阅读说明：本技术 一种针刺非织造布和热轧纺粘非织造布复合的过滤材料 (Filter material compounded by needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric ) 是由 金关秀 胡海霞 祝成炎 于 2020-12-28 设计创作，主要内容包括：本发明公开了针刺非织造布和热轧纺粘非织造布复合的过滤材料,包括针刺非织造纤网层和热轧纺粘非织造纤网层,该过滤材料在获得理想的过滤效率的同时,效阻比也达到较高的水平,此外复合后材料具有优良的力学性能,足以满足空气过滤材料在一般使用情况下的力学性能要求,能够广泛应用于各种空气过滤装置。本发明还公开了该过滤材料的制备方法,充分利用了现有的非织造布生产设备,可降低生产难度和成本,减少能源消耗,提高产品质量,适于工业化生产。(The invention discloses a filter material compounded by needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric, which comprises a needle-punched non-woven fabric layer and a hot-rolled spun-bonded non-woven fabric layer, wherein the filter material achieves ideal filter efficiency and simultaneously has higher effective-resistance ratio, and the compounded material has excellent mechanical property which can sufficiently meet the mechanical property requirement of the air filter material under the common use condition and can be widely applied to various air filter devices. The invention also discloses a preparation method of the filter material, which makes full use of the existing non-woven fabric production equipment, can reduce the production difficulty and cost, reduce the energy consumption, improve the product quality and is suitable for industrial production.)

1. The laminated composite non-woven air filter material with excellent mechanical property and high-efficiency low-resistance characteristic is characterized in that the preparation method comprises the following steps: laminating the needled non-woven fiber web layer and the hot-rolled spun-bonded non-woven fiber web layer, needling under the conditions that the needling depth is 8-10 mm and the needling density is 200-260 needles/cm, and connecting all parts of the filtering material to form a high-efficiency low-resistance air filtering material with excellent mechanical property; wherein the needle punched non-woven web layer is composed of a staple fiber web, the hot rolled spun-bonded non-woven web layer is formed by hot rolling a spun-bonded filament web, and the spun-bonded filament web is composed of spun-bonded filament fibers.

2. The composite nonwoven air filtration material of claim 1, wherein: the needle-punched short fiber net is of a gap structure, the raw material of the needle-punched short fibers is polypropylene, the hot-rolled spun-bonded filament fiber net is of a gap structure, and the raw material of the spun-bonded filament fiber is polypropylene.

3. A method of making a composite nonwoven air filter material as claimed in any one of claims 1-2, comprising the steps of:

(1) polypropylene short fibers are subjected to opening, carding and air-laid web formation, are uniformly laid into a fiber web at a certain density, and are subjected to needle punching processing to prepare polypropylene short fiber needle-punched non-woven fabric;

(2) melting and pressurizing the dried spun-bonded polypropylene polymer through a screw extruder, then spraying the polymer from a spinning assembly to form filaments with certain fineness, and cooling the filaments by utilizing air to form a spun-bonded non-woven fiber net on a net forming curtain;

(3) hot rolling the spun-bonded non-woven fiber web prepared in the step (2) to prepare a hot-rolled spun-bonded non-woven fiber web;

(4) and (3) connecting the needle-punched non-woven fabric prepared in the step (1) and the hot-rolled spun-bonded non-woven fabric prepared in the step (3) through needle punching to prepare the laminated composite non-woven fabric.

4. The method of making a needled nonwoven web according to step (1) of claim 3, wherein the needling process parameters are: the needling depth is 12-16 mm, and the needling density is 300-420 needles/cm.

5. A method of producing a spunbond nonwoven web in accordance with step (2) of claim 3, wherein a spunbond polypropylene chip having a melting point of 162 ℃ and a melt index of 30g/10min is selected; conveying the slices to a slice hopper through airflow, drying the slices in a vacuum drying area, and conveying the dried slices to a screw extruder for melting treatment, wherein the melting temperatures of the 1-5 areas are 200, 210, 220 and 220 ℃ respectively; filtering the melt through a filter screen, and then feeding the melt into a metering pump for metering, wherein the frequency of the metering pump is selected to be 20-30 Hz; inputting the measured melt into a spinning assembly for spinning, then conveying the spun fiber melt to a quenching area, cooling and solidifying the fiber melt into filaments at 15-17 ℃ by cross air blowing, wherein the frequency of the cross air blowing is 28-30 Hz; and inputting the cooled and solidified fiber bundles into a traction nozzle, drawing the fiber bundles at a high speed by compressed air, uniformly dropping the fiber bundles onto a conveying net curtain, laying the fiber bundles into a net, and selecting the frequency of the net curtain to be 5-10 Hz.

6. A method of making a spunbond nonwoven web according to step (3) of claim 3, wherein the spunbond nonwoven web made in step (2) of claim 3 is hot rolled by: the pressure is 1-3 MPa, the temperature is 135-155 ℃, and the pressurizing time is 5-9 s.

7. The method of manufacturing a laminated composite nonwoven fabric according to step (4) of claim 3, wherein the needle-punched nonwoven web layer produced in step (1) of claim 3 and the hot-rolled spun-bonded nonwoven web layer produced in step (3) of claim 3 are laminated, and needle-punched under the conditions of a needle-punching depth of 8 to 10mm and a needle-punching density of 200 to 260 needles/cm, and the filter material is connected at each portion to form an air filter material having excellent mechanical properties, high efficiency and low resistance.

8. The needle punched nonwoven web of claim 4, wherein the polypropylene staple fibers have a diameter of 18 to 25 μm, a length of 38 to 75mm, and an areal density of the web200 to 350g/m²The thickness of the fiber web is 3-6 mm, the average pore diameter of the fiber web is 50-70 mu m, and the coefficient of variation of the pore diameter of the fiber web is 20-35%; the longitudinal breaking strength of the fiber web is 500-700N, the transverse breaking strength of the fiber web is 400-600N, the longitudinal breaking elongation of the fiber web is 130-150%, and the transverse breaking elongation of the fiber web is 140-160%.

9. The spunbond nonwoven web of claim 5, wherein the spunbond filaments have an average diameter of 20 to 25 μm and an areal density of 50 to 150g/m²The thickness of the fiber web is 0.3-0.6 mm, the average pore diameter of the fiber web is 15-45 mu m, and the coefficient of variation of the pore diameter of the fiber web is 50-120%; the longitudinal breaking strength of the fiber web is 50-70N, the transverse breaking strength of the fiber web is 35-55N, the longitudinal breaking elongation of the fiber web is 15-25%, and the transverse breaking elongation of the fiber web is 20-35%.

10. The spunbond nonwoven web of claim 6, wherein the spunbond filament fibers have an average diameter of 20 to 25 μm and an areal density of 50 to 150g/m²The thickness of the fiber net is 0.15-0.35 mm, the average pore diameter of the fiber net is 11-34 mu m, and the coefficient of variation of the pore diameter of the fiber net is 60-150%; the longitudinal breaking strength of the fiber web is 100-160N, the transverse breaking strength of the fiber web is 70-120N, the longitudinal breaking elongation of the fiber web is 8-16%, and the transverse breaking elongation of the fiber web is 12-23%.

11. The laminated composite nonwoven fabric of claim 7, wherein said fiber web has an average fiber diameter of 18 to 25 μm and an areal density of 245 to 490g/m²The thickness of the fiber web is 2.5-5.2 mm, and the average pore size of the fiber web is 7 ℃ -23 mu m, the aperture variation coefficient of the fiber web is 45-90%, the longitudinal breaking strength of the fiber web is 300-450N, the transverse breaking strength of the fiber web is 250-400N, the longitudinal breaking elongation of the fiber web is 45-70%, and the transverse breaking elongation of the fiber web is 65-90%.

Technical Field

The invention relates to the technical field of spinning, in particular to a filter material compounded by needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric and a preparation method thereof.

Background

The phenomenon of air pollution is still very serious in the modern times, and the importance of developing an air filter material with high efficiency, low resistance and better mechanical property for industrial ventilation and filtration is increasing day by day. The non-woven fabric is a fiber aggregate with a three-dimensional porous structure, is an ideal air filter material, and can optimize the microscopic structure and mechanical property of the material by carrying out composite processing on the non-woven materials prepared in different net forming modes so as to prepare the high-quality and high-efficiency air filter material. The needle-punched non-woven fabric has excellent mechanical property, high porosity and uniform pore size distribution, but has large pore size and relatively poor filtering performance. The pore diameter of the spun-bonded non-woven fabric is small, the filtering performance is superior to that of the needle-punched non-woven fabric, but the mechanical performance is relatively poor. The strength and the wear resistance of the filter material can be greatly improved by compounding the needle-punched non-woven fabric and the spun-bonded non-woven fabric, and meanwhile, the filtering performance is improved. However, the existing composite technology is simple superposition and needling reinforcement of two non-woven fabrics, and the filtration efficiency improvement amplitude still cannot reach an ideal level.

Disclosure of Invention

The invention aims to break through the bottleneck in the prior art, and provides a filter material compounded by needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric and a preparation method thereof, which can obtain ideal filter efficiency, achieve higher effect-resistance ratio and excellent mechanical property, and can reduce production cost and energy consumption.

The diameter of the polypropylene short fibers in the needle-punched non-woven fiber web is 18-25 mu m, the length of the polypropylene short fibers is 38-75 mm, and the surface density of the fiber web is 200-350 g/m²The thickness is 3-6 mm, the average pore diameter is 50-70 μm, and the coefficient of variation of pore diameter is 20-35%. The fiber web has a longitudinal breaking strength of 500-700N, a transverse breaking strength of 400-600N, a longitudinal elongation at break of 130-150%, and a transverse elongation at break of 140-160%.

The mean diameter of the spun-bonded filaments in the spun-bonded nonwoven web is 20 to 25 μm, and the areal density of the web is 50 to 150g/m²The thickness is 0.3 to 0.6mm, the average pore diameter is 15 to 45 μm, and the coefficient of variation of pore diameter is 50 to 120%. The fiber web has a longitudinal breaking strength of 50-70N, a transverse breaking strength of 35-55N, a longitudinal elongation at break of 15-25%, and a transverse elongation at break of 20-35%.

The thickness of the spun-bonded non-woven fiber web is reduced to 0.15-0.35 mm after hot rolling, the average pore diameter is reduced to 11-34 mu m, and the coefficient of variation of the pore diameter is increased to 60-150%. The longitudinal breaking strength of the fiber web is increased to 100-160N, the transverse breaking strength is increased to 70-120N, the longitudinal breaking elongation is reduced to 8-16%, and the transverse breaking elongation is reduced to 12-23%.

The average fiber diameter of the laminated composite non-woven fabric is 18 to 25 mu m, and the surface density of the fiber web is 245 to 490g/m²The thickness is 2.5 to 5.2mm, the average pore diameter is 7 to 23 μm, and the coefficient of variation of pore diameter is 45 to 90%. The fiber web has a longitudinal breaking strength of 300-450N, a transverse breaking strength of 250-400N, a longitudinal elongation at break of 45-70%, and a transverse elongation at break of 65-90%.

The reduction in pore size is greater when the needled nonwoven web is combined with the hot-rolled spunbond nonwoven web than when the nonwoven web is combined with a spunbond nonwoven web that has not been hot-rolled. The pore diameter value of the non-woven fabric is the pore diameter of the narrowest position in the pore channel, if one pore channel meets the pore channel which is wider than the pore channel, the final pore diameter value is the final pore diameter value, and if the pore channel meets the narrower pore channel, the final pore diameter value is the latter, so the smaller the pore diameter of the composite unit component is, the smaller the pore diameter of the composite material is.

The invention also provides a preparation method of the filter material compounded by the needle-punched non-woven fabric and the hot-rolled spun-bonded non-woven fabric, and the method adopts the existing equipment, is simple to operate and is suitable for industrial production.

The needled non-woven fiber web layer and the hot-rolled spun-bonded non-woven fiber web layer are laminated, and all parts of the filtering material are connected through needling processing to form the air filtering material with excellent mechanical property, high efficiency and low resistance.

The preparation method of the composite non-woven fabric air filter material comprises the following steps:

(1) polypropylene short fibers with the diameter of 18-25 mu m and the length of 38-75 mm are subjected to opening, carding and air-laid, are uniformly laid into a fiber web with a certain density, and are subjected to needle punching processing to prepare the polypropylene short fiber needle-punched non-woven fabric. The specific process flow is as follows:

the reciprocating plucker → the cotton conveying fan → the condenser → the cotton mixing cord opener → the multi-chamber cotton mixing machine → the cotton conveying fan → the air flow hopper cotton feeding machine → the carding machine → the air flow web former → the double-roller pre-needling machine → the double-needle plate needling machine. The main needling process parameters are that the needling depth is 12-16 mm, and the needling density is 300-420 needles/cm.

(2) Selecting a spun-bonded polypropylene slice with the melting point of 162 ℃ and the melt index of 30g/10 min; conveying the dried slices to a screw extruder for melting treatment, wherein the melting temperatures of 1-5 areas are 200 ℃, 210, 220 and 220 ℃. The melt is filtered by a filter screen and then enters a metering pump for metering, and the frequency of the metering pump is selected to be 20-30 Hz. And (3) inputting the measured melt into a spinning assembly for spinning, then conveying the spun fiber melt to a quenching area, and cooling and solidifying the spun fiber melt into filaments by cross air blowing at the temperature of 15-17 ℃, wherein the frequency of the cross air blowing is 28 Hz. And inputting the cooled and solidified fiber bundles into a traction nozzle, drawing the fiber bundles at a high speed by compressed air, uniformly dropping the fiber bundles onto a conveying net curtain, laying the fiber bundles into a net, and selecting the frequency of the net curtain to be 5-10 Hz.

(3) Carrying out hot rolling on the spun-bonded non-woven fiber web prepared in the step (2), wherein the process comprises the following steps: the hot-rolled spun-bonded non-woven fiber web is prepared by the pressure of 1-3 MPa, the temperature of 135-155 ℃ and the pressurizing time of 3-8 s.

(4) And laminating the needled non-woven fiber web and the hot-rolled spun-bonded non-woven fabric, needling under the conditions that the needling depth is 8-10 mm and the needling density is 200-260 needles/cm, and connecting all parts of the filtering material to form the high-efficiency low-resistance air filtering material with excellent mechanical property.

Compared with the prior art, the invention has the following advantages:

the method is characterized in that the needled non-woven fabric and the spun-bonded non-woven fabric after hot rolling are laminated and compounded, and compared with the simple superposition and needling reinforcement of the traditional needled non-woven fabric/spun-bonded non-woven fabric, the aperture reduction range of the composite filter material is larger, but the thickness reduction range is smaller, so that the effect-resistance ratio also reaches a higher level while the ideal filtering efficiency is obtained. In addition, the composite material has excellent mechanical properties, the breaking strength is more than 250N, the breaking elongation is more than 45%, and the requirements on the mechanical properties of the air filter material under the common use condition can be met. The composition of the composite material and the needle-punched non-woven fiber net with larger surface density and thickness can also make up the defect of poor net forming uniformity of the spun-bonded non-woven fabric to a great extent.

The preparation method of the invention fully utilizes the existing non-woven fabric production equipment, can reduce the production difficulty and cost, reduce the energy consumption, improve the product quality, and is suitable for industrial production.

Drawings

FIG. 1 is a schematic view showing the structure of a filter material in which a needle-punched nonwoven fabric and a hot-rolled spunbond nonwoven fabric are combined according to the present invention.

Wherein, 1: needle punched nonwoven web, 2: a thermally calendered spunbond nonwoven web.

Detailed Description

Example 1

Polypropylene short fiber with the diameter of 17.6 mu m and the length of 38mm is subjected to opening, carding and air-laid, is uniformly laid into a fiber net with certain density, and is subjected to needle punching processing to prepare the polypropylene short fiber needle-punched non-woven fabric. The specific process flow is as follows:

the reciprocating plucker → the cotton conveying fan → the condenser → the cotton mixing cord opener → the multi-chamber cotton mixing machine → the cotton conveying fan → the air flow hopper cotton feeding machine → the carding machine → the air flow web former → the double-roller pre-needling machine → the double-needle plate needling machine. The main needling process parameters are that the needling depth is 12 mm, and the needling density is 320 needles/cm.

Selecting a spun-bonded polypropylene slice with the melting point of 162 ℃ and the melt index of 30g/10 min; conveying the dried slices to a screw extruder for melting treatment, wherein the melting temperatures of 1-5 areas are 200 ℃, 210, 220 and 220 ℃. The melt is filtered by a filter screen and then enters a metering pump for metering, and the frequency of the metering pump is 22 Hz. And (3) inputting the measured melt into a spinning assembly for spinning, then conveying the spun fiber melt to a quenching area, and cooling and solidifying the spun fiber melt into filaments by cross air blowing at the temperature of 15-17 ℃, wherein the frequency of the cross air blowing is 28 Hz. And (3) inputting the cooled and consolidated fiber bundle into a traction nozzle, drawing the fiber bundle at a high speed by compressed air, uniformly dropping the fiber bundle onto a conveying net curtain, laying the fiber bundle into a net, and selecting the frequency of the net curtain to be 7 Hz. The spun-bonded non-woven fiber web is hot rolled, and the process comprises the following steps: the pressure was 2MPa, the temperature was 140 ℃ and the pressing time was 5 seconds, thereby producing a hot-rolled spunbond nonwoven web.

The needled non-woven fiber web and the hot-rolled spun-bonded non-woven fiber web are laminated, needling is carried out under the conditions that the needling depth is 8mm and the needling density is 220 needles/cm, and all parts of the filter material are connected to form the high-efficiency low-resistance air filter material with excellent mechanical property. The structure is shown in the attached drawings.

An SX-L1050 filter material efficiency test bed is adopted to test the filtration efficiency and the filtration resistance of the obtained needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric composite filter material, the filtration speed is 5.33cm/s, the test flow is 32L/min, the upstream dilution is 7-10 times, and the L of the used polystyrene emulsion (PS) is monodisperse and is more than or equal to 0.3 mu m; the area of the sample is 100cm². The filtration efficiency was 91.24% and the filtration resistance was 15.8 Pa.

According to GB/T24218.3-2010, test method for textile nonwovens part 3: in the determination of breaking strength and breaking elongation (bar method), the breaking strength and breaking elongation of the obtained needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric composite filter material were tested by using a YG-065H electronic textile strength tester. The longitudinal breaking strength was 362.8N, the transverse breaking strength was 275.1N, the longitudinal elongation at break was 58.43%, and the transverse elongation at break was 77.90%.

Example 2

Polypropylene short fiber with the diameter of 21.6 mu m and the length of 60mm is subjected to opening, carding and air-laid, is uniformly laid into a fiber net with certain density, and is subjected to needle punching processing to prepare the polypropylene short fiber needle-punched non-woven fabric. The specific process flow is as follows:

the reciprocating plucker → the cotton conveying fan → the condenser → the cotton mixing cord opener → the multi-chamber cotton mixing machine → the cotton conveying fan → the air flow hopper cotton feeding machine → the carding machine → the air flow web former → the double-roller pre-needling machine → the double-needle plate needling machine. The main needling process parameters are that the needling depth is 14 mm, and the needling density is 360 needles/cm.

Selecting a spun-bonded polypropylene slice with the melting point of 162 ℃ and the melt index of 30g/10 min; conveying the dried slices to a screw extruder for melting treatment, wherein the melting temperatures of 1-5 areas are 200 ℃, 210, 220 and 220 ℃. The melt is filtered by a filter screen and then enters a metering pump for metering, and the frequency of the metering pump is selected to be 26 Hz. And (3) inputting the measured melt into a spinning assembly for spinning, then conveying the spun fiber melt to a quenching area, and cooling and solidifying the spun fiber melt into filaments by cross air blowing at the temperature of 15-17 ℃, wherein the frequency of the cross air blowing is 28 Hz. And (3) inputting the cooled and consolidated fiber bundle into a traction nozzle, drawing the fiber bundle at a high speed by compressed air, uniformly dropping the fiber bundle onto a conveying net curtain, laying the fiber bundle into a net, and selecting the frequency of the net curtain to be 5 Hz. The spun-bonded non-woven fiber web is hot rolled, and the process comprises the following steps: the pressure was 1MPa, the temperature was 145 ℃ and the pressing time was 7 seconds, thereby producing a hot-rolled spunbond nonwoven web.

The needled non-woven fiber web and the hot-rolled spun-bonded non-woven fabric are laminated, needling is carried out under the conditions that the needling depth is 9mm and the needling density is 240 needles/cm, and all parts of the filter material are connected to form the high-efficiency low-resistance air filter material with excellent mechanical property. The structure is shown in the attached drawings.

An SX-L1050 filter material efficiency test bed is adopted to test the filtration efficiency and the filtration resistance of the obtained needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric composite filter material, the filtration speed is 5.33cm/s, the test flow is 32L/min, the upstream dilution is 7-10 times, and the L of the used polystyrene emulsion (PS) is monodisperse and is more than or equal to 0.3 mu m; the area of the sample is 100cm². The filtration efficiency was 90.33% and the filtration resistance was 13.6 Pa.

According to GB/T24218.3-2010, test method for textile nonwovens part 3: in the determination of breaking strength and breaking elongation (bar method), the breaking strength and breaking elongation of the obtained needle-punched non-woven fabric and hot-rolled spun-bonded non-woven fabric composite filter material were tested by using a YG-065H electronic textile strength tester. The longitudinal breaking strength was 424.9N, the transverse breaking strength was 352.6N, the longitudinal elongation at break was 62.09%, and the transverse elongation at break was 76.32%.