Efficient filtering non-woven fabric with high stiffness, large air permeability and low resistance and manufacturing method of efficient filtering non-woven fabric

Abstract

The invention discloses an efficient filtering non-woven fabric with high stiffness, large air permeability and low resistance and a manufacturing method thereof.The non-woven fabric is composed of filament fibers and low-melting-point short fibers, the filament fibers account for 60%-75%, the low-melting-point short fibers account for 25%-40%, a stable three-dimensional structure is formed in the non-woven fabric, the stiffness is improved by 40% or above compared with that of a traditional product, and the non-woven fabric is high in air permeability, high in air permeability and high in resistance. The air permeability is increased by more than 50%; the manufacturing method comprises the following steps: weighing and blending cotton; air pressure cotton box and carding; laying a net; pre-needling is conducted; drying oven treatment; two-step hot rolling; and rolling. Through a reasonable raw material formula and a reasonable process, the manufactured non-woven fabric can achieve the effects of high stiffness, large air permeability and low resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of non-woven fabric manufacturing, and particularly to a high-rigidity, large air permeability and low-resistance high-efficiency filter non-woven fabric and a manufacturing method thereof. Background Art

[0002] In modern industrial production and daily life, the application of filtration technology is extremely extensive. From air purifiers that ensure indoor air quality, to water filtration systems that ensure water quality safety, and various filtration devices that remove impurities in industrial production processes, all rely on high-efficiency filtration materials. As a commonly used filtration material, the performance of non-woven fabric directly affects the filtration effect.

[0003] In the prior art, when manufacturing non-woven fabric, in order to improve rigidity, it is often necessary to increase the fiber density or use more binders, but this will lead to a decrease in air permeability and an increase in resistance; in order to increase air permeability by reducing fiber density or lowering the bonding strength, it will lead to insufficient rigidity, affecting the service performance and life of the non-woven fabric. Summary of the Invention

[0004] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to provide a high-rigidity, large air permeability and low-resistance high-efficiency filter non-woven fabric and a manufacturing method thereof.

[0005] To achieve the above purpose, the present invention adopts the following technical scheme: A high-rigidity, large air permeability and low-resistance high-efficiency filter non-woven fabric, the non-woven fabric is composed of filament fibers and low-melting-point short fibers, the filament fibers account for 60%-75%, and the low-melting-point short fibers account for 25%-40%, forming a stable three-dimensional structure inside, with the rigidity increased by more than 40% compared with traditional products and the air permeability increased by more than 50%.

[0006] As a further description of the above technical scheme:

[0007] The filament fibers are one or a combination of polyester filament fibers, polyamide filament fibers, and polypropylene filament fibers; the low-melting-point short fibers are one or a combination of polypropylene low-melting-point short fibers and polyester low-melting-point short fibers.

[0008] As a further description of the above technical scheme:

[0009] The fineness of the filament fibers is 2.0-3.5 dtex, and the length is 45-60 mm; the fineness of the low-melting-point short fibers is 1.0-2.5 dtex, and the length is 30-45 mm.

[0010] A manufacturing method of a high-rigidity, large air permeability and low-resistance high-efficiency filter non-woven fabric, which is used to manufacture the above-mentioned high-rigidity, large air permeability and low-resistance high-efficiency filter non-woven fabric, and includes the following steps:

[0011] Weighing and blending: Using high-precision weighing equipment with an error control within ±0.5%, weigh the filament fiber and low-melting-point staple fiber, and stir in the large blending bin at a speed of 80 - 120 r / min for 15 - 25 min;

[0012] Pneumatic cotton box and carding: Uniformly convey the fiber to the carding machine through a pneumatic cotton box with a pressure of 450 - 550 Pa. The rotational speed of the carding roller of the carding machine is 280 - 350 r / min, and the gauge is 1.5 - 2.5 mm for carding;

[0013] Web laying: Adopt multi-layer web laying technology, and the web laying angle of each layer varies between 0° - 90°;

[0014] Pre-punching: The punching needle density is 80 - 120 needles / cm 2 , and the punching depth is 1.5 - 2.5 mm for pre-punching;

[0015] Oven treatment: Bake in an oven at a temperature of 110 - 140 °C for 8 - 15 min;

[0016] Two-step hot rolling: In the first step, hot roll under the process conditions of 90 °C, with the pressure controlled at 1.0 - 2.0 MPa and the hot rolling speed of 8 - 15 m / min; in the second step, hot roll at 120 - 130 °C, with the pressure controlled at 1.5 - 3.0 MPa and the hot rolling speed of 5 - 12 m / min;

[0017] Rewinding: Rewind the hot-rolled non-woven fabric, and control the rewinding tension at 40 - 80 N / m.

[0018] As a further description of the above technical solution:

[0019] In the weighing and blending step, the precision of the high-precision weighing equipment is ±0.05 g.

[0020] As a further description of the above technical solution:

[0021] The stirring device in the large blending bin is a variable-frequency speed-adjustable stirrer, and the pitch of the stirring blade is in the range of 100 - 200 mm to optimize the stirring effect.

[0022] As a further description of the above technical solution:

[0023] The pneumatic cotton box is equipped with a pneumatic automatic regulation system with an adjustment precision of ±5 Pa, and is internally provided with a fiber distribution uniformity monitoring device.

[0024] As a further description of the above technical solution:

[0025] The surface of the carding roller of the carding machine has an anti-static coating, and the material of the carding roller is wear-resistant alloy steel, which extends the service life.

[0026] As a further description of the above technical solution:

[0027] In the multi-layer web laying technology, the number of web layers is 3 - 6 layers, and electrostatic auxiliary devices are used for pre-fixing between adjacent two fiber webs, which improves the web laying quality.

[0028] As a further description of the above technical solution:

[0029] In the pre-piercing step, the piercing needles are designed with a triangular cross-section to improve the initial strength of the fiber web on the premise of minimizing fiber damage.

[0030] The present invention has the following beneficial effects:

[0031] 1. Compared with the prior art, by optimizing the raw material formula and adopting a two-step hot rolling process, the present invention enables a stable three-dimensional network structure to be formed inside the non-woven fabric, significantly improving the stiffness of the non-woven fabric, enabling it to maintain a stable structure in a high-pressure difference environment, not being easily deformed or damaged; and high-strength filament fibers provide a skeleton support, and low-melting-point short fibers are melted and bonded during the hot rolling process, enhancing the bonding force between fibers.

[0032] 2. Compared with the prior art, through reasonable raw material ratio and process control, the present invention enables the non-woven fabric to have a uniform and connected pore structure, with the air permeability increasing by more than 50%, and at the same time, the air flow resistance is significantly reduced. The multi-layer web laying technology and the two-step hot rolling process ensure the orderliness of fiber arrangement and the rationality of pores, which is beneficial to the smooth passage of gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flowchart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Example 1

[0035] Raw material preparation and mixing: 70% of filament polyester fibers and 30% of low-melting-point polypropylene short fibers are selected. The fineness of the filament polyester fibers is 2.5 dtex, and the length is 51 mm; the fineness of the low-melting-point polypropylene short fibers is 1.5 dtex, and the length is 38 mm. Weighing is carried out with a high-precision electronic scale with an accuracy of ±0.05 g, and the error is controlled within ±0.3%. In the large cotton mixing bin, the stirring device rotates at a speed of 100 r / min and stirs for 15 min.

[0036] Fiber carding and web laying: The air pressure in the pneumatic cotton box is controlled at 500 Pa, the rotation speed of the carding roller of the carding machine is 300 r / min, and the gauge is 2 mm. Three-layer web laying is adopted, and the angles are 0°, 30°, and 60° respectively.

[0037] Pre - needling and oven treatment: The density of the pre - needling needles is 100 needles / cm 2 , and the needling depth is 2 mm. The oven temperature is 120 °C, and it is baked for 10 min.

[0038] Two - step hot rolling: The first step is hot rolling at 90 °C, with a pressure of 1.5 MPa and a hot rolling speed of 12 m / min; the second step is hot rolling at 125 °C, with a pressure of 2 MPa and a hot rolling speed of 10 m / min.

[0039] Rewinding: After cooling, it is rewound, and the rewinding tension is controlled at 50 N / m. After testing, the stiffness reaches 2.8 N, the air permeability is 320 L / (m 2 ·s·Pa), and the filtration efficiency for particulate matter with a particle size of 0.3 μm is 99.95%.

[0040] Example 2

[0041] Raw material preparation and mixing: 65% of filament polyamide fiber and 35% of low - melting - point polyester staple fiber are selected. The fineness of the filament polyamide fiber is 3.0 dtex, and the length is 55 mm; the fineness of the low - melting - point polyester staple fiber is 2.0 dtex, and the length is 40 mm. The weighing error is controlled within ±0.2%. The rotation speed of the mixing device in the large cotton bin is 120 r / min, and it is stirred for 20 min.

[0042] Fiber carding and web laying: The air pressure in the pneumatic cotton box is 450 Pa, the rotation speed of the carding roller of the carding machine is 350 r / min, and the gauge is 1.8 mm. Four - layer web laying is adopted, with angles of 0°, 20°, 40°, and 60°.

[0043] Pre - needling and oven treatment: The density of the pre - needling needles is 120 needles / cm 2 , and the needling depth is 2.2 mm. The oven temperature is 130 °C, and it is baked for 12 min.

[0044] Two - step hot rolling: The first step is hot rolling at 90 °C, with a pressure of 1.8 MPa and a hot rolling speed of 10 m / min; the second step is hot rolling at 130 °C, with a pressure of 2.2 MPa and a hot rolling speed of 8 m / min.

[0045] Rewinding: After cooling, it is rewound, and the rewinding tension is controlled at 60 N / m. The test shows that the stiffness reaches 3.2 N, the air permeability is 310 L / (m 2 ·s·Pa), and the filtration efficiency for particulate matter with a particle size of 0.3 μm is 99.98%.

[0046] Example 3

[0047] Raw material preparation and mixing: 60% of filament polypropylene fiber and 40% of low-melting-point polypropylene staple fiber are selected. The fineness of the filament polypropylene fiber is 2.8 dtex and the length is 50 mm; the fineness of the low-melting-point polypropylene staple fiber is 1.8 dtex and the length is 35 mm. The weighing error is controlled within ±0.4%. The rotation speed of the mixing device in the large cotton bin is 90 r / min and it is stirred for 18 min.

[0048] Fiber carding and web laying: The air pressure in the pneumatic cotton box is 520 Pa, the rotation speed of the carding roller of the carding machine is 280 r / min, and the gauge is 2.2 mm. Five-layer web laying is adopted with angles of 0°, 25°, 45°, 65°, and 85°.

[0049] Pre-punching and oven treatment: The density of the pre-punching needles is 90 needles / cm 2 , and the punching depth is 1.8 mm. The oven temperature is 125 °C and it is baked for 15 min.

[0050] Two-step hot rolling: The first step is hot rolling at 90 °C with a pressure of 1.6 MPa and a hot rolling speed of 11 m / min; the second step is hot rolling at 128 °C with a pressure of 2.1 MPa and a hot rolling speed of 9 m / min.

[0051] Rewinding: Rewinding is carried out after cooling, and the rewinding tension is controlled at 55 N / m. The test shows that the stiffness reaches 2.6 N, the air permeability is 330 L / (m 2 ·s·Pa), and the filtration efficiency for particulate matter with a particle size of 0.3 μm is 99.92%.

[0052] Comparative example

[0053] Select the filter non-woven fabric produced by the traditional process on the market. Under the same test conditions, the stiffness of the traditional non-woven fabric is 1.8 N, the air permeability is 200 L / (m 2 ·s·Pa), and the filtration efficiency for particulate matter with a particle size of 0.3 μm is 95%. By comparison, it can be seen that the non-woven fabric of the embodiment of the present invention is significantly superior to the product of the comparative example in terms of stiffness, air permeability, and filtration efficiency, verifying the advantages of the present invention.

[0054] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An efficient filtration non-woven fabric with high stiffness, large air permeability and low resistance, characterized in that: The non-woven fabric is composed of filament fibers and low-melting-point staple fibers. The filament fibers account for 60%-75%, and the low-melting-point staple fibers account for 25%-40%. A stable three-dimensional structure is formed inside, and the stiffness is increased by more than 40% compared with traditional products, and the air permeability is increased by more than 50%.

2. The highly stiff, large air permeability and low resistance high-efficiency filter non-woven fabric according to claim 1, characterized in that: The filament fibers are one or a combination of polyester filament fibers, polyamide filament fibers, and polypropylene filament fibers; the low-melting-point staple fibers are one or a combination of polypropylene low-melting-point staple fibers and polyester low-melting-point staple fibers.

3. The high-efficiency filtering non-woven fabric with high stiffness, large air permeability and low resistance according to claim 1, characterized in that: The fineness of the filament fibers is 2.0-3.5 dtex, and the length is 45-60 mm; the fineness of the low-melting-point staple fibers is 1.0-2.5 dtex, and the length is 30-45 mm.

4. A manufacturing method of a highly stiff, large air permeability and low resistance efficient filtration non-woven fabric, characterized in that: This method is used to manufacture the high-stiffness, large-air-permeability and low-resistance high-efficiency filter non-woven fabric described in any one of claims 1-3, and includes the following steps: Weighing and blending cotton: Using high-precision weighing equipment with an error control within ±0.5%, weighing the filament fibers and low-melting-point staple fibers, and stirring in a large cotton blending bin at a speed of 80-120 r / min for 15-25 min; Air-pressure cotton box and carding: Uniformly transporting the fibers to a carding machine through an air-pressure cotton box with an air pressure of 450-550 Pa. The rotational speed of the carding roller of the carding machine is 280-350 r / min, and the gauge is 1.5-2.5 mm for carding; Web laying: Adopting a multi-layer web laying technology, and the web laying angle of each layer changes between 0° and 90°; Pre-needling: The needle density is 80 - 120 needles / cm 2 , and the needling depth is 1.5 - 2.5 mm for pre-needling; Oven treatment: Baking in an oven at a temperature of 110-140 °C for 8-15 min; Two-step hot rolling: First, hot rolling under the process conditions of 90 °C, with the pressure controlled at 1.0-2.0 MPa and the hot rolling speed of 8-15 m / min; second, hot rolling at 120-130 °C, with the pressure controlled at 1.5-3.0 MPa and the hot rolling speed of 5-12 m / min; Rewinding: Rewinding the hot-rolled non-woven fabric, and the rewinding tension is controlled at 40-80 N / m.

5. The manufacturing method of an efficient filtering non-woven fabric with high stiffness, large air permeability and low resistance according to claim 4, characterized in that: In the step of weighing and blending cotton, the precision of the high-precision weighing equipment is ±0.05 g.

6. The manufacturing method of an efficient filtering non-woven fabric with high stiffness, large air permeability and low resistance according to claim 4, characterized in that: The stirring device in the large cotton blending bin is a variable-frequency speed-adjustable stirrer, and the pitch of the stirring blades is in the range of 100-200 mm to optimize the stirring effect.

7. The manufacturing method of an efficient filtering non-woven fabric with high stiffness, large air permeability and low resistance according to claim 4, characterized in that: The air-pressure cotton box has an air-pressure automatic adjustment system with an adjustment precision of ±5 Pa, and is internally provided with a fiber distribution uniformity monitoring device.

8. The manufacturing method of a highly stiff, large air permeability and low resistance efficient filtration non-woven fabric according to claim 4, characterized in that: The surface of the carding roller of the carding machine has an anti-static coating, and the material of the carding roller is wear-resistant alloy steel to extend the service life.

9. The manufacturing method of an efficient filtering non-woven fabric with high stiffness, large air permeability and low resistance according to claim 4, characterized in that: In the multi-layer web laying technology, the number of web laying layers is 3-6 layers, and adjacent two-layer fiber webs are pre-fixed through an electrostatic auxiliary device to improve the web laying quality.

10. The manufacturing method of a highly stiff, large air permeability and low resistance high-efficiency filter non-woven fabric according to claim 4, characterized in that: In the pre-punching step, the punching needles adopt a triangular cross-section design to improve the initial strength of the fiber web on the premise of minimizing fiber damage.

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