unit with a significantly smaller volume.

[0037] The volume ratio is determined by the rotor eccentricity and rotor lead, and is used to reflect the device's ability to apply forced compaction to materials and generate ultra-high pressure.

[0038] The ultra-high pressure generated in the compaction section can be described by the equivalent pressure P, which is related to the structural parameters of the device and the material state parameters, and satisfies the following equation: ; in, This represents the theoretical maximum bulk density of the material. This refers to the apparent bulk density of the material before it enters the compaction zone caused by a sudden change in volume. The return coefficient is caused by the structural clearance between the stator and rotor. and These are the rotor eccentricities for the feeding section and the pressure section, respectively. and The rotor leads for the feed section and the pressure section are respectively. It is an equivalent coefficient related to the compressibility properties of the material.

[0039] In this embodiment, the rotor adopts a single-head structure with a radius design range of 10-30mm, preferably 17mm; eccentricity... The design range is 2-4mm, with a preferred value of 3mm; the rotor feed section lead. The lead is 50-100mm, with a preferred value of 60mm; in the compaction section, the rotor lead of the large-volume unit is... The lead of the small-volume unit rotor is 10-40mm, with a preferred value of 20mm. The gap between the eccentric rotor and the stator in the plasticizing section is 8-15 mm, with a preferred value of 9 mm. The lead is 0.2–0.5 mm, with a preferred value of 0.25 mm. The lead is consistent with that of the compaction section. Through the coordination of the above structural parameters, the cavity unit generates significant volume shrinkage and expansion during the solid material conveying process, thereby achieving pulse ultra-high pressure and volume pulse deformation on the material.

[0040] In this embodiment, the material is continuously added in granular form from the feed inlet 5 into the cavity unit formed by the stator and the eccentric rotor, and discharged through the discharge outlet 6.

[0041] The process of processing composite materials using the pulsed ultra-high pressure continuous plasticizing device for high solids content composite materials described above is as follows: First, the pulsed ultra-high pressure continuous plasticizing device for high-solids-content composite materials is connected to the heating system and started to bring the stator temperature to the preset plasticizing temperature. Then, premixed high-solids-content composite material particles are added into the device through the feed inlet, and the drive motor is started to make the rotor move within the stator. During the compaction process, the high-solids-content composite material is subjected to pulsed high-pressure compaction within the cavity unit formed by the stator and rotor, due to the periodic contraction and expansion of the cavity volume. During plasticizing, the material pulsates within a single cavity through the gap between the stator and rotor, enhancing the dispersion and mixing effect through multiple recirculation and pulsation (the cross-sections of the stator and rotor in the compaction and plasticizing sections are shown in the figure). Figure 3 and Figure 4 (as shown); finally, the fully mixed composite material is continuously discharged from the outlet.

[0042] In this embodiment, the pressure of the molten material in the molten section is measured by a melt pressure sensor as follows: Figure 5 As shown, the peak pulse pressure can reach 100.91 MPa, indicating that the device can provide stable ultra-high pressure to achieve forced compressive enrichment and mixing dispersion of composite materials.

[0043] like Figures 6 to 8 As shown, the rotors of the compaction section and the plasticizing section can also adopt any one of the following structures: double-head structure, triple-head structure, or quadruple-head structure, depending on the processing requirements.

[0044] like Figure 1 As shown, the stator is also provided with a visualization window 4, which is located between the feeding section and the compaction section. The state of high solid content material particles being conveyed to the compaction section can be observed through the visualization window 4.

[0045] In summary, this invention provides a pulsed ultra-high pressure dispersion and mixing device for high-solids-content composite materials. Based on the synergistic effect of pulsed ultra-high pressure and volume pulse deformation, it can significantly improve the dispersion and mixing effect and the overall performance of the materials. The device has strong structural adaptability and can realize the continuous, stable, and large-scale preparation of various high-solids-content composite materials, showing broad prospects for engineering applications.

[0046] As shown above, the present invention can be well implemented. The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. That is, all equivalent changes, substitutions, combinations and modifications made in accordance with the content of the present invention are covered by the scope of protection of the claims of the present invention.

Claims

1. A pulsed ultra-high pressure dispersion and mixing device for high-solids-content composite materials, wherein the high-solids-content composite material is a plastic material in the form of powder, granules, or fibers, characterized in that: The device includes a stator and a rotor disposed within the stator; one end of the stator is provided with a feed inlet and the other end with a discharge outlet; the rotor and the stator are sequentially constructed with multiple working cavities having different volume characteristics along the transport direction, and the working cavities are used to cause the material to undergo volume compression and volume release during the transport process, thereby forming periodic volume pulse deformation under continuous transport conditions.

2. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 1, characterized in that: The working chamber includes a feeding section, a compaction section, and a plasticizing section arranged sequentially along the material transport direction. The feeding port is connected to the feeding section, and the discharging port is connected to the plasticizing section. The feeding section, compaction section, and plasticizing section have different volume characteristics.

3. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 2, characterized in that: The rotor at the feed inlet has a single-screw feed structure.

4. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 2, characterized in that: The rotors of the compaction section and the plasticizing section are both cyclic lead combination structures. The cyclic lead combination structure consists of a large lead pusher screw and two small lead pusher screws as a cyclic unit, and multiple cyclic units are connected sequentially along the axial direction.

5. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 2, characterized in that: In the compaction section, the gap between the rotor and the stator is less than 0.05 mm; in the plasticizing section, the gap between the rotor and the stator is 0.2–0.5 mm.

6. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 5, characterized in that: In the compaction section, the equivalent spatial boundary of the cavity unit between the stator and rotor can be described by the following function: ； In the formula, This is the eccentricity between the center of the rotor cross-section and the center of the shaft. t is the rotor lead; x is the axial coordinate of the helical advance; t is the rotor pulsation time; T is the rotor's motion period.

7. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 6, characterized in that: The geometric space enclosed by the equivalent spatial boundary corresponds to different effective volumes at different axial positions. By integrating it, the geometric cavity volume at the corresponding position can be obtained, thereby forming cavity units with different volume characteristics at adjacent axial positions. For a specific lead interval... have: ； In the formula, V is the local volume corresponding to the cavity unit; h is the height parameter perpendicular to the cross section, used to characterize the scale of the cavity unit in the third-dimensional direction; xa is the starting position of the lead interval; and γa is the length of the lead interval.

8. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 7, characterized in that: The volume jump between the significantly larger and significantly smaller cavity units can be characterized by the volume ratio R between adjacent cavity units, defined as: ； In the formula, This represents the maximum local volume corresponding to a cavity unit with a significantly larger volume; This represents the local minimum value corresponding to a cavity unit with a significantly smaller volume.

9. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 2, characterized in that: The rotors in the compaction and plasticizing sections are all single-head, double-head, triple-head, or quadruple-head structures.

10. The pulsed ultra-high pressure dispersion and mixing device for high solids content composite materials according to claim 1, characterized in that, A visualization window is provided on the stator.

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