A three-dimensional nonwoven material with a bicomponent Janus-type curled fiber structure and a preparation method thereof

Abstract

The present invention provides a three-dimensional nonwoven material with a two-component Janus-type curled fiber structure and a preparation method, which belongs to the field of melt-blown nonwoven technology. It includes the steps of preparing raw materials, melt-blown spinning and curling, and fiber stacking. The preparation process of the Janus-type curled fiber only requires regulating the differentiated properties of the melt and the asymmetry of the melt jet flow to prepare fibers with a curled structure in one step. Compared with the existing technology, this can reduce the deformation and curling processing in the later stage, which not only shortens the process flow but also saves energy. The prepared three-dimensional material with a two-component Janus-type curled fiber structure has the characteristics of permanent fluffiness, elasticity, and covering performance, and has good commercial value 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 three-dimensional nonwoven material with a two-component Janus-type curled fiber structure and a preparation method thereof, belonging to the technical field of melt-blown nonwovens. Background Art

[0002] Fiber-based three-dimensional materials have the advantages of extremely low volume density, high porosity, high thermal insulation properties, and high temperature resistance. Among them, the difference in shrinkage between the two components in the two-component composite fiber is a prerequisite for the production of three-dimensional materials with Janus-type curled fiber structures. It is made by spinning two polymers with different properties in a certain proportion. Three-dimensional materials with Janus-type curled fiber structures have the characteristics of permanent fluffiness, elasticity, and covering properties. They have good commercial value in the fields of filtration and separation, sound absorption and noise reduction, cold protection and warmth, textile and clothing fabrics, etc. At the same time, they can be widely used in the fields of furniture, home textiles, toys, clothing, medical and sanitary products, chair cushions, etc. Therefore, it is of great significance to develop a three-dimensional material with a Janus-type curled fiber structure.

[0003] In the prior art, CN202311828760.7 discloses a method for preparing flexible, low-thermal-conductivity three-dimensional nanofiber aerogels. This method replaces the original roller with a metal tip as the electrospinning collector. The metal tip accumulates a large amount of charge, effectively inducing the fibers to curl themselves, thereby producing fluffy, soft, and curly ceramic fibers. This method requires auxiliary tools during the preparation of the curly fibers, makes the pore structure of the three-dimensional fiber material uncontrollable, and cannot be produced in large quantities.

[0004] CN202311023037.1 discloses a method for preparing bicomponent nylon self-curling elastic fibers. This method produces bicomponent nylon self-curling elastic fibers through pre-orientation processes such as pre-humidification balancing, drafting, hot plate shaping, and winding. This method requires multiple steps in the preparation process, significantly increasing the workload and energy consumption.

[0005] CN202310861135.6 and CN202310671672.4 respectively disclose "A PLA two-component super-expanded and super-elastic pearl cotton ball processing equipment and its production method" and "A three-dimensional spiral structure elastic ES fiber and its preparation method". This method uses post-processing heat setting and stretching to make the fiber produce a curled structure after stretching. This method has a complex and time-consuming preparation process.

[0006] Therefore, there is an urgent need in the art to develop a preparation method that shortens the process flow and saves energy to obtain a three-dimensional nonwoven material with a curled fiber structure. Summary of the Invention

[0007] The purpose of the present invention is to solve the problem in the prior art that there is no method for preparing bicomponent Janus-type crimped fibers by a melt-blowing method.

[0008] In order to achieve the purpose of solving the above problems, the technical solution adopted by the present invention is to provide a three-dimensional nonwoven material with a bicomponent Janus-type curled fiber structure and a preparation method.

[0009] A first aspect of the present invention provides a method for preparing a three-dimensional nonwoven material having a bicomponent Janus-type crimped fiber structure, comprising the following steps:

[0010] Step 1. Prepare the ingredients:

[0011] 50-80 parts of rigid polymer

[0012] 20-50 parts of elastomeric polymer or flexible polymer

[0013] Wherein, rigid polymers include polyolefins or polyester polymers, and elastomers or flexible polymers include polyester polymers, and the parts are calculated by mass;

[0014] Step 2: The raw materials in step 1 are placed in a blast drying oven and dried at 80° C. for 8-14 hours, mixed evenly to obtain a masterbatch, and the rigid polymer, elastomer or flexible polymer masterbatch is respectively added to a bicomponent melt-blown device for melt-blown spinning to form a Janus melt having dual properties of rigidity and elasticity or flexibility. At the same time, the speed, angle and width of the melt-blown hot air flow are controlled to be asymmetric so that the Janus melt formed in step 2 is radially contracted under the action of the asymmetric melt-blown air flow, so that the fiber is folded and curled to form a bicomponent Janus-type crimped fiber;

[0015] Step 3: stacking the bicomponent Janus-type crimped fibers obtained in step 2 on a mesh curtain to ultimately obtain a three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure.

[0016] Preferably, in step 1, the polyolefin polymers include polypropylene and polyethylene, the polyester polymers include polyoxymethylene, polychlorotrifluoroethylene, polylactic acid, polyhydroxyalkanoate and polymethyl acrylate; the polyester polymers include polyurethane, thermoplastic polyurethane and thermoplastic polyester elastomer, polycaprolactone, polybutylene succinate or polybutylene adipate / terephthalate.

[0017] Preferably, in the step 2, the temperatures of the first to fifth zones of the rigid side screw extruder in the two-component melt-blowing equipment during the melt-blowing process are 170-240°C, 180-250°C, 190-260°C, 200-270°C, and 210-280°C, respectively, and the metering pump frequency is 2-6 Hz. The temperatures of the first to fifth zones of the elastic or flexible side screw extruder are 155-225°C, 165-235°C, and 175-245 ℃, 185~255℃, 195~265℃, the metering pump frequency is 6~18Hz, the die head temperature is 210~280℃; the rigid side air duct width is 0.01~0.2mm, the air duct angle is 60°~80°, the elastic or flexible side air duct width is 0.2~2mm, the air duct angle is 30°~60°, the hot air temperature is 240~260℃, and the hot air pressure is 0.05~0.28MPa.

[0018] Preferably, in step 3, the frequency of the screen transmission is 1 to 3 Hz, and the receiving distance is 10 to 20 cm.

[0019] The technical principles of the preparation method are as follows:

[0020] Because the Janus melt is composed of a rigid polymer on one side and an elastomer or flexible polymer on the other, the crystallization dynamics and cooling effects on both sides of the Janus melt stream differ. After asymmetric airflow stretching and shearing, the Janus melt stream gradually cools on the meltblown spinning line, forming an axial temperature field. This axial temperature field causes a viscosity difference between the two sides of the Janus melt. According to the Poisson effect, the elastomer or flexible polymer side of the melt undergoes radial contraction under the stretching action of the melt jet. As the asymmetry of the airflow (the difference in airflow velocity and angle on both sides) increases, the elastomer or flexible polymer side of the melt increases its contraction and transforms into a folded curl. After the strain is released, the rigid polymer on one side of the Janus melt is axially compressed, causing the Janus melt to form a curled structure. The curl of the fiber is closely related to the modulus ratio of the elastomer or flexible polymer and the viscosity difference between the two sides of the Janus melt.

[0021] The second aspect of the present invention provides a three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure prepared by the above method, which has a pore size of 8 to 30 μm, a porosity of ≥98%, and a bulk density of 25 to 48 mg / cm 3 .

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The preparation process of this Janus-type crimped fiber only requires differential control of the melt, airflow velocity, and angle to produce a crimped fiber in a single step. Compared with existing technologies, this can reduce the deformation and crimping process in the later stage, shortening the process and saving energy.

[0024] (2) The three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure prepared by a one-step method can not only control the pore size and increase the porosity, but also enhance its application potential in the fields of filtration and separation, sound absorption and noise reduction, cold protection and warmth preservation, and textile and clothing fabrics. It can also be widely used in furniture and home textiles, toys, clothing, medical and sanitary products, chair cushions and other fields. The method is highly versatile and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The three-dimensional nonwoven material of the rigid and elastomeric polymer bicomponent Janus type curled fiber structure prepared by the present invention

[0026] Figure 2 The three-dimensional nonwoven material of rigid and flexible polymer bicomponent Janus type curled fiber structure prepared by the present invention DETAILED DESCRIPTION

[0027] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0028] like Figure 1-2 As shown, the present invention provides a three-dimensional nonwoven material with a bicomponent Janus-type curled fiber structure and a preparation method thereof.

[0029] The specific method is:

[0030] First, a rigid polymer (one of polyolefin polymers (polypropylene, polyethylene) and polyester polymers (polyoxymethylene, polychlorotrifluoroethylene, polylactic acid, polyhydroxyalkanoate, polymethyl acrylate)), one of elastomeric polymers (polyurethane, thermoplastic polyurethane and thermoplastic polyester elastomer, etc.) or one of flexible polymers (polycaprolactone, polybutylene succinate, polyurethane, polybutylene adipate / terephthalate, etc.) is placed in a blast drying oven for drying, and then added to a granulator for uniform mixing to obtain a melt-blown masterbatch; the rigid polymer melt-blown masterbatch and the elastomer or flexible polymer masterbatch are respectively added to two feeders in the melt-blowing equipment for melt-blowing spinning, and then a three-dimensional nonwoven material with a Janus-type bicomponent crimped fiber structure is obtained by melt-blowing asymmetric airflow stretching shear-fiber stacking. The three-dimensional network structure material obtained by the present invention has a pore size of 8 to 30 μm, a porosity of ≥98%, and a volume density of 25 to 48 mg / cm 3, which enhances its application potential in the fields of filtration and separation, sound absorption and noise reduction, and cold protection and warmth preservation.

[0031] The present invention will be described in detail below with reference to specific embodiments, but the present invention is by no means limited thereto.

[0032] Example 1

[0033] A rigid polymer, polylactic acid, and an elastomeric polymer, polyurethane, were separately added to a two-component meltblown machine for meltblowing. The meltblowing machine parameters were: a 6Hz metering pump frequency for the polylactic acid, a meltblowing temperature controlled at 185-225°C, a 0.4mm air duct width, and a 70° air duct angle; a 12Hz metering pump frequency for the polyurethane, a meltblowing temperature controlled at 155-185°C, a 1.2mm air duct width, and a 45° air duct angle. The die temperature, hot air temperature, and pressure were 225°C, 225°C, and 0.2MPa, respectively. A three-dimensional nonwoven material with a Janus-shaped crimped fiber structure was produced through the meltblowing process.

[0034] Example 2

[0035] A rigid polymer, polypropylene, and a flexible polymer, polycaprolactone, were separately added to a two-component meltblown machine for meltblowing. The meltblowing machine parameters were: a 5Hz metering pump frequency for the polypropylene, a meltblowing temperature controlled at 180-220°C, a 0.5mm air duct width, and a 65° air duct angle; a 15Hz metering pump frequency for the polycaprolactone, a meltblowing temperature controlled at 155-185°C, a 2mm air duct width, and a 55° air duct angle. The die temperature, hot air temperature, and pressure were 220°C and 220°C, respectively, respectively, and 0.2MPa, resulting in a three-dimensional nonwoven material with a Janus-shaped crimped fiber structure.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a three-dimensional nonwoven material with a bicomponent Janus-type curled fiber structure, characterized in that: The following steps are involved: Step 1. Prepare the ingredients: 50-80 parts of rigid polymer 20-50 parts of elastomeric polymer or flexible polymer Wherein, rigid polymers include polyolefins or polyester polymers, and elastomers or flexible polymers include polyester polymers, and the parts are calculated by mass; Step 2: Place the raw materials in step 1 in a blast drying oven and dry them at 80°C for 8-14 hours, mix them evenly to obtain a masterbatch, and add the rigid polymer, elastomer or flexible polymer masterbatch into a two-component melt-blown device for melt-blown spinning to form a Janus melt with dual properties of rigidity and elasticity or flexibility. At the same time, pass the Janus melt through an air duct, control the angle and width of the air duct, and undergo asymmetric airflow stretching and shearing. The elastomer or flexible polymer side melt will produce radial contraction under the stretching action of the melt-blown air flow. The fiber will produce radial contraction and fold curling under the synergistic effect of the asymmetry of the melt-blown hot air flow and the differentiated properties of the Janus melt, thereby forming a two-component Janus-type crimped fiber; wherein the width of the rigid side air duct opening is 0.01-0.2 cm, the air duct angle is 60°-80°, the width of the elastic or flexible side air duct opening is 0.2-2 mm, and the air duct angle is 30°-60°; the air flow asymmetry refers to the difference in air flow velocity and angle on both sides; Step 3: stacking the bicomponent Janus-type crimped fibers obtained in step 2 on a mesh curtain to ultimately obtain a three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure.

2. The method for preparing a three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure according to claim 1, wherein: In step 1, polyolefin polymers include polypropylene and polyethylene, polyester polymers include polyoxymethylene, polychlorotrifluoroethylene, polylactic acid, polyhydroxyalkanoate and polymethyl acrylate; polyester polymers include polyurethane, thermoplastic polyurethane and thermoplastic polyester elastomer, polycaprolactone, polybutylene succinate or polybutylene adipate / terephthalate.

3. The method for preparing a three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure according to claim 1, wherein: In the step 2, the temperatures of zones 1 to 5 of the rigid side screw extruder in the two-component melt-blowing equipment during the melt-blowing process are 170-240°C, 180-250°C, 190-260°C, 200-270°C, and 210-280°C, respectively, and the metering pump frequency is 2-6 Hz. The temperatures of zones 1 to 5 of the elastic or flexible side screw extruder are 155-225°C, 165-235°C, 175-245°C, 185-255°C, and 195-265°C, respectively, the metering pump frequency is 6-18 Hz, the die head temperature is 210-280°C, the hot air temperature is 240-260°C, and the hot air pressure is 0.05-0.28 MPa.

4. The method for preparing a three-dimensional nonwoven material with a bicomponent Janus-type crimped fiber structure according to claim 1, wherein: In the step 3, the frequency of the screen transmission is 1 to 3 Hz, and the receiving distance is 10 to 20 cm.

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