Preparation method of high-fluffiness non-woven fabric

Abstract

The invention discloses a preparation method of a high-fluffiness non-woven fabric, and belongs to the field of non-woven fabric preparation. The preparation method of the high-fluffiness non-woven fabric comprises the following steps: S1, spinning and cooling: respectively carrying out melt extrusion and filtration on a PP raw material and a mixture of a PE raw material and a COPP raw material, and then carrying out confluence spinning, cooling drafting and air flow division to obtain bicomponent fibers; s2, drafting and lapping: lapping the bicomponent fibers in the step S1; s3, hot air consolidation: conveying the fiber web in the step S2 to a hot air pre-consolidation device, and performing hot air pre-consolidation under hot air with the temperature of 100-150 DEG C and the air pressure of 2500-3000 Pa; then conveying the non-woven fabric into a hot air consolidation device, and carrying out hot air consolidation under hot air with the temperature of 130-150 DEG C to obtain the high-fluffiness non-woven fabric; the method can be used for preparing the non-woven fabric with higher fluffiness.

Description

Technical Field

[0001] The invention relates to the field of non-woven fabric preparation, and more specifically, to a method for preparing high-loft non-woven fabric. Background Art

[0002] Nonwoven fabrics, also known as non-woven fabrics, are made of directional or random fibers and are a new generation of environmentally friendly materials. However, the lack of fluffiness of traditional nonwoven fabrics has always been a technical challenge. The common method of enhancing the fluffiness of nonwoven fabrics is to add fluffiness-promoting materials to the raw materials; however, during the preparation of the fiber web, the fluffiness material may destroy the raw material structure, thereby affecting the tensile strength of the prepared nonwoven fabric and reducing the frequency of use of the nonwoven fabric.

[0003] In order to solve the above problems, a Chinese patent with patent number CN2018104006490 published on June 19, 2020, discloses a method for preparing a high-loft non-woven fabric and a non-woven fabric; the method uses a hydroentanglement machine to pre-consolidate the non-woven fabric, and then uses a dryer to dry the prepared non-woven fabric to obtain a high-loft non-woven fabric; however, the non-woven fabric prepared by this method needs to strictly control the drying temperature during the drying process to reduce damage to the fiber, which increases the difficulty of preparing the non-woven fabric. In addition, after the fiber web is prepared, it is still necessary to go through pre-drying and standing steps before hydroentanglement can be performed. During the static process, the relative humidity and temperature of the environment must be strictly controlled, which further increases the complexity of non-woven fabric preparation and leads to higher costs.

[0004] Therefore, it is necessary to provide a new method for preparing a high-fluff non-woven fabric, which has low preparation cost and simple preparation process; in addition, the non-woven fabric prepared by this method has high fluffiness. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing high-fluff non-woven fabrics. The method adopts non-contact hot air consolidation technology to transfer heat from a hot air pre-consolidation device to the fiber web. In this way, while reducing the impact on product density, it ensures that the non-woven fabric has higher fluffiness.

[0006] To solve the above problems, the present invention adopts the following technical solutions.

[0007] A method for processing a high-loft nonwoven fabric comprises the following steps:

[0008] S1: Spinning and cooling: melt-extrude and filter the mixture of PP raw material, PE raw material and COPP raw material, and then perform converging spinning, cooling, drawing and air separation to obtain bicomponent fibers;

[0009] S2: Drafting and laying: Laying the bicomponent fibers in step S1;

[0010] S3: hot air consolidation: the fiber web of step S2 is transferred to a hot air pre-consolidation device, and hot air pre-consolidation is performed under hot air at a temperature of 100-150°C and a wind pressure of 2500-3000Pa; then it is transferred to a hot air consolidation device, and hot air consolidation is performed under hot air at a temperature of 130-150°C to obtain a high-loft non-woven fabric.

[0011] Furthermore, in the step S1, the temperature of the converging spinning is 200-300°C, and the temperature of the cooling and drawing is 15-20°C; the main exhaust of the airflow separation is 25-65%, and the auxiliary exhaust is 50-60%.

[0012] Furthermore, in the step S1, the extrusion temperature is 230-250°C.

[0013] The present invention also provides a high-loft non-woven fabric processing device, which is used for the above-mentioned high-loft non-woven fabric processing method.

[0014] Furthermore, a processing device for high-loft non-woven fabric includes a web-forming system and a post-finishing system connected thereto, the post-finishing system includes a hot air pre-consolidation device, the hot air pre-consolidation device includes a pre-consolidation body and thermal insulation cotton, an air supply channel is opened inside the pre-consolidation body, and both ends of the pre-consolidation body are fixedly connected with air inlets connected to the air supply channel; heating cavities connected to the air supply channel are opened on both side walls of the pre-consolidation body, and an electric heating rod is embedded and fixedly connected at the upper end of the pre-consolidation body; a base is fixedly connected to the lower end of the pre-consolidation body, the thermal insulation cotton is half-covered on the outside of the pre-consolidation body and the base, and the lower end of the thermal insulation cotton is detachably connected to the base; a drainage groove is opened inside the base, and the drainage groove is connected to the heating cavity and the lower end of the base; a fixing frame is fixedly connected to the lower end of the air inlet.

[0015] Furthermore, the pre-consolidation body includes a pair of detachably connected pre-consolidation shells; after the pre-consolidation shells are installed, the air supply channel is located above the center line; grooves are provided on both sides of the pre-consolidation body, and cover plates are detachably connected to the outer ends of the grooves, and the heating cavity is surrounded by the grooves and the cover plates. Furthermore, an installation space for embedding the power supply heating rod is provided in the pre-consolidation body, and the installation space is connected to the groove and the air supply channel.

[0016] Furthermore, the base includes an upper base and a pair of lower bases, the pair of lower bases are fixedly connected to the lower end of the upper base, and the lower end of the upper base and the upper end of the lower base form an air guide gap; a pair of air guide grooves are opened at the upper end of the upper base, and a plurality of air guide holes are opened at the lower end of the air guide grooves, and the air guide holes connect the air guide gap and the air guide grooves; after installation, a gap for air flow is left between the pair of lower bases, and the gap is connected to the air guide gap; base baffles are fixedly connected to both ends of the upper base and the lower base, and the baffles completely cover the two ends of the upper base and the lower base; the drainage groove is composed of an air guide groove, an air guide gap, air guide holes and a gap.

[0017] Furthermore, a guide column protruding toward the upper base is provided in the air guide gap, and the distance between the guide column and the upper base is smaller than the height of the air guide gap.

[0018] Furthermore, the web-forming system includes a material system, a screw extruder, a cooling side blowing system, a web-forming machine and a hot rolling mill; the material system, the screw extruder, the cooling side blowing system and the web-forming machine are arranged in sequence from top to bottom.

[0019] Furthermore, the post-finishing system also includes a hot rolling mill, a hot air consolidation device and a winder; the hot rolling mill, the hot air pre-consolidation device, the hot air consolidation device and the winder are arranged in sequence from the location of the web forming system to the direction away from the web forming system.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] 1. The preparation method of this scheme uses hot air consolidation non-contact fiber web consolidation technology to transfer heat to the fiber web through airflow. This method has little effect on the density of the product and can make the prepared non-woven fabric have higher fluffiness. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the preparation process of the high-loft non-woven fabric of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the overall preparation device of the present invention;

[0024] Figure 3 It is a schematic diagram of the three-dimensional structure of the hot air pre-consolidation device of the present invention;

[0025] Figure 4 It is a schematic diagram of a partial explosion structure of a hot air pre-consolidation body of the present invention;

[0026] Figure 5 It is a partial structural schematic diagram of the hot air pre-consolidation body of the present invention;

[0027] Figure 6 is a cross-sectional schematic diagram of the hot air pre-consolidation device of the present invention;

[0028] Figure 7 It is a schematic diagram of the structure of the base portion of the hot air pre-consolidation device of the present invention;

[0029] Figure 8 It is a schematic diagram of the exploded structure of the base of the hot air pre-consolidation device of the present invention;

[0030] Fig. 9 It is a schematic diagram of the hot air flow direction of the hot air pre-consolidation device of the present invention.

[0031] Description of the numbers in the figure:

[0032] 1 material system, 2 twin-screw extruder, 3 cooling side blowing system, 4 web forming machine, 5 hot rolling mill, 6 hot air consolidation device, 7 hot air pre-consolidation device, 71 air inlet, 711 first air inlet, 712 second air inlet, 713 baffle, 72 pre-consolidation body, 721 pre-consolidation shell, 7211 air supply channel, 7212 groove, 7213 installation space, 722 cover plate, 73 electric heating rod, 74 thermal insulation cotton, 75 base, 751 upper base, 7511 air guide groove, 7512 air guide hole, 752 lower base, 7521 air guide gap, 753 base baffle, 76 fixed frame, 8 winder. DETAILED DESCRIPTION

[0033] Embodiment 1:

[0034] See also Figure 1-Figure 9 A preparation device for high-loft non-woven fabrics includes a web-forming system and a post-finishing system connected thereto, wherein the web-forming system includes a material system 1, a twin-screw extruder 2, a cooling side blowing system 3 and a web-forming machine 4 arranged from top to bottom; the post-finishing system includes a hot rolling mill 5, a hot air pre-consolidation device 7, a hot air consolidation device 6 and a winder 8 arranged from left to right.

[0035] The hot air pre-consolidation device 7 includes an air inlet 71 , a pre-consolidation body 72 , a plurality of electric heating rods 73 , a base 75 and a fixing frame 76 .

[0036] like Figure 3-Figure 4As shown, the air inlet 71 includes a first air inlet 711 and a second air inlet 712, and baffles 713 are detachably connected to the outer ends of the first air inlet 711 and the second air inlet 712; the first air inlet 711 is connected to the space for air circulation inside the pre-consolidation body. A pair of air inlets 71 are fixedly connected to the two ends of the pre-consolidation body 72, and a plurality of electric heating rods 73 are embedded and fixedly connected inside the pre-consolidation body 72; the base 75 is fixedly connected to the lower end of the pre-consolidation body 72; the outer sides of the pre-consolidation body 72 and the base 75 are half-covered with insulation cotton 74, and the lower end of the insulation cotton 74 is detachably connected to the base 75. Such a design can effectively reduce the heat loss of the hot air pre-consolidation device 7. The fixing frame 76 is fixedly connected to the lower end of the air inlet 71 to ensure that the hot air pre-consolidation device 7 is not easily offset during use.

[0037] like Figure 5-Figure 6 As shown, the pre-consolidation body 72 includes a pair of pre-consolidation shells 721, which are detachably connected. When the pair of pre-consolidation shells 721 are connected together, an air supply channel 7211 is provided at a position slightly above the center line thereof, and a groove 7212 is provided on the side of the pre-consolidation shell 721 away from the air supply channel 7211; a cover plate 722 is detachably connected on the side where the groove 7212 is located, and the cover plate 722 completely covers the outside of the groove 7212, and together with the pre-consolidation shell 721, a closed heating cavity is formed. An installation space 7213 for installing a plurality of power supply heating rods 73 is provided inside the pre-consolidation shell 721, and the installation space 7213 is located between the air supply channel 7211 and the heating cavity, and an air supply hole connected to the air supply channel 7211 and the heating cavity is provided on the side wall of the installation space 7213, so that the air flow passing through the air supply hole can be heated. In addition, a pair of horizontally placed protrusions are provided inside the groove 7212, which increases the contact area between the pre-consolidation shell 721 and the wind flow, thereby improving the heating efficiency of the hot air pre-consolidation device 7 on the incoming wind flow.

[0038] like Figure 7-Figure 8As shown, the base 75 includes an upper base 751 and a pair of lower bases 752, and the pair of lower bases 752 are fixedly connected to the lower end of the upper base 751; a gap for air flow is reserved at the connection of the pair of bases 752, so that the heated hot air can flow out from the lower end of the lower base 752. The upper end of the upper base 751 is provided with an air guide groove 7511 connected to the heating cavity, and the upper end of the lower base 752 and the lower end of the upper base 751 form an air guide gap 7521. The bottom end of the air guide groove 7511 is provided with a plurality of air guide holes 7512, which are connected to the air guide gap 7521, so that the heated air flow can be introduced into the upper base 751 along the air guide groove 7511; and then flow out from the gap between the pair of lower bases 752 along the air guide gap 753. Such a design can make the hot air form a hot air fluid with a higher speed, which provides a guarantee for the fluffiness and successful consolidation of the fiber web during the preparation of non-woven fabrics.

[0039] The lower base 752 protrudes upward toward the wind guide gap 7521 to form a guide column. The distance between the guide column and the upper base 751 is smaller than the height of the wind guide gap 7521, so that the wind flow can be throttled when flowing in the wind guide gap 7521, thereby improving the flow rate and uniformity of the hot air, so that the hot air pre-consolidation device 7 can generate a wind flow with high uniformity and high flow rate.

[0040] A protrusion is provided at the downward position of the center line of the upper base 751, and the protrusion matches the gap between a pair of lower bases 752; a fine flow channel is formed between the protrusion and the pair of lower bases 752, so that the hot air in the air guide gap 7521 can be gathered into the gap, so that the hot air can flow out of the gap evenly and quickly, ensuring that the hot air has a faster wind speed and the uniformity of the hot air, so that the non-woven fabric prepared by the hot air pre-consolidation device 7 can have a higher fluffiness.

[0041] A base baffle 753 is fixedly connected to both ends of the upper base 751 and the lower base 752. The base baffle 753 completely covers both ends of the upper base 751 and the lower base 752, effectively preventing hot air from leaking from both ends of the base 75, thereby ensuring the normal use of the hot air pre-consolidation device 7.

[0042] like Fig. 9 As shown, during use, the electric heating rod 73 is first turned on to heat the pre-consolidation device 7, and then the first air inlet 711 is detachably connected to the external air generating device, and then the baffle 713 is fixed to the outer end of the second air inlet 712, so that the incoming air flow cannot flow out from the second air inlet 712. Fig. 9 As shown by the red guide line in the middle, the air flows through the air supply channel 7211 and the heating cavity in sequence and then gathers in the air guide groove 7511, and flows out from the gap between the two lower bases 752 under the action of the air guide holes 7512 and the air guide gap 7521.

[0043] Preparation method of high-loft non-woven fabric:

[0044] (I) Preparation of bicomponent fibers: Parallel bicomponent fibers are made by metering raw material slices with different melt indexes into a feeder. The different melt indexes result in the fibers having twist characteristics, which give the fabric a high fluffiness and three-dimensional feel.

[0045] The material system 1 is controlled so that the PP raw material and the mixture of PE and COPP are put into the twin-screw extruder 2 at the A, B and C positions for melt extrusion and filtration to obtain the melt, and the temperature of the twin-screw extruder 2 is 230-250°C; then the melt is conveyed to the cooling side blowing system at a rate of 300-500kg / h for converging spinning, cooling drawing and airflow separation to obtain the bicomponent fiber. The temperature of the converging spinning is 200-230°C, and the monomers or other low molecular weight substances that do not meet the requirements are discharged during the converging spinning. The temperature of the cooling drawing is 15-20°C, and the wind pressure is 1200-1800Pa. The main exhaust of the airflow separation is 55-65%; the auxiliary exhaust is 50-60%.

[0046] (II) Preparation of non-woven fabrics

[0047] The bicomponent fibers prepared in parts A, B and C in step (i) are laid on the web-forming machine 4 in order from left to right, and the fiber web is laid at a speed of 250 m / min to form a uniform fiber web. The fiber web is passed through the hot rolling mill 5 and then passed under the hot air pre-consolidation device 7, and hot air pre-consolidation is performed at a temperature of 100°C and a wind pressure of 2500-3000 Pa; then it is conveyed to the hot air consolidation device 6, and hot air consolidation is performed at a temperature of 130-150°C to obtain a high-loft non-woven fabric. After the non-woven fabric is prepared, it is tested online and then conveyed to the winder 8 for winding into a roll. The rolled non-woven fabric is cut according to customer requirements, and the edge material is recovered and packaged.

[0048] Comparative Example 1:

[0049] The operation of this comparative example is different from that of Example 1 as follows: the bicomponent fibers prepared in parts A, B and C in step (I) are laid on a web-forming machine 4 in order from left to right at a speed of 280 m / min to form a uniform web, and the web is pre-consolidated and consolidated by a hot rolling mill 5 to obtain a non-woven fabric. After the non-woven fabric is prepared, it is tested online and then conveyed to a winder 8 to be wound into a roll. The rolled non-woven fabric is cut according to the customer's requirements, and the edge material is recovered and packaged.

[0050] Comparative Example 2:

[0051] The operation different from that of Example 1 is as follows: the two-component fibers prepared in parts A, B and C in step (i) are laid on a web-forming machine 4 in order from left to right at a speed of 300 m / min to obtain a fiber web, which is then passed into a dryer for pre-drying at a drying temperature of 95°C. After drying to a liquid content of 35%, the fiber web is allowed to stand at normal pressure for 50 hours at 40°C and a relative humidity of 65%. After standing, the fiber web is passed into a spunlace machine for spunlace treatment at a water flow temperature of 25°C, and then passed into a dryer for drying to obtain a high-fluff non-woven fabric.

[0052] Test Example 1:

[0053] The high-loft non-woven fabrics of Example 1, Comparative Example 1 and Comparative Example 2 with the same thickness and the same mass were subjected to performance tests, and the test results are shown in Table 1.

[0054] Table 1 Performance results of high-loft nonwoven fabrics involved in Example 1, Comparative Example 1 and Comparative Example 2

[0055]

[0056] It can be seen from Table 1 that the air permeability of the high-loft non-woven fabric prepared by this scheme is higher than that of Comparative Example 1 and Comparative Example 2, which indicates that the high-loft non-woven fabric prepared by this method has a higher air permeability. In addition, the breaking strength of the present application is significantly higher than the breaking strength of the high-elastic non-woven fabric involved in Comparative Example 1 and Comparative Example 2.

Claims

1. A method for processing a high-loft nonwoven fabric, characterized in that: The following steps are involved: S1: Spinning and cooling: melt-extrude and filter the mixture of PP raw material, PE raw material and COPP raw material, and then perform converging spinning, cooling, drawing and air separation to obtain bicomponent fibers; S2: Drafting and laying: Laying the bicomponent fibers in step S1; S3: hot air consolidation: the fiber web of step S2 is transferred to a hot air pre-consolidation device (7) and hot air pre-consolidation is performed under hot air at a temperature of 100-150°C and a wind pressure of 2500-3000Pa; it is then transferred to a hot air consolidation device (6) and hot air consolidation is performed under hot air at a temperature of 130-150°C to obtain a high-loft non-woven fabric.

2. The method for processing a high-loft nonwoven fabric according to claim 1, characterized in that: In the step S1, the temperature of the converging spinning is 200-300° C., and the temperature of the cooling and drawing is 15-20° C.; the main exhaust of the airflow separation is 25-65%, and the auxiliary exhaust is 50-60%.

3. The method for processing a high-loft nonwoven fabric according to claim 1, characterized in that: In the step S1, the extrusion temperature is 230-250°C.

4. A processing device for high-loft nonwoven fabric, characterized in that: A method for processing a high-loft nonwoven fabric as described in claims 1-3.

5. A high-loft nonwoven fabric processing device according to claim 4, comprising a web forming system and a post-finishing system connected thereto, characterized in that: The post-finishing system comprises a hot air pre-consolidation device (7), the hot air pre-consolidation device (7) comprises a pre-consolidation body (72) and a heat-insulating cotton (74), an air supply channel (7211) is provided inside the pre-consolidation body (72), and both ends of the pre-consolidation body (72) are fixedly connected with air inlets (71) connected with the air supply channel (7211); the two side walls of the pre-consolidation body (72) are provided with heating cavities connected with the air supply channel (7211), and the pre-consolidation body (72) is provided with a heat-insulating cotton (74). An electric heating rod (73) is embedded in and fixedly connected to the upper end of the pre-consolidation body (72); a base (75) is fixedly connected to the lower end of the pre-consolidation body (72); the thermal insulation cotton (74) is half-covered on the outer side of the pre-consolidation body (72) and the base (75), and the lower end of the thermal insulation cotton (74) is detachably connected to the base (75); a drainage groove is opened inside the base (75), and the drainage groove is connected to the heating cavity and the lower end of the base (75); a fixing frame (76) is fixedly connected to the lower end of the air inlet (71).

6. A high-loft nonwoven fabric processing device according to claim 4, characterized in that: The pre-consolidation body (72) comprises a pair of detachably connected pre-consolidation shells (721); after the pre-consolidation shells (721) are installed, the air supply channel (7211) is located above the center line thereof; grooves (7212) are provided on both sides of the pre-consolidation body (72), and cover plates (722) are detachably connected to the outer ends of the grooves (7212); the heating cavity is surrounded by the grooves (7212) and the cover plates (722).

7. The high-loft nonwoven fabric processing device according to claim 4, characterized in that: The pre-consolidation body (72) is provided with an installation space (7213) in which the power supply heating rod (73) is embedded, and the installation space (7213) is connected to the groove (7212) and the air supply channel (7211).

8. The high-loft nonwoven fabric processing device according to claim 4, characterized in that: The base (75) comprises an upper base (751) and a pair of lower bases (752); the pair of lower bases (752) are fixedly connected to the lower end of the upper base (751), and the lower end of the upper base (751) and the upper end of the lower base (752) form an air guide gap (7521); a pair of air guide grooves (7511) are provided at the upper end of the upper base (751), and a plurality of air guide holes (7512) are provided at the lower end of the air guide grooves (7511), and the air guide holes (7512) form an air guide gap (7521). and connected to the air guide groove (7511); after installation, a gap for air flow is left between the pair of lower bases (752), and the gap is connected to the air guide gap (7521); base baffles (753) are fixedly connected to both ends of the upper base (751) and the lower base (752), and the baffles (753) completely cover both ends of the upper base (751) and the lower base (752); the air guide groove is composed of the air guide groove (7511), the air guide gap (7521), the air guide hole (7512) and the gap.

9. The high-loft nonwoven fabric processing device according to claim 4, characterized in that: The web forming system comprises a material system (1), a screw extruder (2), a cooling side blowing system (3), a web forming machine (4) and a hot rolling mill (5); the material system (1), the screw extruder (2), the cooling side blowing system (3) and the web forming machine (4) are arranged in sequence from top to bottom.

10. The high-loft nonwoven fabric processing device according to claim 4, characterized in that: The post-finishing system further comprises a hot rolling mill (5), a hot air consolidation device (6) and a coiler (8); the hot rolling mill (5), the hot air pre-consolidation device (7), the hot air consolidation device (6) and the coiler (8) are arranged in sequence from the location of the web forming system to a direction away from the web forming system.

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