Biodegradable self-crimping bi-component composite elastic fiber

Abstract

The invention discloses a biodegradable self-crimping bi-component composite elastic fiber, which is prepared by using biodegradable poly (butylene succinate) and polylactic acid as raw materials according to a dosage ratio of 20 / 80-80 / 20, carrying out vacuum drying, then carrying out screw extrusion melting parallel composite spinning, and carrying out blowing, cooling, oiling, drafting, winding and other processes. The self-crimping bi-component composite elastic fiber has good compatibility and biodegradability, can effectively reduce environmental pollution, also has good mechanical properties, tensile elasticity and elastic recovery performance, and is suitable for the elastic fiber application fields of textiles, medical appliances, household articles and the like.

Description

Technical Field

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

[0002] Elastic composite fiber, also known as self-curling fiber, is made of raw materials with different structures or properties in a certain proportion through composite spinning. Its characteristic is that the difference in thermal shrinkage and initial modulus of the two components on the same fiber is used to make the fiber bend away from the fiber axis, presenting a permanent three-dimensional spiral curl. This curl has the characteristics of long-lasting stability and good elasticity, which can give the fabric better elasticity and fluffiness. Since there is no need to perform additional elastic treatment on the fiber, it not only saves energy loss, but also avoids mechanical damage to the fiber by the elasticizing equipment. It has a high application value and is therefore favored and valued by the fiber manufacturing industry.

[0003] In recent years, with the increase and expansion of the market demand for elastic fibers, most of the raw materials currently used for preparing elastic fibers are traditional polymers that are difficult to degrade, such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polyamide 6 (PA6). For example: the paper "Self-curling Structure and Performance of PTT / PET Parallel Composite Fibers" [Luo Jin, Donghua University, 2010], obtained PTT / PET self-curling fibers by melt composite spinning, and analyzed and characterized the curling characteristics of PTT / PET parallel two-component fibers, indicating that the fibers have good elastic durability; Patent CN111118665A discloses a polyester-nylon composite yarn and a preparation method thereof, specifically a PA6 / PET parallel composite fiber with a three-dimensional spiral structure, which solves the problem of "uneven stripes" of parallel composite fibers in knitted fabrics, but produces polluting waste after use; Patent CN104499091B discloses a polyester parallel composite yarn and a preparation method thereof, specifically a PBT and modified PET parallel composite yarn with a high dyeing rate, which has a much higher dyeing rate than ordinary fibers, and less floating color is formed after dyeing. The obtained material has broad prospects in the field of clothing fabrics, but still has the potential pollution of non-degradable treatment.

[0004] The waste generated after the use of the traditional polymer raw materials involved in the production of the above elastic fibers will bring white pollution and microplastic pollution to the environment: these wastes remain in the fields, affecting the absorption of water and nutrients by crops, inhibiting the growth and development of crops, leading to reduced crop yields, and seriously polluting groundwater; they stay in nature for a long time, and plastics, paper scraps and dust fly with the wind, polluting the air and the living environment of animals; in addition, the tiny plastic particles that exist in the environment for a long time enter the human body through eating and breathing, seriously affecting human health. In order to solve the above problems, the present invention proposes a solution for preparing self-curling fibers using biodegradable materials as raw materials. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and provide a biodegradable self-curling two-component composite elastic fiber to solve the problem that the waste generated by the use of polymer raw materials in the existing elastic fiber production will bring white pollution and microplastic pollution to the environment.

[0006] The technical solution of the present invention is: a biodegradable self-curling two-component composite elastic fiber, including component A and component B with good compatibility, and its characteristics are: the component A is polybutylene succinate, which is an aliphatic bio-based degradable polyester with excellent comprehensive performance, good crystallization performance and relatively excellent fiber-forming performance; the component B is polylactic acid, which is a bio-based polymer formed by fermentation, purification and a series of reactions using corn, potato, beet or grain starch as raw materials. Polylactic acid is environmentally friendly and degradable, and directly generates carbon dioxide and water after degradation, and the production process has low energy consumption. The fiber products prepared not only have good antibacterial properties but also are refreshing and sweat-conducting; the mass ratio of the polybutylene succinate to the polylactic acid is 20 / 80 to 80 / 20.

[0007] The biodegradable self-curling bicomponent composite elastic fiber is prepared by a parallel spinning method, which specifically includes the following steps:

[0008] Step (i) After vacuum drying, the polybutylene succinate chips are melt pre-treated by a screw extruder (wherein the temperature of the main screw is 215-225° C., and the temperature of the auxiliary screw is 220-225° C.), and then accurately metered by a metering pump and transported to a spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold;

[0009] Step (ii) After vacuum drying, the polylactic acid chips are melt pre-treated by a screw extruder (wherein the main screw temperature is 215-225° C., and the auxiliary screw temperature is 220-225° C.), and then accurately metered by a metering pump and transported to a spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold;

[0010] Step (iii) The melts of polybutylene succinate and polylactic acid are simultaneously injected into a spinneret inside a parallel composite spinning device, and after composite, several fiber monofilaments with a parallel structure are extruded, and then subjected to air-blowing cooling treatment, oiling treatment, drawing treatment and winding treatment to effectively improve the uniformity and weavability of the fibers, thereby obtaining a biodegradable self-curling bicomponent composite elastic fiber.

[0011] Furthermore, in the above technical solution: the intrinsic viscosity of the polybutylene succinate is 1.5-1.8 dL / g, and the melting temperature is 185-220°C; the number average molecular weight of the polylactic acid is 200000-300000 g / mol, and the melting temperature is 190-225°C.

[0012] Furthermore, in the method for preparing the above-mentioned biodegradable self-curling bicomponent composite elastic fiber, the spinning temperature of the composite spinning device is 190-225°C.

[0013] Furthermore, in the method for preparing the above-mentioned biodegradable self-curling bicomponent composite elastic fiber, the blowing cooling treatment adopts a side blowing method, the blowing cooling air temperature is 10-15° C., and the blowing cooling air pressure is 100-200 Pa.

[0014] Specifically, the side blowing method can be two stages, the cooling air temperature of the first stage is 12.5-15°C, and the cooling air temperature of the second stage is 10-12.5°C.

[0015] Furthermore, in the method for preparing the above-mentioned biodegradable self-curling bicomponent composite elastic fiber, the stretching treatment uses 2 pairs or more of stretching rollers, the stretching multiple is 1.5 to 2.5, and the stretching heat setting temperature is 70 to 95°C.

[0016] Furthermore, in the method for preparing the above-mentioned biodegradable self-curling bicomponent composite elastic fiber, the winding speed used in the winding process is 2500-3200 m / min.

[0017] Furthermore, in the method for preparing the above-mentioned biodegradable self-curling two-component composite elastic fiber, several of the fiber monofilaments are bent in an "S" shape when placed freely and have a fluffy and bulky part.

[0018] Furthermore, in the method for preparing the above-mentioned biodegradable self-curling bicomponent composite elastic fiber, the composite spinning linear density between several of the fiber monofilaments is 100-200 dtex.

[0019] Thus, by adopting the technical solution of the present invention, a biodegradable self-curling two-component composite elastic fiber is finally prepared, wherein the two components are arranged in parallel, one component is polybutylene succinate, and the other component is polylactic acid.

[0020] Compared with the prior art, after adopting the technical solution of the present invention, biodegradable raw materials are used, which have good compatibility and biodegradability, can effectively reduce environmental pollution, avoid soil and water pollution and ecological damage caused by long-term retention of waste in the natural environment, and have good application prospects and market value; moreover, there is no phase separation phenomenon in its cross section, it has high chemical stability, the breaking strength can reach 2.4-3.0 cN / dtex, the breaking elongation can reach 20-60%, the elastic recovery rate can reach 70-90%, it has good mechanical properties, tensile elasticity and elastic recovery performance, and is suitable for elastic fiber application fields such as textiles, medical devices and household items.

[0021] In addition, the preparation method of the biodegradable self-curling two-component composite elastic fiber is simple and practical, easy to operate, and can be spun using a composite spinning device to achieve industrial mass production, with a wide range of applications. DETAILED DESCRIPTION

[0022] 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.

[0023] Example 1

[0024] Polybutylene succinate is used as component A and polylactic acid is used as component B, and the two are screw extruded, melted and composite spun in parallel at a mass ratio of 20:80.

[0025] Step (i) The polybutylene succinate chips with a characteristic viscosity of 1.53 dL / g are vacuum dried at 70°C for 24 hours, heated and melted by a main screw with a main screw temperature of 215°C, accurately metered by a metering pump, and transported to a spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold.

[0026] Step (ii) vacuum drying the polylactic acid chips with a number average molecular weight of 250,000 g / mol at 70°C for 24 hours, heating and melting them through a secondary screw with a secondary screw temperature of 222°C, accurately metering them through a metering pump, and evenly distributing them to the parallel composite spinning device in the spinning manifold.

[0027] Step (iii) The melts of polybutylene succinate and polylactic acid are simultaneously injected into the spinneret inside the parallel composite spinning device. The temperature of the composite spinning device is 222° C. After composite, several fiber monofilaments with a parallel structure are extruded, and are cooled by side blowing and spinning tunnel, wherein the blowing cooling temperature is 11.5° C. and the blowing cooling air pressure is 100 Pa. Then, the fibers are subjected to a bunching and oiling treatment, a stretching treatment with a stretching multiple of 2.0 times, and a winding machine with a speed of 3000 m / min to obtain a biodegradable self-curling bicomponent composite elastic fiber.

[0028] Example 2

[0029] Polybutylene succinate is used as component A and polylactic acid is used as component B, and the two are screw extruded, melted and composite spun in parallel at a mass ratio of 30:70.

[0030] Step (i) The polybutylene succinate chips with a characteristic viscosity of 1.53 dL / g are vacuum dried at 70°C for 24 hours, heated and melted by a main screw with a main screw temperature of 215°C, accurately metered by a metering pump, and transported to a spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold.

[0031] Step (ii) vacuum drying the polylactic acid chips with a number average molecular weight of 250,000 g / mol at 70°C for 24 hours, heating and melting them through a secondary screw with a secondary screw temperature of 222°C, accurately metering them through a metering pump, and evenly distributing them to the parallel composite spinning device in the spinning manifold.

[0032] Step (iii) The melts of polybutylene succinate and polylactic acid are simultaneously injected into the spinneret inside the parallel composite spinning device. The temperature of the composite spinning device is 222° C. After composite, several fiber monofilaments with a parallel structure are extruded, and are cooled by side blowing and spinning tunnel, wherein the blowing cooling temperature is 11.5° C. and the blowing cooling air pressure is 100 Pa. Then, the fibers are subjected to a bunching and oiling treatment, a stretching treatment with a stretching multiple of 2.0 times, and a winding machine with a speed of 3000 m / min to obtain a biodegradable self-curling bicomponent composite elastic fiber.

[0033] Example 3

[0034] Polybutylene succinate is used as component A and polylactic acid is used as component B, and the two are screw extruded, melted and composite spun in parallel at a mass ratio of 20:80.

[0035] Step (i) The polybutylene succinate chips with a characteristic viscosity of 1.86 dL / gdL / g are vacuum dried at 70°C for 24 hours, heated and melted by a main screw with a main screw temperature of 225°C, accurately metered by a metering pump, and transported to a spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold.

[0036] Step (iii) The polylactic acid chips with a number average molecular weight of 250,000 g / mol are vacuum dried at 70°C for 24 hours, heated and melted by a secondary screw at a temperature of 222°C, accurately measured by a metering pump, and transported to the spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold.

[0037] Step (iii) The melts of polybutylene succinate and polylactic acid are simultaneously injected into the spinneret inside the parallel composite spinning device. The temperature of the composite spinning device is 225°C. After composite, several fiber monofilaments with a parallel structure are extruded, and are cooled by side 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 bundling oiling treatment, stretching treatment with a stretching multiple of 2.5 times and winding by a winding machine at a speed of 3000m / min to obtain a biodegradable self-curling bicomponent composite elastic fiber.

[0038] Example 4

[0039] Polybutylene succinate is used as component A and polylactic acid is used as component B, and the two are screw extruded, melted and composite spun in parallel at a mass ratio of 30:70.

[0040] Step (i) The polybutylene succinate chips with a characteristic viscosity of 1.86 dL / gdL / g are vacuum dried at 70°C for 24 hours, heated and melted by a main screw with a main screw temperature of 225°C, accurately metered by a metering pump, and transported to a spinning manifold, and evenly distributed to the parallel composite spinning device in the spinning manifold.

[0041] Step (ii) vacuum drying the polylactic acid chips with a number average molecular weight of 250,000 g / mol at 70°C for 24 hours, heating and melting them through a secondary screw with a secondary screw temperature of 222°C, accurately metering them through a metering pump, and evenly distributing them to the parallel composite spinning device in the spinning manifold.

[0042] Step (iii) The melts of polybutylene succinate and polylactic acid are simultaneously injected into the spinneret inside the parallel composite spinning device. The temperature of the composite spinning device is 225°C. After composite, several fiber monofilaments with a parallel structure are extruded, and are cooled by side 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 bundling oiling treatment, stretching treatment with a stretching multiple of 2.5 times and winding by a winding machine at a speed of 3000m / min to obtain a biodegradable self-curling bicomponent composite elastic fiber.

[0043] Comparative Example 1

[0044] Polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT) are melt-spun in parallel at a mass ratio of 50:50 to obtain PET / PTT composite elastic fibers.

[0045] Performance testing and result comparison——

[0046] 1. The mechanical properties of the composite elastic fibers obtained in Examples 1 to 4 and Comparative Example 1 were tested. The specific testing methods are as follows.

[0047] Viscosity characteristic test: The intrinsic viscosity of the polymer was measured using an Ubbelohde viscometer at 25±0.01°C, with the intrinsic viscosity in a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (1:1 w / w) and a polymer concentration of 0.50 g·dL -1 .

[0048] Number average molecular weight detection: The molecular weight of polyester was tested by ultra-high performance polymer chromatography (APC, Waters Company), and the mobile phase was hexafluoroisopropanol with a flow rate of 0.3 mL min -1 .

[0049] Breaking strength and breaking elongation test: The test was carried out using a YG020B electronic single yarn strength tester. The fiber clamping length was 200 mm, the stretching rate was 200 mm / min, the pre-tension was 5 cN, and each group of samples was tested 15 times. The average value was taken to obtain the fiber's breaking strength and breaking elongation.

[0050] Elastic recovery rate test: YG026Q fabric strength tester is used for testing, and a relatively uniform part of the composite fiber (randomly cut length) is selected to test the elastic recovery rate of the sample with a fixed elongation of 20% and 30 times of drawing. The fiber clamping length is 250mm and the stretching rate is 50mm / min.

[0051] The calculation formula of elastic recovery rate is:

[0052]

[0053] Specifically, L0 is the gauge length, L1 is the length of the specimen when the pre-tension is applied after the specimen returns to zero position and stops for 60 seconds, L2 is the length of the specimen when it is stretched to a fixed elongation, L is the elongation when the pre-tension is reached when the specimen is loosely clamped, and L is 0 when the pre-tension is clamped.

[0054] Specific test results and test standards are shown in Table 1.

[0055] Table 1: Mechanical properties test data of Examples 1 to 4 and Comparative Example 1

[0056]

[0057] As shown in Table 1, the breaking strength data of Examples 1 to 4 relative to Comparative Example 1 clearly show that the strength of Examples 1 to 4 is better; the elastic recovery rate data of Examples 3 to 4 relative to Comparative Example 1 clearly show that the elasticity of Examples 2 to 4 is better. In summary, it can be seen that each embodiment of the present invention has good mechanical strength, tensile elasticity and elastic recovery.

[0058] 2. The biodegradability of Examples 1 to 4 and Comparative Example 1 was tested. The testing method was in accordance with GB / T 32366-2015. The specific testing standards and test results are shown in Table 2.

[0059] Table 2: Biodegradation rate test data of Examples 1 to 4 and Comparative Example 1

[0060]

[0061] As shown in Table 2: Compared with Comparative Example 1, Examples 1 to 4 of the present invention have better compatibility and degradability, so that the environment is effectively protected.

[0062] In the technical solution of the present invention, the raw materials are completely biodegradable and green and environmentally friendly: polybutylene succinate and polylactic acid, which are the technical key of this case. The elastic modulus of these materials is significantly different, and they are ideal raw materials for bio-based self-curling elastic fibers. The two-component composite elastic fibers are then processed through the parallel spinning process, which have good tensile deformation resistance and low elastic recovery fatigue. For related equipment or components such as composite spinning devices, ordinary technicians in this field can make conventional settings according to the existing technology. This case has no special requirements for its model selection and combined use.

[0063] Through the above description, it can be found that compared with the prior art, after adopting the technical solution of the present invention, biodegradable raw materials are used, which has good compatibility and biodegradability, can effectively reduce environmental pollution, avoid soil and water pollution and ecological damage caused by long-term retention of waste in the natural environment, and has good application prospects and market value; moreover, there is no phase separation phenomenon in its cross section, it has high chemical stability, the breaking strength can reach 2.4-3.0 cN / dtex, the breaking elongation can reach 20-60%, and the elastic recovery rate can reach 70-90%. It has good mechanical properties, tensile elasticity and elastic recovery performance, and is suitable for elastic fiber application fields such as textiles, medical devices and household items. In addition, the preparation method of this kind of biodegradable self-curling two-component composite elastic fiber is simple and practical, easy to operate, and can be spun using a composite spinning device to achieve industrial mass production, and has a wide range of applications.

[0064] 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 biodegradable self-curling two-component composite elastic fiber, comprising component A and component B having good compatibility, characterized in that: The component A is polybutylene succinate, the component B is polylactic acid, and the mass ratio of the component A to the component B is 20 / 80 to 80 / 20. The composite elastic fiber is prepared by a parallel spinning method through the following steps: Step S1: vacuum drying the slices of component A and component B, extruding them into melts through a screw extruder, accurately metering them through a metering pump, and then transporting them into a spinning manifold, and then evenly distributing them to a parallel composite spinning device; Step S2: Synchronously injecting the melts of polybutylene succinate and polylactic acid into the spinneret inside the parallel composite spinning device, extruding several fiber monofilaments with a parallel structure after composite, and then subjecting them to air-cooling treatment, oiling treatment, drawing treatment and winding treatment to obtain a biodegradable self-curling two-component composite elastic fiber.

2. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S1, the intrinsic viscosity of the polybutylene succinate is 1.5-1.8 dL / g, and the melting temperature is 185-220°C; the number average molecular weight of the polylactic acid is 200,000-300,000 g / mol, and the melting temperature is 190-225°C.

3. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S2, the spinning temperature of the composite spinning device is 190-225°C.

4. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S2, the air blowing cooling treatment adopts a side air blowing method, the air blowing cooling air temperature is 10-15°C, and the air blowing cooling air pressure is 100-200Pa.

5. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S2, the stretching process uses 2 pairs or more of stretching rollers, the stretching multiple is 1.5 to 2.5, and the stretching heat setting temperature is 70 to 95°C.

6. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S2, the winding process adopts a winding speed of 2500-3200 m / min.

7. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S2, several fiber monofilaments are bent in an "S" shape and have a fluffy portion when placed freely.

8. The biodegradable self-curling bicomponent composite elastic fiber according to claim 1, characterized in that: In step S2, the composite spinning linear density of the plurality of fiber monofilaments is 100-200 dtex.

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