Elastic low-melting cotton fiber, vertical cotton material as well as preparation method and application of elastic low-melting cotton fiber and vertical cotton material

Abstract

The invention discloses an elastic low-melting cotton fiber and a preparation method thereof, the elastic low-melting cotton fiber comprises hollow inner-layer polyester and surface-layer polyester compounded on the surface of the inner-layer polyester by adopting a treating agent, the raw material of the surface-layer polyester is TPEE, the raw material of the hollow inner-layer polyester is one or more of PET, PBT and PTT, and the treating agent is stearate; the fiber has high hollowness, high compression amount and high resilience amount, after the composite surface of the inner-layer polyester and the surface-layer polyester of the elastic low-melting cotton fiber is treated by a stearate treating agent, chemical connection with higher composite strength can be integrally formed on the composite surface, and the inner-layer polyester cannot be easily torn after being stretched; particularly, the stretching processing performance of the high-hollowness fiber is remarkably improved, so that the hollow fiber still has high compression amount and high compression resilience amount after being stretched under the high-hollowness condition.

Description

Technical Field

[0001] The present invention relates to the technical field of fibers and standing cotton materials, and specifically to an elastic low-melting cotton fiber and a preparation method thereof, including standing cotton materials suitable for filling clothing, home textiles, etc., a preparation method of the standing cotton material, and the use of the standing cotton material in filling materials. Background Art

[0002] Multi-component hollow fiber is a chemical fiber with a porous cross-section. The number of holes includes single hole and multi-hole. The multi-component hollow fiber is formed by a plurality of single-component hollow fibers arranged in parallel. The single-hole multi-component fiber includes parallel type and coated type. The parallel type is made by a closed-loop spinning compound of more than two C-shaped spinnerets, and the coated type is made by a plurality of concentric annular spinnerets. The multi-component hollow fiber can form a two-dimensional curved or three-dimensional spiral structure through the difference in elastic properties of different components, thereby giving the textile material made of the fiber good fluffiness and elasticity.

[0003] At present, the multi-component hollow fiber in the prior art has become a relatively mature technology, and its raw material selection is also diverse. For example, the publication number CN1059719C discloses a parallel two-component composite porous hollow three-dimensional curly fiber, and the technical scheme discloses raw material combinations such as PE / PP, PET / PBT and high-viscosity PET / low-viscosity PET; another example is a fine denier polyester hollow fiber and a preparation method thereof disclosed in the publication number CN113957554B, and the technical scheme uses PET of different viscosities as raw materials to prepare the hollow fiber; the technical scheme reduces the hollowness of the hollow fiber, so that the hollow fiber has both high fluffiness and high compression resilience.

[0004] However, the present application discovered that the hollowness of hollow fibers plays an important role in the thermal insulation and lightweight properties of the fibers. The smaller the hollowness, the heavier the fibers and the lower the thermal insulation properties. In addition, too small a hollowness will lead to a decrease in fiber compression and the problem of compression and closure of the pores after fiber stretching. Therefore, how to make hollow fibers have high hollowness while also having high compression and high rebound is of great significance to hollow fibers.

[0005] On the other hand, the current vertical cotton materials are basically made of ordinary PET fibers and a certain proportion of low-melting-point fibers mixed into a web. However, due to the uniformity of the mixture, it is impossible to truly achieve that each fiber forms a bonding point and then intersects. The finished vertical cotton products made in this way are more likely to become loose and deformed when subjected to external forces at the points where no bonding points are formed.

[0006] At the same time, attempts were made to use 100% two-dimensional skin-core structured elastic low-melting-point fibers (the skin layer is thermoplastic elastomer and the core layer is PET) to make standing cotton materials. However, due to its two-dimensional structure, although the fibers have a certain degree of disorderly curling after heat shrinkage, since the core itself is made of PET material and the fiber morphology is not a three-dimensional structure, the standing cotton products prepared from this material are relatively rigid, feel noticeably harder, and are limited in use.

[0007] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed before the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0008] In order to overcome the problem that the two-component hollow fiber in the prior art cannot have high hollowness, high compression and high rebound; the present invention provides an elastic low-melting cotton fiber and a preparation method thereof; the elastic low-melting cotton fiber is a two-component single-hole hollow fiber, the material of the hollow inner layer polyester is PET, PBT or PTT, the material of the surface layer polyester is TPEE, the hollow inner layer polyester and the surface layer polyester are compounded using stearate as a treating agent, the hollowness of the fiber can reach 45-52%, the compression rate can reach 75-80%, and the rebound rate can reach 85-95%, and the fiber has high hollowness as well as high compression and high rebound.

[0009] The specific technical scheme of the present invention is:

[0010] An elastic low-melting cotton fiber comprises a hollow inner polyester layer and a surface polyester layer compounded on the surface of the inner polyester layer with a treatment agent, wherein the raw material of the surface polyester layer is a thermoplastic elastic material, the raw material of the hollow inner polyester layer is one or more of PET, PBT and PTT, and the treatment agent is stearate.

[0011] According to some preferred implementation aspects of the present invention, the elastic low-melting cotton fiber includes 30-70 parts of surface polyester, 30-70 parts of inner polyester, and 0.1-1 part of a treating agent, calculated by weight.

[0012] According to some preferred implementation aspects of the present invention, the thermoplastic elastic material is TPEE.

[0013] According to some preferred embodiments of the present invention, the treating agent is one or more selected from zinc stearate, calcium stearate, barium stearate, magnesium stearate and lead stearate.

[0014] According to some preferred embodiments of the present invention, the elastic low-melting cotton fiber is an elastic curly fiber, and its curly shape is a three-dimensional spiral or an Ω curly shape.

[0015] According to some preferred implementation aspects of the present invention, the elastic low-melting cotton fiber has a hollowness of 45-52%, a compression rate of 75-80%, a resilience rate of 85-95%, and a dry heat shrinkage rate of 2-30% at 180°C.

[0016] The present invention provides an elastic low-melting cotton fiber, which is a two-component single-hole hollow fiber. The raw material of the inner hollow polyester is PET, PBT or PTT, and the raw material of the surface polyester is TPEE. The hollow inner polyester and the surface polyester are treated with stearate when they are compounded. The fiber has high hollowness and high resilience and high compression rebound. TPEE is a type of linear block copolymer containing polyester hard segments and aliphatic polyester or polyether soft segments. Therefore, when TPEE is compounded with PET, PBT or PTT, the polyester hard segment in TPEE can be compatible with high molecular weight polyesters such as PET, PBT or PTT, so that the inner polyester material can form an integral body with the polyester hard segment in the surface polyester after compounding. In addition, compared with TPEE, the inner polyester material has higher plasticity. TPEE contains soft segment molecular chains, and TPEE has higher toughness and elasticity. Therefore, the inner polyester can provide excellent processability when used as the inner layer of the hollow fiber, so that the hollow fiber can form a fixed shape, while the surface TPEE can give full play to its high toughness and high elasticity to give the hollow fiber excellent elastic properties.

[0017] When the present invention prepares a two-component single-hole hollow fiber using only the surface polyester and the inner polyester as raw materials, it is found that the polyester hard segment in the surface polyester can be dissolved into the inner polyester, while the soft segment molecular chain in the surface polyester has poor compatibility with the inner polyester, so their composite surfaces are connected in the form of hydrogen bonds. When the hollow fiber is stretched, the inner polyester is highly plastic and prone to fine tearing, resulting in a significant decrease in the compression rebound performance of the hollow fiber. In particular, as the hollowness of the hollow fiber increases, the inner polyester is more likely to tear during stretching. Therefore, in order to solve the above problems, the present application uses stearate as a treating agent to act on the composite surface of the surface polyester and the inner polyester, which can significantly inhibit the tearing of the inner plastic polyester layer when the hollow fiber is stretched, and can significantly improve the tensile processability of the hollow fiber.

[0018] The present invention also provides a method for preparing the above-mentioned elastic low-melting cotton fiber, wherein the elastic low-melting cotton fiber is prepared by hollow parallel melt spinning using surface polyester, inner layer polyester and a treating agent as raw materials, wherein the molten surface polyester is ejected from an outer ring spinneret hole, the molten inner layer polyester is ejected from an inner ring spinneret hole, and the molten treating agent is ejected from a middle ring spinneret hole.

[0019] According to some preferred implementation aspects of the present invention, the hollow concentric parallel melt spinning includes pre-treatment, front spinning and post-spinning.

[0020] According to some preferred implementation aspects of the present invention, the pretreatment comprises the following steps: drying the inner layer polyester, the surface layer polyester and the treatment agent respectively;

[0021] The drying temperature of the inner layer of polyester is 110-120°C and the drying time is 4-6 hours;

[0022] The drying temperature of the surface polyester is 95-105°C and the drying time is 2-6 hours;

[0023] The drying temperature of the treatment agent is 70-80°C, and the drying time is 5-10 hours.

[0024] According to some preferred embodiments of the present invention, the pre-spinning comprises the following steps:

[0025] The dried surface polyester is injected into a first screw mixer for melt mixing to form a molten inner polyester, the dried inner polyester is injected into a second screw mixer for melt mixing to form a molten inner polyester, and the dried treatment agent is heated until it is melted to form a molten treatment agent;

[0026] Injecting molten surface polyester into the first spinning box, injecting molten inner polyester into the second spinning box, and injecting molten treatment agent into the third spinning box;

[0027] First, the molten inner layer polyester is extruded from the inner ring spinneret hole, and then the molten surface layer polyester is extruded from the outer ring spinneret hole. At the same time, the molten inner layer polyester, the molten treatment agent and the molten surface layer polyester are respectively extruded from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole to form a single-hole composite fiber yarn. The single-hole composite fiber yarn is then cooled by ring blowing. After cooling, the fiber yarn is fed into a stretching machine for cold stretching. After cold stretching, the fiber yarn is fed into a winding machine to make a pre-spinning raw yarn.

[0028] According to some preferred implementation aspects of the present invention, the pre-spinning conditions include:

[0029] The temperature in the first screw mixer is 200-265°C, and the temperature in the first spinning box is 220-275°C;

[0030] The temperature in the second screw mixer is 250-300°C, and the temperature in the second spinning box is 250-300°C;

[0031] The temperature of the third spinning box is 100-300°C.

[0032] Ring blowing temperature 10~30℃, ring blowing speed 0.5~10m / s;

[0033] Winding speed 500~1500m / min;

[0034] The cold stretching ratio is 150-350%.

[0035] According to some preferred embodiments of the present invention, the post-spinning comprises the following steps: feeding the pre-spinning raw yarn obtained by pre-spinning into the post-spinning machine for sequentially stretching, curling, oiling, relaxing, heat setting and cutting into elastic low-melting cotton fibers.

[0036] According to some preferred embodiments of the present invention, the post-spinning conditions include: oil tank temperature 30-50°C, water bath temperature 60-90°C, steam box temperature 80-99°C, steam box opening 0-60%, oven temperature 50-120°C, crimping main pressure 3-4kg, and total draft ratio 150-350%.

[0037] The preparation method of the above-mentioned elastic low-melting cotton fiber provided by the present invention adopts a hollow parallel melt spinning method. A three-ring spinneret is used in the method. The three-ring spinneret is provided with a middle ring spinneret hole and an outer ring spinneret hole in sequence with the center of the inner ring spinneret hole as the center. The radii of the inner ring, middle ring and outer ring increase in sequence. The present invention first performs a drying pretreatment on the surface polyester, the inner layer polyester and the treatment agent respectively. After drying, the surface polyester, the inner layer polyester and the treatment agent are pre-spun. In the pre-spinning process, the surface polyester, the inner layer polyester and the treatment agent are first melted respectively. Then, the molten surface polyester, the inner layer polyester and the treatment agent are respectively injected into the spinning box corresponding to the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole. The molten surface polyester is ejected from the outer ring spinneret hole, the molten inner layer polyester is ejected from the inner ring spinneret hole, and the molten treatment agent is ejected from the inner ring spinneret hole. The middle ring spinneret sprays out, and in the initial stage of the spinneret spraying out the molten polyester, the molten inner layer polyester is sprayed out first and then the molten surface layer polyester is sprayed out, so that the starting end of the hollow fiber is cooled and closed, and then the molten inner layer polyester, the molten treatment agent and the molten surface layer polyester are sprayed out at the same time for spinning and compounding, and the sprayed fiber filaments are ring-blown cooled and cold-stretched to make pre-spun raw yarns, and then the pre-spun raw yarns are stretched and qualitatively processed through the post-spinning process of stretching, curling, oiling, heat setting and cutting to make elastic low-melting cotton fibers. In the method, the treating agent is directly made into a molten state and is extruded together with the surface polyester and the inner polyester as an interlayer. During extrusion, the treating agent can directly treat the composite surface of the surface polyester and the inner polyester, so that the polyether or polyester soft segment molecules of the surface polyester and the inner polyester can be chemically connected under the action of stearate, so that the overall composite surface of the surface polyester and the inner polyester forms a chemically bonded whole. The stearate can also modify the surface of the inner polyester to improve its surface toughness. In the subsequent stretching process, the surface of the inner polyester will not be easily torn.

[0038] Another object of the present invention is to provide a standing cotton material comprising the elastic low-melting cotton fibers as described above, which has excellent structural stability and excellent elasticity while taking into account softness.

[0039] Specifically, the vertical cotton material of the present invention includes one, two or three of a first fiber with a fineness of 0.5 to 3D, a second fiber with a fineness of 3 to 7D, and a third fiber with a fineness of 7 to 25D. The first fiber, the second fiber, and the third fiber are the elastic low-melting cotton fibers mentioned above, which are of a skin-core structure, and the polyester material of the skin layer (surface layer) is a thermoplastic elastic material TPEE, and the polyester material of the core layer (inner layer) is one or more of PET, PBT, and PTT. The core layer is a hollow structure, and the finally formed two-component hollow fiber has a three-dimensional spiral structure.

[0040] According to some preferred implementation aspects of the present invention, the lengths of the first fiber, the second fiber, and the third fiber are 38-101 mm.

[0041] The present invention also provides a method for preparing the vertical cotton material as described above, comprising the following steps: opening, mixing, combing, laying, vertical forming, hot air setting, cutting, rolling, cutting, and rolling a plurality of fiber raw materials in sequence to obtain the vertical cotton material. The oven temperature during hot air setting is 190-200°C, and the oven belt speed is 0.5-3m / min.

[0042] The present invention also provides an application of the above-mentioned vertical cotton material in soft filling materials such as clothing and home textiles; that is, a filling material including the above-mentioned vertical cotton material is provided.

[0043] In some embodiments, such as pad filling materials, the vertical cotton material does not contain the first fiber, but is composed of the second fiber and the third fiber. The mass ratio between the second fiber and the third fiber is 5-7:4, preferably 6:4; the inner layer polyester of the second fiber is PBT, and the inner layer polyester of the third fiber is PET. The dry heat shrinkage rate of the fiber is preferably 8%-15%.

[0044] In other embodiments, such as clothing filling materials, the vertical cotton material does not contain the third fiber, and is composed of the first fiber and the second fiber. The mass ratio between the first fiber and the second fiber is 6-8:3, preferably 7:3; the inner layer polyester of the first fiber is PTT, and the inner layer polyester of the second fiber is PBT. The dry heat shrinkage rate of the fiber is preferably 3%-8%.

[0045] Due to the adoption of the above technical scheme, compared with the prior art, the present invention is beneficial in that: the elastic low-melting cotton fiber of the present invention is a single-hole two-component hollow fiber, the fiber includes a surface polyester, an inner polyester and a treatment agent, the surface polyester is PTEE, the inner polyester is PET, PBT or PTT, the treatment agent is stearate, the treatment agent treats the composite surface of the inner polyester and the outer polyester, the fiber has high hollowness, high compression and high rebound, the hollowness can reach 45-52%, the compression rate can reach 75-80%, the rebound rate can reach 85-95%; the dry heat shrinkage rate at 180°C is 2-30%. After the composite surface of the inner polyester and the surface polyester of the elastic low-melting cotton fiber is treated with the stearate treatment agent, the composite surface can form a chemical connection with higher composite strength as a whole, so that the inner polyester will not be easily torn after being stretched, especially significantly improving the tensile processing performance of the high hollow fiber, so that the hollow fiber still has high compression and high compression rebound after being stretched under high hollow conditions. The vertical cotton material of the present invention has strong fiber bonding property, good fluffiness and softness of the finished product, good resistance to external force damage and extremely strong resilience. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] The invention relates to the technical field of composite fibers, and discloses an elastic low-melting cotton fiber and a preparation method thereof. The elastic low-melting cotton fiber comprises a hollow inner polyester layer and a surface polyester layer composited on the surface of the inner polyester layer by a treatment agent, wherein the raw material of the surface polyester layer is TPEE, the raw material of the hollow inner polyester layer is one or more of PET, PBT and PTT, and the treatment agent is stearate; the fiber has high hollowness, high compression and high resilience, and after the composite surface of the inner polyester layer and the surface polyester layer of the elastic low-melting cotton fiber is treated with a stearate treatment agent, the composite surface can form a chemical connection with higher composite strength as a whole, and the inner polyester layer will not be easily torn after being stretched, especially significantly improving the stretching processing performance of the high-hollowness fiber, so that the hollow fiber still has high compression and high compression resilience after being stretched under high-hollowness conditions.

[0048] Example 1

[0049] The elastic low-melting cotton fiber in this embodiment includes a hollow inner layer polyester and a surface layer polyester compounded on the surface of the inner layer polyester with a treating agent. The raw material of the surface layer polyester is 50 parts of TPEE, the raw material of the hollow inner layer polyester is 50 parts of PBT, and the treating agent is 0.5 parts of zinc stearate.

[0050] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0051] Pretreatment: TPEE, PBT and zinc stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 100°C and the drying time was 4 hours; the drying temperature of PBT was 115°C and the drying time was 5 hours; the drying temperature of zinc stearate was 75°C and the drying time was 8 hours;

[0052] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0053] The dried PBT is injected into the second screw mixer for melt mixing to form molten PBT, and the temperature of each zone of the second screw mixer is: 250-280°C in zone 1, 250-300°C in zone 2, 250-300°C in zone 3, 250-300°C in zone 4, and 250-300°C in zone 5; the dried zinc stearate is heated to melt to form molten zinc stearate, and the heating temperature is 150°C;

[0054] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 250°C; inject molten PBT into the second spinning box, the box temperature of the second spinning box is 275°C; inject molten zinc stearate into the third spinning box, the temperature of the third spinning box is 225°C; first extrude molten PBT from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then molten PBT, molten zinc stearate and molten TPEE are extruded from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and a single-hole composite fiber is formed after extrusion, and then cooled by ring blowing (ring blowing temperature 20°C, ring blowing speed 5m / s), and after cooling, the fiber is fed into a stretching machine for cold stretching, and the stretching ratio is 200%; after cold stretching, the fiber is fed into a winder to form a pre-spun raw fiber, and the winder speed is 1000m / min;

[0055] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 40°C, water bath temperature 75°C, steam box temperature 90°C, curling pressure 3.5kg, oven temperature 85°C, and total drawing ratio 200%.

[0056] Example 2

[0057] The elastic low-melting cotton fiber in this embodiment includes a hollow inner layer polyester and a surface layer polyester compounded on the surface of the inner layer polyester with a treating agent. The raw material of the surface layer polyester is 30 parts of TPEE, the raw material of the hollow inner layer polyester is 70 parts of PBT, and the treating agent is 0.1 parts of calcium stearate.

[0058] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0059] Pretreatment: TPEE, PBT and calcium stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 95°C and the drying time was 2 hours; the drying temperature of PBT was 110°C and the drying time was 4 hours; the drying temperature of calcium stearate was 70°C and the drying time was 5 hours;

[0060] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0061] The dried PBT is injected into the second screw mixer for melt mixing to form molten PBT, and the temperature of each zone of the second screw mixer is: 250-280°C in zone 1, 250-300°C in zone 2, 250-300°C in zone 3, 250-300°C in zone 4, and 250-300°C in zone 5; the dried calcium stearate is heated to melt to form molten calcium stearate, and the heating temperature is 200°C;

[0062] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 220°C; inject molten PBT into the second spinning box, the box temperature of the second spinning box is 250°C; inject molten calcium stearate into the third spinning box, the temperature of the third spinning box is 200°C; first extrude molten PBT from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then extrude molten PBT, molten calcium stearate and molten TPEE from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and form a single-hole composite fiber yarn after extrusion, and then cool it by ring blowing (ring blowing temperature 25°C, ring blowing speed 6m / s), and after cooling, feed the fiber yarn into a stretching machine for cold stretching, and the stretching ratio is 150%; after cold stretching, feed the fiber yarn into a winder to make a pre-spun raw yarn, and the winder speed is 500m / min;

[0063] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 30°C, water bath temperature 60°C, steam box temperature 80°C, curling pressure 3kg, oven temperature 50°C, and total drawing ratio 150%.

[0064] Example 3

[0065] The elastic low-melting cotton fiber in this embodiment includes a hollow inner layer polyester and a surface layer polyester compounded on the surface of the inner layer polyester with a treating agent. The raw material of the surface layer polyester is 70 parts of TPEE, the raw material of the hollow inner layer polyester is 30 parts of PBT, and the treating agent is 1 part of barium stearate.

[0066] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0067] Pretreatment: TPEE, PBT and barium stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 105°C and the drying time was 6 hours; the drying temperature of PBT was 120°C and the drying time was 6 hours; the drying temperature of barium stearate was 80°C and the drying time was 10 hours;

[0068] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0069] The dried PBT is injected into the second screw mixer for melt mixing to form molten PBT, and the temperature of each zone of the second screw mixer is: 250-280°C in zone 1, 250-300°C in zone 2, 250-300°C in zone 3, 250-300°C in zone 4, and 250-300°C in zone 5; the dried barium stearate is heated to melt to form molten barium stearate, and the heating temperature is 230°C;

[0070] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 275°C; inject molten PBT into the second spinning box, the box temperature of the second spinning box is 300°C; inject molten barium stearate into the third spinning box, the temperature of the third spinning box is 250°C; first extrude molten PBT from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then extrude molten PBT, molten barium stearate and molten TPEE from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and form a single-hole composite fiber yarn after extrusion, and then cool it by ring blowing (ring blowing temperature 30°C, ring blowing speed 10m / s), and after cooling, feed the fiber yarn into a stretching machine for cold stretching, and the stretching ratio is 300%; after cold stretching, feed the fiber yarn into a winder to make a pre-spun raw yarn, and the winder speed is 1500m / min;

[0071] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 50°C, water bath temperature 90°C, steam box temperature 99°C, curling pressure 4kg, oven temperature 120°C, and total drawing ratio 350%.

[0072] Example 4

[0073] The elastic low-melting cotton fiber in this embodiment includes a hollow inner polyester layer and a surface polyester layer compounded on the surface of the inner polyester layer with a treating agent. The raw material of the surface polyester layer is 40 parts of TPEE, the raw material of the hollow inner polyester layer is 60 parts of PBT, and the treating agent is 0.6 parts of magnesium stearate.

[0074] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0075] Pretreatment: TPEE, PBT and magnesium stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 100°C and the drying time was 4 hours; the drying temperature of PBT was 115°C and the drying time was 5 hours; the drying temperature of magnesium stearate was 70°C and the drying time was 5 hours;

[0076] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0077] The dried PBT is injected into the second screw mixer for melt mixing to form molten PBT, and the temperature of each zone of the second screw mixer is: 250-280°C in zone 1, 250-300°C in zone 2, 250-300°C in zone 3, 250-300°C in zone 4, and 250-300°C in zone 5; the dried magnesium stearate is heated to melt to form molten magnesium stearate, and the heating temperature is 210°C;

[0078] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 250°C; inject molten PBT into the second spinning box, the box temperature of the second spinning box is 275°C; inject molten magnesium stearate into the third spinning box, the temperature of the third spinning box is 250°C; first extrude molten PBT from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then molten PBT, molten magnesium stearate and molten TPEE are extruded from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and a single-hole composite fiber is formed after extrusion, and then cooled by ring blowing (ring blowing temperature 15°C, ring blowing speed 5m / s), and after cooling, the fiber is fed into a stretching machine for cold stretching, and the stretching ratio is 180%; after cold stretching, the fiber is fed into a winder to form a pre-spun raw fiber, and the winder speed is 1200m / min;

[0079] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 40°C, water bath temperature 75°C, steam box temperature 90°C, curling pressure 3kg, oven temperature 80°C, and total drawing ratio 200%.

[0080] Example 5

[0081] The elastic low-melting cotton fiber in this embodiment includes a hollow inner layer polyester and a surface layer polyester compounded on the surface of the inner layer polyester with a treating agent. The raw material of the surface layer polyester is 60 parts of TPEE, the raw material of the hollow inner layer polyester is 40 parts of PBT, and the treating agent is 0.4 parts of lead stearate.

[0082] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0083] Pretreatment: TPEE, PBT and lead stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 100°C and the drying time was 4 hours; the drying temperature of PBT was 110°C and the drying time was 6 hours; the drying temperature of lead stearate was 80°C and the drying time was 5 hours;

[0084] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0085] The dried PBT is injected into the second screw mixer for melt mixing to form molten PBT, and the temperature of each zone of the second screw mixer is: 250-280°C in zone 1, 250-300°C in zone 2, 250-300°C in zone 3, 250-300°C in zone 4, and 250-300°C in zone 5; the dried lead stearate is heated to melt to form molten lead stearate, and the heating temperature is 120°C;

[0086] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 250°C; inject molten PBT into the second spinning box, the box temperature of the second spinning box is 275°C; inject molten lead stearate into the third spinning box, the temperature of the third spinning box is 200°C; first extrude molten PBT from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then molten TPEE, molten lead stearate and molten PBT are extruded from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and a single-hole composite fiber is formed after extrusion, and then cooled by ring blowing (ring blowing temperature 25°C, ring blowing speed 6m / s), and after cooling, the fiber is fed into a stretching machine for cold stretching, and the stretching ratio is 250%; after cold stretching, the fiber is fed into a winder to form a pre-spun raw fiber, and the winder speed is 800m / min;

[0087] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 45°C, water bath temperature 75°C, steam box temperature 90°C, curling pressure 4kg, oven temperature 100°C, and total drawing ratio 200%.

[0088] Example 6

[0089] The elastic low-melting cotton fiber in this embodiment includes a hollow inner layer polyester and a surface layer polyester compounded on the surface of the inner layer polyester with a treating agent. The raw material of the surface layer polyester is 50 parts of TPEE, the raw material of the hollow inner layer polyester is 50 parts of PTT, and the treating agent is 0.4 parts of lead stearate.

[0090] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0091] Pretreatment: TPEE, PTT and lead stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 100°C and the drying time was 4 hours; the drying temperature of PTT was 110°C and the drying time was 6 hours; the drying temperature of lead stearate was 80°C and the drying time was 5 hours;

[0092] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0093] The dried PTT is injected into the second screw mixer for melt mixing to form molten PTT, and the temperature of each zone of the second screw mixer is: 200-220°C in zone 1, 220-230°C in zone 2, 220-230°C in zone 3, 220-230°C in zone 4, and 220-230°C in zone 5; the dried lead stearate is heated to melt to form molten lead stearate, and the heating temperature is 130°C;

[0094] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 250°C; inject molten PTT into the second spinning box, the box temperature of the second spinning box is 230°C; inject molten lead stearate into the third spinning box, the temperature of the third spinning box is 200°C; first extrude molten PTT from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then extrude molten TPEE, molten lead stearate and molten PTT from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and form a single-hole composite fiber yarn after extrusion, and then cool it by ring blowing (ring blowing temperature 25°C, ring blowing speed 6m / s), and after cooling, feed the fiber yarn into a stretching machine for cold stretching, and the stretching ratio is 200%; after cold stretching, feed the fiber yarn into a winder to make a pre-spun raw yarn, and the winder speed is 600m / min;

[0095] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 45°C, water bath temperature 75°C, steam box temperature 90°C, curling pressure 4kg, oven temperature 100°C, and total drawing ratio 200%.

[0096] Example 7

[0097] The elastic low-melting cotton fiber in this embodiment includes a hollow inner layer polyester and a surface layer polyester compounded on the surface of the inner layer polyester with a treating agent. The raw material of the surface layer polyester is 60 parts of TPEE, the raw material of the hollow inner layer polyester is 40 parts of PET, and the treating agent is 0.5 parts of lead stearate.

[0098] The method for preparing the elastic low-melting cotton fiber in this embodiment comprises the following steps:

[0099] Pretreatment: TPEE, PET and lead stearate were placed in an oven for drying respectively; the drying temperature of TPEE was 100°C and the drying time was 4 hours; the drying temperature of PET was 100°C and the drying time was 6 hours; the drying temperature of lead stearate was 80°C and the drying time was 5 hours;

[0100] Pre-spinning: Inject the dried TPEE into the first screw mixer for melt mixing to form molten TPEE. The temperature of each zone of the first screw mixer is: 200-220°C in zone 1, 220-250°C in zone 2, 220-250°C in zone 3, 220-265°C in zone 4, and 220-265°C in zone 5;

[0101] The dried PET is injected into the second screw mixer for melt mixing to form molten PET, and the temperature of each zone of the second screw mixer is: 250-280°C in zone 1, 250-280°C in zone 2, 250-280°C in zone 3, 250-280°C in zone 4, and 250-280°C in zone 5; the dried lead stearate is heated to melt to form molten lead stearate, and the heating temperature is 150°C;

[0102] Inject molten TPEE into the first spinning box, the box temperature of the first spinning box is 250°C; inject molten PET into the second spinning box, the box temperature of the second spinning box is 280°C; inject molten lead stearate into the third spinning box, the temperature of the third spinning box is 200°C; first extrude molten PET from the inner ring spinneret hole, and then extrude molten TPEE from the outer ring spinneret hole to make the fiber starting end composite closed, and then molten TPEE, molten lead stearate and molten PET are extruded from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole respectively at the same time, and a single-hole composite fiber is formed after extrusion, and then cooled by ring blowing (ring blowing temperature 25°C, ring blowing speed 6m / s), and after cooling, the fiber is fed into a stretching machine for cold stretching, and the stretching ratio is 250%; after cold stretching, the fiber is fed into a winder to form a pre-spun raw fiber, and the winder speed is 750m / min;

[0103] Post-spinning: The pre-spinning raw yarn obtained by the pre-spinning is fed into the post-spinning machine for drawing, curling, oiling, relaxing, heat setting and cutting in sequence to make elastic low-melting cotton fiber. The post-spinning conditions are: oil tank temperature 45°C, water bath temperature 75°C, steam box temperature 90°C, curling pressure 4kg, oven temperature 100°C, and total drawing ratio 200%.

[0104] Example 8

[0105] The vertical cotton material in this embodiment does not contain the first fiber, wherein the second fiber accounts for 60% and the third fiber accounts for 40%. The second fiber adopts 5D*64 specifications, the surface polyester is PTEE, the inner polyester is PTT, and the dry heat shrinkage rate is 8%; the third fiber adopts 10D*64 specifications, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 8%.

[0106] The cotton sample specification of the present embodiment is: 40kg / m 3 *5cm. The main process conditions during preparation are: oven temperature 195℃, oven belt speed 0.7m / min. 40kg / m 3 *5cm represents: material density is 40kg / m 3 , cotton-like thickness 5cm.

[0107] Example 9

[0108] The vertical cotton material in this embodiment does not contain the first fiber, wherein the second fiber accounts for 60% and the third fiber accounts for 40%. The second fiber adopts 5D*64 specifications, the surface polyester is PTEE, the inner polyester is PBT, and the dry heat shrinkage rate is 8%; the third fiber adopts 10D*64 specifications, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 8%.

[0109] The cotton sample specification of the present embodiment is: 40kg / m 3 *5cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 0.7m / min.

[0110] Example 10

[0111] The vertical cotton material in this embodiment does not contain the first fiber, wherein the second fiber accounts for 60% and the third fiber accounts for 40%. The second fiber adopts 5D*64 specifications, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 8%; the third fiber adopts 10D*64 specifications, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 8%.

[0112] The cotton sample specification of the present embodiment is: 40kg / m 3 *5cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 0.7m / min.

[0113] Embodiment 11

[0114] The vertical cotton material in this embodiment does not contain the first fiber, wherein the second fiber accounts for 60% and the third fiber accounts for 40%. The second fiber adopts 5D*64 specifications, the surface polyester is PTEE, the inner polyester is PBT, and the dry heat shrinkage rate is 8%; the third fiber adopts 10D*64 specifications, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 15%.

[0115] The cotton sample specification of the present embodiment is: 40kg / m 3 *5cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 0.7m / min.

[0116] Example 12

[0117] The vertical cotton material in this embodiment does not contain the third fiber, wherein the first fiber accounts for 70% and the second fiber accounts for 30%. The first fiber adopts 2D*51 specification, the surface polyester is PTEE, the inner polyester is PTT, and the dry heat shrinkage rate is 3%; the second fiber adopts 3D*64 specification, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 3%.

[0118] The cotton sample specification of the Li cotton material in this embodiment is: 100g / m 2 *2cm. The main process conditions during preparation are: oven temperature 195℃, oven belt speed 3m / min. 100g / m 2 *2cm represents: material surface density is 100g / m 2 , thickness 2cm.

[0119] Embodiment 13

[0120] The vertical cotton material in this embodiment does not contain the third fiber, wherein the first fiber accounts for 70% and the second fiber accounts for 30%. The first fiber adopts 2D*51 specification, the surface polyester is PTEE, the inner polyester is PBT, and the dry heat shrinkage rate is 3%; the second fiber adopts 3D*64 specification, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 3%.

[0121] The cotton sample specification of the Li cotton material in this embodiment is: 100g / m 2 *2cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 3m / min.

[0122] Embodiment 14

[0123] The vertical cotton material in this embodiment does not contain the third fiber, wherein the first fiber accounts for 70% and the second fiber accounts for 30%. The first fiber adopts 2D*51 specification, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 3%; the second fiber adopts 3D*64 specification, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 3%.

[0124] The cotton sample specification of the Li cotton material in this embodiment is: 100g / m 2 *2cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 3m / min.

[0125] Embodiment 15

[0126] The vertical cotton material in this embodiment does not contain the third fiber, wherein the first fiber accounts for 70% and the second fiber accounts for 30%. The first fiber adopts 2D*51 specification, the surface polyester is PTEE, the inner polyester is PBT, and the dry heat shrinkage rate is 3%; the second fiber adopts 3D*64 specification, the surface polyester is PTEE, the inner polyester is PET, and the dry heat shrinkage rate is 8%.

[0127] The cotton sample specification of the Li cotton material in this embodiment is: 100g / m 2 *1.5cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 3m / min.

[0128] The above examples are development comparisons for material application scenarios. Among them, Examples 8 to 11 are developed for pad material applications. From the perspective of the softness of the final cotton product, the PTT fiber has the softest feel (Example 8), while the heat drying shrinkage rate is 15% (Example 11), the cotton product is obviously compact and the feel will become harder, but the stiffness is the strongest.

[0129] Embodiments 12 to 15 are developed for application in clothing or thin materials. From the perspective of the softness of the final cotton product, the fiber using PTT has the softest feel (embodiment 12), while the heat drying shrinkage rate is 8% (embodiment 15), and the cotton product is obviously compact, feels harder, and is the thinnest.

[0130] Judging from the above results, different product effects can be achieved by adjusting the fiber ratio and dry heat shrinkage rate to meet the different needs of different scenarios and products.

[0131] Example 17 Preparation method

[0132] This embodiment provides a method for preparing a vertical cotton material as in the above embodiment, comprising the following steps: opening, mixing, combing, laying, vertical forming, hot air setting, cutting, winding, cutting, and winding a plurality of fiber raw materials in sequence to obtain a vertical cotton material. Each step is a conventional method in the art and will not be described in detail here. The oven temperature and oven belt speed during hot air setting are all recorded in the above embodiments 8-15.

[0133] Comparative Example 1

[0134] Compared with Example 1, no stearate was used in Comparative Example 1, and the other conditions were basically the same as those in Example 1.

[0135] Comparative Example 2

[0136] Comparative Example 2 adopts the method of Comparative Example 1, and controls the hollowness of the fiber to 30%.

[0137] Comparative Example 3

[0138] Comparative Example 3 adopts the method of Comparative Example 1, and controls the hollowness of the fiber to 10%.

[0139] Comparative Example 4

[0140] Compared with Example 6, no treating agent was used in Comparative Example 4, and the other conditions were basically the same as those in Example 6.

[0141] Comparative Example 5

[0142] Compared with Example 7, in Comparative Example 5, a post-treatment agent is used, and the other conditions are basically the same as those in Example 7.

[0143] Comparative Example 6 (Excessive dosage of stearate)

[0144] Compared with Example 1, the amount of stearate used in Comparative Example 6 is 5 parts, which is too high. The other conditions are basically the same as those in Example 1.

[0145] Comparative Example 7

[0146] The vertical cotton material in this comparative example contains 40% 5D*64 three-dimensional hollow PET polyester fiber, 30% 10D*51 two-dimensional solid ordinary polyester low-melting point fiber, and 30% 7D*64 three-dimensional hollow PET polyester fiber (dry heat shrinkage rate 5%).

[0147] The cotton sample specification of the neutral cotton material in this comparative example is: 40kg / m 2 *5cm. The main process conditions during preparation are: oven temperature 195℃, oven belt speed 0.7m / min

[0148] Comparative Example 8

[0149] The vertical cotton material in this comparative example contains 40% 5D*64 three-dimensional hollow PET polyester fiber, 40% 6D*51 two-dimensional elastic thermoplastic low-melting point fiber (surface polyester elastomer PTEE 40%, inner layer polyester PET 60%), and 20% 7D*64 three-dimensional hollow PET polyester fiber (dry heat shrinkage rate 5%).

[0150] The cotton sample specification of the neutral cotton material in this comparative example is: 40kg / m 2 *5cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 0.7m / min.

[0151] Comparative Example 9

[0152] The vertical cotton material in this comparative example contains 70% of 2D*51 two-dimensional PET polyester fiber and 30% of 3D*51 two-dimensional common low-melting point fiber.

[0153] The cotton sample specification of the neutral cotton material in this comparative example is: 100g / m 2 *2cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 3m / min.

[0154] Comparative Example 10

[0155] The vertical cotton material in this comparative example contains 70% 2D*51 two-dimensional PET polyester fiber and 30% 4D*51 two-dimensional elastic thermoplastic low-melting point fiber (surface layer polyester elastomer PTFE 40%, inner layer polyester PET 60%).

[0156] The cotton sample specification of the neutral cotton material in this comparative example is: 100g / m 2 *2cm. The main process conditions during preparation are: oven temperature 195°C, oven belt speed 3m / min.

[0157] Test and result discussion:

[0158] 1) Targeting fiber

[0159] The properties of the elastic low-melting cotton fibers obtained in Examples 1 to 7 and Comparative Examples 1 to 6 were tested, and the test items included: hollowness, compression rate, resilience, breaking strength and breaking elongation. The test results are shown in Table 1.

[0160] Among them, the hollowness test method refers to the longitudinal section test method in "Discussion on the hollowness measurement method of single-hole hollow circular cross-section fiber. Textile standards and quality. Mayuan";

[0161] The compression and rebound test methods include the following steps:

[0162] Weigh 400g of elastic low-melting cotton fiber, comb the fiber flat and open it, and evenly place it in a 10L large beaker. Place 625g of polytetrafluoroethylene pressed sheet on the fiber in the beaker; start timing at this time, and place a 2kg weight on the polytetrafluoroethylene pressed sheet after 30s. The residence time is 30s. Take the 2kg weight out of the polytetrafluoroethylene pressed sheet for 30s. Repeat the above operation three times, and then start measuring the height. Note that each time you measure the height, read the height of the upper layer of the polytetrafluoroethylene pressed sheet, and quickly read the height of the beaker wall in four directions each time, and take the average value of the height in the four directions as the height. =H0, place two 2kg weights on the surface of the polytetrafluoroethylene sheet, the residence time is 30s, start measuring the height, pay attention to read the upper height of the polytetrafluoroethylene sheet each time the height is measured, quickly read the height of the beaker wall in four directions each time, and take the average value of the height in the four directions as H1; take the two 2kg weights out of the polytetrafluoroethylene sheet surface 180s later, start measuring the height, pay attention to read the upper height of the polytetrafluoroethylene sheet each time the height is measured, quickly read the height of the beaker wall in four directions each time, and take the average value of the height in the four directions as H2;

[0163] The actual height is the difference between the measured height H1 (cm) and the thickness of the polytetrafluoroethylene sheet (2cm) and the bottom of the beaker (0.25cm). The compression rate is (H0-H1) / H0.

[0164] The compression rebound rate is (H2-H1) / (H0-H1);

[0165] The test methods for elongation at break and breaking strength refer to "GB / T 14344-2022. Test method for tensile properties of chemical fiber filaments".

[0166] Table 1 Performance test results of elastic low-melting cotton fibers of Examples 1-7 and Comparative Examples 1-6

[0167] Hollowness(%) Compression rate (%) Rebound rate (%) Breaking strength (cN / dtex) Elongation at break (%) Example 1 50 80 95 2.8 120 Example 2 52 75 85 4.0 40 Example 3 45 78 88 1.5 180 Example 4 51 79 90 2.3 150 Example 5 48 76 93 3.2 80 Example 6 50 78 92 2.9 135 Example 7 50 77 91 2.8 118 Comparative Example 1 50 83 33 1.2 58 Comparative Example 2 30 65 78 2.78 85 Comparative Example 3 10 34 95 2.82 98 Comparative Example 4 50 80 28 1.5 79 Comparative Example 5 50 81 43 1.8 65 Comparative Example 6 50 10 3 / /

[0168] As shown in Table 1, Examples 1-7 are elastic low-melting cotton fibers provided by the present invention, and the hollowness of the cotton fibers is 45-52%, the compression rate is 75-80%, the rebound rate is 85-95%, the breaking strength is 1.5-4.0 cN / dtex, and the breaking elongation is 40-180%; the fiber has both high compression performance and high rebound performance under high hollowness conditions.

[0169] Comparative Examples 1-3 are elastic low-melting cotton fibers that have not been treated with stearate. By analyzing the results of Comparative Examples 1 to 3 and Example 1, it is found that when the hollowness of Comparative Example 1 is the same as that of Example 1, the fiber compression rate of Comparative Example 1 is not significantly different from that of Example 1, but the rebound rate of Comparative Example 1 is significantly lower than the fiber compression rate of Example 1, and the inner layer polyester and the surface layer polyester of the fiber of Example 1 are complete, smooth and without cracks, while the inner layer polyester of the fiber of Comparative Example 1 is torn, which indicates that when the hollowness of Comparative Example 1 is high, the plasticity of the inner layer polyester is high and cannot withstand tensile deformation, resulting in tearing, which leads to a significant decrease in the rebound performance of the fiber after compression. After the fiber of Example 1 is treated with stearate, the inner layer polyester and the surface layer polyester of the fiber do not tear after tensile deformation, and the fiber structure is complete, so that the fiber of Example 1 has both high compression performance and high rebound performance under high hollowness conditions.

[0170] In addition, through the analysis of the results of comparative examples 1-3, it was found that the hollowness has a great influence on the compression rate and rebound rate of the hollow fiber. The smaller the hollowness, the higher the rebound performance of the fiber, but the compression performance of the fiber will also be significantly reduced. Through microscopic observation of the longitudinal sections of the fibers of comparative examples 1 and 3, it was found that the smaller the hollowness, the higher the tear resistance of the inner layer of the polyester in the fiber. When the hollowness of comparative example 2 was reduced to 30%, the inner layer of the polyester did not tear. Although the reduction in hollowness can ensure the strength of the fiber, the compression performance of the fiber is also significantly reduced, and it cannot have both high compression rate and high rebound rate properties.

[0171] Comparative Examples 4 and 5 are hollow fibers prepared using PTT and PET as inner layer polyester materials without using stearate treatment. The results of Comparative Examples 4 and 5 show that when PTT and PET are used as inner layer polyesters and composited with surface layer polyesters, using stearate as a treatment agent can make the hollow fibers have both high compressibility and high resilience under high hollowness conditions.

[0172] In Comparative Example 6, an excessive amount of stearate was used, and it was found that both the compression rate and the rebound rate were significantly reduced. The stearate formed an interlayer between the inner polyester layer and the outer polyester layer, resulting in a change in the layered structure of the fiber. The hardened stearate caused the rebound resilience and compressibility of the hollow fiber to be significantly reduced, making it unusable.

[0173] 2) For vertical cotton materials (cushion materials)

[0174] The vertical cotton materials of the above-mentioned Examples 8-11 and Comparative Examples 7-8 were tested for resilience, indentation hardness, and thickness loss rate in durability tests. The results are shown in Table 2 below. The test methods are:

[0175] Resilience: GB / T 6670-2008 "Determination of rebound properties of soft foam polymer materials by falling ball method";

[0176] Indentation hardness: GB / T 10807-2006 Determination of hardness of soft foam polymeric materials (indentation method);

[0177] Durability test thickness loss rate: GB / T 10802-2006 General purpose soft polyether polyurethane foam plastics "Constant load repeated compression fatigue performance".

[0178] Table 2 Test results of cushion materials

[0179] project Resilience Indentation hardness Durability test thickness loss rate Example 8 50％ 550N 3.2％ Example 9 55％ 640N 3.7％ Example 10 55％ 700N 4％ Embodiment 11 58％ 750N 5％ Comparative Example 7 35％ 850N 15％ Comparative Example 8 45％ 790N 7％

[0180] The results in Table 2 show that compared with Comparative Examples 7-8, Examples 8-11 have significantly lower indentation hardness, that is, the material is softer; the resilience is significantly better, and the loss of thickness in the durability test is smaller. At the same time, if the fiber dry heat shrinkage rate is too large, it will also affect the increase of indentation hardness and the increase of durable thickness loss.

[0181] 3) For vertical cotton materials (clothing materials)

[0182] The compression rate, recovery rate, thickness loss rate after washing, cotton-like deformation degree after washing, and softness of hand feel of the above-mentioned Examples 12-15 and Comparative Examples 9-10 were tested, and the results are shown in Table 3. The test methods are:

[0183] Compression rate and recovery rate: refer to FZ / T 64003-2021 "Compression and resilience performance test method for spray-coated cotton wool sheets", in which the weights of 2kg and 4kg are changed to 2.65kg and 5.3kg respectively;

[0184] After washing index test:

[0185] Material preparation: Spread the cotton sample with the same 60g / m 2 300T calendered polyester woven fabric, quilted into 7cm*7cm quilting grid size, take 50cm*50cm sample, and fix it with stitches around. Use the same drum washing machine and the same washing method (normal temperature, dehydration speed 800r / min) to wash 10 times. Hang to dry.

[0186] Thickness loss rate after washing: Spread the dried material flat on the table and measure the thickness before and after washing. Thickness loss rate after washing = (thickness before washing - thickness after washing) / thickness before washing.

[0187] Deformation of cotton sample after washing: After washing and drying the material, remove the quilting line and observe the cotton sample for looseness, kinks, holes and other problems. Compare with the cotton sample state before washing, and take the state before washing as the standard to rate it from 0 to 5. 0 is the initial state (i.e. the state before washing), and 5 is the worst state.

[0188] Softness of hand feel: Three or more experienced people will compare the hand feel of several cotton samples, with the hardest being 1. If the hand feel is basically the same, the scores can be tied. Finally, the scores of each cotton sample given by the three people will be added up and divided by 3 to take the average.

[0189] Table 3 Test results of clothing materials

[0190] project Compression Response rate Thickness loss rate after washing Degree of cotton-like deformation after washing Softness Example 12 60％ 90％ 5.2％ 2 4 Example 13 57％ 93％ 5％ 2 2.67 Embodiment 14 55％ 94％ 5％ 2 3 Embodiment 15 48％ 98％ 2％ 1 1 Comparative Example 9 72％ 81％ 13％ 4 2 Comparative Example 10 66％ 85％ 10％ 3 2.67

[0191] The results in Table 3 show that compared with Comparative Examples 9-10, Examples 12-15 have a smaller depression rate and a significantly higher recovery rate, indicating that the resilience of the Examples is significantly superior. Moreover, the deformation degree of the cotton sample after washing is significantly smaller, and the softness of the hand feel is acceptable. However, if the dry heat shrinkage rate is too large, the cotton sample will appear hardened, and the thickness of the cotton product will also become thinner.

[0192] The hollowness of hollow fibers plays an important role in lightweighting the thermal insulation performance of fibers. The smaller the hollowness, the heavier the fiber and the lower the thermal insulation performance. In addition, too small a hollowness will lead to a decrease in fiber compression and the problem of compression and closure of the pores after fiber stretching. The elastic low-melting cotton fiber of the present invention is a single-hole two-component hollow fiber. The raw materials of the fiber are surface polyester, inner polyester and a treating agent. The surface polyester is PTFE, the inner polyester is PBT, and the treating agent is stearate. The treating agent treats the composite surface of the inner polyester and the outer polyester. The fiber has high hollowness, high compression and high rebound. The hollowness can reach 45-52%, the compression rate can reach 75-80%, and the rebound rate can reach 85-95%. After the composite surface of the inner polyester and the surface polyester of the elastic curled fiber is treated with the stearate treating agent, the composite surface can form a chemical connection with higher composite strength as a whole, and the inner polyester will not be easily torn after being stretched, especially the stretching processing performance of the high hollowness fiber is significantly improved, so that the hollow fiber still has high compression and high compression rebound after being stretched under the condition of high hollowness.

[0193] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An elastic low-melting cotton fiber, characterized in that: It comprises a hollow inner polyester layer and a surface polyester layer which is compounded with a treatment agent on the surface of the inner polyester layer. The raw material of the surface polyester layer is a thermoplastic elastic material, the raw material of the inner polyester layer is one or more of PET, PBT and PTT, and the treatment agent is stearate.

2. The elastic low-melting cotton fiber according to claim 1, characterized in that: The mass fraction of the surface layer polyester is 30 to 70 parts, the mass fraction of the inner layer polyester is 30 to 70 parts, and the mass fraction of the treatment agent is 0.1 to 1 part.

3. The elastic low-melting cotton fiber according to claim 1, characterized in that: The thermoplastic elastic material is TPEE.

4. The elastic low-melting cotton fiber according to claim 1, characterized in that: The treatment agent is one or more selected from zinc stearate, calcium stearate, barium stearate, magnesium stearate and lead stearate.

5. The elastic low-melting cotton fiber according to claim 1, characterized in that: The elastic low-melting cotton fiber is an elastic curly fiber, and its curly shape is a three-dimensional spiral or an Ω curly shape.

6. The elastic low-melting cotton fiber according to claim 1, characterized in that: The elastic low-melting cotton fiber has a hollowness of 45-52%, a compression rate of 75-80%, a resilience rate of 85-95%, and a dry heat shrinkage rate of 2-30% at 180°C.

7. A method for preparing elastic low-melting cotton fiber according to any one of claims 1 to 6, characterized in that: The steps include: The elastic low-melting cotton fiber is prepared by hollow parallel melt spinning with surface polyester, inner polyester and treating agent as raw materials. The molten surface polyester is ejected from the outer ring spinneret hole, the molten inner polyester is ejected from the inner ring spinneret hole, and the molten treating agent is ejected from the middle ring spinneret hole.

8. The method for preparing elastic low-melting cotton fiber according to claim 7, characterized in that: The hollow concentric parallel melt spinning includes pre-treatment, front spinning and back spinning.

9. The method for preparing elastic low-melting cotton fiber according to claim 8, characterized in that: The pretreatment comprises the following steps: drying the inner layer polyester, the surface layer polyester and the treatment agent respectively; The drying temperature of the inner layer of polyester is 110-120°C and the drying time is 4-6 hours; The drying temperature of the surface polyester is 95-105°C and the drying time is 2-6 hours; The drying temperature of the treatment agent is 70-80°C, and the drying time is 5-10 hours.

10. The method for preparing elastic low-melting cotton fiber according to claim 8, characterized in that: The pre-spinning comprises the following steps: The dried surface polyester is injected into a first screw mixer for melt mixing to form a molten inner polyester, the dried inner polyester is injected into a second screw mixer for melt mixing to form a molten inner polyester, and the dried treatment agent is heated until it is melted to form a molten treatment agent; Injecting molten surface polyester into the first spinning box, injecting molten inner polyester into the second spinning box, and injecting molten treatment agent into the third spinning box; First, the molten inner layer polyester is extruded from the inner ring spinneret hole, and then the molten surface layer polyester is extruded from the outer ring spinneret hole. At the same time, the molten inner layer polyester, the molten treatment agent and the molten surface layer polyester are respectively extruded from the inner ring spinneret hole, the middle ring spinneret hole and the outer ring spinneret hole to form a single-hole composite fiber yarn. The single-hole composite fiber yarn is then cooled by ring blowing. After cooling, the fiber yarn is fed into a stretching machine for cold stretching. After cold stretching, the fiber yarn is fed into a winding machine to make a pre-spinning raw yarn.

11. The method for preparing elastic low-melting cotton fiber according to claim 8 or 10, characterized in that: The pre-spinning conditions include: The temperature in the first screw mixer is 200-265°C, and the temperature in the first spinning box is 220-275°C; The temperature in the second screw mixer is 250-300°C, and the temperature in the second spinning box is 250-300°C; The temperature of the third spinning box is 100-300°C; Ring blowing temperature 10~30℃, ring blowing speed 0.5~10m / s; Winding speed 500~1500m / min; The cold stretching ratio is 150-350%.

12. The method for preparing elastic low-melting cotton fiber according to claim 8, characterized in that: The post-spinning comprises the following steps: feeding the pre-spinning raw yarn obtained by the pre-spinning into the post-spinning machine for sequentially stretching, curling, oiling, relaxing, heat setting and cutting into segments to obtain elastic low-melting cotton fibers.

13. The method for preparing elastic low-melting cotton fiber according to claim 8 or 12, characterized in that: The post-spinning conditions include: oil tank temperature of 30-50°C, water bath temperature of 60-90°C, steam box temperature of 80-99°C, steam box opening of 0-60%, oven temperature of 50-120°C, crimping main pressure of 3-4kg, and total draft ratio of 150-350%.

14. A standing cotton material comprising the elastic low-melting cotton fiber according to any one of claims 1 to 6.

15. The vertical cotton material according to claim 14, characterized in that: It comprises one, two or three of a first fiber with a fineness of 0.5 to 3D, a second fiber with a fineness of 3 to 7D, and a third fiber with a fineness of 7 to 25D, wherein the first fiber, the second fiber and the third fiber are the elastic low-melting cotton fibers described in any one of claims 1 to 6.

16. The vertical cotton material according to claim 15, characterized in that: The lengths of the first fibers, the second fibers, and the third fibers are 38 to 101 mm.

17. A method for preparing a vertical cotton material as described in any one of claims 14 to 16, comprising the following steps: opening, mixing, combing, laying, vertical forming, hot air setting, cutting, rolling, slicing, and rolling a variety of fiber raw materials in sequence to obtain the vertical cotton material.

18. A filling material, characterized in that: Comprising the vertical cotton material as described in any one of claims 14-16.

19. The filling material according to claim 18, characterized in that The filling material is a pad material, and the vertical cotton material in the pad material is composed of second fibers and third fibers.

20. The filling material according to claim 18, characterized in that The filling material is a clothing material, and the vertical cotton material in the clothing material is composed of first fibers and second fibers.