High-bulk low-lint three-dimensional melt-blown wood pulp nonwoven fabric and its preparation process

Abstract

The application discloses a kind of high-bulk low-dropping three-dimensional melt-blown wood pulp nonwoven fabric and its preparation process, comprising: first fluffy net layer, absorbent wood pulp fiber web layer and second fluffy net layer, melt-blown fiber raw material is sent into screw extruder, extrusion melt is respectively sent into first metering pump, second metering pump and third metering pump, melt is sent into first spinneret using first metering pump, first ultrafine melt-blown fiber is sprayed out, first ultrafine melt-blown fiber is drafted using high-temperature hot air, first fluffy net layer is formed on the web curtain of web former, first negative pressure suction device is installed below the forming position of first fluffy net layer under the web curtain of web former, the speed of suction fan in first negative pressure suction device is adjusted, so that the negative pressure is switched between-2kPa and-4kPa, the bulk of surface is high, the absorbency of absorbent wood pulp fiber web layer is good, the stability of wood pulp fiber is high, and the problem of dropping is reduced.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabrics, and in particular to a three-dimensional meltblown wood pulp nonwoven fabric with high bulk and low shedding, and its preparation process. Background Technology

[0002] In the production process of meltblown nonwoven fabric, wood pulp fibers are added to improve absorbency. By combining meltblown fibers and wood pulp fibers, twin-spun nonwoven fabric is formed.

[0003] To improve the surface air permeability of twin-spun nonwoven fabrics, it is necessary to maintain their high bulkiness. However, this results in poor bonding strength between wood pulp fibers and meltblown fibers, causing easy shedding of fibers, which affects the user experience and requires improvement. Summary of the Invention

[0004] The main technical problem solved by this invention is to provide a three-dimensional meltblown wood pulp nonwoven fabric with high bulk and low lint, and its preparation process, which improves absorbency and surface bulk and reduces lint.

[0005] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is to provide a process for preparing meltblown wood pulp nonwoven fabric, comprising the following steps: S1. Formation of the first loose mesh layer: Meltblown fiber raw material is fed into a screw extruder. After the melt is extruded, it is fed into the first metering pump, the second metering pump and the third metering pump respectively. The first metering pump is used to feed the melt into the first spinneret to spray out the first ultrafine meltblown fiber. The first ultrafine meltblown fiber is stretched by high temperature hot air to form the first loose web layer on the conveyor screen of the web forming machine. A first negative pressure suction device is installed below the first loose web layer forming position under the conveying screen of the web forming machine. The speed of the suction fan in the first negative pressure suction device is adjusted so that the negative pressure switches between -2kPa and -4kPa, with a switching interval of 2~4s. The linear speed of the conveying screen is 15~30 m / min. S2. Forming of absorbent wood pulp fiber web: The melt is fed into the second spinneret using a second metering pump, and the second ultrafine meltblown fiber is extruded. After the wood pulp fibers are combed into a single fiber state, high-temperature hot air is used to send the wood pulp fibers to the airflow web forming nozzle to spray out the wood pulp fibers. The second ultrafine meltblown fiber and wood pulp fiber are mixed in the airflow field of high temperature hot air and laid on the first loose web layer to obtain an absorbent wood pulp fiber web layer. A second negative pressure suction device is installed below the absorbent wood pulp fiber web forming position under the conveyor screen of the web forming machine. The speed of the suction fan in the second negative pressure suction device is adjusted so that the negative pressure is maintained at -5kPa. S3. Forming of the second loose mesh layer: The melt is fed into the third spinneret using a third metering pump, and the third ultrafine meltblown fiber is ejected. The third ultrafine meltblown fiber is stretched using high-temperature hot air, forming a second fluffy web layer on the absorbent wood pulp fiber web layer, resulting in a three-layer composite three-dimensional meltblown wood pulp nonwoven fabric. A third negative pressure suction device is installed below the second loose web layer forming position under the conveyor curtain of the web forming machine. The speed of the suction fan in the third negative pressure suction device is adjusted so that the negative pressure switches between -6kPa and -8kPa, with a switching interval of 2~4s.

[0006] In a preferred embodiment of the present invention, the meltblown fiber raw material is PP or PLA.

[0007] In a preferred embodiment of the present invention, the temperature of the high-temperature hot air is 160~230°C.

[0008] In a preferred embodiment of the present invention, the absorbent wood pulp fiber web layer contains 2 to 3 parts by weight of the second ultrafine meltblown fiber and 7 to 8 parts by weight of the wood pulp fiber.

[0009] In a preferred embodiment of the present invention, the diameter of the first ultrafine meltblown fiber is 2-4 micrometers, the diameter of the second ultrafine meltblown fiber is 2-4 micrometers, and the diameter of the third ultrafine meltblown fiber is 2-4 micrometers.

[0010] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is to provide a three-dimensional meltblown wood pulp nonwoven fabric with high bulk and low shedding, comprising: a first bulky web layer, an absorbent wood pulp fiber web layer and a second bulky web layer, wherein the absorbent wood pulp fiber web layer is disposed above the first bulky web layer and the second bulky web layer is disposed above the absorbent wood pulp fiber web layer, and is prepared by the above-mentioned meltblown wood pulp nonwoven fabric preparation process.

[0011] The beneficial effects of this invention are as follows: The three-dimensional meltblown wood pulp nonwoven fabric with high bulk and low shedding, and its preparation process, as pointed out in this invention, form a three-layer composite three-dimensional structure through a first bulky web layer, an absorbent wood pulp fiber web layer, and a second bulky web layer. The first and second bulky web layers improve the bulk of the surface, and the absorbent wood pulp fiber web layer improves the absorbency and stability of the wood pulp fibers. In addition, the protection of the first and second bulky web layers reduces the problem of wood pulp fiber shedding. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of the structure of a three-dimensional meltblown wood pulp nonwoven fabric with high bulk and low shedding, according to the present invention. Detailed Implementation

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Please see Figure 1 The embodiments of the present invention include: A high-loft, low-shedding three-dimensional meltblown wood pulp nonwoven fabric includes: a first loose web layer 1, an absorbent wood pulp fiber web layer 3, and a second loose web layer 2, such as... Figure 1 As shown, the absorbent wood pulp fiber web layer 3 is disposed above the first fluffy web layer 1, and the second fluffy web layer 2 is disposed above the absorbent wood pulp fiber web layer 3, forming a three-dimensional composite structure, which is prepared by the following process.

[0015] A process for preparing meltblown wood pulp nonwoven fabric includes the following steps: S1. Formation of the first loose mesh layer: The meltblown fiber raw material is fed into a screw extruder, and after the melt is extruded, it is fed into the first metering pump, the second metering pump and the third metering pump respectively. They all share one screw extruder, which reduces costs. The melt is fed into the first spinneret head using the first metering pump, and the first ultrafine meltblown fiber with a diameter of 2-4 micrometers is sprayed out. The first ultrafine meltblown fiber is stretched using high temperature hot air of 160-230℃, and the first loose web layer 1 is formed on the conveyor screen of the web forming machine. To ensure the forming stability of the first fluffy web layer 1 and improve its fluffiness, it is necessary to change the negative pressure of the suction. Specifically, a first negative pressure suction device is installed below the forming position of the first fluffy web layer 1 under the conveyor curtain of the web forming machine. The speed of the suction fan in the first negative pressure suction device is adjusted so that the negative pressure switches between -2kPa and -4kPa, with a switching interval of 2~4s. The linear speed of the conveyor curtain is 15~30 m / min. When the negative pressure is -4kPa, the first ultrafine meltblown fiber is accelerated to adhere to the conveyor screen and the exhaust is forced. After solidification, the forming stability of the first fluffy mesh layer 1 is ensured. When the negative pressure is -2kPa, the suction force is reduced, allowing some of the first ultrafine meltblown fiber to be deposited naturally and fluffy, which improves the fluffiness of the first fluffy mesh layer 1, strengthens the sense of layering, and improves the three-dimensionality. S2. Forming of absorbent wood pulp fiber web: The melt is fed into the second spinneret using a second metering pump, and the second ultrafine meltblown fiber with a diameter of 2-4 micrometers is extruded. After the wood pulp fibers are combed into a single fiber state, high-temperature hot air is used to send the wood pulp fibers to the airflow web forming nozzle to spray out the wood pulp fibers. The second ultrafine meltblown fiber and wood pulp fiber are mixed in a high-temperature hot air flow field of 160~230℃ and laid on the first fluffy web layer 1 to obtain an absorbent wood pulp fiber web layer 3. A second negative pressure suction device is installed below the absorbent wood pulp fiber web forming position under the conveyor curtain of the web forming machine. The speed of the suction fan in the second negative pressure suction device is adjusted so that the negative pressure is maintained at -5kPa, ensuring the bonding of the second ultrafine meltblown fiber to the wood pulp fiber and attaching it to the first fluffy web layer 1. In this embodiment, the second ultrafine meltblown fiber in the absorbent wood pulp fiber web layer 3 has a weight ratio of 2 to 3 parts, and the wood pulp fiber has a weight ratio of 7 to 8 parts. The large proportion of wood pulp fiber ensures absorbency, and the second ultrafine meltblown fiber is used to bond the wood pulp fiber, improve structural stability, and reduce the problem of shedding. S3. Forming of the second loose mesh layer: The melt is fed into the third spinneret using a third metering pump, extruding third ultrafine meltblown fibers with a diameter of 2-4 micrometers. High-temperature hot air at 160-230℃ is used to draw the third ultrafine meltblown fibers, forming a second fluffy web layer 2 on the absorbent wood pulp fiber web layer 3. Figure 1 As shown, a three-layer composite three-dimensional meltblown wood pulp nonwoven fabric is obtained; A third negative pressure suction device is installed below the forming position of the second fluffy web layer 2 under the conveyor screen of the web forming machine. The speed of the suction fan in the third negative pressure suction device is adjusted so that the negative pressure switches between -6kPa and -8kPa, with a switching interval of 2~4s. When the negative pressure is -8kPa, the third ultrafine meltblown fiber is accelerated to adhere to the absorbent wood pulp fiber web layer 3, and the exhaust is forced. After solidification, the forming stability of the second fluffy web layer 2 is ensured. When the negative pressure is -6kPa, the suction force on the third ultrafine meltblown fiber is reduced, allowing some of the third ultrafine meltblown fiber to naturally fluff and deposit, thereby improving the fluffiness of the second fluffy web layer 2, achieving two benefits at once.

[0016] In this embodiment, the meltblown fiber raw material is PP or PLA. PP material has a strong structure and low cost, but requires a high temperature of hot air. PLA material is degradable, environmentally friendly, and requires a low temperature of 160~180℃.

[0017] In summary, the present invention discloses a high-loft, low-shedding three-dimensional meltblown wood pulp nonwoven fabric and its preparation process. The production difficulty is low, and the obtained high-loft, low-shedding three-dimensional meltblown wood pulp nonwoven fabric has high surface loft and good air permeability, especially good air permeability and flow guiding effect in the planar direction. The absorbent wood pulp fiber web layer ensures moisture absorption and reduces the shedding problem.

[0018] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A process for preparing meltblown wood pulp nonwoven fabric, characterized in that, Includes the following steps: S1. Formation of the first loose mesh layer: Meltblown fiber raw material is fed into a screw extruder. After the melt is extruded, it is fed into the first metering pump, the second metering pump and the third metering pump respectively. The first metering pump is used to feed the melt into the first spinneret to spray out the first ultrafine meltblown fiber. The first ultrafine meltblown fiber is stretched by high temperature hot air to form the first loose web layer on the conveyor screen of the web forming machine. A first negative pressure suction device is installed below the first loose web layer forming position under the conveying screen of the web forming machine. The speed of the suction fan in the first negative pressure suction device is adjusted so that the negative pressure switches between -2kPa and -4kPa, with a switching interval of 2~4s. The linear speed of the conveying screen is 15~30 m / min. S2. Forming of absorbent wood pulp fiber web: The melt is fed into the second spinneret using a second metering pump, and the second ultrafine meltblown fiber is extruded. After the wood pulp fibers are combed into a single fiber state, high-temperature hot air is used to send the wood pulp fibers to the airflow web forming nozzle to spray out the wood pulp fibers. The second ultrafine meltblown fiber and wood pulp fiber are mixed in the airflow field of high temperature hot air and laid on the first loose web layer to obtain an absorbent wood pulp fiber web layer. A second negative pressure suction device is installed below the absorbent wood pulp fiber web forming position under the conveyor screen of the web forming machine. The speed of the suction fan in the second negative pressure suction device is adjusted so that the negative pressure is maintained at -5kPa. S3. Forming of the second loose mesh layer: The melt is fed into the third spinneret using a third metering pump, and the third ultrafine meltblown fiber is ejected. The third ultrafine meltblown fiber is stretched using high-temperature hot air, forming a second fluffy web layer on the absorbent wood pulp fiber web layer, resulting in a three-layer composite three-dimensional meltblown wood pulp nonwoven fabric. A third negative pressure suction device is installed below the second loose web layer forming position under the conveyor curtain of the web forming machine. The speed of the suction fan in the third negative pressure suction device is adjusted so that the negative pressure switches between -6kPa and -8kPa, with a switching interval of 2~4s.

2. The preparation process of meltblown wood pulp nonwoven fabric according to claim 1, characterized in that, The meltblown fiber raw material is PP or PLA.

3. The preparation process of meltblown wood pulp nonwoven fabric according to claim 1, characterized in that, The temperature of the high-temperature hot air is 160~230℃.

4. The preparation process of meltblown wood pulp nonwoven fabric according to claim 1, characterized in that, In the absorbent wood pulp fiber web, the second ultrafine meltblown fiber has a weight ratio of 2-3 parts, and the wood pulp fiber has a weight ratio of 7-8 parts.

5. The preparation process of meltblown wood pulp nonwoven fabric according to claim 1, characterized in that, The diameter of the first ultrafine meltblown fiber is 2-4 micrometers, the diameter of the second ultrafine meltblown fiber is 2-4 micrometers, and the diameter of the third ultrafine meltblown fiber is 2-4 micrometers.

6. A three-dimensional meltblown wood pulp nonwoven fabric with high bulk and low lint, characterized in that, include: The fabric comprises a first fluffy web layer, an absorbent wood pulp fiber web layer, and a second fluffy web layer, wherein the absorbent wood pulp fiber web layer is disposed above the first fluffy web layer and the second fluffy web layer is disposed above the absorbent wood pulp fiber web layer, and is prepared by the preparation process of meltblown wood pulp nonwoven fabric according to any one of claims 1 to 5.

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