1. The flame-retardant FDY spinning process is characterized by comprising the following steps of:

s100: taking a PET raw material with phosphorus content of more than 6500mg/Kg as a slice;

s200: slicing PET raw materials, crystallizing, drying, adding master batches, and blending;

s300: adding the sliced crystal and master batch mixture into a screw extruder, and heating the mixture by the screw extruder to form a melt structure;

s400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber, drafting by a hot roller and shaping;

s600: winding the shaped spun yarn on a paper tube to form a yarn spindle structure;

the drying temperature of the raw material slices is within the range of 110-150 ℃, the drying time is within the range of 4-6 h, the crystallization temperature of the raw material slices is 120-160 ℃, the temperature of each zone of a screw extruder is within the range of 260-280 ℃, and the heat preservation temperature of biphenyl is within the range of 270-285 ℃.

2. A flame retardant FDY spinning process as claimed in claim 1, wherein: the phosphorus content of the PET raw material is within the range of 6500-7000 mg/Kg.

3. A flame retardant FDY spinning process as claimed in claim 1, wherein: in step S200, the drying time of the raw material slice crystals is 5 hours.

4. A flame retardant FDY spinning process as claimed in claim 1, wherein: in the step S500, after oiling the fiber, the fiber is sequentially stretched and pulled by a first roller body and a second roller body respectively, so that the fiber is deformed to a preset thickness degree and then is shaped, wherein the temperature of the first roller body is 70-85 ℃, and the temperature of the second roller body is 110-130 ℃.

5. A flame retardant FDY spinning process as claimed in claim 1, wherein: in step S600, the winding speed of the set spinning is 3600 m/min.

6. A flame retardant FDY spinning process according to any of claims 1 to 5, wherein: in the step S300, adding the colored master batches into the mixture, wherein the mass ratio of the colored master batches is 1-8%; after the colored master batch is added, the temperature of each zone of a screw of the screw extruder is in the range of 265-285 ℃, and the heat preservation temperature of biphenyl is in the range of 275-290 ℃.

7. A flame retardant FDY spinning process as claimed in claim 1, wherein: in step S400, the temperatures of the respective zones of the screw extruder are: the temperature of the first zone is 260-266 ℃, the temperature of the second zone is 263-271 ℃, the temperature of the third zone is 266-274 ℃, the temperature of the fourth zone is 270-276 ℃, the temperature of the fifth zone is 273-279 ℃, the temperature of the sixth zone is 275-280 ℃ and the temperature of the spinning melt is 275-280 ℃.

8. A flame retardant FDY spinning process as claimed in claim 7, wherein: in the step S300, adding the colored master batches into the mixture, wherein the mass ratio of the colored master batches is 1-8%; after the colored master batch is added, the temperature of each zone of a screw extruder is in the range of 265-285 ℃, and the heat preservation temperature of biphenyl is in the range of 275-290 ℃;

in step S400, the temperatures of the zones of the screw extruder are: the temperature of the spinning melt is 280-285 ℃ in the first zone, 265-271 ℃, 268-276 ℃ in the second zone, 271-279 ℃ in the third zone, 275-281 ℃ in the fourth zone, 278-284 ℃ in the fifth zone and 280-285 ℃ in the sixth zone.

Background

FDY, a fully drawn yarn, is a fully drawn yarn that can be obtained as a wound yarn having a high degree of orientation and a moderate degree of crystallinity by introducing a drawing effect during spinning. The conventional fully drawn yarns with terylene and chinlon belong to chemical fiber filaments. The FDY fabric has smooth and soft hand feeling and is often used for weaving the silk-like fabric. Has wide application in clothing and home textiles.

With the importance of human life, public and household textiles such as high-speed rails, automobiles, aviation seat covers, interior decoration, data lines, bedding and the like have higher and higher requirements on flame retardance, the traditional spun yarns need to have flame retardance, the phosphorus content in raw materials needs to be increased, however, in the actual production process, the melt fluidity of semi-finished spinning is changed along with the change of the phosphorus content, the traditional forming temperature parameters are not suitable for spinning forming with the changed melt fluidity, so that the flame-retardant FDY spinning forming is difficult, and the spinning production is influenced.

Disclosure of Invention

The invention aims to provide a flame-retardant FDY spinning process, and aims to solve the technical problem in the prior art.

In order to achieve the purpose, the flame-retardant FDY spinning process provided by the embodiment of the invention comprises the following steps:

s100: taking a PET raw material with phosphorus content of more than 6500mg/Kg as a slice;

s200: slicing PET raw materials, crystallizing, drying, adding master batches, and blending;

s300: adding the sliced crystal and master batch mixture into a screw extruder, and heating the mixture by the screw extruder to form a melt structure;

s400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber, drafting by a hot roller and shaping;

s600: winding the shaped spun yarn on a paper tube to form a yarn spindle structure;

the drying temperature of the raw material slices is within the range of 110-150 ℃, the drying time is within the range of 4-6 h, the crystallization temperature of the raw material slices is 120-160 ℃, the temperature of each zone of a screw extruder is within the range of 260-280 ℃, and the heat preservation temperature of biphenyl is within the range of 270-285 ℃.

Optionally, the phosphorus content of the PET raw material is within the range of 6500-7000 mg/Kg.

Alternatively, in step S200, the raw material slice crystals are dried for 5 hours.

Optionally, in step S500, after oiling the fiber, the fiber is sequentially stretched and pulled by a first roller and a second roller, so that the fiber is deformed to a preset thickness and then is shaped, wherein the temperature of the first roller is 70-85 ℃, and the temperature of the second roller is 110-130 ℃.

Optionally, in step S600, the winding speed of the set spinning is 3600 m/min.

Optionally, in step S300, adding the colored master batch into the mixture, wherein the mass ratio of the colored master batch is 1-8%; after the colored master batch is added, the temperature of each zone of a screw of the screw extruder is in the range of 265-285 ℃, and the heat preservation temperature of biphenyl is in the range of 275-290 ℃.

Alternatively, in step S400, the temperatures of the zones of the screw extruder are: the temperature of the first zone is 260-266 ℃, the temperature of the second zone is 263-271 ℃, the temperature of the third zone is 266-274 ℃, the temperature of the fourth zone is 270-276 ℃, the temperature of the fifth zone is 273-279 ℃, the temperature of the sixth zone is 275-280 ℃ and the temperature of the spinning melt is 275-280 ℃.

Optionally, in step S300, adding the colored master batch into the mixture, wherein the mass ratio of the colored master batch is 1-8%; after the colored master batch is added, the temperature of each zone of a screw extruder is in the range of 265-285 ℃, and the heat preservation temperature of biphenyl is in the range of 275-290 ℃; in step S400, the temperatures of the zones of the screw extruder are: the temperature of the spinning melt is 280-285 ℃ in the first zone, 265-271 ℃, 268-276 ℃ in the second zone, 271-279 ℃ in the third zone, 275-281 ℃ in the fourth zone, 278-284 ℃ in the fifth zone and 280-285 ℃ in the sixth zone.

One or more technical schemes in the flame-retardant FDY spinning process provided by the embodiment of the invention at least have one of the following technical effects: compared with the prior art that the melt fluidity of the semi-finished spinning product is changed due to the change of the phosphorus content in the actual production process of the spinning, the traditional forming temperature parameters are not suitable for the spinning forming with the changed melt fluidity, so that the flame-retardant FDY spinning forming is difficult, and the technical problem of spinning production is influenced:

(1) the flame-retardant FDY spinning process provided by the invention adds the PET raw material slices with the phosphorus content of more than 6500mg/Kg into the master batch, changes the crystallization temperature, the drying temperature and the drying time of the raw material slices in a targeted manner, ensures that the intrinsic viscosity of the dried raw material is reduced to be less than 0.01dl/g, ensures that the raw material keeps stable rheological property in the subsequent extrusion, filamentation, stretching, traction and winding processes, ensures that the spinning production is carried out orderly while the spinning finished product can be molded smoothly, and stabilizes the production efficiency.

(2) The temperature of each zone of the screw in the flame-retardant FDY spinning process is 260-280 ℃, the heat preservation temperature of biphenyl is 270-285 ℃, and the physical indexes of the obtained FDY flame-retardant colored yarn product are produced by matching with a proper traction roller, a proper stretching roller and a proper winding speed: the breaking strength is 3CN/dtex, the breaking elongation is 22-36%, the national standard is reached, and the fabric of the flame-retardant fiber produced by the technology reaches the flame-retardant B1 grade (GB 20286).

Detailed Description

The following detailed description of the embodiments of the present invention is intended to be illustrative of the embodiments of the present invention and is not to be construed as limiting the invention.

In the description of the embodiments of the present invention, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used merely for convenience in describing the embodiments of the present invention and to simplify the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. Specific meanings of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific situations.

In the invention, all parts and percentages are weight units, all raw materials, equipment and the like can be purchased from the market or commonly used in the industry, wherein, PET raw material slices and master batches with phosphorus content ranging from 6000mg/Kg to 7500mg/Kg can be purchased from the market.

In one embodiment of the present invention, there is provided a flame retardant FDY spinning process comprising the steps of:

s100: taking a PET raw material with phosphorus content of more than 6500mg/Kg as a slice;

s200: slicing PET raw materials, crystallizing, drying, adding master batches, and blending;

s300: adding the sliced crystal and master batch mixture into a screw extruder, and heating the mixture by the screw extruder to form a melt structure;

s400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber, drafting by a hot roller and shaping;

s600: winding the shaped spun yarn on a paper tube to form a yarn spindle structure;

the drying temperature of the raw material slices is within the range of 110-150 ℃, the drying time is within the range of 4-6 h, the crystallization temperature of the raw material slices is 120-160 ℃, the temperature of each zone of a screw extruder is within the range of 260-280 ℃, and the heat preservation temperature of biphenyl is within the range of 270-285 ℃.

Specifically, compare in the spinning among the prior art in the actual production process, semi-manufactured goods spinning fuse-element fluidity can change because of the change of phosphorus content, and traditional shaping temperature parameter is not suitable for the spinning shaping that the fuse-element fluidity changes, leads to fire-retardant FDY spinning shaping difficulty, influences the technical problem of spinning production: the flame-retardant FDY spinning process provided by the invention adds the PET raw material slices with the phosphorus content of more than 6500mg/Kg into the master batch, changes the crystallization temperature, the drying temperature and the drying time of the raw material slices in a targeted manner, ensures that the intrinsic viscosity of the dried raw material is reduced to be less than 0.01dl/g, ensures that the raw material keeps stable rheological property in the subsequent extrusion, filamentation, stretching, traction and winding processes, ensures that the spinning production is carried out orderly while the spinning finished product can be molded smoothly, and stabilizes the production efficiency.

Meanwhile, the temperature of each area of a screw in the flame-retardant FDY spinning process is 260-280 ℃, the heat preservation temperature of biphenyl is 270-285 ℃, and under the temperature parameters, the physical indexes of the obtained FDY flame-retardant colored yarn product are produced: the breaking strength is 3CN/dtex, the breaking elongation is 22-36%, the national standard is reached, and the fabric of the flame-retardant fiber produced by the technology reaches the flame-retardant B1 grade (GB 20286).

In another embodiment of the invention, the phosphorus content of the PET raw material is within the range of 6500-7000 mg/Kg, and the phosphorus content within a proper range can ensure the crystallization forming of the raw material, thereby being beneficial to the development of the subsequent spinning process.

In another embodiment of the present invention, in step S200, the raw material slice crystallization drying time is 5 hours, and after increasing the phosphorus content, the softening point of the raw material is lowered, compared with the conventional crystallization drying time of 6 to 8 hours, the drying time of 5 hours can both improve the raw material crystallization efficiency and ensure the crystallization effect.

In another embodiment of the present invention, in step S500, after oiling the fiber, the fiber is sequentially drawn and stretched by a first roller and a second roller, so that the fiber is deformed to a predetermined thickness and then is shaped, the temperature of the first roller is 70 to 85 ℃, the temperature of the second roller is 110 to 130 ℃, and the temperature of a conventional FDY spinning two-roller is: compared with the temperature of a conventional FDY spinning two-roller, the temperature of the two-roller is relatively low, the two-roller is more suitable for stretching and drawing a melt with the viscosity reduced to less than 0.01dl/g after the phosphorus content is increased, and the spinning forming effect is improved.

In another embodiment of the present invention, in step S600, the winding speed of the shaped spun yarn is 3600m/min, the winding speed of the traditional FDY spinning forming is 4000 to 4800m/min, and the maximum value of the elongation at break of the product after adding the phosphorus is 36%, at the maximum limit, the traditional winding speed is higher than the maximum winding speed adapted to the elongation at break, and the shaped spun yarn is easily broken, so the winding speed in the embodiment of the present invention is significantly reduced, and the present invention is more suitable for the spinning winding forming after adding the phosphorus.

In another embodiment of the present invention, in step S400, the temperatures of the zones of the screw extruder are: the temperature of the spinning melt is 275-280 ℃, the temperature of each zone of the screw is correspondingly adjusted downwards according to the rheological property and the viscosity of the melt, and the melt can be smoothly heated and moved to the output end of the screw extruder.

In another embodiment of the invention, in the step S300, the colored master batches are added into the mixture, wherein the mass ratio of the colored master batches is 1-8%; after the colored master batch is added, the rheological property and the viscosity of a melt are changed, and the temperature of each zone of the screw needs to be adjusted up by 5%, so that the temperature of each zone of the screw extruder is 265-285 ℃, and the heat preservation temperature of biphenyl is 275-290 ℃.

In another embodiment of the present invention, in step S400, the temperatures of the zones of the screw extruder are: the temperature of the spinning melt is 280-285 ℃ in the first zone, 265-271 ℃, 268-276 ℃ in the second zone, 271-279 ℃ in the third zone, 275-281 ℃ in the fourth zone, 278-284 ℃ in the fifth zone and 280-285 ℃ in the sixth zone.

The properties in the examples and comparative examples were determined according to the following methods and methods known in the industry:

intrinsic viscosity [ eta ] (dl/g), test method: reference GB/T14190-2008;

breaking strength (CN/dtex), test method: reference GB/T3916-1997;

elongation at break (%), test method: reference GB/T3916-1997;

flame retardancy, test method: GB 20286-;

the number of broken yarns is determined by the following steps: the number of yarn breaks occurring when 100kg filaments were formed by spinning and drawing was counted, and a smaller number of yarn breaks was considered to have better spinnability.

In order to ensure that the spinning production can be carried out smoothly, the traditional spinning process usually tests the crystallization intrinsic viscosity and the melt intrinsic viscosity at the output end of a screw extruder, combines the breaking strength, the breaking elongation and the spinnability of a finished product, namely the quality of a spinning finished product, and adjusts the temperature parameter, the time parameter and the speed parameter in the spinning process so as to achieve the effect of controlling the intrinsic viscosities of crystals and melts. Specifically, the following comparative example of a conventional FDY spinning process is given:

comparative example 1

S100: crystallizing and drying the PET raw material slices, wherein the crystallization temperature is 170 ℃, the drying temperature is 160 ℃, and the drying time is 7 hours;

s200: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first region 270 deg.C, second region 274 deg.C, third region 278 deg.C, fourth region 282 deg.C, fifth region 286 deg.C, and sixth region 293 deg.C;

s300: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s400: oiling the fiber yarns, and drafting and shaping by a hot roller, wherein the temperature of one roller is 85 ℃, and the temperature of two rollers is 135 ℃;

s500: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 4400 m/min.

Wherein, in step S100, the intrinsic viscosity of the crystal is measured to be 0.01dl/g, the intrinsic viscosity of the melt output by the screw extruder is measured to be 0.015dl/g in step S200, the breaking strength of the spinning is measured to be 3.5CN/dtex in step S500, the breaking elongation is 30 percent, and the flame retardant grade is B2 grade.

To ensure that the spinning process with phosphorus-containing raw material is working properly, the following examples and comparative examples of the present invention are conducted with the aim of approaching the test parameters in comparative example 1, e.g. to ensure that the intrinsic viscosity after drying is reduced to approximately 0.01dl/g and to ensure that the intrinsic viscosity of the spun melt is reduced to approximately 0.015 dl/g.

In order to ensure that the product produced by the spinning process using the phosphorus-containing raw material can achieve the preset flame retardant performance (B1 grade) and product quality level, the following examples and comparative examples performed in the invention are all aimed at approaching the test parameters in comparative example 1, for example, the breaking strength of the formed spinning should be above 3CN/dtex, and the elongation at break should be in the range of 22% to 36%.

Regarding the effect of phosphorus content on flame retardant properties:

corresponding examples and comparative examples are given below for the adjustment of the phosphorus content parameter:

example 1

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: slicing PET raw materials, crystallizing, drying and adding master batches for blending, wherein the crystallization temperature is 175 ℃, the drying temperature is 165 ℃, and the drying time is 7 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first region 270 deg.C, second region 274 deg.C, third region 278 deg.C, fourth region 282 deg.C, fifth region 286 deg.C, and sixth region 293 deg.C;

s400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, and drafting and shaping by a hot roller, wherein the temperature of one roller is 90 ℃, and the temperature of two rollers is 140 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 4400 m/min.

Example 2

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 7000mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with the master batch, wherein the crystallization temperature is 180 ℃, the drying temperature is 170 ℃, and the drying time is 7 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first region 270 deg.C, second region 274 deg.C, third region 278 deg.C, fourth region 282 deg.C, fifth region 286 deg.C, and sixth region 293 deg.C;

s400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, drafting and shaping by a hot roller, wherein the temperature of one roller is 95 ℃, and the temperature of two rollers is 145 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 4600 m/min.

Comparative example 2

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6000mg/Kg as a slice;

s200: the PET raw material slices are crystallized, dried and blended with the master batches, wherein the crystallization temperature is 170 ℃, the drying temperature is 160 ℃, and the drying time is 7 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first region 270 deg.C, second region 274 deg.C, third region 278 deg.C, fourth region 282 deg.C, fifth region 286 deg.C, and sixth region 293 deg.C;

s400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, and drafting and shaping by a hot roller, wherein the temperature of one roller is 85 ℃, and the temperature of two rollers is 135 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 4400 m/min.

Comparative example 3

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 7500mg/Kg as a slice;

s200: slicing PET raw materials, crystallizing, drying and adding master batches for blending, wherein the crystallization temperature is 185 ℃, the drying temperature is 175 ℃, and the drying time is 7 hours;

s300: adding the mixture of the slice crystals and the master batch into a screw extruder, wherein the temperature of the first zone is 270 ℃, the temperature of the second zone is 274 ℃, the temperature of the third zone is 278 ℃, the temperature of the fourth zone is 282 ℃, the temperature of the fifth zone is 286 ℃, and the temperature of the sixth zone is 293 ℃;

unlike the comparative examples and examples described above, which are affected by the excessively high phosphorus content of the raw material chips when the conditions of the remaining parameters are not changed much, the melt injection speed at the output end of the screw extruder is low when step S300 is performed in the comparative examples, and the fibrous structure cannot be formed.

The spinning process parameters described in example 1, example 2, comparative example 2 and comparative example 3 are shown in the following table:

	comparative example 2	Example 1	Example 2	Comparative example 3
					Phosphorus content mg/Kg	6000	6500	7000	7500
Crystallization of beta-cyclodextrin	170	175	180	185
					Drying at DEG C	160	165	170	175
Time h	7	7	7	7
					Screw arbor deg.C	270～293	270～293	270～293	270～293
One roll of	85	90	95	\
					Two rolls C	135	140	145	\
Winding m/min	4400	4400	4600	\

The results of the flame retardant rating tests of examples 1, 2 and 2 are shown in the following table (comparative example 3 failed to form a spun yarn and failed to perform the flame retardant rating test):

comparative example 2	Example 1	Example 2
			B2	B1	B1

It will be appreciated by those skilled in the art that under similar process conditions, the higher the phosphorus content, the better the flame retardant properties of the product, and in combination with the above test results, the flame retardant rating for the spun yarn produced by the conventional spinning process can reach B1 rating when the phosphorus content is in the range of 6500 to 7000mg/Kg, beyond which the spun yarn cannot be shaped as shown in comparative example 3; below this range, as shown in comparative example 2, the flame retardant rating for spinning is B2, and the ideal flame retardant standard cannot be achieved, so the optimum range of phosphorus content is 6500 to 7000 mg/Kg.

Regarding the effect of crystallization temperature, drying temperature and drying time on the spinning process:

from comparative example 1, it can be seen that after the PET raw material chips are crystallized, the intrinsic viscosity of the crystals is 0.01dl/g, and the intrinsic viscosity is used as a criterion for judging the rheological property of the crystals in the screw, and the following are examples and comparative examples of the process of the present invention with respect to the influence of the crystallization temperature, drying temperature and drying time on the spinning process:

example 3

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: and (3) slicing the PET raw material, crystallizing, drying and adding the master batch for blending, wherein the crystallization temperature is 120 ℃, the drying temperature is 110 ℃, and the drying time is 6 hours.

Example 4

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: and (3) carrying out crystallization, drying and blending by adding the PET raw material slices and the master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 h.

Example 5

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: and (3) slicing the PET raw material, crystallizing, drying and adding the master batch for blending, wherein the crystallization temperature is 160 ℃, the drying temperature is 150 ℃, and the drying time is 4 hours.

Comparative example 4

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: and (3) carrying out crystallization, drying and blending by adding the PET raw material slices and the master batches, wherein the crystallization temperature is 170 ℃, the drying temperature is 160 ℃, and the drying time is 7 h.

Comparative example 5

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: and (3) carrying out crystallization, drying and blending by adding the PET raw material slices and the master batches, wherein the crystallization temperature is 115 ℃, the drying temperature is 105 ℃, and the drying time is 8 h.

Comparative example 6

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: and (3) carrying out crystallization, drying and blending by adding the PET raw material slices and the master batches, wherein the crystallization temperature is 165 ℃, the drying temperature is 155 ℃, and the drying time is 4 h.

The spinning process parameters for examples 3-5, comparative example 1, and comparative examples 4-6 are shown in the following table:

the results of the intrinsic viscosity dl/g test for the crystals of examples 3 to 5, comparative example 1 and comparative examples 4 to 6 are shown in the following table:

comparative example 1	Comparative example 4	Comparative example 5	Example 3	Example 4	Example 5	Comparative example 6
							0.01	0.004	0.02	0.01	0.009	0.01	0.004

From the above test results it is possible to: in the traditional spinning process, the intrinsic viscosity of the crystallization and master batch mixture is 0.01dl/g when the crystallization and master batch mixture enters a screw extruder, the mixture shows medium rheological property in the screw extruder, the mixture can be heated and stirred sufficiently to improve the spinnability of a melt after the screw extrusion, comparative example 4 and comparative example 6 are close to the traditional spinning process parameters, but the crystallization viscosity property is reduced due to the influence of phosphorus content, the crystallization rheological property is improved, the crystallization temperature and the drying temperature are reduced, the drying time is shortened, as shown in examples 3-5, the intrinsic viscosity of the crystallization is close to that of comparative example 1, when the crystallization temperature is lower than 120 ℃ and the drying temperature is lower than 110 ℃, the intrinsic viscosity of the crystallization is increased, as shown in comparative example 5, the crystallization temperature is 120-160 ℃, the most suitable drying temperature is 110-150 ℃, the drying time corresponds to the most suitable range of 4 to 6 hours.

Concerning the influence of the screw temperature of the screw extruder on the intrinsic viscosity of the melt at the screw extruder output:

from comparative example 1, it can be seen that the intrinsic viscosity of the melt at the output end of the screw extruder is 0.015dl/g, and using the intrinsic viscosity as a criterion for judging the spinnability of the melt, the following are examples and comparative examples of the process of the present invention with respect to the influence of the temperature of each zone of the screw on the spinning process, wherein, in order to ensure the crystal viscosity characteristics to be in a desired state, the phosphorus content, crystallization temperature, drying temperature and drying time in the following examples and comparative examples are the same as those in example 4, specifically as follows:

example 7

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first zone 260 deg.C, second zone 264 deg.C, third zone 268 deg.C, fourth zone 272 deg.C, fifth zone 276 deg.C, and sixth zone 280 deg.C.

Comparative example 7

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: 250 ℃ in the first zone, 254 ℃ in the second zone, 258 ℃ in the third zone, 262 ℃ in the fourth zone, 267 ℃ in the fifth zone and 273 ℃ in the sixth zone.

Comparative example 8

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first region 270 deg.C, second region 274 deg.C, third region 278 deg.C, fourth region 282 deg.C, fifth region 286 deg.C, and sixth region 293 deg.C.

The spinning process parameters for example 7, comparative example 7 and example 8 are shown in the following table:

the results of the melt intrinsic viscosity dl/g test for example 7, comparative example 7 and example 8 are shown in the following table:

comparative example 7	Example 7	Comparative example 8	Comparative example 1
				0.02	0.015	0.006	0.015

From the above test results it is possible to: in the comparative example 1, the melt intrinsic viscosity of the output end of the screw extruder is 0.015dl/g, the melt intrinsic viscosity containing phosphorus is reduced along with the temperature increase of a screw zone of the screw extruder, when the temperature range of the screw zone of the screw extruder is 260-280 ℃, the intrinsic viscosity of the melt is closest to the comparative example 1, and the rheological property of the melt is closest to the comparative example 1, so that in the spinning process of the raw material containing phosphorus, the temperature of the screw zone of the screw extruder is set to be 260-280 ℃, the heat preservation temperature range of corresponding biphenyl heat preservation equipment is close to the temperature range, and the biphenyl heat preservation temperature is 270-285 ℃.

Regarding the effect of the temperature of the drawing and stretching rollers, and the winding speed of the paper tube on the quality of the spinning product:

from comparative example 1, the breaking strength of the formed spinning product is 3.5CN/dtex, the breaking elongation is 30%, the following are examples and comparative examples of the process of the invention aiming at the influence of the temperature of the drawing roller and the winding speed of the paper tube on the quality of the spinning product, wherein, in order to ensure that the viscosity characteristic of the melt at the output end of the screw extruder is in a perfect state, the screw temperature parameters in the following examples and comparative examples are the same as those in example 7, and specifically the following are as follows:

example 8

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first zone 260 deg.C, second zone 264 deg.C, third zone 268 deg.C, fourth zone 272 deg.C, fifth zone 276 deg.C, and sixth zone 280 deg.C.

S400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, drafting and shaping by a hot roller, wherein the temperature of one roller is 70 ℃, and the temperature of two rollers is 110 ℃;

s600: and winding the shaped spun yarn on a paper tube to form a yarn spindle structure, wherein the winding speed is 3400 m/min.

Example 9

A flame-retardant FDY spinning process comprises the following steps:

s100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first zone 260 deg.C, second zone 264 deg.C, third zone 268 deg.C, fourth zone 272 deg.C, fifth zone 276 deg.C, and sixth zone 280 deg.C.

S400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, and drafting and shaping by a hot roller, wherein the temperature of one roller is 80 ℃, and the temperature of two rollers is 120 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 3800 m/min.

Example 10

S100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first zone 260 deg.C, second zone 264 deg.C, third zone 268 deg.C, fourth zone 272 deg.C, fifth zone 276 deg.C, and sixth zone 280 deg.C.

S400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, drafting and shaping by a hot roller, wherein the temperature of one roller is 85 ℃, and the temperature of two rollers is 130 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 4000 m/min.

Comparative example 9

S100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first zone 260 deg.C, second zone 264 deg.C, third zone 268 deg.C, fourth zone 272 deg.C, fifth zone 276 deg.C, and sixth zone 280 deg.C.

S400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, drafting and shaping by a hot roller, wherein the temperature of one roller is 65 ℃, and the temperature of two rollers is 105 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 3000 m/min.

Comparative example 10

S100: taking a PET raw material with the phosphorus content of 6500mg/Kg as a slice;

s200: the PET raw material is sliced, crystallized, dried and blended with master batches, wherein the crystallization temperature is 140 ℃, the drying temperature is 130 ℃, and the drying time is 5 hours;

s300: adding the slice crystal and master batch mixture into a screw extruder, heating the mixture by the screw extruder to form a melt structure, wherein the temperature of each zone of a screw of the screw extruder is as follows: first zone 260 deg.C, second zone 264 deg.C, third zone 268 deg.C, fourth zone 272 deg.C, fifth zone 276 deg.C, and sixth zone 280 deg.C.

S400: the melt output by the screw extruder is sprayed out by a spinneret plate, and is cooled and blown into a fibrous filament;

s500: oiling the fiber yarns, drafting and shaping by a hot roller, wherein the temperature of one roller is 90 ℃, and the temperature of two rollers is 135 ℃;

s600: and winding the shaped spinning on a paper tube to form a spindle structure, wherein the winding speed is 4400 m/min.

The spinning process parameters for examples 8-10 and comparative examples 9-10 are shown in the following table:

the results of the breaking strength and elongation at break tests for the products of examples 8-10 and comparative examples 9-10 are shown in the following table:

in comparative example 1, the breaking strength of the formed spun product is 3.5CN/dtex, the breaking elongation is 30%, according to the test results of comparative examples 9 to 10 and examples 8 to 10, the breaking strength and the breaking elongation of the formed spun product are gradually increased along with the increase of the temperature of one roller (traction roller), the temperature of two rollers (stretching rollers) and the winding speed, according to the test results of examples 8 to 10, when the temperature of one roller is 70 to 85 ℃, the temperature of two rollers is 110 to 130 ℃ and the winding speed is 3400 to 4000m/min, the breaking strength and the breaking elongation of the spun product are the closest to those of comparative example 1, so that the most suitable temperature of one roller, temperature of two rollers and winding speed are 70 to 85 ℃, 110 to 130 ℃ and 3400 to 4000m/min respectively.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.