Method for preparing filling fiber by regenerating polyester waste silk

Abstract

The invention discloses a method for preparing filling fibers by regenerating waste polyester filaments, and relates to the technical field of filling fibers. The preparation method comprises the following steps: firstly, preparing a modifier containing a beta-diketone structure from butyl glycolate and 4-(hydroxymethyl) acetophenone, and carrying out regeneration treatment on waste polyester filaments to form silver-containing low-melting-point polyester chips; the preparation method comprises the following steps: firstly, blending and spinning a polyester fiber with a high-melting-point polyester chip, forming an asymmetric fiber section by adopting a special-shaped spinning head, and then performing hot steam drafting treatment, so that the fiber generates a non-uniform microstructure during hot steam drafting, different shrinkage reactions are generated, and the self-coiling capability is obtained; the low-melting-point components are heated to form bonding points at fiber lap joints, the low-melting-point components cooperate with self-coiling of the fibers, a three-dimensional cavity structure with a good entanglement effect is formed, the fluffy effect of the filling fibers is enhanced, meanwhile, the high-melting-point components do not deform after being heated, the fiber supporting and skeleton effects are achieved, and the rebound and shaping effects of the filling fibers are enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of filling fibers, and in particular to a method for preparing filling fibers by regenerating polyester waste yarns. Background Art

[0002] Waterfowl feathers, such as goose down and duck down, are commonly used in duvets, sleeping bags, and various other cold-weather products. The global outbreak of avian influenza has led to a sharp decline in down production, resulting in a price increase. Consumers are also concerned about the safety of down. Natural feathers can cause a foul odor if not properly washed, so it is important to remove any odor-causing contaminants beforehand to maintain the cleanliness of the feathers.

[0003] Since the industrial production of polyester in the 1950s, it has been widely used in fiber manufacturing due to its excellent comprehensive performance. However, with the extensive use of polyester products, the accumulation of waste polyester textiles has increased year by year. The difficulty in degrading polyester materials not only damages the ecological environment, but also causes a huge waste of resources. How to efficiently recycle and reuse waste PET textiles in a recyclable, harmless and high-value manner has become a hot issue in the current polyester fiber industry. The present invention creatively proposes a polyester regeneration method, and uses it as a raw material to prepare down-like filling fiber materials to replace traditional down fillings. Summary of the Invention

[0004] The object of the present invention is to provide a method for preparing filling fiber by regenerating polyester waste yarn, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing filling fiber by regenerating polyester waste yarn, comprising the following preparation steps: (1) Cut the polyester waste into 5 cm in length, crush it after oil extraction, mix it with ethylene glycol, put it into a twin-screw extruder, melt extrude it, filter and remove impurities to obtain a melt; (2) Mix the melt, modifier and zinc acetate in a mass ratio of 1:0.1~0.2:0.0001, react at normal pressure and 180~200℃ for 1.5~3h, add 0.0001~0.0002 times the mass of the melt of antimony trioxide and 0.0002~0.0004 times the mass of the melt of triphenyl phosphate, heat to 230~250℃, evacuate to 100~600Pa, and continue to react. After 30-120 minutes, cool to 50°C, add silver hexafluoroantimonate-methanol solution under stirring at 100-120 rpm, with the mass ratio of silver hexafluoroantimonate to modifier being 1:1.5-2.0, stir for 2-3.5 hours, and then continue stirring for 2 hours under a vacuum degree of 1000 Pa, cool to room temperature, slice, and dry at 100°C for 12 hours to obtain low-melting-point polyester chips with a melting point of 120-160°C; (3) The high-melting point polyester chips and the low-melting point polyester chips were mixed and spun at 220-235°C using a Y-type spinning head to obtain fibers. The fibers were then stretched under hot steam perpendicular to the fiber direction at a stretching ratio of 2.1-2.5 times. The polyester waste fibers were then dried at 100°C for 2 hours to prepare filling fibers.

[0006] Furthermore, the length of the polyester waste yarn after being cut in step (1) is 5 cm.

[0007] Furthermore, the mass ratio of the ethylene glycol to the polyester waste in step (1) is 0.4-0.7:1.

[0008] Furthermore, the melt extrusion conditions in step (1) are as follows: the screw speed is 240×10 -6 r / min, extrusion temperature is 130~255℃.

[0009] Furthermore, the preparation method of the modifier described in step (2) is as follows: at room temperature, add 50-60 parts of benzene and 6-8 parts of potassium tert-butoxide by weight, raise the temperature to 60°C, add 2.0-3.2 parts of 4-(hydroxymethyl)acetophenone, stir at 30-50 rpm for 1 hour, then add 6-12 parts of butyl glycolate, continue to heat to 78°C, stir at 30-50 rpm for 8 hours under argon protection, cool to room temperature, pour into 100 parts of ice water, stir at 60 rpm for 30 minutes, adjust the pH to 3.5-4.7 with hydrochloric acid, pour into a separating funnel, separate the organic layer, wash the organic layer with distilled water until neutral, and then dry with anhydrous magnesium sulfate for 8 hours, filter and collect the liquid, and evaporate to constant weight at a vacuum degree of -0.08 MPa and 69°C.

[0010] Furthermore, the concentration of the silver hexafluoroantimonate-methanol solution in step (2) is 0.017 g / mL.

[0011] Furthermore, in step (3), the weight ratio of the high-melting-point polyester chips to the low-melting-point polyester chips is 4 to 10:1.

[0012] Furthermore, the hot steam in step (3) uses 0.1-2 g / L sodium citrate aqueous solution as a steam source, and the steam temperature is 120-160°C.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention first utilizes a condensation reaction between the ester group of butyl glycolate and the acetone group of 4-(hydroxymethyl)acetophenone to generate a modifier containing a β-diketone structure. Subsequently, the polyester waste silk is degreased and then subjected to alcoholysis to form a melt, which is then mixed with the modifier and silver nitrate. The ethylene terephthalate in the melt undergoes condensation polymerization with the hydroxyl groups at both ends of the modifier molecular chain. Simultaneously, the silver nitrate coordinates with the β-diketone to attach silver ions to the polyester molecular chain. The present invention introduces steric hindering groups into the original polyethylene terephthalate molecular chain to destroy the regularity and symmetry of the polyester molecular chain, thereby lowering the melting point of the polyester, thereby obtaining silver-containing low-melting-point polyester chips. The invention uses a blend of low-melting point polyester chips and high-melting point polyester chips for spinning, and adopts a heterogeneous spinning head to form an asymmetric fiber cross-section. The fibers are then subjected to a hot steam drawing process. The hot steam of the invention uses a sodium citrate aqueous solution as a steam source. The steam forms the solution into extremely small droplets, so that the sodium citrate fully contacts the fibers, thereby reducing silver ions into nanosilver. Due to the presence of a coordination structure, the generated nanosilver can be fixed in the fibers and is not easily separated, thereby enhancing the antibacterial effect. The invention utilizes the blend of high-melting point polyesters and the asymmetric shape of the fiber cross-section to produce an uneven microstructure of the fibers during hot steam drawing. The microstructures vary in the fiber cross-section direction, thereby generating different shrinkage reactions, thereby enabling the fibers to have a self-rolling ability and form three-dimensional curls. Simultaneously, the low-melting point component is heated to form bonding points at the fiber overlap, which cooperates with the fiber self-rolling to form a three-dimensional cavity structure with a good entanglement effect, thereby enhancing the fluffy effect of the filling fiber. Simultaneously, the high-melting point component does not deform when heated, and acts as a fiber support and skeleton, thereby enhancing the rebound and shaping effect of the filling fiber. DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0015] Example 1; (1) At room temperature, 50 parts of benzene and 6 parts of potassium tert-butoxide were added by weight, the temperature was raised to 60°C, 2.0 parts of 4-(hydroxymethyl)acetophenone were added, and 6 parts of butyl glycolate were added after stirring at 30 rpm for 1 hour. The temperature was continued to rise to 78°C, and under argon protection, the mixture was stirred at 30 rpm for 8 hours. The mixture was cooled to room temperature, poured into 100 parts of ice water, stirred at 60 rpm for 30 minutes, and the pH was adjusted to 3.5 with hydrochloric acid. The mixture was poured into a separating funnel, the organic layer was separated, and the organic layer was washed with distilled water until neutral, and then dried with anhydrous magnesium sulfate for 8 hours. The liquid was filtered and evaporated to constant weight at a vacuum degree of -0.08 MPa and 69°C to obtain a modifier. (2) The polyester waste was cut into 5 cm in length, crushed after the oil was removed, and fully mixed with ethylene glycol at a mass ratio of 0.4:1. The mixture was then fed into a twin-screw extruder and the screw speed was set at 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (3) The melt, modifier and zinc acetate were mixed in a mass ratio of 1:0.1:0.0001, reacted at normal pressure and 180°C for 1.5h, antimony trioxide 0.0001 times the mass of the melt and triphenyl phosphate 0.0002 times the mass of the melt were added, the temperature was raised to 230°C, vacuumed to 100Pa, and the reaction was continued for 30min. The mixture was cooled to 50°C and stirred at 100rpm. A silver hexafluoroantimonate-methanol solution with a concentration of 0.017g / mL was added. The mass ratio of silver hexafluoroantimonate to modifier was 1:1.5. After stirring for 2h, the mixture was stirred for 2h under a vacuum degree of 1000Pa, cooled to room temperature, sliced, and dried at 100°C for 12h to obtain low-melting-point polyester chips with a melting point of 142°C. (4) The high melting point polyester chips and the low melting point polyester chips were mixed in a weight ratio of 4:1, and spun into fibers at 220-235°C using a Y-type spinning head. The fibers were then stretched under hot steam perpendicular to the fiber direction at a stretching ratio of 2.1 times, and then dried at 100°C for 2 hours to obtain a bulkiness of 650 inches. 3 / 30g, and the antibacterial rate of 99% of polyester waste yarn is recycled to prepare filling fiber; the hot steam adopts 0.1g / L sodium citrate aqueous solution as steam source, and the steam temperature is 135℃.

[0016] Example 2; (1) At room temperature, 55 parts of benzene and 7 parts of potassium tert-butoxide were added by weight, the temperature was raised to 60°C, 2.6 parts of 4-(hydroxymethyl)acetophenone were added, and 8 parts of butyl glycolate were added after stirring at 40 rpm for 1 hour. The temperature was continued to rise to 78°C, and under argon protection, the mixture was stirred at 40 rpm for 8 hours. The mixture was cooled to room temperature, poured into 100 parts of ice water, stirred at 60 rpm for 30 minutes, and the pH was adjusted to 4.0 with hydrochloric acid. The mixture was poured into a separating funnel, the organic layer was separated, and the organic layer was washed with distilled water until neutral, and then dried with anhydrous magnesium sulfate for 8 hours. The liquid was filtered and evaporated to constant weight at a vacuum degree of -0.08 MPa and 69°C to obtain a modifier. (2) The polyester waste was cut into 5 cm in length, crushed after oil extraction, and fully mixed with ethylene glycol at a mass ratio of 0.55:1. The mixture was then fed into a twin-screw extruder and the screw speed was set at 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (3) The melt, modifier and zinc acetate were mixed in a mass ratio of 1:0.15:0.0001, reacted at normal pressure and 190 ° C for 2.2 hours, added with 0.00015 times the mass of the melt antimony trioxide and 0.0003 times the mass of the melt triphenyl phosphate, heated to 244 ° C, evacuated to 300 Pa, continued to react for 100 minutes, cooled to 50 ° C, stirred at 110 rpm, and added with a concentration of 0.017 g / mL silver hexafluoroantimonate-methanol solution. The mass ratio of silver hexafluoroantimonate to modifier was 1:1.8. After stirring for 3 hours, the mixture was stirred for 2 hours under a vacuum degree of 1000 Pa, cooled to room temperature, sliced, and dried at 100 ° C for 12 hours to obtain low-melting-point polyester chips with a melting point of 140 ° C; (4) The high melting point polyester chips and the low melting point polyester chips were mixed in a weight ratio of 7:1, and spun at 220~235℃ using a Y-type spinning head to obtain fibers. The fibers were then stretched under hot steam perpendicular to the fiber direction with a stretching ratio of 2.2 times, and then dried at 100℃ for 2 hours to obtain a bulkiness of 680 inches. 3 / 30g, and the antibacterial rate of 99% of polyester waste yarn is recycled to prepare filling fiber; the hot steam adopts 1g / L sodium citrate aqueous solution as steam source, and the steam temperature is 135℃.

[0017] Example 3; (1) At room temperature, 60 parts of benzene and 8 parts of potassium tert-butoxide were added by weight, the temperature was raised to 60°C, 3.2 parts of 4-(hydroxymethyl)acetophenone were added, and 12 parts of butyl glycolate were added after stirring at 50 rpm for 1 hour. The temperature was continued to rise to 78°C, and under argon protection, the mixture was stirred at 50 rpm for 8 hours. The mixture was cooled to room temperature, poured into 100 parts of ice water, stirred at 60 rpm for 30 minutes, and the pH was adjusted to 4.7 with hydrochloric acid. The mixture was poured into a separating funnel, the organic layer was separated, and the organic layer was washed with distilled water until neutral, and then dried with anhydrous magnesium sulfate for 8 hours. The liquid was filtered and evaporated to constant weight at a vacuum degree of -0.08 MPa and 69°C to obtain a modifier. (2) The polyester waste was cut into 5 cm in length, crushed after the oil was removed, and fully mixed with ethylene glycol at a mass ratio of 0.7:1. The mixture was then fed into a twin-screw extruder and the screw speed was set at 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (3) The melt, modifier and zinc acetate were mixed in a mass ratio of 1:0.2:0.0001, reacted at normal pressure and 200 ° C for 3 hours, added with 0.0002 times the mass of the melt antimony trioxide and 0.0004 times the mass of the melt triphenyl phosphate, heated to 250 ° C, evacuated to 600 Pa, continued to react for 120 minutes, cooled to 50 ° C, stirred at 120 rpm, and added with a concentration of 0.017 g / mL silver hexafluoroantimonate-methanol solution. The mass ratio of silver hexafluoroantimonate to modifier was 1:2.0. After stirring for 3.5 hours, the mixture was stirred for 2 hours under a vacuum degree of 1000 Pa, cooled to room temperature, sliced, and dried at 100 ° C for 12 hours to obtain low-melting-point polyester chips with a melting point of 160 ° C; (4) Mix high melting point polyester chips and low melting point polyester chips in a weight ratio of 4 to 10:1, use a Y-type spinning head, and spin them at 220 to 235 ° C to obtain fibers. Then, draw them under hot steam perpendicular to the fiber direction with a draw ratio of 2.5 times, and then dry them at 100 ° C for 2 hours to obtain a bulkiness of 620 inches. 3 / 30g, and the antibacterial rate of 99% of polyester waste yarn is recycled to prepare filling fiber; the hot steam adopts 2g / L sodium citrate aqueous solution as steam source, and the steam temperature is 150℃.

[0018] Comparative Example 1: (1) Polyester waste was cut into 5 cm in length, crushed after oil extraction, and mixed with ethylene glycol at a mass ratio of 0.55:1. The mixture was then fed into a twin-screw extruder and the extruder was extruded at a screw speed of 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (2) The melt, ethylene glycol, and zinc acetate were mixed in a mass ratio of 1:0.15:0.0001, reacted at normal pressure and 190°C for 2.2 hours, antimony trioxide (0.00015 times the mass of the melt) and triphenyl phosphate (0.0003 times the mass of the melt) were added, the temperature was raised to 244°C, vacuumed to 300 Pa, and the reaction was continued for 100 minutes. The mixture was cooled to 50°C, and a silver hexafluoroantimonate-methanol solution with a concentration of 0.017 g / mL was added under stirring at 110 rpm. The mass ratio of silver hexafluoroantimonate to the modifier was 1:1.8. After stirring for 3 hours, the mixture was stirred for 2 hours under a vacuum degree of 1000 Pa, cooled to room temperature, sliced, and dried at 100°C for 12 hours to obtain polyester chips. (3) High melting point polyester chips and polyester chips were mixed in a weight ratio of 7:1, and spun at 220~235℃ using a Y-type spinning head to obtain fibers. The fibers were then stretched under hot steam perpendicular to the fiber direction with a stretching ratio of 2.2 times, and then dried at 100℃ for 2 hours to obtain a bulkiness of 550 inches. 3 / 30g, and the antibacterial rate of 88% of polyester waste yarn is recycled to prepare filling fiber; the hot steam adopts 1g / L sodium citrate aqueous solution as steam source, and the steam temperature is 135℃.

[0019] Comparative Example 2; (1) At room temperature, 55 parts of benzene and 7 parts of potassium tert-butoxide were added by weight, the temperature was raised to 60°C, 2.6 parts of 4-(hydroxymethyl)acetophenone were added, and 8 parts of butyl glycolate were added after stirring at 40 rpm for 1 hour. The temperature was continued to rise to 78°C, and under argon protection, the mixture was stirred at 40 rpm for 8 hours. The mixture was cooled to room temperature, poured into 100 parts of ice water, stirred at 60 rpm for 30 minutes, and the pH was adjusted to 4.0 with hydrochloric acid. The mixture was poured into a separating funnel, the organic layer was separated, and the organic layer was washed with distilled water until neutral, and then dried with anhydrous magnesium sulfate for 8 hours. The liquid was filtered and evaporated to constant weight at a vacuum degree of -0.08 MPa and 69°C to obtain a modifier. (2) The polyester waste was cut into 5 cm in length, crushed after oil extraction, and fully mixed with ethylene glycol at a mass ratio of 0.55:1. The mixture was then fed into a twin-screw extruder and the screw speed was set at 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (3) The melt, modifier and zinc acetate were mixed in a mass ratio of 1:0.15:0.0001, reacted at normal pressure and 190 ° C for 2.2 hours, added with 0.00015 times the mass of the melt antimony trioxide and 0.0003 times the mass of the melt triphenyl phosphate, heated to 244 ° C, evacuated to 300 Pa, continued to react for 100 minutes, cooled to 50 ° C, stirred at 110 rpm, and added with a concentration of 0.017 g / mL silver hexafluoroantimonate-methanol solution. The mass ratio of silver hexafluoroantimonate to modifier was 1:1.8. After stirring for 3 hours, the mixture was stirred for 2 hours under a vacuum degree of 1000 Pa, cooled to room temperature, sliced, and dried at 100 ° C for 12 hours to obtain low-melting-point polyester chips with a melting point of 140 ° C; (4) The low melting point polyester chips were spun at 220-235℃ using a Y-type spinning head to obtain fibers, which were then stretched under hot steam perpendicular to the fiber direction with a stretching ratio of 2.2 times. The fibers were then dried at 100℃ for 2 hours to obtain a bulkiness of 510 inches. 3 / 30g, and the antibacterial rate of 99% of polyester waste yarn is recycled to prepare filling fiber; the hot steam adopts 1g / L sodium citrate aqueous solution as steam source, and the steam temperature is 135℃.

[0020] Comparative Example 3; (1) At room temperature, 55 parts of benzene and 7 parts of potassium tert-butoxide were added by weight, the temperature was raised to 60°C, 2.6 parts of 4-(hydroxymethyl)acetophenone were added, and 8 parts of butyl glycolate were added after stirring at 40 rpm for 1 hour. The temperature was continued to rise to 78°C, and under argon protection, the mixture was stirred at 40 rpm for 8 hours. The mixture was cooled to room temperature, poured into 100 parts of ice water, stirred at 60 rpm for 30 minutes, and the pH was adjusted to 4.0 with hydrochloric acid. The mixture was poured into a separatory funnel, the organic layer was separated, and the organic layer was washed with distilled water until neutral, and then dried with anhydrous magnesium sulfate for 8 hours. The liquid was filtered and evaporated to constant weight at a vacuum degree of -0.08 MPa and 69°C to obtain a modifier. (2) The polyester waste was cut into 5 cm in length, crushed after oil extraction, and fully mixed with ethylene glycol at a mass ratio of 0.55:1. The mixture was then fed into a twin-screw extruder and the screw speed was set at 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (3) The melt, modifier and zinc acetate were mixed in a mass ratio of 1:0.15:0.0001, reacted at normal pressure and 190 ° C for 2.2 hours, added with 0.00015 times the mass of the melt antimony trioxide and 0.0003 times the mass of the melt triphenyl phosphate, heated to 244 ° C, evacuated to 300 Pa, continued to react for 100 minutes, cooled to 50 ° C, stirred at 110 rpm, and added with a concentration of 0.017 g / mL silver hexafluoroantimonate-methanol solution. The mass ratio of silver hexafluoroantimonate to modifier was 1:1.8. After stirring for 3 hours, the mixture was stirred for 2 hours under a vacuum degree of 1000 Pa, cooled to room temperature, sliced, and dried at 100 ° C for 12 hours to obtain low-melting-point polyester chips with a melting point of 140 ° C; (4) The high melting point polyester chips and the low melting point polyester chips were mixed in a weight ratio of 7:1, and spun at 220~235℃ using a Y-type spinning head to obtain fibers. The fibers were then drawn at a drawing ratio of 2.2 times and dried at 100℃ for 2 hours to obtain a bulkiness of 580 inches. 3 / 30g, and the antibacterial rate of 76% of polyester waste yarn is recycled to prepare filling fiber; the hot steam uses 1g / L sodium citrate aqueous solution as the steam source, and the steam temperature is 135℃.

[0021] Comparative Example 4; (1) At room temperature, 55 parts of benzene and 7 parts of potassium tert-butoxide were added by weight, the temperature was raised to 60°C, 2.6 parts of 4-(hydroxymethyl)acetophenone were added, and 8 parts of butyl glycolate were added after stirring at 40 rpm for 1 hour. The temperature was further raised to 78°C, and under argon protection, the mixture was stirred at 40 rpm for 8 hours. The mixture was cooled to room temperature, poured into 100 parts of ice water, stirred at 60 rpm for 30 minutes, and the pH was adjusted to 4.0 with hydrochloric acid. The mixture was poured into a separatory funnel, the organic layer was separated, and the organic layer was washed with distilled water until neutral, and then dried with anhydrous magnesium sulfate for 8 hours. The liquid was filtered and evaporated to constant weight at a vacuum degree of -0.08 MPa and 69°C to obtain a modifier. (2) The polyester waste was cut into 5 cm in length, crushed after oil extraction, and fully mixed with ethylene glycol at a mass ratio of 0.55:1. The mixture was then fed into a twin-screw extruder and the screw speed was set at 240 × 10 -6 r / min, melt extrusion at an extrusion temperature of 130~255℃, filtering and removing impurities to obtain a melt; (3) The melt, modifier, and zinc acetate were mixed in a mass ratio of 1:0.15:0.0001, reacted at normal pressure and 190°C for 2.2 hours, antimony trioxide 0.00015 times the mass of the melt and triphenyl phosphate 0.0003 times the mass of the melt were added, the temperature was raised to 244°C, vacuumed to 300 Pa, the reaction was continued for 100 minutes, cooled to room temperature, sliced, and dried at 100°C for 12 hours to obtain low-melting-point polyester chips with a melting point of 140°C; (4) The high melting point polyester chips and the low melting point polyester chips were mixed in a weight ratio of 7:1, and spun into fibers at 220-235°C using a Y-type spinning head. The fibers were then stretched under hot steam perpendicular to the fiber direction at a stretching ratio of 2.2 times, and then dried at 100°C for 2 hours to obtain a bulkiness of 600 inches. 3 / 30g, and the antibacterial rate of 0% polyester waste yarn is recycled to prepare filling fiber; the hot steam adopts 1g / L sodium citrate aqueous solution as steam source, and the steam temperature is 135℃.

[0022] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for preparing filling fiber by regenerating polyester waste, characterized in that: The method comprises the following preparation steps: (1) Cut the polyester waste into 5 cm in length, crush it after oil extraction, mix it with ethylene glycol, put it into a twin-screw extruder, melt extrude it, filter and remove impurities to obtain a melt; (2) Mix the melt, modifier and zinc acetate in a mass ratio of 1:0.1~0.2:0.0001, react at normal pressure and 180~200℃ for 1.5~3h, add 0.0001~0.0002 times the mass of the melt of antimony trioxide and 0.0002~0.0004 times the mass of the melt of triphenyl phosphate, heat to 230~250℃, evacuate to 100~600Pa, and continue to react. After 30-120 minutes, cool to 50°C, add silver hexafluoroantimonate-methanol solution under stirring at 100-120 rpm, with the mass ratio of silver hexafluoroantimonate to modifier being 1:1.5-2.0, stir for 2-3.5 hours, and then continue stirring for 2 hours under a vacuum degree of 1000 Pa, cool to room temperature, slice, and dry at 100°C for 12 hours to obtain low-melting-point polyester chips with a melting point of 120-160°C; (3) The high-melting point polyester chips and the low-melting point polyester chips were mixed and spun at 220-235°C using a Y-type spinning head to obtain fibers. The fibers were then stretched under hot steam perpendicular to the fiber direction at a stretching ratio of 2.1-2.5 times. The polyester waste fibers were then dried at 100°C for 2 hours to prepare filling fibers.

2. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The length of the polyester waste yarn after cutting in step (1) is 5 cm.

3. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The mass ratio of the ethylene glycol to the polyester waste in step (1) is 0.4-0.7:

1.

4. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The melt extrusion conditions in step (1) are: screw speed is 240×10 -6 r / min, extrusion temperature is 130~255℃.

5. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The preparation method of the modifier in step (2) is as follows: at room temperature, add 50-60 parts of benzene and 6-8 parts of potassium tert-butoxide by weight, heat to 60°C, add 2.0-3.2 parts of 4-(hydroxymethyl)acetophenone, stir at 30-50 rpm for 1 hour, then add 6-12 parts of butyl glycolate, continue to heat to 78°C, stir at 30-50 rpm for 8 hours under argon protection, cool to room temperature, pour into 100 parts of ice water, stir at 60 rpm for 30 minutes, adjust the pH to 3.5-4.7 with hydrochloric acid, pour into a separatory funnel, separate the organic layer, wash the organic layer with distilled water until neutral, dry with anhydrous magnesium sulfate for 8 hours, filter and take the liquid, and evaporate to constant weight at a vacuum degree of -0.08 MPa and 69°C.

6. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The concentration of the silver hexafluoroantimonate-methanol solution in step (2) is 0.017 g / mL.

7. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The weight ratio of the high-melting point polyester chips to the low-melting point polyester chips in step (3) is 4 to 10:

1.

8. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The hot steam in step (3) uses 0.1-2 g / L sodium citrate aqueous solution as the steam source, and the steam temperature is 120-160°C.

9. The method for preparing filling fiber by regenerating polyester waste according to claim 1, characterized in that: The melting point of the high melting point polyester chips in step (3) is 260-262°C.