Self-adhesive coarse denier bi-component composite fiber and preparation method thereof

Abstract

The invention discloses a self-adhesive coarse denier bi-component composite fiber which is composed of a plurality of monofilaments of skin-core structures, the skin layer of each monofilament is PBS, the core layer of each monofilament is PET, and the mass ratio of the skin layer to the core layer is 1 / 1-1 / 2; in the same bundle of composite fiber, the skin layers PBS of the adjacent monofilaments are bonded together to form a coarse denier fiber, and the overall section of the composite fiber is of a sea-island-like structure. During preparation, polymer slices are used as raw materials, monofilaments with skin-core structures are melted and extruded in parallel by a screw extruder, skin layers of the bundled monofilaments are mutually bonded, and the coarse denier bi-component composite fiber is obtained through the procedures of blowing, cooling, oiling, drafting, winding and the like. According to the scheme, biodegradable raw materials are adopted, chemical adhesives are not needed, and the composite material is skin-friendly, environmentally friendly, good in mechanical property and tensile elasticity, free of toxicity and irritation and capable of being used as an ideal material for manufacturing vamps, clothes and hygienic products.

Description

Technical Field

[0001] The invention relates to a composite fiber, in particular to a self-adhesive coarse-denier two-component composite fiber and a preparation method thereof, belonging to the technical field of textile materials. Background Art

[0002] Hot-melt adhesive coarse denier polyester fiber is widely praised in the market for its rapid bonding, wide application, and no volatile organic compound (VOCs) pollution. In recent years, hot-melt adhesive polyester mainly uses PET-based low melting point modified polyester (LMPET). The low melting point modified polyester is used as the skin layer and the conventional polyethylene terephthalate (PET) is used as the core layer to obtain the skin-core hot-melt adhesive coarse denier polyester fiber. The product is used in many fields such as stiff mesh, shoe materials, curtains and high-end clothing linings.

[0003] The low melting point modified polyester mentioned above is still a petroleum-based polyester. The waste generated after use will bring white pollution and microplastic pollution to the environment. In addition, LMPET has problems such as high cost, difficulty in drying and spinning. The country will further promote the development of green textiles and will improve energy efficiency, resource utilization, clean production, and improve the green manufacturing system as the green development direction of the textile industry.

[0004] Polybutylene succinate (PBS) is a kind of aliphatic bio-based degradable green polyester that has been developing strongly in recent years. It has excellent comprehensive properties, good crystallization performance, excellent fiber-forming performance, and shows good development prospects in the fiber field. In order to solve the above problems and implement the purpose of green development of the textile industry, the inventor of this case has developed a technical solution for preparing coarse denier composite fibers using PBS as raw material after research, so as to improve the comprehensive performance of such composite fibers. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and provide a self-adhesive coarse denier two-component composite fiber and a preparation method thereof, so as to solve the various problems existing in the prior art of using low-melting point modified polyester to prepare hot-melt adhesive coarse denier polyester fiber.

[0006] The technical solution of the present invention is: a self-bonding coarse-denier two-component composite fiber, which is characterized in that the composite fiber is composed of multiple monofilaments with a sheath-core structure, the sheath layer of the monofilament is polybutylene succinate (PBS), the core layer is polyethylene terephthalate (PET), and the mass ratio of the sheath layer to the core layer is 1 / 1 to 1 / 2; in the same bundle of composite fibers, the sheath layers PBS of adjacent monofilaments are bonded together to form a coarse-denier fiber, and the overall cross-section of the composite fiber is similar to an island structure.

[0007] Preferably, the linear density of the self-bonding coarse denier bicomponent composite fiber is 100-150 dtex, the breaking strength is 2.5-3.0 cN / dtex, and the breaking elongation is 40-60%.

[0008] The present invention also provides a method for preparing the self-adhesive coarse denier bicomponent composite fiber, which is prepared by using polymer chips as raw materials, melt extrusion by a screw extruder and skin-core spinning, and comprises the following steps:

[0009] Step (i), polyethylene terephthalate (PET) chips are used as the core layer raw material, dried and melt-extruded through a main screw, the PET melt is accurately metered by a metering pump and transported to a spinning box, and then evenly distributed to a core-skin composite spinning device to serve as the core layer of the fiber monofilament;

[0010] Step (ii), polybutylene succinate (PBS) slices are used as the raw material for the cortex, dried and melt-extruded through a secondary screw, the PBS melt is accurately metered by a metering pump and transported to the spinning box, and then evenly distributed to the core-skin composite spinning device as the cortex of the fiber monofilament;

[0011] Step (iii), the melts of the core layer and the skin layer are simultaneously injected into the spinneret of the skin-core composite spinning device, and after composite, fiber monofilaments with a skin-core structure are extruded, and the skin layers are bonded to each other after the monofilaments are bundled. After the blowing, cooling, oiling, drawing and winding processes, a self-bonding coarse denier two-component composite fiber is obtained.

[0012] Furthermore, in the method for preparing the above-mentioned self-bonding coarse denier two-component composite fiber, in which: in step (i), the intrinsic viscosity of the PET slice is 0.6-0.7 dL / g, and the melting temperature is 280-290°C; in step (ii), the intrinsic viscosity of the PBS slice is 1.7-1.9 dL / g, and the melting temperature is 220-235°C.

[0013] Furthermore, in the preparation method of the above-mentioned self-bonding coarse denier two-component composite fiber, in step (iii): the spinning temperature of the core-sheath composite spinning device is 280-290°C; the wind pressure of the blowing process is 50-150Pa, and the wind temperature is 10-15°C; the cooling process adopts spinning tunnel cooling, and the cooling section length is 1.30-1.60 meters; the drawing process adopts at least two pairs of drawing rollers, the heat setting temperature is 70-95°C, and the drawing multiple is 1.5-2.5; the winding speed of the winding process is 2000-3200m / min.

[0014] Specifically, the drafting process can be divided into three stages: the first stage has a drafting multiple of 1.1 to 1.5 and a drafting temperature of 10 to 60°C; the second stage has a drafting multiple of 1.4 to 2.2 and a drafting temperature of 20 to 60°C; the third stage has a drafting multiple of 1.4 to 2.2 and a drafting temperature of 20 to 60°C. The drafting operation is carried out in stages, so that the polymer macromolecules can be oriented and crystallized under the action of the drafting stress, so as to avoid excessive self-adhesion between the monofilaments, and can assist in the rapid shaping of the composite fiber.

[0015] By adopting the technical solution of the present invention, since the melting points and crystallization properties of PBS and PET are extremely different, the cooling and solidification time required for PBS is relatively long. Therefore, during the bundling process, the cortexes of adjacent composite fiber monofilaments can be bonded to each other to form coarse denier fibers. When the spun fiber product enters the next application, the cortex of the corresponding core-sheath composite fiber is melted by heat, still has a bonding effect, and has the characteristic of a small heat shrinkage rate, without the need to add additional chemical adhesives.

[0016] Compared with the prior art, the present invention adopts biodegradable raw materials to prepare hot-melt coarse denier polyester fibers, which do not require the use of chemical adhesives, are skin-friendly and environmentally friendly, effectively protect the environment, and also have good mechanical properties, tensile elasticity, and are non-toxic and non-irritating. It can be used as an ideal material for manufacturing uppers, clothing and sanitary products, providing a sustainable solution material for the upgrading of related products, and has good application prospects and market value.

[0017] Moreover, the preparation method provided by the present invention is simple to operate, and the process and process parameters are obtained after careful research and testing. It is practical and reliable, and its sheath-core components have high flow matching. It also has the advantages of high spinning speed, continuous spinning and uninterrupted spinning, and is suitable for industrial production. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific examples, but it should not be understood that the protection scope of the above subject matter of the present invention is limited to the following examples. Among them, the raw materials used are commercially available or homemade using methods known in the industry.

[0019] Example 1

[0020] Polybutylene succinate (PBS slice: intrinsic viscosity is 1.73 dL / g) and polyethylene terephthalate (PET slice: intrinsic viscosity is 0.67 dL / g) are screw extruded and melt-compositely spun at a mass ratio of 1:1.

[0021] 1. PET chips are used as the core layer raw material. After drying, they are melted by the main screw. The temperature of the main screw is 288°C. The polyethylene terephthalate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the skin-core composite spinning device in the spinning box.

[0022] 2. PBS slices are used as the raw material for the cortex. After drying, they are melted by the auxiliary screw. The temperature of the auxiliary screw is 232°C. The polybutylene succinate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the core-skin composite spinning device in the spinning box.

[0023] 3. The two melts simultaneously enter the sheath-core composite spinning device, the temperature of the sheath-core composite spinning device is 288°C, and the fibers with a sheath-core structure are extruded after being compounded by the sheath-core spinneret. The fibers are bonded after being bundled and cooled by blowing and spinning tunnel, wherein the blowing cooling temperature is 11.5°C and the blowing cooling air pressure is 100Pa. Then, the fibers are successively subjected to the bundling oiling treatment, the stretching process with a stretching multiple of 1.8 times and the winding process with a speed of 2500m / min to obtain a self-bonding coarse denier two-component composite fiber.

[0024] Example 2

[0025] Polybutylene succinate (PBS slice: intrinsic viscosity is 1.73 dL / g) and polyethylene terephthalate (PET slice: intrinsic viscosity is 0.67 dL / g) are screw extruded and melt-compositely spun at a mass ratio of 1:1.5.

[0026] 1. PET chips are used as the core layer raw material. After drying, they are melted by the main screw. The temperature of the main screw is 288°C. The polyethylene terephthalate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the skin-core composite spinning device in the spinning box.

[0027] 2. PBS slices are used as the raw material for the cortex. After drying, they are melted by the auxiliary screw. The temperature of the auxiliary screw is 232°C. The polybutylene succinate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the core-skin composite spinning device in the spinning box.

[0028] 3. The two melts simultaneously enter the sheath-core composite spinning device, the temperature of the sheath-core composite spinning device is 288°C, and the fibers with a sheath-core structure are extruded after being compounded by the sheath-core spinneret. The fibers are bonded after being bundled and cooled by blowing and spinning tunnel, wherein the blowing cooling temperature is 11.5°C and the blowing cooling air pressure is 100Pa. Then, the fibers are successively subjected to the bundling oiling treatment, the stretching process with a stretching multiple of 2 times and the winding process with a speed of 3000m / min to obtain a self-bonding coarse denier two-component composite fiber.

[0029] Example 3

[0030] Polybutylene succinate (PBS slice: intrinsic viscosity is 1.85 dL / g) and polyethylene terephthalate (PET slice: intrinsic viscosity is 0.67 dL / g) are screw extruded and melt-compositely spun at a mass ratio of 1:1.

[0031] 1. PET chips are used as the core layer raw material. After drying, they are melted by the main screw. The temperature of the main screw is 288°C. The polyethylene terephthalate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the skin-core composite spinning device in the spinning box.

[0032] 2. PBS slices are used as the raw material for the cortex. After drying, they are melted by the auxiliary screw. The temperature of the auxiliary screw is 238°C. The polybutylene succinate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the core-skin composite spinning device in the spinning box.

[0033] 3. The two melts simultaneously enter the sheath-core composite spinning device, the temperature of the sheath-core composite spinning device is 288°C, and the fibers with a sheath-core structure are extruded after being compounded by the sheath-core spinneret. The fibers are bonded after being bundled and cooled by blowing and spinning tunnel, wherein the blowing cooling temperature is 11.5°C and the blowing cooling air pressure is 100Pa. Then, the fibers are successively subjected to the bundling oiling treatment, the stretching process with a stretching multiple of 2 times and the winding process with a speed of 3000m / min to obtain a self-bonding coarse denier two-component composite fiber.

[0034] Example 4

[0035] Polybutylene succinate (PBS slice: intrinsic viscosity is 1.85 dL / g) and polyethylene terephthalate (PET slice: intrinsic viscosity is 0.67 dL / g) are screw extruded and melt-compositely spun at a mass ratio of 1:1.5.

[0036] 1. PET chips are used as the core layer raw material. After drying, they are melted by the main screw. The temperature of the main screw is 288°C. The polyethylene terephthalate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the skin-core composite spinning device in the spinning box.

[0037] 2. PBS slices are used as the raw material for the cortex. After drying, they are melted by the auxiliary screw. The temperature of the auxiliary screw is 238°C. The polybutylene succinate melt is accurately measured by a metering pump and transported to the spinning box. It is evenly distributed to the core-skin composite spinning device in the spinning box.

[0038] 3. The two melts simultaneously enter the sheath-core composite spinning device, the temperature of the sheath-core composite spinning device is 288°C, and the fibers with a sheath-core structure are extruded after being compounded by the sheath-core spinneret. The fibers are bonded after being bundled and cooled by blowing and spinning tunnel, wherein the blowing cooling temperature is 11.5°C and the blowing cooling air pressure is 100Pa. Then, the fibers are successively subjected to the bundling oiling treatment, the stretching process with a stretching multiple of 2 times and the winding process with a speed of 3000m / min to obtain a self-bonding coarse denier two-component composite fiber.

[0039] Comparative Example 1

[0040] The skin layer material is PET-based low-melting point modified polyester (LMPET), and the core layer material is conventional PET. The ratio between the skin layer and the core layer is 1:1 by mass ratio, and the melting point difference between the skin layer and the core layer is 45°C to 70°C. The skin layer and the core layer are melt-composite spun (various parameters: main screw temperature is 288°C, sub-screw temperature is 230°C, spinning assembly temperature is 288°C; cooling air temperature is 11.5°C, cooling air pressure is 100Pa; maximum spinning speed during spinning is 3000m / min; drafting multiple is 2.0 times) to obtain LMPET / PET composite fiber.

[0041] Comparative Example 2

[0042] The skin layer material is PET-based low-melting point modified polyester (LMPET), and the core layer material is conventional PET. The ratio between the skin layer and the core layer is 1:1.5 by mass ratio, and the melting point difference between the skin layer and the core layer is 45°C to 70°C. The skin layer and the core layer are melt-composite spun (various parameters: main screw temperature is 288°C, sub-screw temperature is 230°C, spinning assembly temperature is 288°C; cooling air temperature is 11.5°C, cooling air pressure is 100Pa; maximum spinning speed during spinning is 3000m / min; drafting multiple is 2.0 times) to obtain LMPET / PET composite fiber.

[0043] 1. The following is the mechanical property test and comparison of the hot melt adhesive coarse denier polyester fiber prepared in the embodiment of this case and the comparative example. The specific test method is as follows:

[0044] (1) Intrinsic viscosity test: The intrinsic viscosity of the polymer was measured using an Ubbelohde viscometer at 25±0.01°C in a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (1:1 w / w) with a polymer concentration of 0.50 g·dL. -1 .

[0045] (2) Number average molecular weight detection: Ultra-high performance polymer chromatography (APC, Waters) was used to test the molecular weight of polyester. The mobile phase used was hexafluoroisopropanol with a flow rate of 0.3 mL min -1 .

[0046] (3) Breaking strength and breaking elongation test: The test was carried out using a YG020B electronic single yarn strength tester with a fiber clamping length of 200 mm, a tensile rate of 50 mm / min, and a pre-tension of 5 cN. Each group of samples was tested 15 times, and the average values ​​were taken to obtain the breaking strength and breaking elongation of the fiber.

[0047] The specific spinning conditions and test results are shown in Table 1.

[0048] Table 1: Spinning conditions and tensile properties of Examples 1 to 4 and Comparative Examples 1 to 2

[0049] Cortex Core layer Skin-to-core mass ratio Maximum spinning speed (m / min) Linear density / dtex Strength (cN / dtex) Elongation(%) Example 1 PBS PET 1:1 2500 112 2.60 49 Example 2 PBS PET 1:1.5 3000 105 2.65 46 Example 3 PBS PET 1:1 3000 103 2.76 45 Example 4 PBS PET 1:1.5 3000 102 2.94 41 Comparative Example 1 LMPET PET 1:1 3000 106 2.63 45 Comparative Example 2 LMPET PET 1:1.5 3000 105 2.67 38

[0050] It can be seen from Examples 1 to 4 and Comparative Examples 1 to 2 that when polybutylene succinate (PBS) is used as the skin layer, it has excellent spinnability, the maximum spinning speed is not less than 2500 m / min, and the composite spinning with polyethylene terephthalate (PET) shows the industrializable characteristics of high spinning speed and stable continuous production, and its mechanical properties are comparable to those of LMPET / PET composite fibers, and it has strong practicality.

[0051] 2. The biodegradability of the hot melt adhesive coarse denier polyester fibers prepared in Examples 1 to 4 and Comparative Examples 1 to 2 was tested. The testing method was in accordance with GB / T 32366-2015, and the specific test results are shown in Table 2.

[0052] Table 2: Biodegradation rate test data of Examples 1 to 4 and Comparative Examples 1 to 2

[0053] Biodegradation rate standard Biodegradability Example 1 ≥60% qualified Example 2 ≥60% qualified Example 3 ≥60% qualified Example 4 ≥60% qualified Comparative Example 1 ≥60% Failure Comparative Example 2 ≥60% Failure

[0054] As shown in Table 2: Compared with Comparative Examples 1-2, Examples 1-4 have better degradability, can effectively protect the environment and reduce pollution.

[0055] In the technical solution of the present invention, the use of biodegradable polybutylene succinate and polyethylene terephthalate as raw materials to prepare composite fibers is the technical key of this case, wherein polybutylene succinate is used as the skin material and conventional polyethylene terephthalate is used as the core material, and the self-bonding coarse denier two-component composite fiber (i.e., self-bonding coarse denier PBS / PET fiber) finally obtained is a two-component skin-core structure composite fiber. For related equipment or components such as the skin-core composite spinning device, ordinary technicians in this field can make conventional settings according to the existing technology, and this case has no special requirements for its model selection and combined use.

[0056] In this way, by adopting the technical scheme of the present invention, since the melting point and crystallization properties of polybutylene succinate and polyethylene terephthalate are extremely different, the cooling and solidification time required for polybutylene succinate is relatively long. Therefore, during the bundling process, the cortical polybutylene succinate of adjacent composite fiber monofilaments can bond with each other to form coarse denier fibers; when the spun product enters the next application, the cortical layer of the corresponding core-sheath composite fiber is heated and melted, still has a bonding effect, and has the characteristic of a small thermal shrinkage rate.

[0057] From the above description, it can be found that compared with the prior art, after adopting the technical scheme of the present invention, biodegradable raw materials are used, and there is no need to use chemical adhesives. It is skin-friendly and environmentally friendly, effectively protects the environment, and also has good mechanical properties, tensile elasticity, and is non-toxic and non-irritating. It can be used as an ideal material for manufacturing uppers, clothing and sanitary products, and provides a sustainable solution material for the upgrading of related products, and has certain application prospects and market value; moreover, the preparation method of this self-bonding coarse denier two-component composite fiber is simple to operate, practical and reliable, and its skin-core components have high flow matching. At the same time, it has the advantages of high spinning speed, continuous spinning and uninterrupted spinning, and is suitable for industrial production.

[0058] The technical scheme, working process and implementation effect of the present invention are described in detail above. It should be noted that what is described is only a typical example of the present invention. In addition, the present invention may also have many other specific implementation methods. Any technical scheme formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

Claims

1. A self-adhesive coarse denier bicomponent composite fiber, characterized in that: The composite fiber is composed of multiple monofilaments with a sheath-core structure, wherein the sheath layer of the monofilament is polybutylene succinate (PBS), and the core layer is polyethylene terephthalate (PET), and the mass ratio of the sheath layer to the core layer is 1 / 1 to 1 / 2; in the same bundle of composite fibers, the sheath layers PBS of adjacent monofilaments are bonded together to form coarse denier fibers, and the overall cross-section of the composite fiber presents a sea-island structure.

2. The self-adhesive coarse-denier bicomponent composite fiber according to claim 1, characterized in that: The composite fiber has a linear density of 100 to 150 dtex, a breaking strength of 2.5 to 3.0 cN / dtex, and a breaking elongation of 40 to 60%.

3. The method for preparing the self-adhesive coarse denier bicomponent composite fiber according to claim 1, characterized in that: The polymer chips are used as raw materials and prepared by melt extrusion and skin-core spinning using a screw extruder, including the following steps: Step S1: Polyethylene terephthalate (PET) chips are used as the core layer raw material, which are dried and melt-extruded through a main screw. The PET melt is accurately metered by a metering pump and transported to a spinning box, and then evenly distributed to a core-skin composite spinning device to serve as the core layer of the fiber monofilament. Step S2: polybutylene succinate (PBS) slices are used as the raw material for the cortex, which is dried and melt-extruded by a secondary screw. The PBS melt is accurately metered by a metering pump and transported to the spinning box, and then evenly distributed to the core-skin composite spinning device to serve as the cortex of the fiber monofilament. Step S3: The melts of the core layer and the skin layer are simultaneously injected into the spinneret of the core-skin composite spinning device. After composite, fiber monofilaments with a core-skin structure are extruded. After the monofilaments are bundled, the skin layers are bonded to each other. After blowing, cooling, oiling, drawing and winding processes, a self-bonding coarse denier two-component composite fiber is obtained.

4. The method for preparing the self-adhesive coarse denier bicomponent composite fiber according to claim 3, characterized in that: In step S1, the intrinsic viscosity of the PET chips is 0.6-0.7 dL / g, and the melting temperature is 280-290°C.

5. The method for preparing the self-adhesive coarse-denier bicomponent composite fiber according to claim 3, characterized in that: In step S2, the intrinsic viscosity of the PBS slice is 1.7-1.9 dL / g, and the melting temperature is 220-235°C.

6. The method for preparing the self-adhesive coarse-denier bicomponent composite fiber according to claim 3, characterized in that: In step S3, the spinning temperature of the core-sheath composite spinning device is 280-290°C.

7. The method for preparing the self-adhesive coarse-denier bicomponent composite fiber according to claim 3, characterized in that: In step S3, the wind pressure of the blowing process is 50-150 Pa, and the wind temperature is 10-15°C.

8. The method for preparing the self-adhesive coarse-denier bicomponent composite fiber according to claim 3, characterized in that: In step S3, the cooling process adopts spinning tunnel cooling, and the length of the cooling section is 1.30 to 1.60 meters.

9. The method for preparing the self-adhesive coarse-denier bicomponent composite fiber according to claim 3, characterized in that: In step S3, the stretching process uses at least two pairs of stretching rollers, the heat setting temperature is 70-95°C, and the stretching ratio is 1.5-2.

5.

10. The method for preparing the self-adhesive coarse denier bicomponent composite fiber according to claim 3, characterized in that: In step S3, the winding speed of the winding process is 2000 to 3200 m / min.