CN115573048A

CN115573048A - Bright production process for producing melt direct spinning fine denier PET

Info

Publication number: CN115573048A
Application number: CN202211152807.8A
Authority: CN
Inventors: 朱闻宇; 朱毅; 王金海; 程志杰; 刘金铭
Original assignee: Jiangsu Jiatong Energy Co ltd
Current assignee: Jiangsu Jiatong Energy Co ltd
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2023-01-06

Abstract

The invention provides a bright production process for producing melt direct-spinning fine-denier PET, which comprises PET melt conveying, color paste conveying, spinning box entering, FDY spinning and FDY finishing. Wherein, the spinning temperature of the melt direct spinning fine denier PET is 295 ℃, the cooling mode adopts circular blowing, and when the circular blowing temperature is 21 ℃, the circular blowing humidity is 90 percent RH, the circular blowing process air pressure is 40Pa and the circular blowing speed is 0.35m/s, the product can be continuously and stably produced, the product quality is stable, and all indexes of the product reach high-grade products.

Description

Bright production process for producing melt direct spinning fine denier PET

Technical Field

The invention relates to the technical field of polyester fully drawn yarns, in particular to a production process for producing melt direct-spun fine-denier PET (polyethylene terephthalate) super-bright fully drawn yarns.

Background

The terylene as one of the synthetic fiber varieties has the advantages of large yield, wide application and simple process, and accounts for more than 60 percent of the world synthetic fiber yield. The fabric has excellent physical and mechanical properties and textile properties, is low in price, firm and durable, good in elasticity, difficult to wrinkle and deform, corrosion-resistant, stiff and smooth in insulation, easy to wash and quick to dry, and is widely applied to clothes, bedding, interior decoration, national defense and military industry, other industries and the like in four seasons.

In recent years, with the development of global economy, the change of consumption concept and the appearance of new fiber products, new processes and new technologies, people pursuit for clothes in four seasons becomes more and more personalized and high-grade. The terylene is used as the chemical fiber variety with the largest total amount in all textile fibers, and the product differentiation is the ultimate development direction, so that the terylene has great development potential and wide market. The development of differential polyester varieties and the improvement of the added value of products, further the improvement of the economic benefits of enterprises, are of great importance to the influence of the whole chemical fiber industry. The woven simulation silk fabric and the warp-knitted fabric which take fine denier terylene super bright Fully Drawn Yarn (FDY) as raw materials have soft and smooth hand feeling and are often used for manufacturing outdoor sportswear, high-grade women's clothes in spring and summer, high-grade clothes of underwear and home textile products.

The fine denier terylene is bright, taking 40D/48F FDY as an example, the preparation process in the prior art has the following defects: traditional fine denier fully drawn yarn is because fibre self tension is too little, and the silk strip shakes the problem easily to appear when the process ring is bloied, if adopt traditional technological parameter to produce, appears the fuse-element phenomenon of rupture easily, spinnability variation, appears hard first silk scheduling problem.

The patent document with the application number of 201310577811.3 discloses a system for producing POY and FDY composite polyester yarns by using a melt direct spinning stock solution and a preparation method thereof, wherein a PET melt tower is communicated with a melt cooler, a color paste bin and the melt cooler are respectively communicated with a multi-element coupler, the multi-element coupler is communicated with a dynamic mixer, the dynamic mixer is communicated with a spinning manifold, and the spinning manifold is respectively communicated with a POY device and an FDY device to obtain the system for producing the POY and FDY composite polyester yarns by using the melt direct spinning stock solution. However, the production process parameters of the production system are not clear enough, and further regulation and control are needed

In view of the above, there is a need to invent a bright production process for producing melt direct-spun fine-denier PET.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a bright production process for producing melt direct-spinning fine-denier PET.

The technical scheme adopted by the invention for solving the technical problem is as follows:

the invention discloses a preparation method of a bright production process for producing melt direct-spinning fine-denier PET, which comprises the following steps:

step (1), PET melt conveying

Conveying a PET melt prepared by polyester reaction in a PET melt tower to a booster pump through a discharge pump and a heat insulation pipeline, and conveying the PET melt to a melt cooler for cooling through the booster pump and conveying to a spinning line;

step (2) color paste conveying

Adding color paste into a color paste bin, feeding the color paste into a multi-element coupler through the color paste bin, coupling the PET melt and the color paste through the multi-element coupler, mixing the coupled PET melt and the color paste through a static mixer, and stirring and mixing the PET melt and the color paste through the static mixer to realize uniform dispersion dyeing of the polyester melt;

step (3), entering a spinning manifold

The melt which is uniformly dyed by the static mixer enters a spinning manifold, and the spinning manifold is communicated with a spinning component of the FDY;

step (4) FDY spinning

After the step (3), forming fully drawn yarns through a spinneret plate in a spinning box body, separating the fully drawn yarns through a circular air-blowing cooling device, feeding the separated fully drawn yarns into an oil nozzle bundling device through a channel for oiling, feeding the fully drawn yarns into a pre-networking device, performing preliminary networking through a pre-networking nozzle, fully drawing the fully drawn yarns under the action of a first yarn guide disc and a second yarn guide disc, feeding the fully drawn yarns into a main network, and feeding the fully drawn yarns into a winding machine for winding and forming to obtain FDY (fully drawn yarn) cakes;

the fuel spray nozzle bundling device comprises a fuel spray nozzle bundling device, a fuel spray nozzle bundling device and a fuel spray nozzle bundling device, wherein the fuel spray nozzle of the fuel spray nozzle bundling device is V-shaped;

the spinning temperature in the spinning box body is 295-297 ℃;

the wind speed in the circular blowing cooling device is 0.25-0.55m/s, the wind pressure is 20-60Pa, the wind temperature is 17-23 ℃, and the humidity is 65-100 percent RH;

the air pressure of the main network is 0.2-0.3MPa, and the network degree of the main network is controlled to be 20-30/m.

Step (5) FDY is arranged and stored in storage

And (3) carrying out color judgment, appearance inspection and physical inspection on the FDY spinning yarn on the stocking leg, then packaging the qualified products in a grading manner, and finally putting the packaged finished products into a finished product stereoscopic warehouse.

On the basis of the scheme and as a preferable scheme of the scheme, the intrinsic viscosity of the PET melt in the step (1) is 0.635-0.645 dL-g, the melting point is 258-262 ℃, the b value is 2.0-6.30, and the L value is 85-90.

On the basis of the above scheme and as a preferable scheme of the scheme, the output end of the discharging pump in the step (1) is provided with a melt filter.

On the basis of the scheme, as a preferable scheme of the scheme, a color paste accurate metering device is arranged between the color paste storage bin and the multi-element coupler in the step (2), and a melt distribution valve is arranged at the output end of the static mixer in the step (2).

On the basis of the above scheme and as a preferable scheme of the above scheme, the first godet and the second godet in the step (4) are in a vertically staggered distribution, and the second godet is positioned above the first godet.

On the basis of the scheme, as a preferable scheme of the scheme, the temperature of the first godet is 90-100 ℃, and the speed is 1750-1950m/min; the temperature of the second godet is 130-140 ℃, and the speed is 4750-4950m/min.

On the basis of the above scheme and as a preferable scheme of the above scheme, the winding speed of the winder in the step (4) is 4600-5000m/min.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

through multiple optimization of production process and parameters, compared with the traditional fine denier fully drawn yarns, the melt direct spinning fine denier PET produced by the invention has the advantages that the problem of shaking of strands is not easy to occur when the strands are blown circularly, the spinnability is good, and the problems of melt fracture, hard end yarns and the like are avoided. Through multiple optimization of production process and parameters, the variety realizes continuous and stable production, and the quality indexes of the product all reach high-grade products.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the subject disclosure unless such concepts are mutually inconsistent.

The foregoing and other aspects, embodiments and features of the present teachings will be more fully understood from the following description. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a process flow diagram of the present invention.

Wherein, 1, PET melt tower; 2. a discharge pump; 3. a heat-insulating pipeline; 4. a booster pump; 5. a melt conveying cooler; 6. a melt cooler; 7. a multi-element coupler; 8. a color paste bin; 9. a color paste accurate metering device; 10. a static mixer; 11. a melt distribution valve; 12. spinning manifold; 13. a circular air blow cooling device; 14. the oil nozzle cluster oiling device; 15. a pre-network device; 16. a first godet; 17. a second godet; 18. a main network; 19. and (4) a winding machine.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

The use of "first," "second," and similar terms in the description and in the claims of the present application does not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. Similarly, the singular forms "a," "an," or "the" do not denote a limitation of quantity, but rather denote the presence of at least one, unless the context clearly dictates otherwise. The terms "comprises," "comprising," or the like, mean that the elements or items listed before "comprises" or "comprising" encompass the features, integers, steps, operations, elements, and/or components listed after "comprising" or "comprising," and do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

As a textile raw material with high added value, the light fabric made of the fine denier terylene by the super-bright weaving has the advantages of excellent soft and smooth hand feeling, soft luster, good air permeability and drapability and unique style. According to the invention, by controlling and optimizing corresponding production process parameters, the fine-denier polyester bright PET-FDY product (taking 40D/48F as an example) with stable quality and excellent performance is produced, the diversity and the differentiation rate of the product of an enterprise are increased, and the market competitiveness of the enterprise is improved. The following is a detailed description with reference to examples.

Example 1

The preparation method of the bright production process for producing the melt direct-spun fine denier PET comprises the following steps:

(1) PET melt transport

Conveying a PET melt prepared by polyester reaction in a PET melt tower to a booster pump through a discharge pump and a heat insulation pipeline, and conveying the PET melt to a melt cooler for cooling through the booster pump and conveying to a spinning line; wherein the PET melt has an intrinsic viscosity of 0.640 dL.g, a melting point of 260 ℃, a b value of 4.0 and an L value of 88;

(2) Color paste conveying

(3) Entering a spinning manifold

(4) FDY spinning

wherein the spinning temperature in the spinning box body is 295 ℃; the wind speed in the circular blowing cooling device is 0.35m/s, the wind pressure is 40Pa, the wind temperature is 21 ℃, and the humidity is 90 percent RH; the spinning temperature is 295 ℃, and the cooling mode adopts circular blowing; the oiling rate of the strand silk is controlled to be 0.8 percent; the air pressure of the main network is 0.2MPa, and the network degree of the main network is controlled to be 25/m.

Step (5) FDY is arranged and stored in storage

Further, the temperature of the first godet is 95 ℃, and the speed is 1850m/min; the temperature of the second godet is 135 ℃, and the speed is 4850m/min; and (4) the winding speed of the winding machine in the step (4) is 4800m/min.

Example 2

(1) PET melt transport

Conveying a PET melt prepared by polyester reaction in a PET melt tower to a booster pump through a discharge pump and a heat insulation pipeline, and conveying the PET melt to a melt cooler for cooling through the booster pump and conveying to a spinning line; wherein the PET melt has an intrinsic viscosity of 0.645 dL.g, a melting point of 261 ℃, a b value of 5.0 and an L value of 88;

(2) Color paste conveying

(3) Entering a spinning manifold

(4) FDY spinning

wherein the spinning temperature in the spinning box body is 296 ℃; the wind speed in the circular blowing cooling device is 0.30m/s, the wind pressure is 50Pa, the wind temperature is 22 ℃, and the humidity is 95 percent RH; the spinning temperature is 296 ℃, the cooling mode adopts circular blowing, and the oiling rate of the strand silk is controlled to be 0.7 percent; the air pressure of the main network is 0.3MPa, and the network degree of the main network is controlled to be 30/m.

Step (5), FDY (fully drawn yarn) arranging and warehousing

Further, the temperature of the first godet is 93 ℃, and the speed is 1950m/min; the temperature of the second godet is 135 ℃, and the speed is 4950m/min; and (4) the winding speed of the winder in the step (4) is 4900m/min.

Comparative example 1

And randomly drawing FDY of commercial fine denier terylene super bright 40D/48F for performance test.

And (4) performance testing:

(1) Linear density of

The linear density test was carried out on the samples according to GB/T14343-2008 "test method for the linear density of chemical fibres".

(2) Strength test

According to GB/T14344-2008 'test method for tensile property of chemical fiber filament', the sample is subjected to performance tests of breaking strength, breaking elongation and the like.

(3) Unevenness of evenness

According to GB/T14346-2015 capacitance method for testing the evenness of chemical fiber filaments, the performance of the evenness of the sample is tested.

(4) Heat shrinkage Performance test

The samples were tested for heat shrinkage according to GB/T6505-2017 test method for chemical fiber filament heat shrinkage (after treatment).

(5) Dyeing uniformity

The samples were tested for heat shrinkage performance according to GB/T6508-2015 polyester filament dyeing evenness test method.

Samples were taken according to the relevant performance test standards, and the samples of the above examples 1-2 and comparative examples were subjected to the performance tests of linear density, strength, evenness, thermal shrinkage dyeing uniformity, etc., and the physical properties were compared as shown in the following table:

by combining the data analysis in the table and through the research on the terylene FDY 40D/48F series process, the following optimal production process parameters are obtained:

1) The spinning temperature is 295 ℃, the cooling mode adopts circular blowing, and the cooling conditions are as follows: a circular blowing temperature of 21 ℃, a circular blowing humidity of 90 percent RH, a circular blowing process air pressure of 40Pa and a circular blowing speed of 0.35m/s; the oiling rate of the strand silk is controlled between 0.7 and 0.9 percent.

2) After multiple process adjustments, the temperature of the first and second hot rollers is 95 ℃ and 135 ℃, and the speed of the first and second hot rollers is 1850m/min and 4850m/min; the stretching multiple is 2.2 to 2.8 times, and the network degree of the fine denier terylene big lustrous 40D/48F FDY yarn is controlled to be 20 to 30/m under the air pressure of 0.2 to 0.3 MPa; the winding speed is about 4800m/min.

The parameter adjustment of the embodiment 1-2 of the invention shows that the influencing factors influencing the continuous and stable production of fine denier terylene, the stable product quality and the excellent quality comprise: spinning temperature, cooling forming parameters, oil feeding amount, hot roller temperature, stretching multiple, main network pressure and winding speed.

Spinning temperature

In the melt direct spinning production process, the spinning temperature is taken as the most important process condition, and the selection is very important. Whether the spinning temperature is properly selected will directly affect the quality of the fibers and the proper performance of the spinning. The melt uniformity and rheological property are good at proper spinning temperature, the spinnability is good, and the produced product is stable. The spinning temperature is too high, the thermal decomposition is accelerated, the molecular weight is reduced, the content of low molecular substances is increased, and the melt viscosity is reduced; the broken wool is easy to generate, the end breakage rate is increased, the flying yarns are more, the plate sticking is serious, the bubble yarns are generated, the spinnability is poor, the quality index of the produced finished yarn is reduced, and the fiber quality is seriously influenced. On the contrary, the excessively low spinning temperature causes the viscosity of the melt to be excessively high, the uniformity and the fluidity of the melt to be poor, the conveying load of a pump is increased, and the energy consumption is increased and is not economical; the phenomenon of melt outlet swelling extruded from the spinning assembly tends to be heavy, even melt fracture can occur, spinnability is poor, the probability of hard end filaments is increased, the produced finished filaments are whitish, dull in luster and hard in hand feeling, broken ends are increased during winding and stretching in the subsequent process, and even the number of the broken ends and broken filaments in spinning is increased. Therefore, the spinning temperature must be strictly controlled when spinning fine denier terylene super bright 40D/48F FDY.

Cooling and forming

Cooling forming is one of the important processes of melt spinning, and in the spinning production, cooling ring air is blown to make melt become solid. The evenness unevenness is not only a centralized reflection of the unevenness of physical indexes in the fiber, but also an important index for measuring the quality level of FDY. The cooling conditions such as the temperature, humidity, wind speed and pressure of wind have different influences on the unevenness of the fiber evenness.

Oil feeding quantity

The fine denier yarn has large specific surface area, and the friction between the fiber and air and between the fiber and metal equipment in the spinning process and the static electricity on the fiber are large, so that the filament bundle is seriously shaken and the monofilament bundling is not favorable, thereby being incapable of producing. Therefore, in the actual production, the V-shaped oil nozzle is adopted for oiling and bundling the fibers, so that the oil agent forms a layer of uniform oil film on the surfaces of the fibers to reduce the friction resistance between the fibers and air and the friction between the fibers and metal equipment, improve the cohesive force and the antistatic property between the fibers and improve the distribution uniformity of the filaments during stretching. Therefore, the oil agent is required to have good permeability, spreading width and oil film strength; in actual production, TK-3588 type oil is produced by the group.

Temperature of hot roller

The drawing of the terylene FDY is completed between a G1 godet and a G2 godet, the speed of a first hot roller influences the drawing multiple of a filament bundle and is determined according to the spinning performance and the elongation of the filament bundle. Practice of the preparation process of the invention shows that the temperature of the first hot roller is 10-20 ℃ higher than the glass transition temperature, and after a plurality of process adjustments, the temperatures of the first hot roller and the second hot roller are finally determined to be 95 ℃ and 135 ℃, and the speeds of the first hot roller and the second hot roller are 1850m/min and 4850m/min. The process is cold drawing, uses an unheated godet, and uses a G2 hot roller for heat setting to compensate the post-relaxation phenomenon of the filament, and the hot roller is heated by using a special heating medium, when the winding tension is 0.15cN/dtex, the relaxation rate of 0.4-0.85 can be obtained, and the package forming is good.

Stretching ratio

The speed ratio of the two godet rolls is the drawing multiple, the strength of the polyester fiber is improved along with the increase of the drawing multiple, the elongation is correspondingly reduced, and the reason is that under the action of tension, the orientation degree of macromolecules in the fiber is improved along the axial direction of the fiber in a regular arrangement mode. The fiber strength is mainly determined by the orientation degree of macromolecules to generate slippage and fracture, so that the orientation degree is reduced, and the strength is reduced. On one hand, the dpf is smaller, so that the drawing ratio of the spinneret is increased, and natural drawing breakage is easily caused; on the other hand, the number of single fibers is large, the spinning Cheng Zhangli is large, the tension before winding is large, and the broken ends are increased. Therefore, the proper stretching ratio must be selected to ensure stable production and reliable quality. Practice shows that the stretching multiple of the terylene FDY is about 2.2 to 2.8 times.

Main network pressure

The fine-denier terylene super bright 40D/48F FDY is mainly used as a raw material for downstream weaving high-grade fabrics, such as warp knitting, high-density woven fabrics and the like. Therefore, the yarn is required to have good cohesion. The fine denier yarn has a large winding tension and, because of the large number of single fibers, the cohesion performance is deteriorated. And twisting can not be carried out in the high-speed winding process, so that a network nozzle is arranged behind a winding drafting roller for network processing, tows are entangled to improve the cohesive force of the silk strips, the cohesive performance is improved, and smooth unwinding is ensured. The fine denier yarn has small dpf, and the torque effect of the yarn is small during the network processing, so that higher network degree can be obtained under lower air pressure. According to the requirements of subsequent users and the combination of field production conditions, the fine denier terylene super bright 40D/48F FDY yarn usually has the air pressure of 0.2-0.3MPa and the network degree is controlled at 20-30/m.

Winding speed

Because of high-speed spinning and high-speed drawing, the stress in the yarn is difficult to relax, and the fully drawn yarn with the breaking elongation of more than 35 percent can be obtained by changing different drawing multiples. In principle the speed of the winding head must be lower than the speed of rotation of the second drawing, so as to ensure a certain low-tension shrinkage of the drawn yarn, in order to obtain a satisfactory quality and package of the finished product. And the winding speed of the terylene FDY is selected to be about 4800m/min by combining the field production condition.

Through the use feedback of downstream manufacturers, the FDY product produced by the melt direct-spinning fine-denier PET super-bright production process meets the weaving, dyeing and finishing of textiles, has good effect and completely meets the requirements of post-processing.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A bright production process for producing melt direct-spun fine-denier PET is characterized by comprising the following steps:

step (1), PET melt conveying

step (2), color paste conveying

step (3), entering a spinning manifold

The melt uniformly dyed by the static mixer enters a spinning manifold which is communicated with a spinning component of FDY;

step (4) FDY spinning

the spinning temperature in the spinning box body is 295-297 ℃;

Step (5), FDY (fully drawn yarn) arranging and warehousing

2. The bright production process of PET as claimed in claim 1, wherein the PET melt in step (1) has an intrinsic viscosity of 0.635-0.645 dL-g, a melting point of 258-262 ℃, a b value of 2.0-6.30, and an L value of 85-90.

3. The super bright production process for producing melt direct-spun fine denier PET as claimed in claim 1, wherein the output end of the discharge pump in step (1) is provided with a melt filter.

4. The bright production process for producing the melt direct-spun fine denier PET as claimed in claim 1, wherein a color paste accurate metering device is arranged between the color paste storage bin and the multi-element coupler in the step (2), and a melt distribution valve is arranged at the output end of the static mixer in the step (2).

5. The mass gloss process according to claim 1, wherein the first godet and the second godet of step (4) are arranged in a staggered manner, and the second godet is located above the first godet.

6. The bright production process for producing melt direct-spun fine denier PET as claimed in claim 5, wherein the temperature of the first godet is 90-100 ℃ and the speed is 1750-1950m/min; the temperature of the second godet is 130-140 ℃, and the speed is 4750-4950m/min.

7. The bright production process for producing the melt direct-spun fine denier PET as claimed in claim 1, wherein the winding speed of the winding machine in the step (4) is 4600-5000m/min.