High-loft nonwoven fabric based on meltblown and wood pulp fibers and method of making the same

Abstract

This invention discloses a high-loft nonwoven fabric based on meltblown and wood pulp fibers and its preparation method, comprising the following steps: forming a breathable and fluid-guiding layer, forming an absorbent core layer, hot air bonding, and cold air shaping. High-pressure cold air is blown downwards from above the path of the semi-finished product, and the pressure of the cold air compresses the breathable and fluid-guiding layer and the absorbent core layer. The structure is shaped by the cooling of the ultrafine meltblown fibers in the absorbent core layer. The residual heat of the ultrafine meltblown fibers and the high-temperature hot air are used to bond the wood pulp fibers and the breathable and fluid-guiding layer. In addition, the hot air bonding enhances the structural stability, eliminates the need for hot rolling, ensures high loft, and improves breathability and fluid-guiding effect.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabrics, and in particular to a high-loft nonwoven fabric based on meltblown and wood pulp fibers and its preparation method. Background Technology

[0002] Twin-spun nonwoven fabrics are widely used in wet wipes, filter materials, wiping cloths, feminine hygiene products, and adult incontinence pads.

[0003] Twin-spun nonwoven fabrics are typically produced using meltblown microfiber and wood pulp fiber as base materials through a dry process. The bonding between meltblown microfiber and wood pulp fiber relies on the residual heat of the meltblown microfiber, resulting in an unstable structure. Some processes use hot rolling to assist in web bonding, improving structural stability, but this affects bulkiness, air permeability, and airflow permeability, requiring improvement. Summary of the Invention

[0004] The main technical problem solved by this invention is to provide a high-loft nonwoven fabric based on meltblown and wood pulp fibers and its preparation method, which improves air permeability and flow-guiding effect and ensures high loft.

[0005] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is to provide a method for preparing a nonwoven fabric, comprising the following steps: S1. Forming of the breathable flow-guiding layer: After the wood pulp fibers are combed into single fibers, compressed air is used to send the wood pulp fibers to the first airflow web forming nozzle for spraying. Hollow three-dimensional crimped polyester fibers, after being in a single fiber state, are sent to the second airflow web forming nozzle for spraying using compressed air. Hollow three-dimensional crimped polyester fibers and wood pulp fibers are mixed in a normal temperature airflow field and laid on the condensing screen of the web forming machine to form a breathable and air-guiding layer. S2. Forming of the absorbent core layer: The meltblown fiber raw material is fed into a screw extruder, and after the melt is extruded, it is fed into a metering pump. The metering pump is used to send the melt into a spinneret to spray out ultrafine meltblown fibers with a diameter of 2 to 4 micrometers. After the wood pulp fibers are combed into single fibers, compressed air is used to send the wood pulp fibers to the third airflow web forming nozzle for spraying. Ultrafine meltblown fiber and wood pulp fiber are mixed in a high-temperature hot air flow field and laid on a breathable and guiding layer to obtain an absorbent core layer, forming a semi-finished product of a composite of a breathable and guiding layer and an absorbent core layer. S3, Hot Air Bonding: The semi-finished product is sent into the drying oven. First, low-pressure hot air is blown downward from above the path of the semi-finished product to maintain the molten state and surface adhesion of the ultra-fine meltblown fiber in the absorption core layer, so as to achieve the bonding of some hollow three-dimensional crimped polyester fiber and wood pulp fiber in the breathable guide layer. The negative pressure box set below the semi-finished product path carries away the broken hollow three-dimensional crimped polyester fibers and wood pulp fibers, and guides the molten ultrafine meltblown fibers to penetrate into the breathable flow layer, further bonding the hollow three-dimensional crimped polyester fibers and wood pulp fibers in the breathable flow layer. S4, Cool Air Shaping: High-pressure cold air is blown downwards from above the semi-finished product path. The cold air pressure is used to compress the breathable guide layer and the absorbent core layer. The structure is shaped by the cooling of the ultrafine meltblown fibers in the absorbent core layer.

[0006] In a preferred embodiment of the present invention, the breathable and fluid-guiding layer contains 6 to 7 parts by weight of wood pulp fiber and 3 to 4 parts by weight of hollow three-dimensional crimped polyester fiber.

[0007] In a preferred embodiment of the present invention, the absorbent core layer contains 4 to 5 parts by weight of ultrafine meltblown fiber and 5 to 6 parts by weight of wood pulp fiber.

[0008] In a preferred embodiment of the present invention, the meltblown fiber raw material is PP or PLA.

[0009] In a preferred embodiment of the present invention, in the hot air bonding step, the temperature of the hot air is 150~160℃ and the air pressure is 50~80Pa.

[0010] In a preferred embodiment of the present invention, the temperature of the high-temperature hot air is 150~160°C during the forming step of the absorbent core layer.

[0011] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is to provide a high-loft nonwoven fabric based on meltblown and wood pulp fibers, which is prepared by the above-mentioned nonwoven fabric preparation method, including a breathable guiding layer and an absorbent core layer, wherein the absorbent core layer is located above the breathable guiding layer.

[0012] The beneficial effects of this invention are as follows: The invention discloses a high-loft nonwoven fabric based on meltblown and wood pulp fibers and its preparation method. It utilizes the residual heat of the ultrafine meltblown fibers and high-temperature hot air to bond the wood pulp fibers and the breathable and flow-guiding layer. In addition, the hot air bonding enhances the structural stability. The cold air setting eliminates the need for hot rolling, ensuring high loft, improving breathability and flow-guiding effect, and facilitating the absorption core layer to exert its absorbency. Attached Figure Description

[0013] 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 high-loft nonwoven fabric based on meltblown and wood pulp fibers according to the present invention. Detailed Implementation

[0014] 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.

[0015] Please see Figure 1 The embodiments of the present invention include: A method for preparing a nonwoven fabric includes the following steps: S1. Forming of the breathable and flow-guiding layer 1: The 3-5mm long wood pulp fibers are combed into single fibers and then compressed air is used to send the wood pulp fibers to the first airflow web forming nozzle for spraying. Hollow three-dimensional crimped polyester fibers, after being in a single fiber state, are sent to the second airflow web forming nozzle for spraying using compressed air. Hollow three-dimensional crimped polyester fibers and wood pulp fibers are mixed in a normal temperature airflow field and laid on the condensing screen of the web forming machine to form a breathable flow guiding layer 1. In this embodiment, the wood pulp fiber in the breathable flow guiding layer 1 is 6-7 parts by weight, and the hollow three-dimensional crimped polyester fiber is 3-4 parts by weight. The hollow three-dimensional crimped polyester fiber ensures the high bulkiness of the breathable flow guiding layer 1, resulting in a three-dimensional hollow structure breathable flow guiding layer 1 with good air permeability. It can adsorb and transport liquid through the capillary action of the wood pulp fiber and can guide flow in both the planar and thickness directions. S2, Forming of the absorbent core layer 2: The meltblown fiber raw material is fed into a screw extruder, and after the melt is extruded, it is fed into a metering pump. The metering pump is used to send the melt into a spinneret to spray out ultrafine meltblown fibers with a diameter of 2 to 4 micrometers. In this embodiment, the meltblown fiber raw material is PP or PLA. PLA is environmentally friendly, can be degraded, and avoids environmental pollution. After the wood pulp fibers are combed into single fibers, compressed air is used to send the wood pulp fibers to the third airflow web forming nozzle for spraying. Ultrafine meltblown fiber and wood pulp fiber are mixed in a high-temperature hot air flow field of 150~160℃ and laid on the breathable guide layer to obtain the absorbent core layer 2, forming a semi-finished product of breathable guide layer 1 and absorbent core layer 2. In this embodiment, the weight of the ultrafine meltblown fiber in the absorbent core layer is 4-5 parts, and the weight of the wood pulp fiber is 5-6 parts. The wood pulp fiber content is high and the water absorption is good. The ultrafine meltblown fiber is kept viscous by its own residual heat and high temperature hot air at 150-160°C, so as to achieve the bonding of wood pulp fiber and breathable guide layer 1. S3, Hot Air Bonding: The semi-finished product is sent into the oven, and low-pressure hot air is blown downward from above the path of the semi-finished product. In this embodiment, the temperature of the hot air is 150~160℃ and the air pressure is 50~80Pa. The hot air maintains the molten state and surface adhesion of the ultrafine meltblown fiber in the absorption core layer, thereby achieving the bonding of some hollow three-dimensional crimped polyester fiber and wood pulp fiber in the breathable guide layer 1. The negative pressure box set below the semi-finished product path carries away the broken hollow three-dimensional crimped polyester fibers and wood pulp fibers, and guides the molten ultrafine meltblown fibers to penetrate into the breathable flow layer, further bonding the hollow three-dimensional crimped polyester fibers and wood pulp fibers in the breathable flow layer and improving structural stability. S4, Cool Air Shaping: High-pressure cold air is blown downwards from above the semi-finished product path. The air pressure is 110~150Pa and the temperature is room temperature. The cold air pressure is used to compress the breathable guide layer 1 and the absorbent core layer 2. The structure is shaped by cooling the ultrafine meltblown fibers in the absorbent core layer 2, ensuring high fluffiness while avoiding looseness.

[0016] like Figure 1 The high-loft nonwoven fabric based on meltblown and wood pulp fibers shown is prepared by the above-mentioned method for preparing nonwoven fabric. It includes a breathable and diverting layer 1 and an absorbent core layer 2. The absorbent core layer 2 is located above the breathable and diverting layer 1. The breathable and diverting layer 1 has good breathability, making it more comfortable to use as a feminine hygiene product and an adult incontinence pad. It can also divert fluid, which helps to fully utilize the absorbent properties of the absorbent core layer 2.

[0017] 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 method for preparing a nonwoven fabric, characterized in that, Includes the following steps: S1. Forming of the breathable flow-guiding layer: After the wood pulp fibers are combed into single fibers, compressed air is used to send the wood pulp fibers to the first airflow web forming nozzle for spraying. After the hollow three-dimensional crimped polyester fiber is in a single fiber state, compressed air is used to send the hollow three-dimensional crimped polyester fiber to the second airflow web forming nozzle for spraying. Hollow three-dimensional crimped polyester fibers and wood pulp fibers are mixed in a normal temperature airflow field and laid on the condensing screen of the web forming machine to form a breathable and flow-guiding layer. S2. Forming of the absorbent core layer: The meltblown fiber raw material is fed into a screw extruder, and after the melt is extruded, it is fed into a metering pump. The metering pump is used to send the melt into a spinneret to spray out ultrafine meltblown fibers with a diameter of 2 to 4 micrometers. After the wood pulp fibers are combed into single fibers, compressed air is used to send the wood pulp fibers to the third airflow web forming nozzle for spraying. Ultrafine meltblown fiber and wood pulp fiber are mixed in a high-temperature hot air flow field and laid on a breathable and guiding layer to obtain an absorbent core layer, forming a semi-finished product of a composite of a breathable and guiding layer and an absorbent core layer. S3, Hot Air Bonding: The semi-finished product is sent into the drying oven. First, low-pressure hot air is blown downward from above the path of the semi-finished product to maintain the molten state and surface adhesion of the ultra-fine meltblown fiber in the absorption core layer, so as to achieve the bonding of some hollow three-dimensional crimped polyester fiber and wood pulp fiber in the breathable guide layer. The negative pressure box set below the semi-finished product path carries away the broken hollow three-dimensional crimped polyester fibers and wood pulp fibers, and guides the molten ultrafine meltblown fibers to penetrate into the breathable flow layer, further bonding the hollow three-dimensional crimped polyester fibers and wood pulp fibers in the breathable flow layer. S4, Cool Air Shaping: High-pressure cold air is blown downwards from above the semi-finished product path. The cold air pressure is used to compress the breathable guide layer and the absorbent core layer. The structure is shaped by the cooling of the ultrafine meltblown fibers in the absorbent core layer.

2. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In the breathable and fluid-guiding layer, the wood pulp fiber accounts for 6 to 7 parts by weight, and the hollow three-dimensional crimped polyester fiber accounts for 3 to 4 parts by weight.

3. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In the absorbent core layer, the weight parts of ultrafine meltblown fiber are 4 to 5 parts, and the weight parts of wood pulp fiber are 5 to 6 parts.

4. The method for preparing the nonwoven fabric according to claim 1, characterized in that, The meltblown fiber raw material is PP or PLA.

5. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In the hot air bonding step, the temperature of the hot air is 150~160℃ and the air pressure is 50~80Pa.

6. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In the forming step of the absorbent core layer, the temperature of the high-temperature hot air is 150~160℃.

7. A high-loft nonwoven fabric based on meltblown and wood pulp fibers, characterized in that, The nonwoven fabric prepared by any one of claims 1 to 6 includes a breathable guiding layer and an absorbent core layer, wherein the absorbent core layer is located above the breathable guiding layer.

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