A kind of curled fiber-based three-dimensional nonwoven material and preparation method thereof

Abstract

The present invention discloses a three-dimensional nonwoven material based on a crimped fiber and a preparation method thereof. The raw materials of the three-dimensional nonwoven material include 50 to 80 parts of at least one of a rigid polymer and a polyester polymer, and 20 to 50 parts of an elastomeric polymer. The two components are placed in a blast drying oven for drying, and then added to a granulator for uniform mixing to obtain a melt-blown masterbatch; the melt-blown masterbatch is added to a melt-blown device for melt-blown spinning, and then the fibers are stretched and sheared by melt-jet jets to stack the fibers to obtain the crimped fiber-based three-dimensional nonwoven material. The three-dimensional nonwoven material provided by the present invention has crimped structural fibers, and the crimped fiber-based three-dimensional nonwoven material has application potential in the fields of filtration and separation, sound absorption and noise reduction, cold protection and warmth preservation, textile and clothing fabrics, etc. At the same time, it can be widely used in the fields of furniture and home textiles, toys, clothing, medical and sanitary products, chair cushions, etc.

Description

Technical Field

[0001] The invention relates to a curled fiber-based three-dimensional nonwoven material and a preparation method thereof, belonging to the technical field of polyester fiber materials. Background Art

[0002] Fiber membrane materials are widely used due to their wide range of raw material sources and highly controllable structure. Their pore structure can be manipulated by adjusting factors such as fiber diameter and packing density. However, in the thickness direction, fiber membrane materials are densely packed, making it difficult to achieve three-dimensional pore connectivity. Furthermore, their small thickness results in poor mechanical properties such as bending and burst resistance, limiting their practical application. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a curled fiber-based three-dimensional nonwoven material and a preparation method thereof.

[0004] In order to solve the above problems, the present invention is achieved through the following technical solutions:

[0005] A three-dimensional nonwoven material based on crimped fibers, the raw materials of which include the following components in parts by weight:

[0006] Component A: 50-80 parts of at least one of a rigid polymer and a polyester polymer;

[0007] Component B: 20 ​​to 50 parts of elastomeric polymer.

[0008] Preferably, the rigid polymer is at least one of a polyolefin polymer and a polyester polymer.

[0009] More preferably, the polyolefin polymer is at least one of polypropylene and polyethylene; the polyester polymer is at least one of polyoxymethylene, polychlorotrifluoroethylene, polylactic acid, polyhydroxyalkanoate, and polymethyl acrylate.

[0010] Preferably, the elastomeric polymer is at least one of polyurethane, thermoplastic polyurethane, and thermoplastic polyester elastomer.

[0011] The present invention also provides a method for preparing the above-mentioned curled fiber-based three-dimensional non-woven material, which includes the following steps: placing component A and component B in a blast drying oven for drying, and then adding them to a granulator for uniform mixing to obtain melt-blown masterbatch; adding the melt-blown masterbatch to a melt-blown device for melt-blown spinning, and then stretching and shearing the melt-blown jet-fiber stacking to obtain the curled fiber-based three-dimensional non-woven material.

[0012] Preferably, the drying temperature is 80° C. and the drying time is 8-14 hours.

[0013] Preferably, the setting temperature of the granulator is 220-260° C. and the rotation speed is 60 r / min. After extrusion molding by the granulator, it is cooled and pelletized by a pelletizer to obtain melt-blown masterbatch.

[0014] Preferably, the melt-blowing equipment adopts a melt-blowing equipment with a screw extruder, and its process parameters are:

[0015] The temperatures of the screw extruder zones 1 to 5 are 170-240°C, 180-250°C, 190-260°C, 200-270°C, and 210-280°C, respectively, and the die head temperature is 210-280°C;

[0016] The metering pump frequency is 2 to 6 Hz;

[0017] The hot air temperature is 240-290°C and the hot air pressure is 0.05-0.28MPa;

[0018] The receiving distance is 10-20cm, and the transmission frequency is 1-3Hz;

[0019] The widths of the air duct openings on both sides are 0.01-0.3 cm and 0.3-0.6 cm respectively;

[0020] The air duct angles on both sides are 20°~45° and 50°~80° respectively.

[0021] Preferably, the pore size of the crimped fiber-based three-dimensional nonwoven material is 4 to 25 μm, the porosity is not less than 95%, and the volume density is 6 to 18 mg / cm 3 .

[0022] The three-dimensional nonwoven material provided by the present invention has curled structural fibers, which enhances the application potential of the three-dimensional nonwoven material in the fields of filtration and separation, sound absorption and noise reduction, and cold protection and warmth preservation.

[0023] The technical principles of the present invention are as follows:

[0024] Because the mixed melt is composed of rigid and elastomeric polymers, the crystallization dynamics and cooling effects around the mixed melt stream differ. The polymer chains within the mixed melt are skewed in orientation, resulting in uneven internal stresses and differential shrinkage, potentially leading to a potential for self-coiling. After asymmetric airflow stretching, the mixed melt stream experiences an axial temperature field as it cools on the meltblown spinning line. Simultaneously, heat within the mixed melt stream is transferred from the center through the boundary layer to the surrounding medium, creating a meridional temperature field. These two factors cause the temperature center within the mixed melt stream to deviate from the geometric center of the filament along the cooling airflow direction. The temperature distribution along the mixed melt stream largely determines its rheological properties and significantly influences the crystallization and orientation of the macromolecules. This results in a nonuniform microstructure around the fiber cross-section, endowing the nascent fiber with potential for curling. When air flows through cylindrical filaments, vacuum vortices are generated on the fiber surface, weakening the heat exchange effect and causing the temperature field to deviate from its geometric center. This is also true of typical spinning machines, where there is a difference in orientation between the front and back surfaces, giving the filaments a latent curling potential. The nascent fibers formed by asymmetric airflow exhibit two different orientations along the axis: the airflow velocity and angle differ on the windward and leeward sides, resulting in different birefringence. Furthermore, because the mixed melt is composed of rigid and elastomeric polymers, some of the mixed melt is in plastic deformation, while others have transitioned to highly elastic deformation. The resulting stretched macromolecules have the ability to recover at any time, while the plastically deformed macromolecule orientations are relatively fixed. Consequently, during the stretching process of asymmetric airflow, different internal stresses exist in the fiber cross-section along the axial direction. When the stretching force disappears, the stretched macromolecules in the highly elastic deformation immediately relax, resulting in different contraction phenomena. During the stretching process, the process is rationally adjusted to minimize crystal growth, preventing the macromolecular orientation generated by the high-elastic deformation from being fixed. As a result, the macromolecular orientation, which is stretched along the axial direction after the high-elastic deformation, can shrink and twist around the axial direction, resulting in a macroscopic self-curling phenomenon. This self-curling phenomenon is fully displayed on the fiber and finally fixed through high-temperature heat setting, resulting in a curled fiber-based three-dimensional nonwoven material.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The preparation process of the curly fiber only requires controlling the properties of the melt, the asymmetry of the airflow velocity and the angle, and can quickly produce fibers with a curly structure. The preparation process is short and energy consumption is low.

[0027] (2) Compared to conventional meltblown fiber structures, which are generally straight cylinders, the fiber structures produced by the present invention are curly. Conventional meltblown nonwovens are generally two-dimensional, while the nonwovens produced by the present invention are three-dimensional.

[0028] (3) The crimped fiber-based three-dimensional nonwoven material prepared by the present invention can control the fiber crimp rate by adjusting the properties of the melt and the asymmetry of the airflow velocity and angle to optimize the pore structure parameters, thereby enhancing its application potential in the fields of filtration and separation, sound absorption and noise reduction, cold protection and warmth preservation, textile and clothing fabrics, etc. It can also be widely used in the fields of furniture and home textiles, toys, clothing, medical and sanitary products, chair cushions, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The crimped fiber-based three-dimensional nonwoven material prepared in Example 1;

[0030] Figure 2 The crimped fiber-based three-dimensional nonwoven material prepared in Example 2;

[0031] Figure 3 The crimped fiber-based three-dimensional nonwoven material prepared in Example 3;

[0032] Figure 4 This is a non-crimped fiber-based nonwoven material prepared in a comparative example. DETAILED DESCRIPTION

[0033] To make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0034] Example 1

[0035] (1) 75 parts of polypropylene and 25 parts of polyurethane were mixed uniformly and melt-extruded, and then water-cooled and pelletized to obtain melt-blown masterbatch; the process parameters of the screw extruder were: the temperatures of zones 1 to 4 were 220°C, 235°C, 245°C, and 255°C, respectively;

[0036] (2) The melt-blown masterbatch was fed into a melt-blown machine. The process parameters of the melt-blown machine were as follows: 190°C, 205°C, 220°C, 235°C, and 250°C; the die temperature was 250°C; the metering pump frequency was 5 Hz; the hot air temperature was 260°C; the air flow pressure was 0.18 MPa; the receiving distance was 15 cm; the mesh curtain frequency was 1.5 Hz; the air duct openings were 0.16 cm, 38°, and 0.24 cm, 62°, respectively; the resulting crimped fiber-based three-dimensional nonwoven material had a pore size of 18.2 μm, a porosity of 96.5%, a single fiber crimp rate of 27%, and a bulk density of 12.5 mg / cm 3 .

[0037] Example 2

[0038] (1) 60 parts of polyoxymethylene and 40 parts of thermoplastic polyurethane were mixed uniformly and then melt-extruded, and then water-cooled and pelletized to obtain melt-blown masterbatch; the process parameters of the screw extruder were as follows: the temperatures of zones 1 to 4 were 220°C, 235°C, 245°C, and 260°C, respectively;

[0039] (2) The melt-blown masterbatch was fed into a melt-blown machine. The process parameters of the melt-blown machine were as follows: 210°C, 225°C, 240°C, 255°C, and 270°C, the die temperature was 270°C, the metering pump frequency was 3 Hz, the hot air temperature was 280°C, the air flow pressure was 0.15 MPa, the receiving distance was 10 cm, the mesh curtain frequency was 2.2 Hz, and the air duct openings were 0.09 cm, 24°, and 0.52 cm, 77°, respectively. The resulting crimped fiber-based three-dimensional nonwoven material had a pore size of 23.8 μm, a porosity of 98.4%, a single fiber crimp rate of 39%, and a bulk density of 8.2 mg / cm 3 .

[0040] Example 3

[0041] (1) 50 parts by weight of polyhydroxyalkanoate and 50 parts by weight of thermoplastic polyurethane were mixed uniformly and then melt-extruded, and then water-cooled and pelletized to obtain melt-blown masterbatch; the process parameters of the screw extruder were as follows: the temperatures of zones 1 to 4 were 220°C, 235°C, 245°C, and 260°C, respectively;

[0042] (2) The melt-blown masterbatch was fed into a melt-blown machine. The process parameters of the melt-blown machine were as follows: 180°C, 190°C, 200°C, 215°C, and 230°C, the die temperature was 230°C, the metering pump frequency was 6 Hz, the hot air temperature was 240°C, the air flow pressure was 0.26 MPa, the receiving distance was 20 cm, the mesh curtain frequency was 1.9 Hz, and the air duct openings were 0.17 cm, 30°, and 0.49 cm, 80°, respectively. The resulting crimped fiber-based three-dimensional nonwoven material had a pore size of 16.8 μm, a porosity of 95.8%, a single fiber crimp rate of 23%, and a bulk density of 10.4 mg / cm 3 .

[0043] Comparative Example

[0044] (1) 100 parts by weight of polypropylene was melt-extruded, water-cooled, and pelletized to obtain melt-blown masterbatch; the process parameters of the screw extruder were as follows: the temperatures of zones 1 to 4 were 220°C, 235°C, 245°C, and 260°C, respectively;

[0045] (2) The melt-blown masterbatch was fed into the melt-blown machine. The process parameters of the melt-blown machine were as follows: 210°C, 225°C, 240°C, 255°C, and 270°C, the die temperature was 270°C, the metering pump frequency was 4 Hz, the hot air temperature was 280°C, the air flow pressure was 0.14 MPa, the receiving distance was 30 cm, the mesh curtain frequency was 1.8 Hz, and the air duct openings were all 0.2 cm and 30°. The pore size of the obtained non-crimped fiber-based nonwoven material was 12.3 μm, the porosity was 82.7%, the single fiber curling rate was 0%, and the volume density was 21.6 mg / cm 3 .

Claims

1. A method for preparing a three-dimensional nonwoven material based on crimped fibers, characterized in that: The following steps are involved: Components A and B are placed in a blast drying oven and dried, and then added to a granulator and mixed evenly to obtain a melt-blown masterbatch; the melt-blown masterbatch is added to a melt-blown device for melt-blown spinning, and then the crimped fiber-based three-dimensional nonwoven material is obtained by melt-jet stretching, shearing and fiber stacking; The nascent fibers formed by the asymmetric airflow have two different orientations along the axis, that is, the airflow speed and airflow angle on the windward side and the leeward side are different; after being stretched by the asymmetric airflow, the mixed melt stream gradually cools down on the meltblown spinning line, and there is an axial temperature field. At the same time, the heat inside the mixed melt stream is transferred from the center through the boundary layer to the surrounding medium, thus forming a meridional temperature field. The component A: 50-80 parts of at least one of a rigid polymer and a polyester polymer; the component B: 20-50 parts of an elastomeric polymer; The melt-blowing equipment adopts a melt-blowing equipment with a screw extruder, and its process parameters are: The temperatures of screw extruder zones 1 to 5 are 170~240℃, 180~250℃, 190~260℃, 200~270℃, and 210~280℃, respectively, and the die head temperature is 210~280℃; The metering pump frequency is 2~6Hz; The hot air temperature is 240~290℃, and the hot air pressure is 0.05~0.28MPa; The receiving distance is 10~20cm, and the transmission frequency is 1~3Hz; The widths of the air duct openings on both sides are 0.01~0.3cm and 0.3~0.6cm respectively; The air duct angles on both sides are 20°~45° and 50°~80° respectively.

2. The preparation method according to claim 1, wherein The rigid polymer is at least one of a polyolefin polymer and a polyester polymer.

3. The preparation method according to claim 2, wherein The polyolefin polymer is at least one of polypropylene and polyethylene; the polyester polymer is at least one of polyoxymethylene, polychlorotrifluoroethylene, polylactic acid, polyhydroxyalkanoate, and polymethyl acrylate.

4. The preparation method according to claim 1, wherein The elastomeric polymer is at least one of polyurethane, thermoplastic polyurethane and thermoplastic polyester elastomer.

5. The preparation method according to claim 1, wherein The drying temperature is 80° C. and the drying time is 8-14 hours.

6. The preparation method according to claim 1, wherein The setting temperature of the granulator is 220-260° C. and the rotation speed is 60 r / min. After extrusion molding by the granulator, it is cooled and pelletized by the pelletizer to obtain melt-blown masterbatch.

7. The preparation method according to claim 1, wherein The pore size of the crimped fiber-based three-dimensional nonwoven material is 4-25 μm, the porosity is not less than 95%, and the volume density is 6-18 mg / cm 3 .

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