Method for producing two-component spunbonded nonwoven material and system for producing two-component spunbonded nonwoven material

Abstract

The invention relates to the field of preparation of non-woven materials, and discloses a preparation method of a two-component spunbonded non-woven material, which comprises the following steps: (1) performing sheath-core two-component spinning on molten metallocene polyethylene and molten polyester, the melt index of the metallocene polyethylene being 5-10g / 10min at 240 DEG C under the load of 2.16 kg; (2) the bi-component trickles obtained in the step (1) are subjected to double-side air blowing cooling forming, and filaments are obtained; (3) carrying out wide slit type airflow drafting on the filaments in the step (2), and then carrying out filament separation and net laying; and (4) the fiber web laid in the step (3) is sequentially subjected to hot air setting and hot rolling bonding reinforcement, and the hot air temperature of hot air setting ranges from 110 DEG C to 140 DEG C. By adopting the method, the high-wrinkle skin-core double-component spunbond non-woven material with higher strength and better flexibility can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of non-woven material preparation, and particularly to a preparation method of a bicomponent spunbond non-woven material and a system for producing a bicomponent spunbond non-woven material. Background Art

[0002] With the improvement of living standards and the acceleration of the pace of life, people's dependence on wiping materials is increasing. From baby care to adult care, from household wiping to workplace cleaning, from general equipment cleaning to precision instrument cleaning, etc., wiping materials are everywhere in daily life and industrial production. In view of the difficult cleaning of heavy oil stains and tea stains on microwave ovens, barbecue grills, etc., non-woven fabric manufacturers are constantly seeking new solutions to develop economical and effective strong-decontamination wiping materials suitable for household use.

[0003] Currently, wiping materials are commonly prepared by the method of short fiber carding and hydroentangling. The functionality of wiping materials is achieved by using functional fibers or post-treatment of non-woven materials. Among them, the cost of functional fibers is too high, and their fiber structure may be damaged during the hydroentangling process, thus affecting the performance of functions. The post-treatment method requires adhesives to improve the adhesion of functional materials. On the one hand, it will affect the improvement of production speed. On the other hand, the hygienic performance of the product after adhesive treatment will be affected, and the discharged substances may not conform to the theme of sustainable development due to the presence of adhesives. Therefore, the output and quality of hydroentangled wiping materials will be affected doubly. Some people use the method of post-treatment by dripping plastic on hydroentangled fabrics to increase the friction between the hydroentangled wiping cloth and heavy oil stain devices, so as to achieve the purpose of strong decontamination. However, the post-treatment method has low efficiency and requires a certain amount of adhesives, and the adhesives used may not meet the environmental protection requirements.

[0004] In order to improve the above drawbacks, some people use the hollow orange segment bicomponent spunbond and hydroentangling technology to prepare functional wiping materials. After hydroentangling and fiber opening, the cross-section of the fibers is a non-circular cross-section, and the friction increases after contacting with dirt, resulting in enhanced decontamination ability. However, the hollow orange segment bicomponent spunbond and hydroentangling equipment is complex and the product cost is high, making it difficult to be popularized and applied in ordinary families.

[0005] Therefore, there is an urgent need to develop a new process for preparing functional wiping materials for strong decontamination required for microwave ovens, barbecue grills, tea stains, etc. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problems existing in the prior art, and provide a preparation method of a bicomponent spunbond non-woven material and a system for producing a bicomponent spunbond non-woven material. By using this method, a high-wrinkle skin-core bicomponent spunbond non-woven material with both high strength and good flexibility can be obtained.

[0007] To achieve the above object, on the one hand, the present invention provides a method for preparing a bicomponent spunbond nonwoven material, the method comprising the following steps:

[0008] (1) Perform skin-core bicomponent spinning on molten metallocene polyethylene and molten polyester, wherein the metallocene polyethylene has a melt index of 5-10 g / 10 min at 240 °C and a load of 2.16 kg;

[0009] (2) Perform bilateral blowing and cooling forming on the bicomponent filament obtained in step (1) to obtain filaments;

[0010] (3) Perform wide-slit air drawing on the filaments in step (2), and then perform filament splitting and web laying;

[0011] (4) Perform hot air setting and hot rolling bonding reinforcement on the web laid in step (3) in sequence, wherein the hot air temperature for hot air setting is 110-140 °C.

[0012] Metallocene polyethylene (mPE) is a product of copolymerization of ethylene and α-olefin under a metallocene catalyst system. Due to the use of a metallocene catalyst with a single active center, metallocene polyethylene has advantages such as good rigidity and transparency, high heat-sealing strength, excellent stress cracking resistance, and significant weight reduction. The inventors of the present invention found that using metallocene polyethylene and polyester with a specific melt index as raw materials to prepare a three-dimensional network structure with high wrinkles on the skin layer composed of continuous filaments with metallocene polyethylene as the skin layer and polyester as the core layer, enables the obtained spunbond nonwoven material to have good flexibility while ensuring high strength; the obtained bicomponent spunbond nonwoven material also has a large number of wrinkles, increasing the friction between the spunbond nonwoven material and stains and improving its dirt-holding capacity, which is of great significance for promoting the research process of high-strength decontamination wiping materials.

[0013] On the second aspect, the present invention provides a system for producing a bicomponent spunbond nonwoven material, the system comprising a spinning assembly, a cooling device, a wide-slit drawing device, a diffusion air duct, a forming curtain, a circular mesh hot air dryer, and a hot rolling roller connected in sequence;

[0014] The spinning assembly is used to perform skin-core bicomponent spinning on molten metallocene polyethylene and molten polyester;

[0015] The cooling device is used to perform bilateral blowing and cooling forming on the bicomponent filament from the spinning assembly;

[0016] The wide-slit drawing device is used to perform air drawing on the filaments from the cooling device;

[0017] The diffusion air duct is used to perform filament splitting on the filaments from the wide-slit drawing device;

[0018] The forming wire is used to form a web of filaments from the diffusion air duct.

[0019] The rotary screen hot air dryer is used to thermally set the web from the forming wire.

[0020] The hot rolling roller is used to hot roll and bond the web from the rotary screen hot air dryer for reinforcement.

[0021] Through the above technical solutions, the beneficial effects of the present invention include:

[0022] The bicomponent spunbond nonwoven material with metallocene polyethylene as the skin layer and polyester as the core layer prepared by the method of the present invention has good flexibility while ensuring high strength, which is beneficial to improving the fit with wiped surfaces of different shapes to enhance the oil stain wiping effect; moreover, the skin layer of the bicomponent spunbond nonwoven material has high wrinkles, increasing the friction between the spunbond nonwoven material and the stains, improving the dirt holding capacity of the spunbond nonwoven material, and having a large specific surface area, making it an ideal wiping material for strong decontamination, and can be used as a household nonwoven wiping material for strong decontamination such as microwave ovens, barbecue grills and tea stains. The preparation method of the present invention has high production efficiency, low cost, and greatly improved cost performance. Description of the Drawings

[0023] Figure 1 is a schematic diagram of the system for producing the bicomponent spunbond nonwoven material of the present invention;

[0024] Figure 2 is an electron micrograph of the metallocene polyethylene / polyester skin-core bicomponent spunbond nonwoven material at a non-rolling point after hot rolling and bonding reinforcement in Example 1 of the present invention;

[0025] Figure 3 is an electron micrograph of the punched metallocene polyethylene / polyester skin-core bicomponent spunbond nonwoven material after hot rolling and bonding reinforcement in Example 1 of the present invention.

[0026] Description of the Reference Numerals

[0027] In Figure 1 ,

[0028] 1, feeding hopper; 2, screw extruder; 3, melt filter

[0029] 4, metering pump; 5, spinning pack; 6, cooling device;

[0030] 7, wide and narrow slit drawing device; 8, diffusion air duct; 9, under-mesh air suction device;

[0031] 10, forming wire; 11, rotary screen hot air dryer; 12, hot rolling roller;

[0032] 13, winding device. Detailed Embodiments

[0033] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0034] On the one hand, the present invention provides a method for preparing a bicomponent spunbond nonwoven material, the method comprising the following steps:

[0035] (1) Conducting skin-core bicomponent spinning of molten metallocene polyethylene and molten polyester, wherein the melt index of the metallocene polyethylene at 240 °C and a load of 2.16 kg is 5-10 g / 10 min;

[0036] (2) Cooling and forming the bicomponent filaments obtained in step (1) by blowing air from both sides to obtain filaments;

[0037] (3) Conducting wide-narrow slit air drawing on the filaments in step (2), and then separating the filaments and laying them into a web;

[0038] (4) Sequentially subjecting the web laid in step (3) to hot air setting and hot rolling bonding for reinforcement, wherein the hot air temperature for the hot air setting is 110-140 °C.

[0039] In the prior art, the strong-decontamination wiping material is mainly made by post-treatment of short fiber spunlace with drip molding or opening of hollow orange-petal bicomponent spunlace. The short fiber spunlace drip molding process requires a large amount of water, has low production efficiency, and there are certain problems in environmental protection during the production process, which does not conform to the energy conservation and emission reduction policy; while the hollow orange-petal bicomponent spunlace equipment has high investment, high requirements for opening technology, and correspondingly increased energy consumption, resulting in a relatively high price for the final product and being difficult to be popularized and applied in ordinary families. The present invention prepares a bicomponent spunbond nonwoven material with metallocene polyethylene as the skin layer and polyester as the core layer by a method of melt spinning - blowing air from both sides for cooling and forming - wide-narrow slit air drawing - separating the filaments and laying them into a web - hot air setting - hot rolling bonding for reinforcement. The method has high production efficiency, low cost, and greatly improved cost performance. The bicomponent spunbond nonwoven material prepared by the method of the present invention has good flexibility while ensuring high strength; moreover, the skin layer of the bicomponent spunbond nonwoven material has high wrinkles, increasing the friction between the spunbond nonwoven material and stains, improving the stain-holding capacity of the spunbond nonwoven material, and having a large specific surface area, which is an ideal wiping material for strong decontamination and can be used as a household nonwoven wiping material for strong decontamination such as microwave ovens, barbecue grills, and tea stains.

[0040] According to the present invention, preferably, the amounts of metallocene polyethylene and polyester are such that in the spunbond nonwoven material obtained, based on the total mass of the spunbond nonwoven material, the mass content of metallocene polyethylene is 10-90%, preferably 30-70%; the mass content of polyester is 90-10%, preferably 70-30%. Adopting this preferred embodiment is beneficial to improving the strength of the obtained bicomponent spunbond nonwoven material.

[0041] According to the present invention, preferably, the melt index of the metallocene polyethylene at 240 °C and a load of 2.16 kg is 7-10 g / 10 min. Adopting this preferred embodiment is beneficial to improving the strength and flexibility of the obtained bicomponent spunbond nonwoven material.

[0042] It should be noted that when the melt index of the metallocene polyethylene is lower than 5 g / 10 min, successful spinning cannot be achieved.

[0043] The present invention does not particularly limit the source of the metallocene polyethylene, and it can be various metallocene polyethylenes obtained by conventional methods in the art, as long as the melt index is within the above range.

[0044] According to the present invention, preferably, the intrinsic viscosity of the polyester is 0.6-0.75 dl / g.

[0045] According to the present invention, preferably, the melting point of the polyester is 258-265 °C.

[0046] Adopting this preferred embodiment is beneficial to improving the strength and flexibility of the obtained bicomponent spunbond nonwoven material.

[0047] The present invention does not particularly limit the source of the polyester, and it can be various polyesters obtained by conventional methods in the art, as long as the intrinsic viscosity and melting point are within the above range.

[0048] The present invention does not particularly limit the specific method for melting the metallocene polyethylene and polyester, and conventional methods in the art can be used.

[0049] Preferably, the conditions for melting the metallocene polyethylene include: the temperature of the cold zone is 50-70 °C; the temperature of the first zone is 110-130 °C; the temperature of the second zone is 200-230 °C; the temperature of the third zone is 230-260 °C; the temperature of the fourth zone is 230-260 °C; the temperature of the fifth zone is 230-260 °C. Adopting this preferred embodiment, the melt is melted more uniformly, has a certain viscosity and appropriate die swell, and melt fracture does not occur.

[0050] Preferably, the conditions for melting the polyester include: the temperature in the cold zone is 50 - 70°C; the temperature in the first zone is 200 - 230°C; the temperature in the second zone is 250 - 280°C; the temperature in the third zone is 270 - 290°C; the temperature in the fourth zone is 270 - 290°C; the temperature in the fifth zone is 270 - 290°C. With this preferred embodiment, the melt is melted more uniformly, has a certain viscosity and appropriate die swell, and there will be no droplet-type spinning fluid.

[0051] Preferably, before spinning the molten metallocene polyethylene and the molten polyester, they are each independently metered. With this preferred embodiment, the metallocene polyethylene and the polyester are combined in a specific ratio to obtain a spunbond nonwoven material with a specific composition. This is a conventional operation in the art.

[0052] Preferably, the rotational speed of the metering pump is 10 - 80 r / min.

[0053] Preferably, the molten metallocene polyethylene and the molten polyester are each independently filtered first and then metered.

[0054] The present invention does not particularly limit the operating conditions for the above metering and filtering, and can be carried out with reference to the conventional methods in the art. The present invention will not be further limited herein.

[0055] In order to smoothly obtain the core-sheath bicomponent filament, preferably, the spinning temperature in step (1) is 270 - 290°C.

[0056] Compared with the conventional single-sided blowing cooling forming, the double-sided blowing cooling forming in step (2) of the present invention is beneficial to subsequent filament separation and effectively avoids the situation of fiber adhesion.

[0057] The specific conditions for the double-sided blowing cooling forming of the present invention can be carried out with reference to the conventional blowing cooling forming methods in the art. Preferably, the conditions for the double-sided blowing cooling forming in step (2) include: the air temperature is 12 - 20°C, the air pressure is 4000 - 6000 Pa, and the air speed is 50 - 100 m / min.

[0058] Compared with the narrow slit air draft drawing or mechanical drawing, the wide slit air draft drawing of the present invention is beneficial to subsequent filament splitting and web laying, and effectively prevents the situation of fiber adhesion when the fiber enters the drawing device.

[0059] According to the present invention, preferably, the conditions for the wide slit air draft drawing in step (3) include: the air temperature is 30 - 40°C, the air pressure is 0.2 - 0.8 MPa, and the air speed is 5000 - 8000 m / min.

[0060] According to the present invention, preferably, the width of the narrowest part of the slit is not less than 10 mm, preferably 10 - 15 mm, for example, it can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, and any value within the range formed by any two of these point values. Adopting this preferred embodiment, the slit width is small, the drawing effect is large, which is beneficial to the formation of fine fibers and is beneficial to improving the mechanical properties. Moreover, the deformations of the two components are different during the drawing process, and the surface wrinkled structure can be adjusted.

[0061] According to the present invention, preferably, the conditions for the web laying in step (3) include: the speed of the forming screen is 10 - 100 m / min, and the under-web air suction speed is 8 - 20 m / min. Adopting this preferred embodiment, it matches the conditions of the previous steps and is beneficial to the formation of a uniform fiber web.

[0062] In the method of the present invention, in step (4), the fiber web laid in step (3) is first heat-set and then hot-rolled and bonded for reinforcement. During the heat-setting process, the skin fibers shrink and wrinkle, while the core fibers remain straight, forming a skin-core bicomponent fiber with high wrinkles on the surface. After hot-rolling and bonding for reinforcement, a high-wrinkle skin-core bicomponent spunbond nonwoven material is formed, which is beneficial to increasing the friction between the spunbond nonwoven material and stains, improving the stain-holding capacity of the spunbond nonwoven material, and increasing the specific surface area.

[0063] In the present invention, in step (4), the hot air temperature for heat-setting is 110 - 140 °C, for example, it can be 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, and any value within the range formed by any two of these point values.

[0064] The hot-rolling and bonding for reinforcement in step (4) of the present invention can be carried out with reference to the conventional methods in the art. Preferably, the conditions for the hot-rolling and bonding for reinforcement in step (4) include: the temperature is 110 - 135 °C, and the linear pressure is 30 - 60 N / mm.

[0065] Preferably, the method further includes: trimming and winding the material obtained by the hot-rolling and bonding for reinforcement in step (4) to obtain the bicomponent spunbond nonwoven material. This is a conventional operation in the art.

[0066] The bicomponent spunbond nonwoven material obtained by the present invention can be further perforated subsequently to further increase the roughness.

[0067] According to the present invention, preferably, the method further includes: pre-treating the polyester before melting, and the pre-treatment includes a pre-crystallization process and a drying process.

[0068] According to the present invention, preferably, the temperature of the pre-crystallization is 115 - 125 °C.

[0069] According to the present invention, preferably, the drying temperature is 150 - 170 °C.

[0070] Adopting the above preferred embodiment is beneficial to subsequent high - speed spinning.

[0071] The bicomponent spunbond non - woven material prepared by the method of the present invention has good flexibility while ensuring high strength.

[0072] According to the present invention, preferably, the longitudinal flexural rigidity of the spunbond non - woven material is not greater than 3.5 mg·cm.

[0073] According to the present invention, preferably, the transverse flexural rigidity of the spunbond non - woven material is not greater than 2.5 mg·cm.

[0074] The test of the flexural rigidity of the spunbond non - woven material of the present invention is carried out with reference to the method of GB / T 18318.1 - 2009.

[0075] According to a particularly preferred embodiment of the present invention, a method for preparing a bicomponent spunbond non - woven material, the method comprising the following steps:

[0076] (1) Conduct skin - core bicomponent spinning of molten metallocene polyethylene and molten polyester, wherein the melt index of the metallocene polyethylene at 240 °C and a load of 2.16 kg is 7 - 10 g / 10 min;

[0077] (2) Blow - cool and form the bicomponent filament obtained in step (1) on both sides to obtain filaments;

[0078] (3) Conduct wide - narrow - slit air drawing on the filaments of step (2), and then carry out filament splitting and web laying;

[0079] (4) Sequentially carry out hot - air setting and hot - rolling bonding reinforcement on the web laid in step (3), wherein the hot - air temperature for hot - air setting is 110 - 140 °C;

[0080] The amounts of metallocene polyethylene and polyester are such that in the spunbond non - woven material prepared, based on the total mass of the spunbond non - woven material, the mass content of metallocene polyethylene is 30 - 70%; the mass content of polyester is 70 - 30%;

[0081] The spinning temperature in step (1) is 270 - 290 °C;

[0082] The conditions for the narrow - slit air drawing in step (3) include: air temperature is 30 - 40 °C, air pressure is 0.2 - 0.8 MPa, and air velocity is 5000 - 8000 m / min;

[0083] The conditions for web laying in step (3) include: the speed of the forming screen is 10 - 100 m / min, and the air suction speed under the web is 8 - 20 m / min.

[0084] Adopting the above preferred implementation mode is further conducive to obtaining the bicomponent spunbond nonwoven material of the present invention, which can be used as an ideal wiping material for strong decontamination, and is used for household nonwoven wiping materials that require strong decontamination, such as microwave ovens, barbecue grills, and tea stains.

[0085] The second aspect of the present invention provides a system for producing a bicomponent spunbond nonwoven material, which includes a spinning component 5, a cooling device 6, a wide and narrow slit stretching device 7, a diffusion air duct 8, a forming screen 10, a circular screen hot air drying cylinder 11, and a hot rolling roller 12 connected in sequence;

[0086] The spinning component 5 is used for core - sheath bicomponent spinning of molten metallocene polyethylene and molten polyester;

[0087] The cooling device 6 is used for bilateral blowing and cooling forming of the bicomponent filaments obtained from the spinning component 5;

[0088] The wide and narrow slit stretching device 7 is used for air stretching of the filaments from the cooling device 6;

[0089] The diffusion air duct 8 is used for filament splitting of the filaments from the wide and narrow slit stretching device 7;

[0090] The forming screen 10 is used for web laying of the filaments from the diffusion air duct 8;

[0091] The circular screen hot air drying cylinder 11 is used for hot air setting of the web from the forming screen 10;

[0092] The hot rolling roller 12 is used for hot rolling and bonding reinforcement of the web from the circular screen hot air drying cylinder 11.

[0093] According to the present invention, preferably, the system further includes: an air suction device 9 under the web, which is arranged between the diffusion air duct 8 and the forming screen 10, and is used for assisting web formation.

[0094] Preferably, the system further includes: a screw extruder 2 arranged before the spinning component 5, which is used for melting metallocene polyethylene and polyester.

[0095] Preferably, a feeding hopper 1 is arranged on the screw extruder 2, which is used for feeding metallocene polyethylene and polyester.

[0096] Preferably, the system further includes: a metering pump 4 arranged between the screw extruder 2 and the spinning component 5, which is used for metering and outputting metallocene polyethylene and polyester.

[0097] Preferably, the system further includes a melt filter 3 disposed between the screw extruder 2 and the metering pump 4 for impurity filtration.

[0098] Preferably, the system further includes a winding device 13 disposed after the hot rolling roll 12 for trimming and winding the hot-rolled and bonded reinforcing material.

[0099] According to a specific embodiment of the present invention, as Figure 1 shown. The metallocene polyethylene chips and the pretreated polyester chips are respectively fed into the screw extruder 2 from the feed hopper 1 for melting. The molten metallocene polyethylene and the molten polyester are respectively filtered by the melt filter 3 and metered by the metering pump 4, and then enter the spinning assembly 5 respectively, and converge at the spinneret holes of the spinning assembly 5 to form a core-sheath bicomponent continuous fine stream with metallocene polyethylene as the skin layer and polyester as the core layer and flow out. The bicomponent fine stream enters the wide and narrow slit drawing device 7 for air drawing after being cooled and formed by the bilateral air blowing of the cooling device 6, enters the diffusion air duct 8 for air filament splitting after passing through the narrowest part of the slit, and forms a uniform fiber web on the forming screen 10 with the assistance of the under-mesh air suction device 9. The fiber web is sent into the rotary screen hot air drying cylinder 11 for hot air setting, then hot-rolled and bonded and reinforced by the hot rolling roll 12, and finally trimmed and wound by the winding device 13 to form the bicomponent spunbond nonwoven material.

[0100] The present invention will be described in detail below through embodiments.

[0101] In the following embodiments, the gram weight parameter of the bicomponent spunbond nonwoven material is measured with reference to the standard of GB / T24218.1-2009;

[0102] The thickness parameter of the bicomponent spunbond nonwoven material is measured with reference to the standard of GB / T 24218.2-2009;

[0103] The breaking strength and elongation at break of the bicomponent spunbond nonwoven material are measured with reference to the standard of GB / T 24218.3-2010;

[0104] The bending stiffness of the bicomponent spunbond nonwoven material is measured with reference to the standard of GB / T 18318.1-2009;

[0105] The air permeability of the bicomponent spunbond nonwoven material is measured with reference to the standard of GB / T 5453-1997;

[0106] In the following embodiments, the polyester used is PET chips with the brand CHJ-2-018 of Shandong Chenghuijin Industry Co., Ltd., the intrinsic viscosity is 0.7 dl / g, and the melting point is 261 °C;

[0107] The metallocene polyethylene chips used in the following embodiments are all commercially available products of Shanghai Research Institute of Chemical Industry Co., Ltd.

[0108] Example 1

[0109] Adopt Figure 1 the said system.

[0110] (1) Feed the metallocene polyethylene chips (with a melt index of 7.5 g / 10 min) and the polyester chips after pretreatment (precrystallization temperature of 120 °C and drying temperature of 160 °C) into the screw extruder 2 respectively for melting. The temperature settings of each zone of the metallocene polyethylene screw are 60 °C in the cold zone, 120 °C in zone 1, 210 °C in zone 2, 230 °C in zone 3, 250 °C in zone 4, and 250 °C in zone 5, and the rotation speed of the screw is 25 r / min; the temperature settings of each zone of the polyester screw are 60 °C in the cold zone, 220 °C in zone 1, 275 °C in zone 2, 280 °C in zone 3, 280 °C in zone 4, and 280 °C in zone 5, and the rotation speed of the screw is 28 r / min.

[0111] (2) Feed the molten metallocene polyethylene and the molten polyester into the spinning pack 5 (a core - sheath bicomponent spinning pack) through their respective material paths, melt filters 3, and metering pumps 4 for spinning. The temperatures of the material paths, melt filters, and metering pumps of the two components are set to 250 °C and 280 °C respectively, the temperature of the spinning pack 5 is set to 280 °C, the rotation speed of the metering pump of the metallocene polyethylene is 40 r / min, and the pressure after filtration is 3.2 MPa; the rotation speed of the metering pump of the polyester is 25 r / min, and the pressure after filtration is 3.8 MPa.

[0112] (3) Cool and form the extruded bicomponent filaments under the action of bilateral cooling air at 12 °C, 6000 Pa, and 70 m / min, and perform wide - narrow slit air drawing under the drawing air pressure of 30 °C, 0.4 MPa, and 5000 m / min. The width of the narrowest part of the slit is 12 mm. After the filaments are divided by the diffusion air duct 8, a uniform fiber web is formed on the forming screen 10. The speed of the forming screen is 40 m / min, and the air suction speed under the web is 15 m / min.

[0113] (4) Feed the formed fiber web into the rotary screen hot air dryer 11 for hot air setting. The hot air temperature is 115 °C, and then perform hot rolling bonding and reinforcement under the conditions of a temperature of 128 °C and a linear pressure of 45 N / mm, punch holes, and finally trim and wind to form a core - sheath bicomponent non - woven material. Its performance parameters are shown in Table 1.

[0114] Exemplarily give the electron microscope image of the metallocene polyethylene / polyester core - sheath bicomponent spunbond non - woven material at the non - rolling point after hot rolling bonding and reinforcement, as Figure 2 shown. From Figure 2It can be seen that after hot air treatment and hot rolling bonding reinforcement, where there are no nip points, the fibers still maintain their original structure. The cortical fibers soften and melt-bond at the intersection points due to the action of heat, but the overall fiber structure is not damaged, resulting in a large number of wrinkles on the cortical fibers, which can increase the friction coefficient between the fibers and the surface of the contacted object, and at the same time can also accommodate dirt and improve its dirt removal ability.

[0115] Exemplarily, the electron micrograph of the metallocene polyethylene / polyester sheath-core bicomponent spunbond nonwoven material with holes after hot rolling bonding reinforcement is given, as Figure 3 shown. From Figure 3 it can be seen that after hot rolling bonding reinforcement, the bonding area of the fibers at the nip points increases, and some fiber structures and wrinkles are damaged under pressure. After punching, the roughness increases, and the pores have a larger space to accommodate dirt, and the dirt removal ability is stronger.

[0116] Example 2

[0117] Adopt Figure 1 the said system.

[0118] (1) The metallocene polyethylene chips (melt index is 8 g / 10 min) and the pretreated (precrystallization temperature is 120 °C, drying temperature is 165 °C) polyester chips are respectively fed into the screw extruder 2 for melting. The temperature settings of each zone of the metallocene polyethylene screw are 60 °C in the cold zone, 120 °C in zone 1, 210 °C in zone 2, 230 °C in zone 3, 240 °C in zone 4, 240 °C in zone 5, and the rotation speed of the screw is 20 r / min; the temperature settings of each zone of the polyester screw are 60 °C in the cold zone, 220 °C in zone 1, 275 °C in zone 2, 280 °C in zone 3, 285 °C in zone 4, 285 °C in zone 5, and the rotation speed of the screw is 22 r / min.

[0119] (2) The molten metallocene polyethylene and the molten polyester are sent into the spinning pack 5 (sheath-core bicomponent spinning pack) through their respective material paths, melt filters 3, and metering pumps 4 for spinning. The material paths, melt filters, and metering pumps 4 of the two components are respectively set at 240 °C and 285 °C, the temperature of the spinning pack 5 is set at 285 °C, the rotation speed of the metering pump of metallocene polyethylene is 25 r / min, and the pressure after filtration is 2.6 MPa; the rotation speed of the polyester metering pump is 22 r / min, and the pressure after filtration is 2.8 MPa.

[0120] (3) The extruded bicomponent filaments are cooled and formed under the action of bilateral cooling air at 15 °C, 4000 Pa, and 60 m / min, and are subjected to wide and narrow slit air drawing under the drawing air pressure of 35 °C, 0.5 MPa, and 6000 m / min. The width of the narrowest part of the slit is 10 mm. After the filaments are divided by the diffusion air duct 8, a uniform fiber web is formed on the forming screen 10. The speed of the forming screen is 50 m / min, and the air suction speed under the screen is 13 m / min.

[0121] (4) Feed the formed web into the rotary screen hot air dryer 11 for hot air setting. The hot air temperature is 120 °C. Then, carry out hot rolling bonding and strengthening under the conditions of a temperature of 132 °C and a linear pressure of 40 N / mm. Finally, trim the edges and wind it up to form a core - sheath bicomponent non - woven material. Its performance parameters are shown in Table 1.

[0122] Example 3

[0123] (1) Metallocene polyethylene chips (melt index is 10 g / 10 min) and pre - treated (pre - crystallization temperature is 120 °C, drying temperature is 170 °C) polyester chips are respectively fed into the screw extruder 2 for melting. The temperature settings of each zone of the metallocene polyethylene screw are 60 °C in the cold zone, 120 °C in zone 1, 210 °C in zone 2, 235 °C in zone 3, 260 °C in zone 4, 260 °C in zone 5, and the screw rotation speed is 20 r / min; the temperature settings of each zone of the polyester screw are 60 °C in the cold zone, 220 °C in zone 1, 275 °C in zone 2, 285 °C in zone 3, 290 °C in zone 4, 290 °C in zone 5, and the screw rotation speed is 20 r / min.

[0124] (2) Feed the molten metallocene polyethylene and the molten polyester through their respective feed paths, melt filters 3, and metering pumps 4 into the spinning pack 5 (core - sheath bicomponent spinning pack) for spinning. The temperatures of the feed paths, melt filters, and metering pumps of the two components are set to 260 °C and 290 °C respectively, the temperature of the spinning pack is set to 290 °C, the rotation speed of the metering pump of metallocene polyethylene is 20 r / min, and the pressure after filtration is 2.2 MPa; the rotation speed of the polyester metering pump is 25 r / min, and the pressure after filtration is 3 MPa.

[0125] (3) Cool and form the extruded bicomponent filaments under the action of bilateral cooling air at 16 °C, 5000 Pa, and 96 m / min. Carry out wide - narrow slit air drawing under the drawing air pressure of 40 °C, 0.6 MPa, and 8000 m / min. The width of the narrowest part of the slit is 10 mm. After the filaments are divided by the diffusion air duct 8, a uniform web is formed on the forming screen 10. The speed of the forming screen is 80 m / min, and the air suction speed under the screen is 18 m / min.

[0126] (4) Feed the formed web into the rotary screen hot air dryer 11 for hot air setting. The hot air temperature is 125 °C. Then, carry out hot rolling bonding and strengthening under the conditions of a temperature of 130 °C and a linear pressure of 55 N / mm. Finally, trim the edges and wind it up to form a core - sheath bicomponent non - woven material. Its performance parameters are shown in Table 1.

[0127] Comparative Example 1

[0128] Carry out according to the method of Example 3, except that the hot air setting step is not carried out, and directly carry out the hot rolling bonding and strengthening step. Its performance parameters are shown in Table 1.

[0129] The wrinkles of the skin layer of the obtained core - sheath bicomponent non - woven material are greatly reduced. The friction between the spunbond non - woven material and stains is relatively low, the stain - holding capacity of the spunbond non - woven material is reduced, and the wiping effect becomes significantly worse.

[0130] Table 1

[0131]

[0132] It can be seen from the results in Table 1 that the bicomponent non - woven material prepared by the method of the present invention has significantly higher strength and flexibility. Moreover, it has high wrinkles in the skin layer, which increases the friction between the spunbond non - woven material and stains, improves the stain - holding capacity of the spunbond non - woven material, and has a larger specific surface area. It can be used as a household non - woven wiping material for strong decontamination such as microwave ovens, barbecue grills, and tea stains.

[0133] Test Example 1

[0134] Select the non - woven wiping materials prepared in Example 3 and Comparative Example 1, ordinary spunbond non - woven materials of the same gram weight (Zhejiang Jinsanfa Group), and ordinary hydroentangled wiping materials of the same gram weight (Hainan Xinlong Non - woven Co., Ltd.). After wetting with water, wipe the microwave oven stained with oil, and observe the oil stain removal effect. The oil stain removal effect is shown in Table 2.

[0135] Table 2

[0136] Example number Oil removal rate, % Example 3 ～90 Comparative example 1 ～53 Ordinary spunbond nonwoven material ～42 Ordinary hydroentangled wiping material ～52

[0137] It can be seen from the results in Table 2 that under the same conditions, the spunbond non - woven material prepared by the present invention has significantly better oil stain removal effect.

[0138] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing a bicomponent spunbond nonwoven material, characterized in that, the method comprises the following steps: (1) Conduct skin-core bicomponent spinning on molten metallocene polyethylene and molten polyester, wherein the melt index of the metallocene polyethylene at 240 °C and a load of 2.16 kg is 5-10 g / 10 min; (2) Conduct bilateral blowing and cooling forming on the bicomponent filament obtained in step (1) to obtain filaments; (3) Conduct wide-narrow slit air drawing on the filaments in step (2), and then conduct filament splitting and web laying; (4) Subject the web laid in step (3) to hot air setting and hot rolling bonding reinforcement in sequence, wherein the hot air temperature for the hot air setting is 110-140 °C.

2. The method according to claim 1, wherein, the dosages of the metallocene polyethylene and the polyester are such that in the spunbond nonwoven material obtained, based on the total mass of the spunbond nonwoven material, the mass content of the metallocene polyethylene is 10-90%, preferably 30-70%; the mass content of the polyester is 90-10%, preferably 70-30%; preferably, the melt index of the metallocene polyethylene at 240 °C and a load of 2.16 kg is 7-10 g / 10 min; preferably, the intrinsic viscosity of the polyester is 0.6-0.75 dl / g, and the melting point is 258-265 °C.

3. The method according to claim 1, wherein, the spinning temperature in step (1) is 270-290 °C.

4. The method according to any one of claims 1-3, wherein, the conditions for the bilateral blowing and cooling forming in step (2) include: the air temperature is 12-20 °C, the air pressure is 4000-6000 Pa, and the air velocity is 50-100 m / min.

5. The method according to any one of claims 1-4, wherein, the conditions for the wide-narrow slit air drawing in step (3) include: the air temperature is 30-40 °C, the air pressure is 0.2-0.8 MPa, and the air velocity is 5000-8000 m / min; preferably, the width at the narrowest part of the slit is 10-15 mm; preferably, the conditions for the web laying in step (3) include: the speed of the forming net curtain is 10-100 m / min, and the air suction speed under the net is 8-20 m / min.

6. The method according to any one of claims 1-5, wherein, the conditions for the hot rolling bonding reinforcement in step (4) include: the temperature is 110-135 °C, and the linear pressure is 30-60 N / mm.

7. The method according to any one of claims 1-6, wherein, the conditions for melting the metallocene polyethylene include: the temperature in the cold zone is 50-70 °C; the temperature in the first zone is 110-130 °C; the temperature in the second zone is 200-230 °C; the temperature in the third zone is 230-260 °C; the temperature in the fourth zone is 230-260 °C; the temperature in the fifth zone is 230-260 °C; Preferably, the conditions for melting the polyester include: the temperature in the cold zone is 50-70 °C; the temperature in the first zone is 200-230 °C; the temperature in the second zone is 250-280 °C; the temperature in the third zone is 270-290 °C; the temperature in the fourth zone is 270-290 °C; the temperature in the fifth zone is 270-290 °C.

8. The method according to any one of claims 1-7, wherein, the longitudinal bending stiffness of the spunbond nonwoven material is not greater than 3.5 mg·cm; Preferably, the transverse bending stiffness of the spunbond nonwoven material is not greater than 2.5 mg·cm.

9. A system for producing a bicomponent spunbond nonwoven material, the system comprising a spinneret assembly (5), a cooling device (6), a wide slit drafting device (7), a diffusion air duct (8), a forming screen (10), a circular screen hot air dryer (11) and a hot rolling roller (12) connected in sequence; the spinneret assembly (5) is used for performing skin-core bicomponent spinning of metallocene polyethylene and molten polyester; the cooling device (6) is used for performing double-sided blowing and cooling forming on the bicomponent filaments from the spinneret assembly (5); the wide slit drafting device (7) is used for performing air drafting on the filaments from the cooling device (6); the diffusion air duct (8) is used for splitting the filaments from the wide slit drafting device (7); the forming screen (10) is used for laying the filaments from the diffusion air duct (8); the circular screen hot air dryer (11) is used for performing hot air setting on the web from the forming screen (10); the hot rolling roller (12) is used for performing hot rolling and bonding reinforcement on the web from the circular screen hot air dryer (11).

10. The system according to claim 9, wherein, the system further includes: an under-screen air suction device (9) disposed between the diffusion air duct (8) and the forming screen (10) for assisting in web forming.

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