CN103981635A - Preparation method of porous fiber non-woven fabric - Google Patents

Abstract

The invention relates to a preparation method of a porous fiber non-woven fabric. The aim of the preparation method is to improve the product performance of the conventional non-woven fabric, so that the non-woven fabric meets the requirements on high-precision and high-performance filter. The technical scheme is that the preparation method of the porous fiber non-woven fabric comprises the following steps in sequence: (1) uniformly mixing a polymer and a diluent to obtain a blend with 10 to 60 percent of polymer; (2) melting and extruding the blend in the step (1) by adopting a screw extruder granulator, and directly cooling and granulating in air; (3) producing master batches in the step (2) by melt-down equipment to obtain a primary non-woven fabric; (4) extracting to remove the diluent from the primary non-woven fabric in the step (3), performing pore-forming on fibers in the non-woven fabric, and drying to obtain the porous fiber non-wave fabric; (5) recovering mixed waste liquid of the diluent and an extraction agent for reuse.

Description

A kind of porous fibre nonwoven fabric preparation method

Technical field

The invention belongs to fabrics for industrial use field, be specifically related to a kind of the thermic pore-forming technology that is separated is combined with melt blown technology and prepares the method for porous fibre nonwoven fabric, the nonwoven fabric making can be used for environmental protection, water treatment, air filtration etc.

Background technology

Melt blown technology be rely at a high speed, high temperature gas flow (often approaching melting point polymer) winding-up polymer melt is stretched rapidly it and prepares a kind of method of superfine fibre, can one step forming be nonwoven fabric.Produce by melt blown technology by the random nonwoven fabric being assembled into of piling up of fiber, there is very good structural property, as ultra-fine in fiber, specific area is large, porosity is high, pore space structure connects mutually, solute diffusional resistance is little etc., is especially suitable for use as absorption and isolated by filtration material.Melt spraying non-woven fabrics product is defended the fields such as protection (haze, bird flu, air cleaning), warming heat insulation, absorbing sound and lowering noise, sewage disposal (municipal wastewater, crude oil pollution absorption) and is had unique advantage doctor.Melt blown technology technological process is short, and production efficiency is high, the yearly productive capacity of a production line be hundred tons to kiloton rank.Due to high content of technology, market prospects are large, and its development level has become one of important symbol of weighing a national textile industry comprehensive strength.But, the existing melt blown technology part that still comes with some shortcomings: pure melt processing highly energy-consuming, die head and hot air temperature often need to exceed 260 DEG C, and this can cause again depolymerization problem; Pure melt viscosity is large, extrudes difficulty; Master batch fluidity of molten is had relatively high expectations, need by the melt-blown PP Pipe Compound of high fusion index, use melt index to exceed the polypropylene agglomerate of 800g/10min as required, it need be by degrading conventional polypropylene or produce and obtain with metallocene catalysis, and the conventional polypropylene agglomerate of cost ratio is expensive more than 50%.

Existing melt spraying non-woven fabrics product still cannot meet high accuracy and high-performance is filtered requirement, as dustproof in anti-haze mouth mask, automobile/tank engine etc., if will further improve its product result of use or performance, need to increase its specific area, this can be by being reduced to fibre diameter nanoscale and introducing two kinds of approach of loose structure and realize.It is the spinneret orifice of 63.5 μ m that Nonwoven Technologies company adopts diameter, prepared the polypropylene fibre that fibre diameter is approximately 500nm, but the method yields poorly, spinnerets price is extremely expensive simultaneously, also very easily ftracture and plug, production cost is too high.At present domestic melt-blowing equipment and pp material all cannot meet the working condition of nanofiber.The introducing of loose structure can be by adding inconsistent inorganic nano-particle or polymer in meltblown polymer master batch, then carry out selective removal pore-forming by the method for dissolution with solvents or calcining, but the method can cause fibre machinery performance greatly to decline and have the incomplete problem of dissolving.

Thermic phase detachment technique (thermally induced phase separation is called for short TIPS) is a kind of polymer forming hole method of development in recent years maturation.In 1980, first proposition such as Castro TIPS prepared the method for microporous barrier, and applies for US Patent No. Patent424798.TIPS general principle is as follows: for many nonpolar or low pole thermoplasticity crystallization high polymers, immiscible with some high boiling little molecule liquid (diluent) at normal temperatures, but (the general fusing point higher than crystallization high polymer) can form homogeneous phase solution at rising temperature, reduce after temperature because solvability declines and polymer crystallization factor is brought out generation liquid-liquid (L-L) or solid-liquid (S-L) is separated, then remove diluent with extractant, mixture Central Plains diluent takes up space and becomes hole, finally forms coherent microcellular structure.TIPS method only has heat exchanging process, and does not relate to complicated material exchange process, therefore has the advantages such as simple to operate, influence factor is few, simultaneously membrane porosity high, be difficult for forming defect, good mechanical property, pore size, distribution, porosity are controlled.

Summary of the invention

The object of the invention is to overcome the weak point in above-mentioned background technology, provide a kind of the thermic pore-forming technology that is separated is combined with melt blown technology, realize the method that porous fibre nonwoven fabric is prepared on a large scale; To promote existing non-woven cloth products performance, make it meet high accuracy and high-performance filtration requirement.

The technical solution adopted in the present invention is: a kind of porous fibre nonwoven fabric preparation method, carries out successively according to the following steps:

(1), by even to polymer and mixing diluents, obtain polymer quality percent concentration and be 10～60% blend;

(2) adopt screw extruder pelletizer that the blend in step 1 is melt extruded, and in air direct cooling granulation;

(3) master batch in step 2 is produced and obtained nascent nonwoven fabric with melt-blowing equipment;

(4) diluent in the nascent nonwoven fabric of step 3 is removed in extraction, makes the fiber pore-forming in this nonwoven fabric, after being dried, obtains porous fibre nonwoven fabric;

(5) diluent and extractant mixed waste liquor are reclaimed, reuse.

Polymer used in the present invention requires fibre-forming performance more excellent, and has and the characteristic of diluent high-temperature digestion, low temperature phase-splitting.Because diluent range of choice is very extensive, therefore the polymer that is suitable for porous fibre nonwoven fabric preparation method of the present invention is also very many, for polypropylene, Kynoar, polyethylene, polyester, polystyrene, polyurethane, polyamide, polytrifluorochloroethylene, ethylene-acrylic acid copolymer, polyphenylene sulfide, polyformaldehyde, poly-(4-methyl-1-pentene), polyether-ether-ketone, polyether sulfone, polyacrylonitrile, polysulfones, polyimides, polymethyl methacrylate, ethylene-vinyl alcohol copolymer, polyvinyl butyral, PLA, cellulose acetate, polyvinyl chloride, at least one in vinylidene fluoride-hexafluoropropylene copolymer.In the present invention, the mass percent concentration of polymer in mixture is 10～60%: excessive concentration, there is gelation phase process, and cannot pore-forming; Concentration is too low, and fibrous fracture in spray silk process, cannot form fiber and pile up nonwoven fabric construct, and be that pearl fiber or granule are piled up form.

Diluent used in the present invention is that boiling point is at 150 DEG C of above liquid or solids that also can not dissolve at normal temperatures described polymer, be specially polyethylene glycol (200, 400 and 600), higher alcohols, polyalcohols, phthalate, monoglyceride class, benzoates, phosphoric acid ester, organic carbonate class, citric acid ester type, high-grade fatty ester class, butyrolactone, benzophenone, polymine, benzophenone, aromatic hydrocarbon, mineral oil, atoleine, tetramethyl sulfone, maleic anhydride, solid paraffin, crude vegetal, higher alkane, higher fatty acids, high fatty amine, calcium stearate, isopropylamine alcohol, dimethyl sulfone, diphenyl sulphone (DPS), diphenyl ether, one in benzaldehyde, or the mixing of two or more arbitrary proportions.

The mixing of polymer and diluent is used conventional mixed method, comprise and use mixer as Henschel blender, V-Mixer, ribbon mixer, stirring-type mixer, high-speed mixer etc., polymer/diluent tentatively can be mixed, be beneficial to lower step granulation.

Screw extruder pelletizer draw ratio 20～60, compression ratio 3～6, screw speed 200～600rpm; 170～250 DEG C of extrusion temperatures, extruded velocity 50～300kg/h, direct cooling granulation in air; select technological parameter, the melt-blown master batch that obtains mixing according to actual conditions.

Melt-blowing equipment used in the present invention is conventional overall complete production unit, spinning technology parameter is slit shower nozzle, spinning nozzle diameter 0.2～0.85mm, 30 °～60 ° of air drain angles, slit width 0.35～0.65mm, 150～230 DEG C of die temperature, 180～260 DEG C of hot air temperatures, gas pressure 0.05～0.5Mpa, receiving range 8～30cm, spinning speed 25～150kg/h, selects technological parameter according to actual conditions, obtains diluent mass percent concentration and be 40%～90% nascent nonwoven fabric.

Thereby remove pore-forming on the fiber of the diluent of coming into being in nonwoven fabric in this nonwoven fabric with extractant, extraction process adopts conventional impregnation technology to realize, also can for example, according to related documents (Chinese patent 01144479.7; Chinese patent 200410020242.3, Chinese patent 200510086337.X, Chinese patent 200610113814.1) described method realization.Extracted after dry (conventional heating drying process), obtained porous fibre nonwoven fabric, perforated nonwoven fabrics fabric width is 0.6～3.2m, and grammes per square metre scope is 10～75g/m², average fibre diameter is 500nm～15 μ m, and nonwoven fabric porosity is 50%～80%, and single fiber porosity is 40%～90%, and the distribution of sizes scope of fiber mesopore is 100nm～1.2 μ m.

Extractant used in the present invention is can dissolved dilution agent and liquid that can not dissolve polymer, be specially the one in water, ethanol, acetone, isopropyl alcohol, ethylene glycol, glycerine, n-hexane, gasoline, carrene, chloroform, butanone, ethyl acetate, butanols, methyl alcohol, benzinum, or the mixing of two or more arbitrary proportions.Because extractant boiling point is lower than diluent, thereby can utilize both boiling points to differ larger characteristic, diluent and extractant mixed waste liquor be adopted to conventional distillation or the recycling use respectively of decompression distillation mode, to reduce costs.

The waste gas producing for production process, the present invention absorbs by spray column or the processing of waste gas absorption-combustion system, realizes safety, green production.

The porous fibre nonwoven fabric preparation method who the present invention relates to, also may be used on going in other spinning technique: as first the spinning of polymer/diluent master batch melt extrusion prepared to porous fibre, then be prepared into porous fibre nonwoven fabric by means such as spunbond, acupunctures; Utilize high temperature electrostatic spining technology, can in laboratory scope, prepare a small amount of porous fibre nonwoven fabric sample.

The porous fibre nonwoven fabric preparation method who the present invention relates to, also the shower nozzle in melt-blowing equipment can be changed into internal diameter is 0.1～0.4mm, external diameter is the coaxial shower nozzle of 0.24～0.80mm, shower nozzle inside is logical high velocity, hot air also, rotating speed is that the high speed rotary-drum of 1000～2500rpm is as gathering-device, just can prepare internal diameter is 300nm～8 μ m, and external diameter is the ultra-fine hollow-fibre membrane of 500nm～15 μ m.Compare with the hollow-fibre membrane of existing diameter more than 100 μ m, can greatly improve wastewater treatment efficiency.

The invention has the beneficial effects as follows:

1) diluent is also the plasticizer in polymer processing, adding of Macrodilution agent can make polymer malt viscosity greatly reduce, be beneficial to and extrude and reduce meltblown fibers diameter, also can greatly reduce die head and the hot air temperature in production process, energy consumption is little and slow down depolymerization; In addition the method only need be used conventional polymer master batch, instead of melt-blown special master batch, can reduce raw material use cost.

2) in porous fibre nonwoven fabric, single fiber porosity is the highest can be 90%, and nonwoven fabric grammes per square metre is only original 10%, can greatly reduce consumption of raw materials amount.

3) introducing of loose structure, has increased nonwoven fabric specific area, thereby greatly promotes its application performance in water treatment, field of air filtration.

Brief description of the drawings

A in Fig. 1 figure and b figure are respectively the scanning electron microscope (SEM) photographs of the surperficial and section of polypropylene porous fibre prepared in embodiment 1.

A in Fig. 2 figure and b figure are respectively the scanning electron microscope (SEM) photographs of the surperficial and section of polypropylene porous fibre prepared in embodiment 2.

A in Fig. 3 figure and b figure are respectively the scanning electron microscope (SEM) photographs of the surperficial and section of polypropylene porous fibre prepared in embodiment 3.

A in Fig. 4 figure and b figure are respectively the scanning electron microscope (SEM) photographs of the surperficial and section of Kynoar porous fibre prepared in embodiment 4.

Fig. 5 is the scanning electron microscope (SEM) photograph of polypropylene superfine doughnut section prepared in embodiment 5.

Detailed description of the invention

The present invention will cause the pore-forming technology that is separated and combine with melt blown technology and prepare porous fibre nonwoven fabric, the polymer, diluent and the solvent selection that are suitable for the method are all quite extensive, the permutation and combination of different polymer/diluent/extractants can obtain very many process conditions, but general principle is constant, can obtain the porous fibre nonwoven fabric of different type of polymer, fabric width and grammes per square metre, fibre diameter, fiber porosity, fiber pore-size distribution.The whole technological process of production comprises that mixing-extruding pelletization-melt-blown-extraction-dry-diluent/extractant reclaims, and below in conjunction with Figure of description, the invention will be further described, but the present invention is not limited to following examples.

Embodiment 1 polypropylene/atoleine solid-liquid phase separation system

Polymer raw material is that Qilu Petrochemical is produced polypropylene T30S, and diluent is atoleine, and extractant is n-hexane.Polypropylene mass percent concentration is 30%, first uses at normal temperatures high-speed mixer blend even polypropylene and atoleine.Then use screw extruder granulation, screw extruder pelletizer draw ratio 42, compression ratio 3, screw speed 400rpm, 180 DEG C of extrusion temperatures, extruded velocity 150kg/h, the cooling melt-blown master batch of polypropylene/atoleine that obtains in air.Master batch is carried out to melt-blown production, technological parameter is slit shower nozzle, spinning nozzle diameter 0.42mm, 30 ° of air drain angles, slit width 0.62mm, 185 DEG C of die temperature, 200 DEG C of hot air temperatures, gas pressure 0.1Mpa, receiving range 15cm, spinning speed 100kg/h, nascent nonwoven fabric grammes per square metre is 100g/m², fabric width is 1.6m, nonwoven fabric gathering speed is 10.4m/min.Nascent nonwoven fabric, by conventional impregnating production-line equipment, uses n-hexane continuous impregnating extraction liquids paraffin, the dry polypropylene porous fibre nonwoven fabric that obtains.Porous fibre nonwoven fabric is quenched under liquid nitrogen disconnected, observed respectively fiber surface and cross-section morphology with ESEM, as shown in Figure 1.Porous fibre nonwoven fabric grammes per square metre is 30g/m², average fibre diameter is 10 μ m, and nonwoven fabric porosity is 60%, and single fiber porosity is 70%, and the distribution of sizes scope of fiber mesopore is 300nm～1.2 μ m.Only there is solid-liquid (S-L) and be separated in this system, S-L phase separation temperature is 120 DEG C, and therefore fiber surface forms dense layer surface structure, and fiber section is cell shape pore structure.N-hexane and atoleine mixed waste liquor are 80 DEG C of air-distillations, and n-hexane steam is collected in condensation, and atoleine is stayed bottom, recycle and reuse respectively.

Embodiment 2 polypropylene/n-butyl phthalate/phthalic acid n-octyl liquid-liquid phase separation system

Polymer raw material is that Yanshan Petrochemical is produced polypropylene S1003, and diluent is phthalic acid n-octyl and n-butyl phthalate mixture, and extractant is isopropyl alcohol.Polypropylene mass percent concentration is 20%, and phthalic acid n-octyl mass percent concentration is 64%, and n-butyl phthalate mass percent concentration is 16%.First use at normal temperatures high-speed mixer blend even polypropylene, phthalic acid n-octyl and n-butyl phthalate.Then use screw extruder granulation, screw extruder pelletizer draw ratio 20, compression ratio 4; screw speed 600rpm; 200 DEG C of extrusion temperatures, extruded velocity 300kg/h, the cooling melt-blown master batch of polypropylene/phthalic acid n-octyl/n-butyl phthalate that obtains in air.Master batch is carried out to melt-blown production, technological parameter is slit shower nozzle, spinning nozzle diameter 0.60mm, 40 ° of air drain angles, slit width 0.65mm, 200 DEG C of die temperature, 220 DEG C of hot air temperatures, gas pressure 0.25Mpa, receiving range 20cm, spinning speed 200kg/h, nascent nonwoven fabric grammes per square metre is 200g/m², fabric width is 3.2m, nonwoven fabric gathering speed is 5.2m/min.Nascent nonwoven fabric, by conventional impregnating production-line equipment, uses isopropyl alcohol continuous impregnating extraction phthalic acid n-octyl and n-butyl phthalate, the dry polypropylene porous fibre nonwoven fabric that obtains.Porous fibre nonwoven fabric is quenched under liquid nitrogen disconnected, observed respectively fiber surface and cross-section morphology with ESEM, as shown in Figure 2.Porous fibre nonwoven fabric grammes per square metre is 40g/m², average fibre diameter is 8 μ m, and nonwoven fabric porosity is 75%, and single fiber porosity is 80%, and the distribution of sizes scope of fiber mesopore is 300nm～850nm.This system generation liquid-liquid (L-L) is separated, but L-L phase separation temperature (127 DEG C) and S-L phase separation temperature (113 DEG C) are approaching, and therefore fiber surface forms round hole, and fiber section is co-continuous pore structure.Isopropyl alcohol, phthalic acid n-octyl and n-butyl phthalate mixed waste liquor are 120 DEG C of air-distillations, and IPA vapor is collected in condensation, and phthalic acid n-octyl and n-butyl phthalate are stayed bottom, recycle and reuse respectively.

Embodiment 3 polypropylene/diphenyl ether liquid-liquid phase separation system

Identical with embodiment 1 basic technology parameter, diluent is selected diphenyl ether, and as shown in Figure 3, the distribution of sizes scope of fiber mesopore is 300nm～650nm for fiber surface and cross-section morphology.Only there is liquid-liquid (L-L) and be separated in this system, L-L phase separation temperature is 135 DEG C, and therefore fiber surface forms oval aperture, and fiber section is co-continuous pore structure.

Embodiment 4 Kynoar/n-butyl phthalate solid-liquid phase separation system

Polymer raw material is that Su Wei produces Kynoar 6010, and diluent is n-butyl phthalate, and extractant is ethanol.Kynoar mass percent concentration is 25%, first uses at normal temperatures high-speed mixer blend even Kynoar and n-butyl phthalate, then granulation; Screw extruder pelletizer draw ratio 35, compression ratio 3.5, screw speed 300rpm, 220 DEG C of extrusion temperatures, extruded velocity 80kg/h, the cooling melt-blown master batch of Kynoar/n-butyl phthalate that obtains in air.Master batch is carried out to melt-blown production, technological parameter is slit shower nozzle, spinning nozzle diameter 0.55mm, 35 ° of air drain angles, slit width 0.48mm, 220 DEG C of die temperature, 240 DEG C of hot air temperatures, gas pressure 0.35Mpa, receiving range 30cm, spinning speed 60kg/h, nascent nonwoven fabric grammes per square metre is 80g/m², fabric width is 1.6m, nonwoven fabric gathering speed is 7.8m/min.The nascent nonwoven fabric of collecting floods 2h, 1h and 30min successively in 3 ethanol grooves, for extraction (extraction of batch (-type) dipping) n-butyl phthalate, the dry Kynoar porous fibre nonwoven fabric that obtains.Porous fibre nonwoven fabric is quenched under liquid nitrogen disconnected, observed respectively fiber surface and cross-section morphology with ESEM, as shown in Figure 4.Porous fibre nonwoven fabric grammes per square metre is 20g/m², average fibre diameter is 12 μ m, and nonwoven fabric porosity is 80%, and single fiber porosity is 75%, and the distribution of sizes scope of fiber mesopore is 300nm～550nm.Only there is solid-liquid (S-L) and be separated in this system, S-L phase separation temperature is 138 DEG C, and Kynoar forms spherocrystal packed structures, and therefore fiber surface is borehole structure, and fiber section is the alveolate texture that spherocrystal is piled up.Ethanol and n-butyl phthalate mixed waste liquor are 100 DEG C of air-distillations, and alcohol vapour is collected in condensation, and n-butyl phthalate is stayed bottom, recycle and reuse respectively.

Embodiment 5 polypropylene/atoleine solid-liquid phase separation system

Basic technology parameter and embodiment 1 are same, and melt-blowing equipment is used coaxial shower nozzle instead, and spinning nozzle internal diameter is 0.25mm, and external diameter is 0.42mm, and the high speed rotary-drum that is 1600rpm with rotating speed is as gathering-device.Under liquid nitrogen, quench disconnected, with scanning electron microscopic observation hollow-fibre membrane cross-section morphology, as shown in Figure 5, preparing internal diameter is 7.5 μ m, and external diameter is the ultra-fine hollow-fibre membrane of 10 μ m, and all the other character and embodiment 1 are same.

Above-described embodiment is only explanation technical conceive of the present invention and feature, its objective is to allow to be familiar with these those skilled in the art and can to understand content of the present invention enforcement according to this, can not limit the scope of the invention with this.Any those skilled in the art are not departing within the scope of technical solution of the present invention; when can utilizing the technology contents of above-mentioned announcement to make a little change or being modified to the equivalent embodiment of equivalent variations; in every case be the content that does not depart from technical solution of the present invention; any simple modification, equivalent variations and the modification above embodiment done according to technical spirit of the present invention, within all should being encompassed in protection scope of the present invention.

Claims (9)

1. a porous fibre nonwoven fabric preparation method, carries out successively according to the following steps:

(1), by even to polymer and mixing diluents, obtain polymer quality percent concentration and be 10～60% blend;

(2) adopt screw extruder pelletizer that the blend in step 1 is melt extruded, and in air direct cooling granulation;

(3) master batch in step 2 is produced and obtained nascent nonwoven fabric with melt-blowing equipment;

(4) diluent in the nascent nonwoven fabric of step 3 is removed in extraction, makes the fiber pore-forming in this nonwoven fabric, after being dried, obtains porous fibre nonwoven fabric;

(5) diluent and extractant mixed waste liquor are reclaimed, reuse.

2. the preparation method of porous fibre nonwoven fabric according to claim 1, it is characterized in that: described polymer is polypropylene, Kynoar, polyethylene, polyester, polystyrene, polyurethane, polyamide, polytrifluorochloroethylene, ethylene-acrylic acid copolymer, polyphenylene sulfide, polyformaldehyde, poly-(4-methyl-1-pentene), polyether-ether-ketone, polyether sulfone, polyacrylonitrile, polysulfones, polyimides, polymethyl methacrylate, ethylene-vinyl alcohol copolymer, polyvinyl butyral, PLA, cellulose acetate, polyvinyl chloride, at least one in vinylidene fluoride-hexafluoropropylene copolymer.

3. the preparation method of porous fibre nonwoven fabric according to claim 1, it is characterized in that: described diluent is polyethylene glycol, higher alcohols, polyalcohols, phthalate, monoglyceride class, benzoates, phosphoric acid ester, organic carbonate class, citric acid ester type, high-grade fatty ester class, butyrolactone, benzophenone, polymine, benzophenone, aromatic hydrocarbon, mineral oil, atoleine, tetramethyl sulfone, maleic anhydride, solid paraffin, crude vegetal, higher alkane, higher fatty acids, high fatty amine, calcium stearate, isopropylamine alcohol, dimethyl sulfone, diphenyl sulphone (DPS), diphenyl ether, one in benzaldehyde, or the mixing of two or more arbitrary proportions.

4. the preparation method of porous fibre nonwoven fabric according to claim 1, it is characterized in that: the extractant that the extraction in described step (4) adopts is the one in water, ethanol, acetone, isopropyl alcohol, ethylene glycol, glycerine, n-hexane, gasoline, carrene, chloroform, butanone, ethyl acetate, butanols, methyl alcohol, benzinum, or the mixing of two or more arbitrary proportions.

5. according to the preparation method of the porous fibre nonwoven fabric described in claim 2 or 3 or 4, it is characterized in that: the mixer that the mixing in step (1) is used is at least one in Henschel blender, V-Mixer, ribbon mixer, stirring-type mixer, high-speed mixer.

6. the preparation method of porous fibre nonwoven fabric according to claim 5; it is characterized in that the draw ratio 20～60 of described screw extruder pelletizer, compression ratio 3～6, screw speed 200～600rpm; 170～250 DEG C of extrusion temperatures, extruded velocity 50～300kg/h.

7. the preparation method of porous fibre nonwoven fabric according to claim 6, it is characterized in that melt-blowing equipment adopts slit shower nozzle, its spinning nozzle diameter 0.2～0.85mm, 30 °～60 ° of air drain angles, slit width 0.35～0.65mm, 150～230 DEG C of die temperature, 180～260 DEG C of hot air temperatures, gas pressure 0.05～0.5Mpa, receiving range 8～30cm, spinning speed 25～150kg/h.

8. the preparation method of porous fibre nonwoven fabric according to claim 7, is characterized in that the recovery of diluent and extractant mixed waste liquor, adopts conventional distillation or decompression distillation mode.

9. the preparation method of porous fibre nonwoven fabric according to claim 8, is characterized in that it is 0.1～0.4mm that melt-blowing equipment adopts internal diameter, the coaxial shower nozzle that external diameter is 0.24～0.80mm, and shower nozzle inside is logical high velocity, hot air also; Rotating speed be the high speed rotary-drum of 1000～2500rpm as gathering-device, to prepare internal diameter as 300nm～8 μ m, external diameter is the ultra-fine hollow-fibre membrane of 500nm～15 μ m.