A kind of oriented high-strength micro-nano yarn and preparation method thereof

Abstract

The invention discloses an oriented high-strength micro-nano yarn and a preparation method thereof. A polymer is ejected from a nozzle of a melt-blown spinning system, gradually cooled and solidified in the air to form fibers; collected and stretched by a conical fiber gathering cylinder to form fiber strips; then the fiber strips are drawn by a fiber strip output roller and output, and finally twisted into yarn and wound into bobbin yarn by a twisting and winding system. The conical fiber gathering cylinder in the invention is hollow inside, and a spiral guide groove and strip-shaped holes are arranged on the surface. A fan is used to suck air, and negative pressure is generated in the surface holes of the conical fiber gathering cylinder, and the fibers are gathered into strips. As the conical fiber gathering cylinder rotates, the fibers are fed from the small end of the conical fiber gathering cylinder and output from the large end, resulting in a certain amount of drafting. This drafting can effectively improve the parallel straightness of the fibers in the yarn, and also helps to improve the orientation of the fibers, thereby improving the strength and uniformity of the yarn, and achieving simultaneous completion of fiber gathering and drafting.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-nano fiber materials, and particularly relates to an oriented high-strength micro-nano yarn and a preparation method thereof. Background Art

[0002] Meltblown spinning technology is mainly used for the production of nonwoven fabrics. This technology originated in the early 1950s. The process is to squeeze the molten polymer into a concentrated hot air flow through an extruder. The ultrafine fibers formed under the stretching action of the air flow are blown to the condenser, thereby accumulating into an ultrafine filter material. This process is the prototype of modern meltblown nonwoven technology. Since the 1980s, meltblown nonwoven materials have grown rapidly around the world, maintaining an annual growth rate of 10% to 12%, and have achieved rapid development.

[0003] The process flow of meltblown nonwovens is as follows: polymer chips are heated and melted in a screw extruder, and the melt is transported to the spinneret holes of the spinneret. The polymer melt leaving the spinneret holes is strongly stretched by high-speed and high-temperature airflow to form ultra-fine filaments or ultra-fine staple fibers, and is deposited on a mesh curtain or a receiving roller with the airflow to form a meltblown fiber web.

[0004] The meltblowing process is a processing technology in which the polymer melt is extruded from the die head and is subjected to the action of high-speed hot air flow. Before the polymer jet cools and solidifies, the high-speed air flow is used to stretch the polymer jet to directly form an ultra-fine fiber non-woven fabric on the receiving device.

[0005] Meltblown fibers have a very fine diameter, a large specific surface area, and a small pore size of the fiber mesh, so meltblown nonwoven products have excellent particle interception, particle capture and other properties. At the same time, meltblown products also have unusual capillary action and air permeability (water and blood cannot penetrate, but water vapor can). For this reason, meltblown products can be widely used as filter materials, thermal insulation materials, sanitary materials, medical materials, etc.

[0006] The polymer is fed from the feeding hopper and pushed to the front of the barrel by the screw extrusion screw driven by the screw motor, and passes through 5 heating areas with different temperatures. The temperature of the polymer will gradually increase in the barrel, and its physical state will also change from glass state to high elastic state, and finally become viscous flow state, achieving complete melting. The screw rotates steadily at a certain speed, and the uniform molten polymer is delivered to the spinneret at equal pressure and equal amount. The polymer thin stream extruded after flowing through the spinneret aperture is then stretched by two high-temperature and high-speed airflows to produce micro-nano fibers. Summary of the invention

[0007] Purpose of the invention: In order to solve the deficiencies of the prior art, the present invention provides an oriented high-strength micro-nano yarn and a preparation method thereof.

[0008] Technical solution: An oriented high-strength micro-nano yarn is made by spinning a material that can be melt-blown spun among PET / PP / PA. In the spinning process, the melt-blowing spinning temperature is 250℃~285℃, the pressure of the screw and the spinneret assembly is 1~20Mpa, the melt flow rate is 10cc / min~200cc / min, the hot air pressure is 50~150kPa, the hot air temperature is 230℃~290℃, and the receiving distance is 100mm~600mm.

[0009] As an optimization: the melt index of the meltblown spinning is 50g / 10min to 2000g / 10min.

[0010] A preparation device for oriented high-strength micro-nano yarn, the preparation device comprising: a melt-blown spinning system, a conical fiber gathering cylinder, a fiber strip output roller and a twisting and winding system;

[0011] The polymer is ejected from the nozzle of the melt-blown spinning system, gradually cooled and solidified in the air to form fibers; it is collected and stretched by the conical fiber gathering cylinder to form fiber strips; it is then drawn by the fiber strip output roller and output, and finally twisted into yarn by the twisting and winding system and wound into bobbin yarn;

[0012] Among them, the conical fiber gathering cylinder is hollow inside, and is provided with spiral guide grooves and strip-shaped holes on the surface. The fan is used to suck air to generate negative pressure in the surface holes of the conical fiber gathering cylinder, and the fibers are gathered into strips. As the conical fiber gathering cylinder rotates, the fibers are fed from the small end of the conical fiber gathering cylinder and output from the large end. Due to the different diameters of the large and small ends, the speed of the large end is fast and the speed of the small end is slow. The fiber strips are stretched to a certain extent in the process of input from the small end and output from the large end. This stretching can effectively improve the parallel straightness of the fibers, and also help to improve the orientation of the fibers, thereby enhancing the strength and uniformity of the fibers, and realizing the one-time completion of fiber gathering and stretching.

[0013] As an optimization: the relationship between the diameter of the small end D1 and the large end D2 of the tapered fiber gathering tube and the length L on the fiber drafting is as follows: with the increase of the diameter ratio D2 / D1 and the increase of L, it is helpful to draft and improve the fiber orientation, and improve the strength and uniformity of the yarn; the larger the D2 / D1 ratio and the larger L, the more conducive to drafting and improving orientation, wherein the fiber drafting factor formula is as follows:

[0014]

[0015] Wherein: η is the fiber drafting factor (the fiber drafting multiple is also related to the wind speed, accumulation drum speed, fiber type, etc.); k is the correction coefficient; D1, D2 and L are the small end diameter, large end diameter and length of the accumulation drum respectively. The larger the D2 / D1 ratio and the larger L are, the more conducive to drafting and improving orientation.

[0016] Beneficial effects: The conical fiber gathering cylinder in the present invention is hollow inside, and is provided with spiral guide grooves and strip-shaped holes on the surface. The fan is used to suck air to generate negative pressure in the surface holes of the conical fiber gathering cylinder, and the fibers are gathered into strips. As the conical fiber gathering cylinder rotates, the fibers are fed from the small end of the conical fiber gathering cylinder and output from the large end, resulting in a certain degree of stretching. This stretching can effectively improve the parallel straightness of the fibers in the yarn, and also help to improve the orientation of the fibers, thereby enhancing the strength and uniformity of the yarn, and achieving simultaneous completion of fiber gathering and stretching. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the spinning device of the present invention;

[0018] Figure 2 It is a schematic structural diagram of the tapered fiber collecting tube of the present invention;

[0019] Figure 3 It is a linear schematic diagram of the diameter and length related to the small end D1 and the large end D2 of the present invention;

[0020] Figure 4 It is a schematic diagram of the relationship between the orientation degree of the fiber of the present invention and the D2 / D1 ratio. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0022] Example

[0023] The invention discloses an oriented high-strength micro-nano yarn. The oriented high-strength micro-nano yarn is made by spinning a material capable of melt-blowing spinning among PET / PP / PA. In the spinning process, the melt-blowing spinning temperature is 250-285°C, the pressure of the screw and the spinneret assembly is 1-20Mpa, the melt flow rate is 10cc / min-200cc / min, the hot air pressure is 50-150kPa, the hot air temperature is 230-290°C, the receiving distance is 100mm-600mm, and the melt index of the melt-blowing spinning is 50g / 10min-2000g / 10min.

[0024] like Figure 1As shown, a preparation device for oriented high-strength micro-nano yarn includes: a melt-blown spinning system 1, a conical fiber gathering cylinder 2, a fiber strip output roller 3 and a twisting and winding system 4.

[0025] The polymer is ejected from the nozzle of the melt-blown spinning system 1, gradually cooled and solidified in the air to form fibers; it is collected and stretched by the conical fiber gathering drum 2 to form fiber strips; it is then drawn by the fiber strip output roller 3 and output, and finally twisted into yarn by the twisting and winding system 4 and wound into bobbin yarn.

[0026] like Figure 2 As shown, the conical fiber gathering cylinder 2 is hollow inside, and its surface is provided with spiral guide grooves and strip-shaped holes. The fan is used to suck air to generate negative pressure in the surface holes of the conical fiber gathering cylinder 2, and the fibers are gathered into strips. As the conical fiber gathering cylinder 2 rotates, the fibers are fed from the small end D1 of the conical fiber gathering cylinder 2 and output from the large end D2. Due to the different diameters of the large and small ends, the speed of the large end is fast and the speed of the small end is slow. The fiber strips are stretched to a certain extent in the process of input from the small end and output from the large end. This stretching can effectively improve the parallel straightness of the fibers in the yarn, and also help to improve the orientation of the fibers, thereby improving the quality of the yarn, because this method is excellent in the orientation and parallel straightness of the fibers, thereby improving the strength and uniformity of the yarn, and realizing the simultaneous completion of fiber gathering and stretching.

[0027] like Figure 3 As shown, the relationship between the diameter of the small end D1 and the large end D2 of the tapered fiber gathering tube 2 and the length L on the fiber drafting is as follows: With the increase of the diameter ratio D2 / D1 and the increase of L, it is helpful to draft and improve the fiber orientation, and improve the strength and uniformity of the yarn. The larger the D2 / D1 ratio and the larger L, the more conducive to drafting and improving orientation. Among them, the fiber drafting factor formula is as follows:

[0028]

[0029] Where: η is the fiber drafting factor (the fiber drafting multiple is also related to the wind speed, the rotation speed of the accumulation drum, the fiber type, etc.); k is the correction coefficient; D1, D2 and L are the small end diameter, large end diameter and length of the accumulation drum respectively.

[0030] When k=1, the value of η is as shown in Table 1

[0031] Table 1 Fiber draft factor data table

[0032]

[0033] like Figure 4 As shown, it can be seen that the larger the D2 / D1 ratio and the larger L, the more conducive it is to drafting, improving orientation, and enhancing the strength and uniformity of the yarn.

Claims

1. A device for preparing oriented high-strength micro-nano yarn, characterized in that: The preparation device comprises: a melt-blown spinning system (1), a conical fiber gathering cylinder (2), a fiber strip output roller (3) and a twisting and winding system (4); The polymer is ejected from the nozzle of the melt-blown spinning system (1), gradually cooled and solidified in the air to form fibers, and the receiving distance is 100 mm to 600 mm; it is collected and stretched by a conical fiber gathering cylinder (2) to form fiber strips; it is then drawn by a fiber strip output roller (3) and output, and finally twisted into yarn by a twisting and winding system (4), and wound into a bobbin yarn; The conical fiber gathering cylinder (2) is hollow inside and has spiral guide grooves and strip-shaped holes on its surface. A fan is used to suck air to generate negative pressure on the surface holes of the conical fiber gathering cylinder (2), so that the fibers are gathered into strips. As the conical fiber gathering cylinder (2) rotates, the fibers are fed from the small end of the conical fiber gathering cylinder (2) and output from the large end. Due to the different diameters of the large and small ends, the speed of the large end is fast and the speed of the small end is slow. In the process of the fiber strip being input from the small end and output from the large end, a certain amount of drafting is generated. This drafting can effectively improve the parallel straightness of the fibers, and also help to improve the orientation of the fibers, thereby enhancing the strength and uniformity of the fibers. The relationship between the diameter of the small end D1 and the large end D2 of the tapered fiber gathering cylinder (2) and the length L on the fiber drafting is as follows: with the increase of the diameter ratio D2 / D1 and the increase of L, it is helpful to draft and improve the fiber orientation, and improve the strength and uniformity of the yarn; the larger the D2 / D1 ratio and the larger L, the more conducive to drafting and improving the orientation, wherein the fiber drafting factor formula is as follows: In the formula: η is the fiber drafting factor; k is the correction coefficient; D1, D2 and L are the small end diameter, large end diameter and length of the accumulation tube respectively, the ratio of D2 / D1 is 1.5-5.5, and L is 5-21mm.

2. The device for preparing oriented high-strength micro-nano yarn according to claim 1, characterized in that: A melt-blown spinning material among PET / PP / PA is used to spin oriented high-strength micro-nano yarn. In the spinning process, the melt-blown spinning temperature is 250°C to 285°C, the pressure of the screw and the spinneret assembly is 1 to 20 MPa, the melt flow rate is 10cc / min to 200cc / min, the hot air pressure is 50 to 150 kPa, and the hot air temperature is 230°C to 290°C.

3. The device for preparing oriented high-strength micro-nano yarn according to claim 2, characterized in that: The melt index of the melt-blown spinning is higher than 50 g / 10 min.

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