▎ 摘　　要

NOVELTY - Preparation of spiral yarn involves: (1) taking raw materials, after melt spinning and heat treating, including 8-12 pts. wt. carbon fiber intercalated graphene composite material, 30-40 pts. wt. polyethylene terephthalate fiber, 60-70 pts. wt. polytrimethylene terephthalate fiber and 0.8-2 pts. wt. catalyst; (2) preparing carbon fiber by placing cellulose nanofibers in a tubular furnace, then passing protective gas argon or nitrogen, heating at a heating rate of 2-5 degrees C/minute to 250-280 degrees C and heat preserving for 1-2 hours, then heating at a heating rate of 5-10 degrees C/minute to 600-800 degrees C and heat preserving for 1 hour, after the carbon fiber synthesis reaction is completed, naturally cooling to room temperature under vacuum conditions, and finally taking out the product; and (3) preparing carbon fiber intercalated graphene composite material. USE - The method is useful for preparing spiral yarn. ADVANTAGE - The method enables simple preparation of the spiral yarn with high tensile strength and rolling shrinkage rate. DETAILED DESCRIPTION - Preparation of spiral yarn involves: (1) taking raw materials, after melt spinning and heat treating, including 8-12 pts. wt. carbon fiber intercalated graphene composite material, 30-40 pts. wt. polyethylene terephthalate fiber, 60-70 pts. wt. polytrimethylene terephthalate fiber and 0.8-2 pts. wt. catalyst; (2) preparing carbon fiber by placing cellulose nanofibers in a tubular furnace, then passing protective gas argon or nitrogen, heating at a heating rate of 2-5 degrees C/minute to 250-280 degrees C and heat preserving for 1-2 hours, then heating at a heating rate of 5-10 degrees C/minute to 600-800 degrees C and heat preserving for 1 hour, after the carbon fiber synthesis reaction is completed, naturally cooling to room temperature under vacuum conditions, and finally taking out the product; (3) preparing carbon fiber intercalated graphene composite material by dispersing cellulose nanofibers in an aqueous solution to make a 1 wt.% dispersion, using an ultrasonic mill with a power of 1500 W to process the dispersion, where the processing time is 80-100 minutes, taking an ice water bath to control the temperature of the dispersion at 25 plus minus 1 degrees C, then adding a graphene oxide solution with a molar concentration of 1.5-1.8 mmol/l to the dispersion, mechanically stirring at room temperature and atmospheric pressure with a magnetic stirrer for 10-20 minutes, using an ultrasonic power mill with power of 1500-1800 W to process for 40-60 minutes to obtain a uniformly dispersed dispersion of cellulose nanofibers and graphene oxide, adding hydrazine hydrate to the obtained dispersion of cellulose nanofibers and graphene oxide, stirring and evenly dispersing, using the hydrazine hydrate to adjust the system pH to 10, stirring for 5-10 minutes, sealing the reaction system, heating at 90 degrees C, reacting for 60-80 minutes, flushing with distilled water to a neutral pH of 7-7.5 by dialysis, freeze-drying to obtain a cellulose nanofiber intercalated graphene composite material, finally placing the obtained cellulose nanofiber intercalated graphene composite material in the tubular furnace, introducing protective gas nitrogen or argon, heating at a heating rate of 5-10 degrees C/minute to 700-1000 degrees C and heat preserving for 1-2 hours, and cooling to room temperature at a cooling rate of 5-10 degrees C/minute; (4) preparing spiral yarn by placing the carbon fiber intercalated graphene composite material obtained in step (3), polyethylene terephthalate fiber, polytrimethylene terephthalate fiber and the catalyst in a melt spinning machine for melt spinning to get an initial product of spiral yarn, where the melt spinning temperature is 265-275 degrees C, and the spinning speed is 2000 m/minute; and (5) post-processing of the spiral yarn by treating a single filament yarn in a constant temperature water bath in a relaxed state with hot water at 95-100 degrees C for 10-20 minutes, drying in a naturally ventilated place, and then balancing for 24 hours in a constant temperature and humidity environment, where the constant temperature is 20-25 degrees C, and the relative humidity is 60-65%.