Preparation process of composite covering yarn for high-shrinkage velvet fabric

Abstract

The application relates to the technical field of composite covering yarn, in particular to a preparation process of high-shrinkage velvet composite covering yarn. 2 The process is characterized in that: the polyamide chip and the polyamide master batch are fed into an extruder, are uniformly melted and mixed, the temperature of each section of the screw extruder is set to be between 245-270 DEG C, the screw pressure is 110-120 kg / cm, the screw rotating speed is 50-55 r / min, the melt spinning temperature is 260-265 DEG C, the spinning orifice of the spinning assembly is a flat structure with a rectangular cross section, the length of the cross section of the spinning orifice is 0.18-0.22 mm, the width is 0.11-0.18 mm, and the length-diameter ratio of the spinning orifice is 2.5-3.5. The composite covering yarn prepared based on the method is used for velvet fabric, can make the fabric fluffy surface have a skin-friendly feeling, and the structure of the composite covering yarn itself makes the prepared fabric have excellent characteristics of light weight, moisture permeability, quick drying, comfort, easy cleaning and ironing-free.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite covering yarn, and particularly relates to a preparation process of composite covering yarn for high-shrinkage raised velvet fabric. BACKGROUND

[0002] After years of rapid development, the production of polyamide products has gradually matured and stabilized in technology, the production capacity has expanded year by year, and the market has tended to be saturated. The product performance and style are single, and lack of competitiveness. The competition of conventional varieties is becoming more and more fierce.

[0003] Based on the current market situation, the differentiation and speciality of polyamide products have become the ideal market demand. The development of differentiated and speciality products is one of the focuses of market development in the coming years. Through technical transformation of equipment and innovation and optimization of process technology, the development of differentiated and speciality products is an important direction.

[0004] Velvet fabric is a product that is widely loved by people, and is favored by stars at fashion ceremonies. Raised velvet is a relatively important product at present. However, the shrinkage rate of the current raised velvet product cannot be guaranteed, which makes the prepared raised velvet fabric have insufficient fluffiness, and affects the skin-friendly feeling. At the same time, due to the self-reasons of the prepared raised velvet fabric, it cannot quickly absorb the moisture and sweat on the surface of the skin, resulting in poor wearing comfort.

[0005] Therefore, it is necessary to develop corresponding composite covering yarn related products in the field of raised velvet, in order to improve the overall performance of the raised velvet fabric, expand its application field, and also provide a new economic growth point for enterprises. SUMMARY

[0006] The present application aims to solve the problem of insufficient market differentiation of covering yarn products, and in combination with the deficiencies of raised velvet fabric, a preparation process of composite covering yarn for high-shrinkage raised velvet fabric is provided. The composite covering yarn for raised velvet fabric prepared by the process can expand product differentiation, meet market demand, and improve the economic growth of enterprises.

[0007] Specifically, the present application adopts the following technical scheme:

[0008] A preparation process of composite covering yarn for high-shrinkage raised velvet fabric, the preparation process comprises the following steps:

[0009] (1) melt high-speed spinning: feed the polyamide chip and polyamide master batch into the extruder, melt and mix uniformly, set the temperature of each section of the screw extruder to 245-270 DEG C, wherein the screw pressure is 110-120 kg / cm 2, the screw rotation speed is 50-55 r / min, the melt spinning temperature is 260-265 DEG C, the spinning orifice of the spinning pack is a flat structure with a rectangular cross section, the length of the cross section of the spinning orifice is 0.18-0.22 mm, the width of the cross section of the spinning orifice is 0.11-0.18 mm, and the length-width ratio of the spinning orifice is 2.5-3.5;

[0010] (2) Side blowing cooling: air temperature 17-19 DEG C, humidity 93-95%, air speed 0.45-0.5 m / s;

[0011] (3) Oiling and bundling: the fibers cooled by side blowing are oiled and bundled through an oil nozzle;

[0012] (4) Winding: the oiled and bundled fibers pass through a pre-networker, a godet, a main networker, and then are wound, and the winding speed is 4200-4300 m / min, to obtain the profiled polyurethane POY filament;

[0013] (5) Yarn guiding and heating: the profiled polyurethane POY filament is guided, fed through a first roller, a twist stopper, and a heating box on an empty package integrated machine, and the heating temperature is 170-175 DEG C;

[0014] (6) Cooling and false twisting: the profiled polyurethane POY filament is cooled through a cooling plate after being heated, enters a false twister to be false twisted, the friction disc of the false twister is 6 mm, the combination of the friction discs is 1-7-1, and the D / Y ratio is set to be 1.60-1.65;

[0015] (7) Drafting: after false twisting, the profiled polyurethane POY filament enters a second roller to be drafted, the rotation speed of the second roller is 600-650 m / min, and the drafting multiple is 1.25-1.28;

[0016] (8) Elastane: the elastane at the elastane roller enters a second roller to be drafted through a yarn guide, and the drafting multiple is 3.2-3.5;

[0017] (9) Network: after drafting, the yarn enters a network nozzle to be networked by adjusting the compressed air pressure to be 3.0-3.5 bar;

[0018] (10) Oiling and winding: the yarn passes through a yarn cutter, a yarn guide, and an oil roller to enter a winding area to be wound, to obtain the composite covered yarn for high-shrinkage pile fabric.

[0019] In the process, the circular spinneret section is adjusted to include several port sections with a "rectangular flat groove" shape, and a fiber product with a "rectangular flat groove" section is produced through a matched spinning and drafting process, the main purpose of which is to form a spiral triangular support structure through elastication, so that the fabric has a skin-friendly surface, and through the high-temperature-resistant and high-resilience spandex covering, the rectangular flat groove structure can quickly absorb the moisture and sweat on the skin surface, and through diffusion, it is transmitted to the outer layer, bringing a comfortable feeling of body ventilation and dryness.

[0020] The groove section fiber fabric has excellent properties such as light weight, moisture conductivity, quick drying, comfort, easy cleaning, and ironing-free, and is widely used in sports wear, travel and leisure wear, outdoor wear, underwear, and home textiles. The use of fully-dull cut pieces not only reduces the reflection and flickering of the fiber, but also makes the subsequent fiber have soft luster, good dyeing properties, high fabric drape, and strong shielding performance. The development and production of such products will create a new economic growth point for the company.

[0021] As a preferred, the oil agent used in step (3) is a 6% nylon oil agent pure water emulsion, the pure water conductivity is between 0.4-0.6 μs / cm, and the oiling rate is 0.6-0.7%.

[0022] As a preferred, the oil wheel speed in step (10) is 1.5-2.0 rpm, and the winding overfeed is -5.5% to -7.2%.

[0023] As a preferred, the addition amount of the nylon master batch in step (1) is 8%-11% of the nylon chip.

[0024] As a preferred, the nylon master batch in step (1) includes, by weight: polyamide 100 parts, nano titanium dioxide 3-5 parts, far infrared additive 5-10 parts, antibacterial and acarid-repelling additive 8-12 parts, carbon black 3-5 parts, far infrared additive is nano titanium diboride or nano zirconium diboride; the antibacterial and acarid-repelling additive is nano titanium nitride.

[0025] As a preferred, the temperature of each section of the screw extruder is respectively: the first section 260-270℃, the second section 260-250℃, the third section 245-250℃, the fourth section 250-260℃, and the fifth section 260-270℃.

[0026] As a preferred, the nylon master batch in step (1) includes, by weight: polyamide 100 parts, modified titanium dioxide 5-8 parts, white carbon black 3-5 parts, nano titanium diboride 3-5 parts, and nano titanium nitride 5-7 parts.

[0027] As preferred, the modified titanium dioxide is prepared by the following steps: dispersing europium oxide in water, stirring uniformly to form a rare earth oxide dispersion liquid with a mass fraction of 2%-5%, then adding acid to adjust the pH to 4-5; adding carbamide to the dispersion liquid, stirring uniformly, the amount of carbamide added is 10-15 times of the europium oxide, then adding titanyl sulfate with a weight of 80-100 times of the europium oxide to the dispersion liquid, then reacting at 180-185 DEG C for 12 hours or more, then centrifuging, washing, drying, and calcining at 800-900 DEG C for 0.5-1 hour to obtain the modified titanium dioxide.

[0028] As preferred, the oil agent used in the oiling in step (3) comprises, in terms of weight fractions: 50 parts of mineral oil, 10-15 parts of alkyl polyoxyethylene ether phosphate salt, 20-30 parts of smoothing agent, 5-8 parts of amino-terminated silicone oil, 6-9 parts of polyoxyethylene ether, and 2-4 parts of glycerol random polyether. The three components of amino-terminated silicone oil, polyoxyethylene ether, and glycerol random polyether are used to achieve the expected bundling effect, so that the prepared fabric can have a certain standing and close-to-body effect on the basis of maintaining the loftiness, and help the fabric to quickly absorb the moisture and sweat on the skin surface, improving the wearing comfort.

[0029] Compared with the prior art, the application has the following beneficial effects:

[0030] The composite coated yarn prepared based on the method is used for the pile fabric, and can make the fabric have a skin-friendly feeling on the fluffy surface.

[0031] The structure of the composite coated yarn itself makes the prepared fabric have the excellent properties of light weight, moisture conductivity, quick drying, comfort, easy cleaning, and ironing-free. DETAILED DESCRIPTION

[0032] Representative embodiments will now be further described in detail. It should be understood that the following description is not intended to limit the embodiments to one preferred embodiment. On the contrary, it is intended to cover alternatives, modifications, and equivalents, which can be included within the spirit and scope of the embodiments defined by the appended claims.

[0033] The company has developed a composite coated yarn for high-shrinkage pile, and the specific production process of the product is as follows:

[0034] (1) melt high-speed spinning: the polyamide chip and polyamide master batch are fed into the extruder, melt mixed uniformly, the temperature of each section of the screw extruder is set between 245-270 DEG C, and the specific temperature of each section of the screw extruder is: the first section 260-270 DEG C, the second section 250-260 DEG C, the third section 245-250 DEG C, the fourth section 250-260 DEG C, and the fifth section 260-270 DEG C; wherein the screw pressure is 110-120 kg / cm 2, the screw rotation speed is 50-55 r / min, the melt spinning temperature is 260-265 DEG C, the spinning orifice of the spinning pack is a flat structure with a rectangular cross section, the length of the cross section of the spinning orifice is 0.18-0.22 mm, the width of the cross section of the spinning orifice is 0.11-0.18 mm, the length-width ratio of the spinning orifice is 2.5-3.5; the addition amount of the polyamide master batch is 8%-11% of the polyamide chip; the polyamide master batch comprises, by weight fraction, polyamide 100 parts, modified titanium dioxide 5-8 parts, white carbon black 3-5 parts, nano-titanium diboride 3-5 parts and nano-titanium nitride 5-7 parts;

[0035] (2) side blowing cooling: air temperature 17-19 DEG C, humidity 93-95%, air speed 0.45-0.5 m / s;

[0036] (3) oiling and bundling: the fibers cooled by side blowing are oiled and bundled through an oil nozzle; the oil agent used is 6% polyamide oil agent pure water emulsion, the pure water electric conductivity is between 0.4-0.6 us / cm, and the oiling rate is 0.6-0.7%; the oil agent used for oiling comprises, by weight fraction, mineral oil 50 parts, alkyl polyoxyethylene ether phosphate ester salt 10-15 parts, smoothing agent 20-30 parts, amino-terminated silicone oil 5-8 parts, polyoxyethylene ether 6-9 parts, and glycerol random polyether 2-4 parts;

[0037] (4) winding: the oiled fiber bundle passes through a pre-networker, a godet, a main networker, and then is wound, the winding speed is 4200-4300 m / min, and a profiled polyamide POY filament is obtained;

[0038] (5) godet heating: the profiled polyamide POY filament is heated in a heating box after passing through a godet, a first roller for feeding the filament, and a twist stopper on an empty package integrated machine;

[0039] (6) cooling and false twisting: the profiled polyamide POY filament is cooled by a cooling plate after being heated, enters a false twister to be false twisted, the friction disc of the false twister is 6 mm, the friction disc combination is 1-7-1, and the D / Y ratio is set to 1.60-1.65;

[0040] (7) drafting: after false twisting, the profiled polyamide POY filament enters a second roller for drafting, the rotation speed of the second roller is 600-650 m / min, and the drafting multiple is between 1.25-1.28;

[0041] (8) spandex: the spandex at the spandex roller enters a second roller for drafting, and the drafting multiple is between 3.2-3.5;

[0042] (9) network: after drafting, the profiled polyamide POY filament enters a network nozzle to be networked, and the compressed air pressure is adjusted to 3.0-3.5 bar;

[0043] (10) oiling and winding: the tow is passed through a cutter, a guide, and an oil roller into a winding area to be wound to obtain the composite covering yarn for high-shrinkage pile fabric; the rotating speed of the oil roller is 1.5-2.0 rpm, and the overfeed of winding is -5.5% to -7.2%.

[0044] As to the modified titanium dioxide used, the following steps are adopted to prepare: europium oxide is dispersed in water, stirred uniformly to form a rare earth oxide dispersion liquid with a mass fraction of 2%-5%, then an acid is added to adjust the pH to 4-5; carbamide is added to the dispersion liquid, stirred uniformly, the addition amount of carbamide is 10-15 times of the europium oxide, then 80-100 times of the weight of the europium oxide of titanyl sulfate is added to the dispersion liquid, then the reaction is carried out at 180-185 ℃ for 12 h or more, then the centrifugal washing, drying, and calcination at 800-900 ℃ for 0.5-1 h are carried out, and the modified titanium dioxide is obtained after cooling.

[0045] Example 1:

[0046] A kind of composite covering yarn for high-shrinkage pile fabric, the preparation process is as follows:

[0047] (1) melt high-speed spinning: the polyamide chip and polyamide master batch are fed into the extruder, melt mixed uniformly, the temperature of each section of the screw extruder is set between 245-270 ℃, the temperature of each section of the screw extruder is: the first section 260-270 ℃, the second section 260-250 ℃, the third section 245-250 ℃, the fourth section 250-260 ℃, the fifth section 260-270 ℃; wherein the screw pressure is 110-115 kg / cm 2 , the rotating speed of the screw is 50-53 r / min, the melt spinning temperature is 260-265 ℃, the spinning orifice of the adopted spinning pack is a flat structure with rectangular cross section, the length of the cross section of the spinning orifice is 0.18 mm, the width is 0.11 mm, and the length-width ratio of the spinning orifice is 2.5; the addition amount of the polyamide master batch is 8% of the polyamide chip; the polyamide master batch includes, by weight: polyamide 100 parts, modified titanium dioxide 8 parts, white carbon black 3 parts, nano-titanium diboride 5 parts, and nano-titanium nitride 5 parts;

[0048] (2) side-blowing air cooling: air temperature 19 ℃, humidity 93%, air speed 0.45 m / s;

[0049] (3) oiling and bundling: the fiber cooled by side-blowing air is oiled and bundled through an oil nozzle; the oil agent used is 6% polyamide oil agent pure water emulsion, the pure water conductivity is between 0.4 μs / cm, and the oiling rate is 0.6%; the oil agent used for oiling includes, by weight: mineral oil 50 parts, alkyl polyoxyethylene ether phosphate ester salt 15 parts, smoothing agent 20 parts, amino-terminated silicone oil 8 parts, polyoxyethylene ether 9 parts, and glycerol random polyether 4 parts;

[0050] (4) winding: the oiling fiber bundle passes through the pre-networker, the guide disc, the main networker, to the winding, the winding speed is 4200-4300 m / min, to obtain the profiled polyamide POY filament;

[0051] (5) guide heating: on the empty package integrated machine device, the profiled polyamide POY filament passes through the guide, the first roller of feeding the filament, the twist stopper to the heating box, the heating temperature is 170-172℃;

[0052] (6) cooling false twisting: the profiled polyamide POY filament after heating passes through the cooling plate to be cooled, enters the false twister to be false twisted, the friction disc of the false twister is 6mm, the combination of the friction disc is 1-7-1, and the D / Y ratio is set to 1.60-1.65;

[0053] (7) drawing: after the false twisting, the profiled polyamide POY filament enters the second roller to be drawn, the rotating speed of the second roller is 600-610 m / min, and the drawing multiple is between 1.25-1.26;

[0054] (8) spandex: the spandex at the spandex roller passes through the guide to enter the second roller to be drawn, and the drawing multiple is 3.2;

[0055] (9) network: after the drawing, the network nozzle is entered to adjust the compressed air pressure to 3.0-3.1 bar to be networked;

[0056] (10) oiling and winding: the fiber bundle passes through the filament cutter, the guide, the oil roller to enter the winding area to be wound, to obtain the composite covered yarn for high-shrinkage pile fabric; the rotating speed of the oil roller is 1.5 rpm, and the winding overfeed is -5.5% to -5.8%.

[0057] Example 2:

[0058] A kind of composite covered yarn for high-shrinkage pile, the preparation process is as follows:

[0059] (1) melt high-speed spinning: the polyamide chip and polyamide master batch are fed into the extruder, melt and mix uniformly, the temperature of each section of the screw extruder is set to be between 245-270℃, wherein the screw pressure is 115~120kg / cm 2 , the rotating speed of the screw is 53~55r / min, the melt spinning temperature is 260~265℃, the jet orifice of the adopted jet assembly is the flat structure of cross section rectangular, the cross section length of the jet orifice is 0.22mm, the width is 0.18mm, and the length-width ratio of the jet orifice is 3.5; the addition amount of the polyamide master batch is 11% of the polyamide chip; the polyamide master batch includes, according to weight parts: polyamide 100 parts, modified titanium dioxide 8 parts, white carbon black 5 parts, nano titanium diboride 5 parts and nano titanium nitride 7 parts;

[0060] (2) Side blowing cooling: air temperature 19℃, humidity 93-95%, air speed 0.45-0.5m / s;

[0061] (3) Oiling and bundling: the fibers cooled by side blowing are oiled and bundled through an oil nozzle; the oil used is 6% nylon oil agent pure water emulsion, the pure water conductivity is between 0.6μs / cm, and the oiling rate is 0.7%; the oil agent used for oiling includes, by weight fraction: mineral oil 50 parts, alkyl polyoxyethylene ether phosphate ester salt 15 parts, smoothing agent 30 parts, amino-terminated silicone oil 8 parts, polyoxyethylene ether 9 parts, glycerol random polyether 4 parts;

[0062] (4) Winding: the oiled fiber bundle passes through a pre-networker, a godet, a main networker, and then is wound, with a winding speed of 4200-4300m / min, to obtain profiled nylon POY filaments;

[0063] (5) Godet heating: on an empty package integrated machine device, the profiled nylon POY filaments pass through a godet, a first roller for feeding the filaments, a twist stopper, and a heating box, with a heating temperature of 170-175℃;

[0064] (6) Cooling and false twisting: the profiled nylon POY filaments after heating pass through a cooling plate for cooling, enter a false twister for false twisting, the false twister friction disc is 6mm, the friction disc combination is 1-7-1, and the D / Y ratio is set to 1.64-1.65;

[0065] (7) Drafting: after false twisting, the profiled nylon POY filaments enter a second roller for drafting, with a second roller speed of 600-650m / min, and a drafting multiple of 1.28;

[0066] (8) Elastane: the elastane at the elastane roller passes through a godet and enters a second roller for drafting, with a drafting multiple of 3.4-3.5;

[0067] (9) Network: after drafting, the filaments enter a network nozzle for network adjustment under a compressed air pressure of 3.0-3.5bar;

[0068] (10) Oiling and winding: the filaments pass through a filament cutter, a godet, and an oil roller to enter a winding area for winding, to obtain a composite covered yarn for high-shrinkage pile fabric; the oil roller speed is 2.0rpm, and the winding overfeed is -7.0% to -7.2%.

[0069] Example 3:

[0070] A composite covered yarn for high-shrinkage pile fabric is prepared according to the following process:

[0071] (1) Melt high-speed spinning: nylon chips and nylon masterbatch are fed into an extruder for melt mixing and uniformity, with the temperature of each section of the screw extruder set to 245-270℃, and the screw pressure set to 118-120kg / cm2 , the screw rotation speed is 54-55 r / min, the melt spinning temperature is 260-265 ℃, the spinning orifice of the spinning pack is a flat structure with a rectangular cross section, the length of the cross section of the spinning orifice is 0.22 mm, the width of the cross section of the spinning orifice is 0.11 mm, the length-width ratio of the spinning orifice is 3; the addition amount of the polyamide master batch is 8% of the polyamide chip; the polyamide master batch comprises, by weight fraction, polyamide 100 parts, modified titanium dioxide 5 parts, white carbon black 3 parts, nano titanium diboride 3 parts, and nano titanium nitride 5 parts;

[0072] (2) Side blowing cooling: air temperature 17-18 ℃, humidity 93%, air speed 0.45-0.5 m / s;

[0073] (3) Oiling and bundling: the fibers cooled by side blowing are oiled and bundled through an oil nozzle; the oil agent used is 6% polyamide oil agent pure water emulsion, the pure water conductivity is between 0.4 μs / cm, and the oiling rate is 0.7%; the oil agent used for oiling comprises, by weight fraction, mineral oil 50 parts, alkyl polyoxyethylene ether phosphate ester salt 10 parts, smoothing agent 20 parts, amino-terminated silicone oil 5 parts, polyoxyethylene ether 6 parts, and glycerol random polyether 2 parts;

[0074] (4) Winding: the oiled fiber bundle passes through a pre-networker, a godet, a main networker, and then is wound, the winding speed is 4200-4300 m / min, and a profiled polyamide POY filament is obtained;

[0075] (5) Godet heating: on an empty package all-in-one machine device, the profiled polyamide POY filament passes through a godet, a first roller for feeding, a twist stopper, and then enters a heating box, the heating temperature is 170-175 ℃;

[0076] (6) Cooling false twisting: the profiled polyamide POY filament is cooled by a cooling plate after being heated, enters a false twister to be false twisted, the friction disc of the false twister is 6 mm, the disc combination is 1-7-1, and the D / Y ratio is set to 1.65;

[0077] (7) Drafting: after false twisting, the profiled polyamide POY filament enters a second roller for drafting, the rotation speed of the second roller is 600-650 m / min, and the drafting multiple is 1.25;

[0078] (8) Elastane: the elastane at the elastane roller enters a second roller for drafting, and the drafting multiple is 3.5;

[0079] (9) Network: after drafting, the profiled polyamide POY filament enters a network nozzle, and the compressed air pressure is adjusted to 3.5 bar for network;

[0080] (10) Oiling and winding: the fiber bundle passes through a filament cutter, a godet, and an oil roller to enter a winding area for winding, and a composite covered yarn for high-shrinkage pile fabric is obtained; the rotation speed of the oil roller is 2.0 rpm, and the winding overfeed is -5.5%.

[0081] The performance of the air-covered yarn of the above embodiments is tested as follows:

[0082] Coefficient of variation of fineness CV%: ≤1.2,

[0083] Coefficient of variation of breaking strength CV%: 0≤8,

[0084] Breaking elongation %: M±2.5,

[0085] Coefficient of variation of breaking elongation CV%: ≤5,

[0086] Network degree (pieces / m) M1(1±7%).

[0087] The bundling effect test results of Examples 1-3 are as follows:

[0088] Evaluation method: take a fixed length of yarn bundle, fix the upper end, hang a weight at the lower end to make the yarn bundle droop, after stabilization, cut the yarn bundle from the middle, measure the length dispersed upward at the upper cut position. According to the length, judge the bundling effect. And compare with the yarn bundle without oil agent.

[0089] After testing, the measured length of Examples 1-3 is only 1 / 3 of the yarn bundle without oil agent.

[0090] The antistatic spinning oil is tested according to GB / T14342-1993, and the test results are shown in the following table:

[0091] Example 1 Example 2 Example 3 Surface static (kv) 0.15 0.13 0.13 Antioxidant property Good Good Good

[0092] The antibacterial effect of the coated yarn prepared in Examples 1-3 on Escherichia coli and Staphylococcus aureus is tested, and the results are shown in the following table.

[0093] Example 1 Example 2 Example 3 Escherichia coli 85% 83% 86 Staphylococcus aureus 86% 82% 19%

[0094] It is obvious to those skilled in the art that, on the basis of the above teaching, certain modifications, combinations and variations can also be made.

Claims

1. A process for the preparation of a composite covering yarn for high-shrinkage pile fabrics, characterized by: The preparation process comprises the following steps: (1) melt high-speed spinning: the nylon chip and the nylon master batch are fed into the extruder, melt mixed uniformly, the temperature of each section of the screw extruder is set between 245-270°C, wherein the screw pressure is 110-120 kg / cm 2 , the screw rotation speed is 50-55 r / min, the melt spinning temperature is 260-265°C, the adopted spinning pack has a flat structure of cross-section rectangular spinning orifice, the cross-section length of the spinning orifice is 0.18-0.22 mm, the width is 0.11-0.18 mm, the length-width ratio of the spinning orifice is 2.5-3.5; (2) side blowing cooling: air temperature 17-19℃, humidity 93-95%, air speed 0.45-0.5m / s; (3) oiling and bundling: the fibers cooled by side blowing are oiled and bundled through an oil nozzle; (4) winding: the oiled fiber bundle passes through a pre-networker, a godet, a main networker, and then is wound, with a winding speed of 4200-4300m / min, to obtain profiled polyamide POY filaments; (5) heating of the godet: the profiled polyamide POY filaments are heated in a heating box after passing through a godet, a first roller for feeding the filaments, and a twist stopper, with a heating temperature of 170-175℃; (6) cooling and false twisting: the profiled polyamide POY filaments are cooled by a cooling plate after being heated, and then are subjected to false twisting in a false twister, with a friction disc of the false twister being 6mm, a disc combination being 1-7-1, and a D / Y ratio being set to 1.60-1.65; (7) drawing: after false twisting, the profiled polyamide POY filaments are drawn in a second roller, with a rotation speed of the second roller being 600-650m / min, and a drawing ratio being 1.25-1.28; (8) drawing of the spandex: the spandex at the spandex roller is drawn in a second roller after passing through a godet, with a drawing ratio being 3.2-3.5; (9) network formation: after drawing, the filaments enter a network nozzle, and are subjected to network formation by adjusting the compressed air pressure to 3.0-3.5bar; (10) oiling and winding: the filaments pass through a filament cutter, a godet, and an oil roller to enter a winding area for winding, to obtain a composite covered filament for high-shrinkage pile fabric; The temperature of each section of the screw extruder is respectively: 260-270℃ for the first section, 250-260℃ for the second section, 245-250℃ for the third section, 250-260℃ for the fourth section, and 260-270℃ for the fifth section; The polyamide master batch in step (1) comprises, by weight: polyamide 100 parts, modified titanium dioxide 5-8 parts, white carbon black 3-5 parts, nano titanium diboride 3-5 parts, and nano titanium nitride 5-7 parts; The modified titanium dioxide is prepared by the following steps: europium oxide is dispersed in water, stirred uniformly to form a europium oxide dispersion liquid with a mass fraction of 2-5%, then an acid is added to adjust the pH to 4-5; then carbamide is added to the dispersion liquid and stirred uniformly, the amount of carbamide added is 10-15 times that of the europium oxide, then 80-100 times the weight of the europium oxide of titanyl sulfate is added to the dispersion liquid, then the reaction is carried out at 180-185℃ for 12h or more, then centrifugal washing and drying are carried out, and calcination is carried out at 800-900℃ for 0.5-1h, and then the modified titanium dioxide is obtained after cooling; The oil agent used in step (3) for oiling comprises, by weight: mineral oil 50 parts, alkyl polyoxyethylene ether phosphate ester salt 10-15 parts, smoothing agent 20-30 parts, amino-terminated silicone oil 5-8 parts, polyoxyethylene ether 6-9 parts, and glycerol random polyether 2-4 parts.

2. A process for the preparation of composite covering yarn for high-shrinkage velvet fabric as claimed in claim 1, wherein: The oil agent used in step (3) is a 6% polyamide oil agent pure water emulsion, the pure water conductivity is between 0.4-0.6μs / cm, and the oiling rate is 0.6-0.7%.

3. A process for the preparation of composite covering yarn for high-shrinkage velvet fabric as claimed in claim 1, wherein the said process is characterized by: The speed of the oiler is 1.5-2.0 rpm in step (10), and the winding overfeed is -5.5--7.2%.

4. A process for the preparation of composite covering yarn for high-shrinkage velvet fabric as claimed in claim 1, wherein: The amount of the nylon master batch in step (1) is 8-11% of the nylon chip.