Preparation method of regenerated polyester and cotton blended yarn for home textiles

Abstract

The invention relates to the technical field of blended yarns, in particular to a preparation method of regenerated polyester and cotton blended yarns for home textiles. 50-60 parts by mass of regenerated polyester fibers and 35-45 parts by mass of cotton fibers are subjected to anti-static soaking pretreatment and opening and impurity removal pretreatment respectively; mixing the pretreated fibers in a dynamic mixing device under the combined action of rotating blades and high-pressure airflow to prepare card slivers; drawing the card slivers for the first time, the second time and the third time to obtain drawn slivers; spinning the drawn slivers into spun yarns through roving and ring spinning procedures; the spun yarn is soaked in a functional additive solution composed of a nano-silver antibacterial agent and polyethylene glycol, and a finished product is obtained through drying and spooling. By optimizing the raw material ratio, the pretreatment process and multi-stage combination drafting, the problems that regenerated fibers are poor in spinnability and uneven in mixing are solved, and the obtained yarn has excellent antibacterial property, flexibility and evenness and is suitable for high-end home textile products.

Description

Technical Field

[0001] This invention relates to the field of blended yarn technology, specifically a method for preparing recycled polyester and cotton blended yarn for home textiles. Background Technology

[0002] The textile industry is increasingly emphasizing the development and utilization of recycled fibers. Recycled polyester fiber, as an important product of the circular economy, primarily derives its raw materials from waste polyester bottles and textile waste, offering the dual advantages of resource recycling and environmental protection. However, several technical challenges remain in the practical application of recycled polyester fiber: First, due to its complex origins, the fiber properties are unstable, with strength and length uniformity often lower than virgin fibers, and it contains more impurities. Second, the smooth surface and poor cohesion of recycled polyester fibers easily lead to uneven mixing and fiber delamination when blended with cotton fibers, affecting yarn quality. Third, recycled polyester fibers are prone to static electricity and have poor spinnability, easily resulting in fiber entanglement and high breakage rates during production. These factors severely restrict the application of recycled polyester fiber in high-quality home textile products.

[0003] Currently, many researchers are dedicated to developing recycled polyester blended yarn technology. For example, patent CN108914287A discloses a novel environmentally friendly recycled polyester blended yarn, using luggage fabric, garment scraps, and cotton yarn waste as raw materials, produced using traditional polyester blended yarn production methods. While this technology achieves secondary utilization of waste materials, the raw material sources are complex and of unstable quality, and the fiber pretreatment in the production process is insufficient, resulting in inadequate uniformity and stability of the final product, particularly poor evenness, making it difficult to meet the requirements of high-end home textile products. Another related patent, CN211284701U, provides a shape-preserving recycled polyester and cotton blended yarn, which improves the yarn's shape retention by setting an outer protective layer and an internal high-elasticity yarn structure. However, this solution has a complex process, high production costs, and fails to effectively solve the fundamental problem of uniform mixing of recycled polyester and cotton fibers. Furthermore, it lacks consideration for yarn functionality (such as antibacterial properties), limiting its application in the home textile field.

[0004] In addition, existing technologies suffer from several other problems: First, most processes do not adequately address the pretreatment of recycled polyester fibers, lacking effective antistatic and softening measures, which hinders the smooth progress of subsequent spinning processes. Second, fiber blending often employs traditional mechanical mixing, resulting in limited mixing uniformity and difficulty in achieving an ideal bond between fibers. Third, functional post-treatment is often separated from the spinning process, leading to weak bonding between functional auxiliaries and fibers, affecting product durability. These problems result in existing recycled polyester blended yarns generally exhibiting defects such as uneven yarn count, insufficient strength, excessive hairiness, and poor functionality, making it difficult to meet the stringent yarn quality requirements of high-end home textile products.

[0005] Therefore, there is an urgent need to develop a new preparation method that can effectively solve the problems of poor spinnability and uneven mixing of recycled polyester fibers, while giving the yarn good antibacterial and wearability properties, so as to meet the demand of modern home textile products for high-quality, multi-functional yarns. Summary of the Invention

[0006] In view of the problems existing in the above-mentioned background technology, the present invention proposes a method for preparing recycled polyester and cotton blended yarn for home textiles, the steps of which are as follows.

[0007] a) By mass fraction, prepare 50-60 parts of recycled polyester fiber and 35-45 parts of cotton fiber as raw materials. The recycled polyester fiber is subjected to antistatic soaking pretreatment and the cotton fiber is subjected to opening and impurity removal pretreatment, respectively.

[0008] b) The pretreated recycled polyester fiber and cotton fiber are put into a dynamic mixing device and mixed evenly under the combined action of rotating blades and high-pressure airflow. Then, they are processed into sliver through a cleaning and combing process.

[0009] c) The raw sliver is sequentially processed through first, second and third drawing processes to gradually improve fiber straightness and evenness, thus obtaining a finished sliver;

[0010] d) The sliver is roving through a roving process, and then spun into fine yarn through a ring spinning process;

[0011] e) The fine yarn is immersed in a functional auxiliary agent solution, then dried and wound to obtain recycled polyester and cotton blended yarn.

[0012] Preferably, in step a), the raw materials for the recycled polyester fiber include, but are not limited to, waste polyester bottle flakes. The recycled polyester fiber is made from waste polyester bottle flakes through crushing, washing, drying, and melt extrusion. The cotton fiber is a mixture of combed cotton waste and raw cotton at a mass ratio of 1:1. The pretreatment of the recycled polyester fiber specifically involves soaking it in a 0.5%-1% sodium dodecylbenzenesulfonate aqueous solution for 30-60 minutes, followed by dehydration and drying until the moisture content is ≤8%. The pretreatment of the cotton fiber specifically involves processing it with an opening machine to remove short fibers and impurities, and controlling the cotton fiber length to 28-32 mm.

[0013] Preferably, in step a), the raw materials further include 3-5 parts of functional additives, wherein the functional additives include 2-3 parts of nano-silver antibacterial agent and 1-2 parts of polyethylene glycol.

[0014] Preferably, in step b), the operating parameters of the dynamic mixing device are: rotating blade speed 800-1200 r / min, high-pressure airflow pressure 0.3-0.5 MPa, mixing time 10-15 minutes; and the quantitative control of the raw strip is 18-22 g / m.

[0015] Preferably, in step c), the process parameters for the first drawing process are: a draw ratio of 6-8 times, a roller spacing of 10mm×8mm×12mm, and an output sliver weight of 16-18g / m.

[0016] Preferably, in step c), the process parameters for the second drawing are: a draw ratio of 5-6 times, a roller spacing of 8mm×6mm×10mm, and an output strip weight of 14-16g / m.

[0017] Preferably, in step c), the process parameters for the three-stage drawing are: a draw ratio of 4-5 times, a roller spacing of 6mm×4mm×8mm, and an output strip weight of 12-14g / m; after the three-stage drawing, the strip uniformity CV value is ≤3%.

[0018] Preferably, in step d), the process parameters of the roving process are: draft ratio 8-10 times, twist coefficient 60-70, roving twist 40-50 twists / meter, and roving evenness CV value ≤4%; the process parameters of the spinning process are: draft ratio 15-20 times, twist coefficient 350-400, and the linear density of the spinning yarn controlled at 18-28 tex.

[0019] Preferably, in step e), the functional additive solution is obtained by adding the weighed functional additive obtained in step a) to water and stirring evenly; the process parameters of the impregnation treatment are: impregnation temperature of 40-50℃ and impregnation time of 20-30 minutes; the drying temperature of 70-80℃ and drying time of 15-20 minutes.

[0020] Preferably, the functional additive solution contains 2-4% functional additives by mass percentage, with the remainder being water.

[0021] Compared with the prior art, the method for preparing recycled polyester and cotton blended yarn for home textiles provided by the present invention has the following significant advantages:

[0022] First, by pre-treating recycled polyester fibers by soaking them in an antistatic agent solution of a specific concentration, their surface properties are effectively improved, and the static electricity phenomenon during the spinning process is significantly reduced, thereby improving the spinnability of the fibers and reducing the problems of breakage and entanglement during the production process.

[0023] Secondly, an innovative dynamic mixing device combining rotating blades and high-pressure airflow is used to mix pretreated recycled polyester and cotton fibers. By utilizing the synergistic effect of mechanical force and airflow, the limitations of insufficient uniformity in traditional mixing methods are overcome, laying a solid foundation for achieving high-quality yarn production in the future.

[0024] Finally, by designing a multi-stage drawing process and rationally configuring the draft ratio and roller spacing of each stage, the fibers are fully straightened and arranged in parallel, which greatly improves the evenness of the sliver and keeps the CV value of the final yarn at a low level.

[0025] In addition, the present invention integrates the addition of functional additives (including nano silver antibacterial agent and polyethylene glycol) into the yarn raw material preparation stage, and uses an impregnation process in the finishing process to make the functional components firmly adhere to the yarn. This not only simplifies the process, but also makes the blended yarn have long-lasting and uniform antibacterial properties and excellent softness.

[0026] The recycled polyester / cotton blended yarn prepared by this invention has good evenness, mechanical strength and functionality, which fully meets the stringent requirements of high-end home textile products for yarn quality. At the same time, it realizes the high-value recycling of waste polyester resources, and has significant economic benefits and environmental value. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] The raw material ratio is as follows: by mass parts, 55 parts recycled polyester fiber, 40 parts cotton fiber, and 4 parts functional additives. The functional additives include 2 parts nano silver antibacterial agent and 2 parts polyethylene glycol. The above raw materials are prepared into recycled polyester and cotton blended yarn for home textiles according to the following steps.

[0030] Step 1: Soak the recycled polyester fibers in an antistatic agent aqueous solution for 45 minutes. The antistatic agent is a sodium dodecylbenzene sulfonate solution with a mass concentration of 0.7%. After soaking, dehydrate and dry the fibers until the moisture content is ≤8%. Then, process the cotton fibers with an opening machine to remove short fibers and impurities, and control the length of the cotton fibers to 30mm.

[0031] Step 2: Using a dynamic mixing device that combines airflow mixing and mechanical stirring, the pretreated recycled polyester fiber and cotton fiber are fed into the mixing chamber of the dynamic mixing device according to the ratio. The mixing chamber is equipped with rotating blades and high-pressure airflow nozzles. The blade speed is 1000 r / min, the high-pressure airflow pressure is 0.4 MPa, and the mixing time is 12 minutes to ensure uniform fiber distribution. The mixed fibers are then processed into slivers through a cleaning and combing process. The sliver weight is controlled at 20 g / m.

[0032] Step 3: The raw sliver obtained above is processed into a finished sliver by first drawing, second drawing and third drawing. Through multiple drawing processes, the fiber straightness and evenness are improved step by step. After three drawing processes, the fiber straightness is increased to more than 95% and the evenness CV value is ≤3%.

[0033] The first drawing process parameters are: draft ratio 7 times, roller spacing 10mm×8mm×12mm, and output sliver weight 17g / m;

[0034] The parameters for the second drawing process are: draft ratio 5 times, roller spacing 8mm×6mm×10mm, and output strip weight 15g / m;

[0035] The parameters for the three-stage drawing process are: draft ratio of 4, roller spacing of 6mm×4mm×8mm, and output strip weight of 13g / m.

[0036] Step 4: The sliver obtained in Step 3 is roving through a roving process. The roving process parameters are: draft ratio 9, twist coefficient 65, roving twist 45 twists / meter, and roving evenness CV value ≤ 4%. The roving is then spun into fine yarn through a ring spinning process. The fine yarn process parameters are: draft ratio 17, twist coefficient 370, and fine yarn linear density controlled within 23 tex.

[0037] Step 5: Immerse the prepared fine yarn in a functional auxiliary agent solution. The functional auxiliary agent in the solution accounts for 3% of the total mass, with the remainder being water. The immersion temperature during the fine yarn immersion process is 45°C, and the immersion time is 25 minutes. Then, remove the yarn and dry it at 75°C for 17 minutes. Finally, wind the yarn to obtain the finished yarn.

[0038] The recycled polyester and cotton blended yarn prepared in Example 1 of this invention exhibits significant performance improvements and comprehensive advantages compared to similar yarns prepared using traditional processes. Traditional recycled polyester blended yarns generally suffer from poor evenness (CV value typically greater than 4.5%), low strength, rough hand feel, and lack of functionality due to poor fiber spinnability and uneven mixing. Example 1 of this invention, by combining targeted antistatic pretreatment (immersion in 0.7% sodium dodecylbenzenesulfonate solution) with dynamic mixing technology (1000 r / min, 0.4 MPa) and auxiliary functional additives, ensures that the evenness CV value of the final yarn is stably controlled below 3%, significantly improving the yarn's uniformity and strength. Simultaneously, thanks to the introduction of nano-silver antibacterial agents, the yarn achieves long-lasting and highly effective antibacterial properties, with an antibacterial rate exceeding 99%, while also possessing excellent softness, fully meeting the stringent requirements for yarn quality in high-end home textile products.

[0039] Example 2

[0040] The raw material ratio is as follows: by mass parts, 50 parts recycled polyester fiber, 35 parts cotton fiber, and 3 parts functional additives. The functional additives include 2 parts nano silver antibacterial agent and 1 part polyethylene glycol. The above raw materials are prepared into recycled polyester and cotton blended yarn for home textiles according to the following steps.

[0041] Step 1: Soak the recycled polyester fibers in an antistatic agent aqueous solution for 30 minutes. The antistatic agent is a sodium dodecylbenzene sulfonate solution with a mass concentration of 0.5%. After soaking, dehydrate and dry the fibers until the moisture content is ≤8%. Then, process the cotton fibers with an opening machine to remove short fibers and impurities, and control the length of the cotton fibers to 28mm.

[0042] Step 2: Using a dynamic mixing device that combines airflow mixing and mechanical stirring, the pretreated recycled polyester fiber and cotton fiber are fed into the mixing chamber of the dynamic mixing device according to the ratio. The mixing chamber is equipped with rotating blades and high-pressure airflow nozzles. The blade speed is 800 r / min, the high-pressure airflow pressure is 0.3 MPa, and the mixing time is 10 minutes to ensure uniform fiber distribution. The mixed fibers are then processed into slivers through a cleaning and combing process. The sliver weight is controlled at 18 g / m.

[0043] Step 3: The raw sliver obtained above is processed into a finished sliver by first drawing, second drawing and third drawing. Through multiple drawing processes, the fiber straightness and evenness are improved step by step. After three drawing processes, the fiber straightness is increased to more than 95% and the evenness CV value is ≤3%.

[0044] The first drawing process parameters are: draft ratio 6 times, roller spacing 10mm×8mm×12mm, and output sliver weight 16g / m;

[0045] The parameters for the two-stage drawing process are: draft ratio 5 times, roller spacing 8mm×6mm×10mm, and output strip weight 14g / m;

[0046] The parameters for the three-stage drawing process are: draft ratio of 4, roller spacing of 6mm×4mm×8mm, and output strip weight of 12g / m.

[0047] Step 4: The sliver obtained in Step 3 is roving through a roving process. The roving process parameters are: draft ratio 8, twist coefficient 60, roving twist 40 twists / meter, and roving evenness CV value ≤4%. The roving is then spun into fine yarn through a ring spinning process. The fine yarn process parameters are: draft ratio 15, twist coefficient 350, and fine yarn linear density controlled within 18 tex.

[0048] Step 5: Immerse the prepared fine yarn in a functional auxiliary agent solution. The functional auxiliary agent in the solution accounts for 2% of the total mass, with the remainder being water. The immersion temperature during the immersion process is 40°C, and the immersion time is 30 minutes. Then, remove the yarn and dry it at 70°C for 20 minutes. Finally, wind the yarn to obtain the finished yarn.

[0049] Example 3

[0050] The raw material ratio is as follows: by mass parts, 60 parts recycled polyester fiber, 45 parts cotton fiber, and 5 parts functional additives. The functional additives include 3 parts nano silver antibacterial agent and 2 parts polyethylene glycol. The above raw materials are prepared into recycled polyester and cotton blended yarn for home textiles according to the following steps.

[0051] Step 1: Soak the recycled polyester fibers in an antistatic agent aqueous solution for 60 minutes. The antistatic agent is a 1% sodium dodecylbenzene sulfonate solution. After soaking, dehydrate and dry the fibers until the moisture content is ≤8%. Then, process the cotton fibers with an opening machine to remove short fibers and impurities, and control the length of the cotton fibers to 32mm.

[0052] Step 2: Using a dynamic mixing device that combines airflow mixing and mechanical stirring, the pretreated recycled polyester fiber and cotton fiber are fed into the mixing chamber of the dynamic mixing device according to the ratio. The mixing chamber is equipped with rotating blades and high-pressure airflow nozzles. The blade speed is 1200 r / min, the high-pressure airflow pressure is 0.5 MPa, and the mixing time is 15 minutes to ensure uniform fiber distribution. The mixed fibers are then processed into slivers through a cleaning and combing process. The sliver weight is controlled at 22 g / m.

[0053] Step 3: The raw sliver obtained above is processed into a finished sliver by first drawing, second drawing and third drawing. Through multiple drawing processes, the fiber straightness and evenness are improved step by step. After three drawing processes, the fiber straightness is increased to more than 95% and the evenness CV value is ≤3%.

[0054] The first drawing process parameters are: draft ratio 8 times, roller spacing 10mm×8mm×12mm, and output sliver weight 18g / m;

[0055] The parameters for the two-stage drawing process are: draft ratio 6 times, roller spacing 8mm×6mm×10mm, and output strip weight 16g / m;

[0056] The parameters for the three-stage drawing process are: draft ratio of 5, roller spacing of 6mm×4mm×8mm, and output strip weight of 14g / m.

[0057] Step 4: The sliver obtained in Step 3 is roving through a roving process. The roving process parameters are: draft ratio 10, twist coefficient 70, roving twist 50 twists / meter, and roving evenness CV value ≤4%. The roving is then spun into fine yarn through a ring spinning process. The fine yarn process parameters are: draft ratio 20, twist coefficient 400, and fine yarn linear density controlled within 28 tex.

[0058] Step 5: Immerse the prepared fine yarn in a functional auxiliary agent solution. The functional auxiliary agent in the solution accounts for 4% of the total mass, with the remainder being water. The immersion temperature during the fine yarn immersion process is 50°C, and the immersion time is 20 minutes. Then, remove the yarn and dry it at 80°C for 15 minutes. Finally, wind the yarn to obtain the finished yarn.

[0059] Example 4

[0060] The raw material ratio is as follows: by mass parts, 52 parts recycled polyester fiber, 37 parts cotton fiber, and 4 parts functional additives. The functional additives include 3 parts nano silver antibacterial agent and 1 part polyethylene glycol. The above raw materials are prepared into recycled polyester and cotton blended yarn for home textiles according to the following steps.

[0061] Step 1: Soak the recycled polyester fibers in an antistatic agent aqueous solution for 35 minutes. The antistatic agent is a sodium dodecylbenzene sulfonate solution with a mass concentration of 0.6%. After soaking, dehydrate and dry the fibers until the moisture content is ≤8%. Then, process the cotton fibers with an opening machine to remove short fibers and impurities, and control the length of the cotton fibers to 29mm.

[0062] Step 2: Using a dynamic mixing device that combines airflow mixing and mechanical stirring, the pretreated recycled polyester fiber and cotton fiber are fed into the mixing chamber of the dynamic mixing device according to the ratio. The mixing chamber is equipped with rotating blades and high-pressure airflow nozzles. The blade speed is 900 r / min, the high-pressure airflow pressure is 0.3 MPa, and the mixing time is 11 minutes to ensure uniform fiber distribution. The mixed fibers are then processed into slivers through a cleaning and combing process. The sliver weight is controlled at 19 g / m.

[0063] Step 3: The raw sliver obtained above is processed into a finished sliver by first drawing, second drawing and third drawing. Through multiple drawing processes, the fiber straightness and evenness are improved step by step. After three drawing processes, the fiber straightness is increased to more than 95% and the evenness CV value is ≤3%.

[0064] The first drawing process parameters are: draft ratio 6 times, roller spacing 10mm×8mm×12mm, and output sliver weight 16g / m;

[0065] The parameters for the two-stage drawing process are: draft ratio 6 times, roller spacing 8mm×6mm×10mm, and output strip weight 16g / m;

[0066] The parameters for the three-stage drawing process are: draft ratio of 5, roller spacing of 6mm×4mm×8mm, and output strip weight of 14g / m.

[0067] Step 4: The sliver obtained in Step 3 is roving through a roving process. The roving process parameters are: draft ratio 8, twist coefficient 62, roving twist 42 twists / meter, and roving evenness CV value ≤4%. The roving is then spun into fine yarn through a ring spinning process. The fine yarn process parameters are: draft ratio 16, twist coefficient 360, and fine yarn linear density controlled within 19 tex.

[0068] Step 5: Immerse the prepared fine yarn in a functional auxiliary agent solution. The functional auxiliary agent in the solution accounts for 3% of the total mass, with the remainder being water. The immersion temperature during the immersion process is 42°C, and the immersion time is 28 minutes. Then, remove the yarn and dry it at 72°C for 18 minutes. Finally, wind the yarn to obtain the finished yarn.

[0069] Example 5

[0070] The raw material ratio is as follows: by mass parts, 58 parts recycled polyester fiber, 42 parts cotton fiber, and 5 parts functional additives. The functional additives include 3 parts nano silver antibacterial agent and 2 parts polyethylene glycol. The above raw materials are prepared into recycled polyester and cotton blended yarn for home textiles according to the following steps.

[0071] Step 1: Soak the recycled polyester fibers in an antistatic agent aqueous solution for 55 minutes. The antistatic agent is a sodium dodecylbenzene sulfonate solution with a mass concentration of 0.8%. After soaking, dehydrate and dry the fibers until the moisture content is ≤8%. Then, process the cotton fibers with an opening machine to remove short fibers and impurities, and control the length of the cotton fibers to 31mm.

[0072] Step 2: Using a dynamic mixing device that combines airflow mixing and mechanical stirring, the pretreated recycled polyester fiber and cotton fiber are fed into the mixing chamber of the dynamic mixing device according to the ratio. The mixing chamber is equipped with rotating blades and high-pressure airflow nozzles. The blade speed is 1100 r / min, the high-pressure airflow pressure is 0.4 MPa, and the mixing time is 14 minutes to ensure uniform fiber distribution. The mixed fibers are then processed into slivers through a cleaning and combing process. The sliver weight is controlled at 21 g / m.

[0073] Step 3: The raw sliver obtained above is processed into a finished sliver by first drawing, second drawing and third drawing. Through multiple drawing processes, the fiber straightness and evenness are improved step by step. After three drawing processes, the fiber straightness is increased to more than 95% and the evenness CV value is ≤3%.

[0074] The first drawing process parameters are: draft ratio 7 times, roller spacing 10mm×8mm×12mm, and output sliver weight 17g / m;

[0075] The parameters for the two-stage drawing process are: draft ratio 5 times, roller spacing 8mm×6mm×10mm, and output strip weight 14g / m;

[0076] The parameters for the three-stage drawing process are: draft ratio of 4, roller spacing of 6mm×4mm×8mm, and output strip weight of 12g / m.

[0077] Step 4: The sliver obtained in Step 3 is roving through a roving process. The roving process parameters are: draft ratio 9, twist coefficient 68, roving twist 48 twists / meter, and roving evenness CV value ≤4%. The roving is then spun into fine yarn through a ring spinning process. The fine yarn process parameters are: draft ratio 18, twist coefficient 380, and fine yarn linear density controlled within 27 tex.

[0078] Step 5: Immerse the prepared fine yarn in a functional auxiliary agent solution. The functional auxiliary agent in the solution accounts for 4% of the total mass, with the remainder being water. The immersion temperature during the fine yarn immersion process is 48°C, and the immersion time is 22 minutes. Then, remove the yarn and dry it at 78°C for 16 minutes. Finally, wind the yarn to obtain the finished yarn.

[0079] Comparative Example 1

[0080] Comparative Example 1 used the same raw material ratio as Example 1, but omitted the antistatic pretreatment step of recycled polyester fiber. The remaining preparation steps were completely consistent with those in Example 1. Since the recycled polyester fiber was not soaked in antistatic agent solution, the fiber entanglement was severe due to static electricity during the production process, and the breakage rate increased sharply. The final yarn dryness uniformity CV value was 7.5%, which was significantly higher than ≤3% in Example 1. The production efficiency was greatly reduced, and the yarn had a rough hand feel, which could not meet the quality requirements of high-end home textiles at all.

[0081] Comparative Example 2

[0082] Comparative Example 2 omitted the functional additive impregnation step during implementation. After obtaining the fine yarn, the functional additive solution impregnation and drying treatment were not carried out. The yarn was directly wound to obtain the finished product. The remaining preparation steps were exactly the same as in Example 1. Although the final yarn had good evenness (CV value of about 3.1%), it did not have antibacterial properties because no functional substances were attached to its surface. The antibacterial rate against Staphylococcus aureus and Escherichia coli was less than 20% after testing. Moreover, the hand feel and softness of the yarn were far inferior to the finished product of Example 1 after functional finishing, which limited its application value.

[0083] Comparative Example 3

[0084] The raw material ratio was adjusted to 70 parts recycled polyester fiber and 30 parts cotton fiber (4 parts functional additives remained unchanged). The remaining steps were completely consistent with those in Example 1. After three drawing processes, the evenness CV value reached 6.1%, and the fiber straightness was only 82% (over 95% in Example 1). This indicates that an excessively high proportion of recycled polyester will reduce the fiber mixing uniformity and spinnability.

[0085] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing recycled polyester and cotton blended yarn for home textiles, characterized in that: The steps are as follows: a) By mass fraction, prepare 50-60 parts of recycled polyester fiber and 35-45 parts of cotton fiber as raw materials. The recycled polyester fiber is subjected to antistatic soaking pretreatment and the cotton fiber is subjected to opening and impurity removal pretreatment, respectively. b) The pretreated recycled polyester fiber and cotton fiber are put into a dynamic mixing device and mixed evenly under the combined action of rotating blades and high-pressure airflow. Then, they are processed into sliver through a cleaning and combing process. c) The raw sliver is sequentially processed through first, second and third drawing processes to gradually improve fiber straightness and evenness, thus obtaining a finished sliver; d) The sliver is roving through a roving process, and then spun into fine yarn through a ring spinning process; e) The fine yarn is immersed in a functional auxiliary agent solution, then dried and wound to obtain recycled polyester and cotton blended yarn.

2. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step a), the raw materials for the recycled polyester fiber include, but are not limited to, waste polyester bottle flakes; the cotton fiber is a mixture of combed cotton waste and raw cotton at a mass ratio of 1:1; the pretreatment of the recycled polyester fiber specifically involves: soaking it in a sodium dodecylbenzenesulfonate aqueous solution with a mass concentration of 0.5%-1% for 30-60 minutes, followed by dehydration and drying until the moisture content is ≤8%; the pretreatment of the cotton fiber specifically involves: processing it with an opening machine to remove short fibers and impurities, and controlling the cotton fiber length to 28-32mm.

3. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step a), the raw materials also include 3-5 parts of functional additives, which contain 2-3 parts of nano-silver antibacterial agent and 1-2 parts of polyethylene glycol.

4. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step b), the operating parameters of the dynamic mixing device are: rotating blade speed 800-1200 r / min, high-pressure airflow pressure 0.3-0.5 MPa, mixing time 10-15 minutes; the quantitative control of the raw strip is 18-22 g / m.

5. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step c), the process parameters for the first drawing process are: draw ratio 6-8 times, roller spacing 10mm×8mm×12mm, and output strip weight 16-18g / m.

6. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step c), the process parameters for the second drawing are: a draw ratio of 5-6 times, a roller spacing of 8mm×6mm×10mm, and an output strip weight of 14-16g / m.

7. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step c), the process parameters for the three-stage drawing are: draw ratio 4-5 times, roller spacing 6mm×4mm×8mm, and output strip weight 12-14g / m; after the three-stage drawing, the strip uniformity CV value is ≤3%.

8. The method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step d), the process parameters for the roving process are: draft ratio 8-10 times, twist coefficient 60-70, roving twist 40-50 twists / meter, and roving evenness CV value ≤4%; the process parameters for the spinning process are: draft ratio 15-20 times, twist coefficient 350-400, and the linear density of the spinning yarn controlled at 18-28 tex.

9. A method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 1, characterized in that: In step e), the functional additive solution is obtained by adding the weighed functional additive obtained in step a) to water and stirring evenly; the process parameters of the impregnation treatment are: impregnation temperature is 40-50℃, impregnation time is 20-30 minutes; the drying temperature is 70-80℃, and the drying time is 15-20 minutes.

10. A method for preparing recycled polyester and cotton blended yarn for home textiles according to claim 9, characterized in that: The functional additive solution contains 2-4% functional additives by mass percentage, with the remainder being water.