CN116371084A - A kind of degradable spun-bonded filter material and preparation method thereof - Google Patents

Abstract

The invention relates to a degradable spunbonded filter material and a preparation method thereof, belonging to the technical field of nonwovens. The degradable spun-bonded filter material of the present invention comprises three layers of fiber nets with different fiber diameters; the fibers in the fiber nets are sheath-core composite fibers. The present invention obtains modified polybutylene adipate terephthalate and modified carbon dioxide-based polyurethane through twin-screw granulation technology, and then mixes them with conventional PBAT particles and carbon dioxide-based polyurethane particles respectively, and undergoes a two-component spun-bonding process. , to obtain a three-layer fiber web. The three-layer fiber net is arranged in sequence from top to bottom, thermally bonded and reinforced, and then subjected to corona electret treatment to obtain a degradable spun-bonded filter material. The degradable spun-bonded filter material of the present invention not only has better filtering and antibacterial properties, but also uses degradable materials to avoid environmental pollution caused by non-degradable substances and protect the environment to a certain extent.

Description

A kind of degradable spun-bonded filter material and preparation method thereof

technical field

The invention belongs to the field of non-woven technology, and in particular relates to a degradable spun-bonded filter material and a preparation method thereof.

Background technique

Existing common filter materials and their preparation methods:

The prior art discloses a method of combining electrospinning and melt-blown spinning to prepare a composite non-woven fabric layer with gradient fiber diameters, and at the same time add antistatic agents and antibacterial agents to the melt-blown materials, and The antimicrobial agent is added to the spinning liquid, and its application process is electrospinning and melt blown spinning process, but the filtration resistance of the composite nonwoven fabric prepared by this method is relatively high. In addition, after laminating the multi-layer fiber webs, the multi-layer spunmelt electret filter material is made into sequentially through acupuncture reinforcement treatment, baking treatment, and corona electret treatment. However, the fiber of the filter material is a single-component fiber, and the materials used are all non-degradable materials, and excessive use is not conducive to environmental protection.

Contents of the invention

In order to solve the above technical problems, the present invention provides a degradable spunbonded filter material and a preparation method thereof. The filter material of the invention comprises three layers of fiber nets with different fiber diameters; the fibers in the fiber nets are sheath-core composite fibers. Modified PBAT and modified carbon dioxide-based polyurethane were obtained through twin-screw granulation technology, and then mixed with conventional PBAT particles and carbon dioxide-based polyurethane particles respectively, and a three-layer fiber web was obtained through a two-component spun-bonding process. Three layers of fiber webs with different fiber diameters are arranged sequentially from top to bottom, thermally bonded and reinforced, and then subjected to corona electret treatment to obtain a degradable spunbond filter material. The filter material of the present invention not only has better filtering and antibacterial properties, but also uses degradable materials to avoid environmental pollution caused by non-degradable substances and protect the environment to a certain extent.

The present invention is achieved through the following technical solutions:

The first object of the present invention is to provide a degradable spunbond filter material, which comprises an upper fiber web, a middle fiber web and a lower fiber web from top to bottom; The diameter is 16 μm to 19 μm; the diameter of the fiber in the middle fiber web is 12 μm to 15 μm; the diameter of the fiber in the lower fiber web is 9 μm to 11 μm.

In one embodiment of the present invention, the weights of the upper, middle and lower layers of fiber webs are respectively 25g/m ² to 35g/m ² , 30g/m ² to 40g/m ² , 40g/m ² to 60g/m ² .

In one embodiment of the present invention, the fiber is a sheath-core composite fiber; the skin layer of the fiber is a mixture of modified carbon dioxide-based polyurethane and carbon dioxide-based polyurethane; the core layer of the fiber is modified polyadipic acid A mixture of butylene terephthalate and polybutylene adipate terephthalate.

In one embodiment of the present invention, the modified carbon dioxide-based polyurethane is prepared by the following method:

The antibacterial particles are mixed with carbon dioxide-based polyurethane, heated and melted by a twin-screw extruder, and cooled and dried to obtain the modified carbon dioxide-based polyurethane; the antibacterial particles are selected from nanometer zinc oxide.

In one embodiment of the present invention, the mass ratio of the antibacterial particles to carbon dioxide-based polyurethane is 3-4:15-16.

In one embodiment of the present invention, described modified polybutylene adipate terephthalate is prepared by the following method:

Mix the energy-enhancing additive with polybutylene adipate terephthalate, measure, heat and melt with a twin-screw extruder, and obtain the modified polybutylene adipate terephthalate after cooling and drying The energizer is a mixture of calcium stearate, magnesium stearate and silicon nitride; the mass percentages of the calcium stearate, magnesium stearate and silicon nitride are respectively 40% to 50%, 30% to 40% and 10% to 30%.

In one embodiment of the present invention, the mass ratio of the energizer to polybutylene adipate terephthalate is 2-3:7-8.

Second object of the present invention is to provide a kind of preparation method of degradable spun-bonded filter material, comprising the following steps:

(1) Mix modified carbon dioxide-based polyurethane with carbon dioxide-based polyurethane, heat and melt through a screw extruder, cool, dry, and cut off to obtain a skin layer material; modify polybutylene adipate terephthalate and polyhexamethylene Butylene glycol terephthalate is mixed, heated and melted by a screw extruder, cooled, dried, and cut to obtain a core layer material;

(2) Extrude the cortex material and core layer material obtained in the step (1) through the spinneret holes in the spinning assembly, cool and adjust the initial velocity of the airflow during drafting by side blowing, and then form different diameters after the filaments are separated. The fibers are respectively laid on the porous conveyor belt to obtain the upper fiber web, the middle layer fiber web and the lower layer fiber web;

(3) Arrange the upper layer fiber web, the middle layer fiber web and the lower layer fiber web obtained in step (2) from top to bottom, reinforce by thermal bonding, consolidate into a cloth, and perform corona electret to obtain the degradable spunbond filter material.

In one embodiment of the present invention, in step (2), the skin layer material is added to the hopper 1, heated and melted by the screw extruder 1, the filter 1 filters impurities, and the metering pump 1 is metered; the core layer material is added to the hopper 2, After being heated and melted by the screw extruder 2, filtered by the filter 2, and metered by the metering pump 2, the two reach the spinning assembly to form a thin stream of melt with a skin-core composite structure, and then cooled by side blowing cold air to adjust the initial flow After speed stretching to form continuous filaments, fibers with different diameters are obtained, which are randomly laid on the porous conveyor belt to form an upper fiber web, a middle fiber web and a lower fiber web.

In one embodiment of the present invention, in step (2), the spinning speed of the spinning assembly is above 2400/min, and the fineness of single filament is below 1.6 dtex.

In one embodiment of the present invention, in step (2), the side blowing device is a new type of side blowing device with symmetrical left and right ends. The left and right ends of the novel side blowing device are symmetrical, and each end includes a side blowing box, and a space for cooling fibers is formed between the two side blowing boxes. Among them, the side blowing box is equipped with multi-layer perforated plates and L-shaped deflectors for air distribution and flow diversion, and the hole pattern of each layer of perforated plates is honeycomb-shaped design for air distribution and rectification.

In one embodiment of the present invention, in step (2), fibers with a diameter of 16 μm to 19 μm are prepared when the initial velocity of the airflow is 70 m/s to 80 m/s; the initial velocity of the airflow is 90 m/s to 80 m/s. Fibers with a diameter of 12 μm to 15 μm are prepared at 105 m/s; fibers with a diameter of 9 μm to 11 μm are prepared when the initial air velocity is 110 m/s to 120 m/s.

In one embodiment of the present invention, in step (2), the said splitting device is an electrostatic splitter as the splitting device; wherein, the electrostatic voltage is 26kV, the current is 1mA, and the distance between the discharge needle plate and the ground roller is 50mm.

In one embodiment of the present invention, in step (2), the drafting uses an integral wide slit drafter as the stretching device, and the slit width is 7mm.

In one embodiment of the present invention, in step (3), the temperature of the thermally bonded and reinforced hot roll is 170°C-180°C.

In one embodiment of the present invention, the discharge tip of the corona electret is made of tungsten; the density of the tip is 900 pieces/m ² -1000 pieces/m ² .

In one embodiment of the present invention, in step (3), the conditions of the corona electret: the electret DC voltage is 7kv-18kv, the electret time is 50s-90s, the electret distance is 15cm-20cm, the electret Extreme temperature is 25℃～35℃.

In one embodiment of the present invention, in step (3), the upper, middle and lower three-layer fiber webs with different fiber diameters are arranged sequentially from top to bottom, and hot rollers are used for thermal bonding and reinforcement. Fabrication, winding and molding, and finally corona electret through guide rollers, high-voltage power supply discharge needle-point electrodes, grounded metal rollers, etc., to obtain the degradable spunbonded filter material.

In one embodiment of the present invention, in step (3), the temperature of the thermally bonded hot roll is 170°C-180°C.

In one embodiment of the present invention, the content of antibacterial particles added to the skin layer of the fiber is 3%-8%. The carbon dioxide-based polyurethane of the skin layer component and the antibacterial particle nano-zinc oxide can produce a synergistic effect. Carbon dioxide-based polyurethane with strong water absorption can promote nano-zinc oxide to generate more hydroxyl radicals, and highly chemically active hydroxyl radicals can react with organic matter and kill most viruses and bacteria. The synergistic effect of the two substances in the cortex component greatly enhances the antibacterial function of the filter material.

In one embodiment of the present invention, the content of the energizing additive added to the core layer of the fiber is 5%-10%. The ratio of calcium stearate, magnesium stearate and silicon nitride in the energizer is 5:3:2. The addition of a special ratio of energy-enhancing additives changes the size of the polymer crystal particle size, forming countless small particle sizes, increasing the total surface area of the particle size, and making the charge gather on the surface of countless small particle sizes , thereby increasing the charge storage space and significantly improving the filtration efficiency of the spunbond filter material.

In one embodiment of the present invention, the mass ratio of the energizing agent to the PBAT energizing masterbatch is 20% to 30%; the mass ratio of the PBAT energizing masterbatch to the core layer raw material is 5% to 10% %.

In one embodiment of the present invention, the mass ratio of the antibacterial particles to the modified carbon dioxide-based polyurethane masterbatch is 15% to 20%; the mass ratio of the modified carbon dioxide-based polyurethane masterbatch to the cortex raw material is 3% to 3%. 8%.

The technical solution of the present invention has the following advantages:

(1) The degradable spunbonded filter material of the present invention is provided with three layers of fiber webs with different fiber diameters in the upper, middle and lower layers to gradually filter particulate matter, greatly enhancing the filtering function of the filter material.

(2) A kind of degradable spunbond filter material of the present invention adopts two-component spunbond technology, and its fiber is sheath-core type composite fiber, and the carbon dioxide base polyurethane of cortex fiber, the PBAT of core layer fiber all can Degradable material, that is, the filter material is a degradable filter material, which avoids non-degradable substances from polluting the environment and protects the environment to a certain extent.

(3) The fibers of the degradable spunbonded filter material of the present invention are sheath-core composite fibers. Among them, the cortex components include carbon dioxide-based polyurethane and antibacterial particle nano-zinc oxide. Carbon dioxide-based polyurethane with strong water absorption can promote nano-zinc oxide to generate more hydroxyl radicals, and highly chemically active hydroxyl radicals can interact with The organic matter reacts, killing most viruses and bacteria. The synergistic effect of the two substances in the cortex component greatly enhances the antibacterial function of the filter material. Among them, the core layer component is added with a mixture of calcium stearate, magnesium stearate, and silicon nitride as the main component of the energy-enhancing additive, and the addition of the special proportion of the energy-enhancing additive changes the particle size of the polymer crystal. Size, forming countless small particle sizes, increasing the total surface area of the particle size, making the charge gather on the surface of countless small particle sizes, thereby increasing the storage space of the charge, and significantly improving the performance of the spunbond filter material. Filtration efficiency and stability. At the same time, the high-density electrostatic charge stored in the material can stimulate the protein denaturation of the bacteria and further play an antibacterial effect. Therefore, the energizing agent and the antibacterial particle nano-zinc oxide can also produce a synergistic effect, which greatly improves the antibacterial efficiency of the filter material.

(4) At the end of the preparation of the filter material, corona electret is carried out through guide rollers, high-voltage power supply discharge needle-tip electrodes, grounded metal rollers, etc., through the set ultra-high voltage, super-large distance and special tungsten discharge needle tip , greatly improving the filtration efficiency of the filter material. At the same time, it has a synergistic effect with antibacterial particle nano zinc oxide to further enhance the antibacterial function.

(5) The present invention provides a degradable spunbond filter material, the principle diagram of which is shown in Figure 1. The filter material of the present invention combines twin-screw granulation technology, skin-core two-component spunbond process, thermal Adhesive reinforcement technology and corona electret technology. PBAT energized masterbatch and modified carbon dioxide-based polyurethane masterbatch were obtained by twin-screw granulation technology, and upper, middle and lower three-layer fiber webs with different fiber diameters were obtained by skin-core two-component spunbond technology. The fiber webs are arranged in order from top to bottom. After thermal bonding and reinforcement with hot rolls, corona electret is carried out. The four processes are indispensable, and the degradable spunbond filter material can be obtained only after they are combined together.

(6) In the preparation process of the filter material, a new type of side blowing device with symmetrical left and right ends is adopted to make the cold air flow uniform and the temperature consistent, which greatly reduces the phenomenon of broken filaments and parallel filaments, and improves the uniformity and stability of spinning It is conducive to the production of higher quality and higher quality spunbond filter materials. In addition, the electrostatic separator is used as the separating device to significantly improve the uniformity of the spunbonded filter material; the integral wide slit drafter is used as the stretching device to significantly improve the length, linear density, and Physical and mechanical properties such as strength and elongation.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be described in further detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

Fig. 1 is the preparation schematic diagram of a kind of degradable spunbonded filter material among the present invention;

Fig. 2 is the structural representation of the three-layer fiber net in the embodiment of the present invention;

Fig. 3 is a schematic cross-sectional view of a sheath-core bicomponent fiber in an embodiment of the present invention;

Among them: 1, upper fiber web; 2, middle fiber web; 3, lower fiber web; 4, fiber core layer; 5, fiber cortex;

Fig. 4 is the equipment process flowchart in the embodiment of the present invention;

Fig. 5 is a cross-sectional view of the spinning assembly of the sheath-core type two-component spunbond equipment in an embodiment of the present invention;

Among them: 6, hopper; 7, screw extruder; 8, filter; 9, metering pump; 10, spinning assembly; 11, new side blowing device; 12, integral wide slit drafter; 13, heat Adhesive reinforcement; 14, winding device; 15, corona electret device; 16, high-voltage power supply; 17, discharge needle-point electrode; 18, grounded metal roller.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention.

In the following examples and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials and reagents used can be obtained from commercial sources unless otherwise specified.

The PBAT granules of the present invention were purchased from Ningbo Baifude Environmental Protection Technology Co., Ltd. Specifications: density: 1.15g/cm ³ -1.28g/cm ³ , melting point: 115°C-130°C, transparency: 30%-60%; stearic acid Calcium particles were purchased from Jiangshan Yitian Technology Co., Ltd. Specifications: melting point: 150°C-160°C, calcium content: 6.4-7.4%; magnesium stearate powder was purchased from Tuoyi New Materials (Guangzhou) Co., Ltd. Specifications: melting point : 108℃～115℃, density: 1.02g/cm ³ ～1.13g/cm ³ ; silicon nitride powder was purchased from Suzhou Sailon Nano New Material Industry Co., Ltd., specifications: average particle size: 20nm, specific surface area: 93m ² /g, density: 3.4g/cm ³ ; carbon dioxide-based polyurethane was purchased from Hangzhou Puli Material Technology Co., Ltd., specifications: the content of carbon dioxide-based polyurethane is 99.1%; nano-zinc oxide was purchased from Nanjing Baoket New Material Co., Ltd. Specifications: particle size 15nm~20nm, ZnO content: 99%, specific surface area: 55m ² /g.

Example 1

This embodiment provides a method for preparing a degradable spun-bonded filter material with energy-enhancing/antibacterial functions, including the following steps:

Add the energizing agent and PBAT granules to the two hoppers of the twin-screw granulator respectively, blend and melt in the twin-screw extruder at a temperature of 180°C, extrude, cool in a water bath, dry, and cut into granules to obtain PBAT Energizing Masterbatch. Among them, the mass ratio of the energy-enhancing additive to the PBAT energy-enhancing masterbatch is 20%; the energy-enhancing additive is a mixture of calcium stearate, magnesium stearate, and silicon nitride, and the calcium stearate in the energy-enhancing additive , magnesium stearate, and silicon nitride in a mass ratio of 5:3:2.

The antibacterial granules and carbon dioxide-based polyurethane granules were added to the two hoppers of the twin-screw granulator respectively, blended and melted in the twin-screw extruder at a temperature of 200°C, extruded, cooled in a water bath, dried, and cut into granules to obtain Modified carbon dioxide-based polyurethane masterbatch. Wherein, the mass ratio of the antibacterial particles to the modified carbon dioxide-based polyurethane masterbatch is 15%, and the antibacterial particles are nanometer zinc oxide.

The modified carbon dioxide-based polyurethane masterbatch is mixed with conventional carbon dioxide-based polyurethane particles as the raw material of the skin layer, and the mass ratio of the modified carbon dioxide-based polyurethane masterbatch to the raw material of the skin layer is 3%; the PBAT energized masterbatch is mixed with conventional PBAT as the core layer raw material , the mass ratio of PBAT energized masterbatch to the core material is 5%.

The specific equipment process flow chart for preparing degradable spunbond filter materials with energy-enhancing/antibacterial functions is shown in Figure 4; the cross-sectional view of the spinning assembly of the skin-core two-component spunbond equipment is shown in Figure 5; It can be seen from Figure 5 that the raw materials for the skin layer and the core layer are added to the two hoppers of the skin-core type two-component spunbond equipment, heated and melted by the respective screw extruders, filtered by the filter, and metered by the metering pump. Finally, the thin stream of melt that reaches the spinning assembly to form a skin-core composite structure is cooled by side blowing, the initial velocity of the airflow is adjusted during drafting, and the fibers are separated to prepare fibers with a skin-core structure (skin-core bicomponent fibers) The cross-sectional schematic diagram is shown in Figure 2), the fibers of the skin-core structure reach the web curtain, and the upper, middle and lower three-layer fiber webs with different fiber diameters are prepared respectively. When the initial velocity of air-flow is 80m/s when drafting, it is 16 μ m that fiber diameter is prepared, and the grammage is 25g/m ² upper fiber web; 12 μm, grammage is 30g/m ² middle layer fiber net; When the initial velocity of airflow is 120m/s when drafting, the lower layer fiber web with fiber diameter 9μm, grammage is 40g/m ² is prepared. Will make The upper, middle, and lower three-layer fiber webs (the structural diagram of the three-layer fiber web is shown in Figure 2) are arranged sequentially from top to bottom, and are thermally bonded and reinforced by hot rolls at a temperature of 175°C, consolidated into cloth, and wound molding, and finally corona electret in an electrostatic field of 8kV/cm for 55 seconds to obtain a degradable spunbonded filter material with both energy-enhancing and antibacterial functions.

The filtration efficiency and filtration resistance of the degradable spunbond filter material with energy-enhancing/antibacterial functions tested by the TSI8130 filter material comprehensive performance test bench: at a flow rate of 32L/min, the mass median diameter of sodium chloride aerosol is 0.26μm When the filter resistance is 36Pa, the filter efficiency is 81%.

Example 2

This embodiment provides a method for preparing a degradable spun-bonded filter material with energy-enhancing/antibacterial functions, including the following steps:

Add the energizing agent and PBAT granules to the two hoppers of the twin-screw granulator respectively, blend and melt in the twin-screw extruder at a temperature of 180°C, extrude, cool in a water bath, dry, and cut into granules to obtain PBAT Energizing Masterbatch. Among them, the mass ratio of the energy-enhancing additive to the PBAT energy-enhancing masterbatch is 24%; the energy-enhancing additive is a mixture of calcium stearate, magnesium stearate, and silicon nitride, and the calcium stearate in the energy-enhancing additive , magnesium stearate, silicon nitride ratio is 5:3:2.

The antibacterial granules and carbon dioxide-based polyurethane granules were added to the two hoppers of the twin-screw granulator respectively, blended and melted in the twin-screw extruder at a temperature of 200°C, extruded, cooled in a water bath, dried, and cut into granules to obtain Modified carbon dioxide-based polyurethane masterbatch. Wherein, the mass ratio of the antibacterial particles to the modified carbon dioxide-based polyurethane masterbatch is 16%, and the antibacterial particles are nanometer zinc oxide.

The modified carbon dioxide-based polyurethane masterbatch is mixed with conventional carbon dioxide-based polyurethane particles as the raw material of the skin layer, and the mass ratio of the modified carbon dioxide-based polyurethane masterbatch to the raw material of the skin layer is 6%; the PBAT energized masterbatch is mixed with conventional PBAT as the core layer raw material , the mass ratio of PBAT energized masterbatch to the core material is 4%.

The specific equipment process flow chart for preparing degradable spunbond filter materials with energy-enhancing/antibacterial functions is shown in Figure 4; the cross-sectional view of the spinning assembly of the skin-core two-component spunbond equipment is shown in Figure 5; It can be seen from Figure 5 that the raw materials for the skin layer and the core layer are added to the two hoppers of the skin-core type two-component spunbond equipment, heated and melted by the respective screw extruders, filtered by the filter, and metered by the metering pump. Finally, the thin stream of melt that reaches the spinning assembly to form a skin-core composite structure is cooled by side blowing, the initial velocity of the airflow is adjusted during drafting, and the fibers are divided to prepare fibers with a skin-core structure. The fibers of the skin-core structure reach the net For the curtain, the upper, middle and lower layers of fiber webs were prepared respectively. When the initial velocity of the air-flow was 76m/s when drawing, the fiber diameter of 17 μm and the grammage were 28g/ ^m2 ; when the initial velocity of the air-flow was 100m/s, the fiber diameter was prepared as 13 μm, grammage is the middle layer fiber web of 33g/m ² ; When the initial speed of airflow is 115m/s when drafting, the lower layer fiber web that the fiber diameter is 10 μm, grammage is 48g/m ² is prepared, will make The upper, middle and lower three-layer fiber webs with different fiber diameters (the structural diagram of the three-layer fiber web is shown in Figure 2) are arranged sequentially from top to bottom, and are thermally bonded and reinforced by using a hot roll at a temperature of 175 °C. Fabrication, winding and molding, and finally corona electret in an electrostatic field of 12kV/cm for 60 seconds, a degradable spunbond filter material with both energy-enhancing and antibacterial functions can be obtained.

The filtration efficiency and filtration resistance of the degradable spunbond filter material with energy-enhancing/antibacterial functions tested by TSI8130 filter material comprehensive performance test bench: at a flow rate of 32L/min, the mass median diameter of sodium chloride aerosol is 0.26m When the filter resistance is 39Pa, the filter efficiency is 83%.

Example 3

This embodiment provides a method for preparing a degradable spun-bonded filter material with energy-enhancing/antibacterial functions, including the following steps:

Add the energizing agent and PBAT granules to the two hoppers of the twin-screw granulator respectively, blend and melt in the twin-screw extruder at a temperature of 180°C, extrude, cool in a water bath, dry, and cut into granules to obtain PBAT Energizing Masterbatch. Among them, the mass ratio of the energy-enhancing additive to the PBAT energy-enhancing masterbatch is 27%; the energy-enhancing additive is a mixture of calcium stearate, magnesium stearate, and silicon nitride, and the calcium stearate in the energy-enhancing additive , magnesium stearate, silicon nitride ratio is 5:3:2.

The antibacterial granules and carbon dioxide-based polyurethane granules were added to the two hoppers of the twin-screw granulator respectively, blended and melted in the twin-screw extruder at a temperature of 200°C, extruded, cooled in a water bath, dried, and cut into granules to obtain Modified carbon dioxide-based polyurethane masterbatch. Wherein, the mass ratio of the antibacterial particles to the modified carbon dioxide-based polyurethane masterbatch is 17%, and the antibacterial particles are nanometer zinc oxide.

The modified carbon dioxide-based polyurethane masterbatch is mixed with conventional carbon dioxide-based polyurethane particles as the raw material of the skin layer, and the mass ratio of the modified carbon dioxide-based polyurethane masterbatch to the raw material of the skin layer is 5%; the PBAT energized masterbatch is mixed with conventional PBAT as the core layer raw material , the mass ratio of PBAT energized masterbatch to the core material is 7%.

The specific equipment process flow chart for preparing degradable spunbond filter materials with energy-enhancing/antibacterial functions is shown in Figure 4; the cross-sectional view of the spinning assembly of the skin-core two-component spunbond equipment is shown in Figure 5; It can be seen from Figure 5 that the raw materials for the skin layer and the core layer are added to the two hoppers of the skin-core type two-component spunbond equipment, heated and melted by the respective screw extruders, filtered by the filter, and metered by the metering pump. Finally, the thin stream of melt that reaches the spinning assembly to form a skin-core composite structure is cooled by side blowing, and the initial speed and splitting of the airflow during drafting are adjusted to prepare fibers with a skin-core structure. The fibers of the skin-core structure reach the net For the curtain, the upper, middle and lower layers of fiber webs were prepared respectively. When the initial velocity of the air-flow was 73m/s when drawing, the fiber diameter was 18 μm and the grammage was 30g/m ^The upper fiber web was prepared; when the initial velocity of the air-flow was 95m/s, the fiber diameter was prepared as 14 μm, grammage is the middle layer fiber web of 36g/m ² ; When the initial velocity of airflow is 110m/s when drafting, the fiber diameter is 11 μm, the grammage is the lower layer fiber web of 55g/m ² prepared, will make The upper, middle and lower three-layer fiber webs with different fiber diameters (the structural diagram of the three-layer fiber web is shown in Figure 2) are arranged sequentially from top to bottom, and are thermally bonded and reinforced by using a hot roll at a temperature of 175 °C. Fabrication, winding and molding, and finally corona electret in an electrostatic field of 12kV/cm for 70 seconds, a degradable spunbond filter material with both energy-enhancing and antibacterial functions can be obtained.

The filtration efficiency and filtration resistance of the degradable spunbond filter material with energy-enhancing/antibacterial functions tested by TSI8130 filter material comprehensive performance test bench: at a flow rate of 32L/min, the mass median diameter of sodium chloride aerosol is 0.26m When the filter resistance is 45Pa, the filter efficiency is 89%.

Example 4

This embodiment provides a method for preparing a degradable spun-bonded filter material with energy-enhancing/antibacterial functions, including the following steps:

Add the energizing agent and PBAT granules to the two hoppers of the twin-screw granulator respectively, blend and melt in the twin-screw extruder at a temperature of 180°C, extrude, cool in a water bath, dry, and cut into granules to obtain PBAT Energizing Masterbatch. Among them, the mass ratio of the energy-enhancing additive to the PBAT energy-enhancing masterbatch is 29%; the energy-enhancing additive is a mixture of calcium stearate, magnesium stearate, and silicon nitride, and the calcium stearate in the energy-enhancing additive , magnesium stearate, silicon nitride ratio is 5:3:2.

The antibacterial granules and carbon dioxide-based polyurethane granules were added to the two hoppers of the twin-screw granulator respectively, blended and melted in the twin-screw extruder at a temperature of 200°C, extruded, cooled in a water bath, dried, and cut into granules to obtain Modified carbon dioxide-based polyurethane masterbatch. Wherein, the mass ratio of the antibacterial particles to the modified carbon dioxide-based polyurethane masterbatch is 18%, and the antibacterial particles are nanometer zinc oxide.

The modified carbon dioxide-based polyurethane masterbatch is mixed with conventional carbon dioxide-based polyurethane particles as the raw material of the skin layer, and the mass ratio of the modified carbon dioxide-based polyurethane masterbatch to the raw material of the skin layer is 7%; the PBAT energized masterbatch is mixed with conventional PBAT as the core layer raw material , the mass ratio of PBAT energized masterbatch to the core material is 8%.

The specific equipment process flow chart for preparing degradable spunbond filter materials with energy-enhancing/antibacterial functions is shown in Figure 4; the cross-sectional view of the spinning assembly of the skin-core two-component spunbond equipment is shown in Figure 5; It can be seen from Figure 5 that the raw materials for the skin layer and the core layer are added to the two hoppers of the skin-core type two-component spunbond equipment, heated and melted by the respective screw extruders, filtered by the filter, and metered by the metering pump. Finally, the thin stream of melt that reaches the spinning assembly to form a skin-core composite structure is cooled by side blowing, and the initial speed and splitting of the airflow during drafting are adjusted to prepare fibers with a skin-core structure. The fibers of the skin-core structure reach the net For the curtain, the upper, middle and lower layers of fiber webs were prepared respectively. When the initial velocity of the air-flow was 70m/s when drawing, the fiber diameter was 19 μm and the grammage was 35g/m ^The upper fiber web was prepared; when the initial velocity of the air-flow was 90m/s, the fiber diameter was prepared as 15 μm, grammage is the middle fiber web of 40g/m ² ; When the initial speed of airflow is 110m/s when drafting, the lower layer fiber web with fiber diameter of 11 μm and grammage of 60g/m ² is prepared, and the prepared The upper, middle and lower three-layer fiber webs with different fiber diameters (the structural diagram of the three-layer fiber web is shown in Figure 2) are arranged sequentially from top to bottom, and are thermally bonded and reinforced by using a hot roll at a temperature of 175 °C. Fabrication, winding and molding, and finally corona electret in an electrostatic field of 14kV/cm for 70 seconds, a degradable spunbond filter material with both energy-enhancing and antibacterial functions can be obtained.

The filtration efficiency and filtration resistance of the degradable spunbond filter material with energy-enhancing/antibacterial functions tested by TSI8130 filter material comprehensive performance test bench: at a flow rate of 32L/min, the mass median diameter of sodium chloride aerosol is 0.26m When the filter resistance is 50Pa, the filter efficiency is 93%.

Comparative example 1

This comparative example is similar to Example 1, the only difference is that no energy-enhancing additive, that is, a mixture of calcium stearate, magnesium stearate, and silicon nitride, is added to the core layer component of the filter material fiber.

Comparative example 2

This comparative example is similar to Example 1, the only difference is that no antibacterial particles, ie nano zinc oxide, are added to the skin layer component of the filter material fiber.

Comparative example 3

This comparative example is similar to Example 1, the only difference being that the upper, middle and lower layers of fiber webs are thermally bonded and reinforced, and then directly consolidated into cloth and wound into shape without corona electret treatment.

Performance Testing

The degradable spunbonded filter material with both energy-enhancing/antibacterial functions prepared in Examples 1-3 and Comparative Examples 1-3 was tested for filtration performance, antibacterial performance, strength performance and air permeability. The standards for the test basis are as follows:

(1) Use TSI8130 filter material automatic tester to test the filtration performance of the obtained two-component spunbond filter material: when the flow rate is 32L/min and the median diameter of the sodium chloride aerosol mass is 0.26m, the filtration resistance and filtration efficiency are tested .

(2) Antibacterial performance test index: T/YNIA 001-2021 "Antibacterial and antiviral nonwoven materials"

(3) Degradation performance test index: GB T22047-2008 "Determination of the final aerobic biodegradability of plastic materials in soil by measuring the oxygen demand in a closed ventilator or measuring the released carbon dioxide".

Table 1 Example 1-3, the performance test results of the degradable spunbonded filter material with energy-enhancing/antibacterial function prepared in Comparative Example 1-3

The results in Table 1 show that in a degradable spunbonded filter material with energy enhancement/antibacterial function prepared in Examples 1-4, energy enhancement additives, antibacterial particles, modified carbon dioxide-based polyurethane masterbatches and PBAT energy enhancement The content of the masterbatch gradually increases, the fiber diameter of the three-layer fiber net and the weight of the fiber net gradually increase, the electret voltage of the corona electret gradually increases, and the electret time gradually increases, so the filtration efficiency of the filter material, antibacterial rate gradually increased.

A degradable spunbond filter material with energy-enhancing/antibacterial functions prepared in Comparative Example 1 did not add energy-enhancing additives, so the filtration efficiency of the filter material was low, but the bacteriostatic rate remained basically unchanged.

A degradable spunbonded filter material with energy-enhancing/antibacterial functions prepared in Comparative Example 2 did not add antibacterial particles, so the filtration efficiency of the filter material remained basically unchanged, but the antibacterial rate was low.

A degradable spunbonded filter material with both energy-enhancing and antibacterial functions prepared in Comparative Example 3 was not subjected to corona electret treatment, so the filter material had low filtration efficiency and low bacteriostatic rate.

To sum up, the present invention improves the material filtration efficiency through parameters such as the energizing agent, the setting of the three-layer fiber net, and the corona electret process.

Apparently, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in various forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. However, the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. a degradable spun-bonded filter material is characterized in that, the spun-bonded filter material comprises an upper layer fiber web, a middle layer fiber web and a lower layer fiber web successively from top to bottom; the diameter of the fiber in the described upper layer fiber web is 16 μm to 19 μm; the diameter of the fiber in the middle fiber web is 12 μm to 15 μm; the diameter of the fiber in the lower fiber web is 9 μm to 11 μm. 2. The spunbond filter material according to claim 1, wherein the fiber is a sheath-core type composite fiber; the cortex of the fiber is a mixture of modified carbon dioxide-based polyurethane and carbon dioxide-based polyurethane; The core layer is a mixture of modified polybutylene adipate terephthalate and polybutylene adipate terephthalate. 3. The spunbonded filter material according to claim 2, wherein the modified carbon dioxide-based polyurethane is prepared by the following method: The antibacterial particles are mixed with carbon dioxide-based polyurethane, heated and melted by a twin-screw extruder, and cooled and dried to obtain the modified carbon dioxide-based polyurethane; the antibacterial particles are selected from nanometer zinc oxide. 4. The spunbond filter material according to claim 2, characterized in that, the mass ratio of the antibacterial particles to carbon dioxide-based polyurethane is 3-4:15-16. 5. spunbonded filter material according to claim 2, is characterized in that, described modified polybutylene adipate terephthalate is prepared by the following method: Mix the energy-enhancing additive with polybutylene adipate terephthalate, measure, heat and melt with a twin-screw extruder, and obtain the modified polybutylene adipate terephthalate after cooling and drying The energizer is a mixture of calcium stearate, magnesium stearate and silicon nitride; the mass percentages of the calcium stearate, magnesium stearate and silicon nitride are respectively 40% to 50%, 30% to 40% and 10% to 30%. 6 . The spunbonded filter material according to claim 5 , wherein the mass ratio of the energizer to polybutylene adipate terephthalate is 2 to 3:7 to 8. 7. A kind of preparation method of degradable spunbond filter material, is characterized in that, comprises the following steps: (1) Mix modified carbon dioxide-based polyurethane with carbon dioxide-based polyurethane, heat and melt through a screw extruder to obtain a skin layer material; Butylene glycol formate is mixed, heated and melted by a screw extruder to obtain a core material; (2) Extrude the cortex material and core layer material obtained in the step (1) through the spinneret holes in the spinning assembly, cool and adjust the initial velocity of the airflow during drafting by side blowing, and then form different diameters after the filaments are separated. The fibers are respectively laid on the porous conveyor belt to obtain the upper fiber web, the middle layer fiber web and the lower layer fiber web; (3) Arrange the upper layer fiber web, the middle layer fiber web and the lower layer fiber web obtained in step (2) from top to bottom, reinforce by thermal bonding, consolidate into a cloth, and perform corona electret to obtain the degradable spunbond filter material. 8. The preparation method according to claim 7, characterized in that, in step (2), fibers with a diameter of 16 μm to 19 μm are prepared when the initial velocity of the airflow is 70 m/s to 80 m/s; the airflow Fibers with a diameter of 12 μm to 15 μm are prepared when the initial velocity is 90 m/s to 105 m/s; fibers with a diameter of 9 μm to 11 μm are prepared when the initial velocity of the airflow is 110 m/s to 120 m/s. 9. The preparation method according to claim 7, characterized in that, in step (3), the temperature of the thermally bonded and reinforced hot roll is 170°C-180°C. 10. preparation method according to claim 7, is characterized in that, in step (3), described corona electret satisfies one or more in the following conditions: 1) The material of the discharge tip of the corona electret is tungsten; 2) The density of the needle tips is 900 pieces/m ² to 1000 pieces/m ² ; 3) The electret DC voltage of the corona electret is 7kv-18kv, the electret time is 50s-90s, the electret distance is 15cm-20cm, and the electret temperature is 25°C-35°C.

Images