One-step processing technology and production equipment for differential shrinkage mixed fiber polyester

Abstract

The invention discloses a differential shrinkage mixed fiber polyester one-step processing technology, which comprises the following steps: after final shrinkage molding of a PET polyester melt through a polyester final shrinkage kettle, injecting the PET polyester melt into a spinning manifold through a melt filter, a booster pump, a melt conveying pipeline, a cooler and a static mixer in sequence; after being distributed, melts in the spinning box body are respectively shunted into a first metering pump and a second metering pump to be injected into corresponding spinning assemblies for feeding; after one half of the spinning assembly discharges filaments, POY tows are obtained through circular blowing cooling and oil nozzle oiling, the other half of the tows enter IBox five hot rollers through a GR0 draw-off godet to be stretched to form FDY tows, and the FDY tows and the POY tows enter a pre-network at the same time to be subjected to network fiber mixing to form preformed ITY tows; and then sequentially entering a GR2 draw-off godet, a main network and a GR3 draw-off godet, carrying out full-automatic integrated winding and doffing to form ITY tows, and finally carrying out quality inspection, packaging and warehousing. The method has the remarkable advantages of being short in technological process, low in energy consumption, high in production efficiency, uniform and stable in quality and high in additional value, and the differential shrinkage rate can be flexibly adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of the production of differential shrinkage conjugated polyester fibers, and particularly relates to a one-step processing technology and production equipment for differential shrinkage conjugated polyester fibers. Background Art

[0002] POY is a wound yarn with a pre-oriented and low-crystalline structure, having an elongation at break of 100 - 150% and a boiling water shrinkage rate of 40% - 70%; FDY is a fully-oriented drawn yarn obtained by effectively introducing drawing during high-speed spinning when the winding speed reaches over 4000 m / min. The FDY processing technology is a one-step continuous process of spinning → drawing → winding. Therefore, the orientation and crystallization of FDY are higher than those of POY. The elongation at break is 28 - 36%, and the boiling water shrinkage rate is generally 5% - 7%. The physical and mechanical properties of FDY have met the requirements of textile processing and it belongs to the finished yarn. The traditional production of polyester POY / FDY conjugated yarn mainly adopts a two-step process of spinning first and then blending. This blending yarn production process has slow speed, low production efficiency, low equipment automation level, large floor area in the workshop, large investment in supporting equipment, high energy and raw material consumption. However, the product has a high differential shrinkage rate and a unique style, and is suitable for weaving high-end clothing and home textile fabrics. The current mainstream production process is the high-speed blending one-step technology developed during the "11th Five-Year Plan". Although it has obvious advantages such as significantly improved production efficiency, short process, fixed length and fixed weight compared with the two-step process, due to the spinning and drawing methods such as fiber splitting by spinneret, side blowing cooling, mainly 12-end spinning at a certain position, oiling on the oil roller, and winding around the hot roller, it is difficult to control the fiber aggregate structure, the differential shrinkage index is unstable, it is difficult to produce fine denier filaments and high-F filaments, and the weaving is prone to hairiness and the processing efficiency is low. Problems such as the transformation of POY / FDY synchronous high-speed spinning equipment, the tension matching at the fiber mixing point, and high-speed and high texturing degree lead to difficulties in controlling the fiber aggregate structure, unstable differential shrinkage index, and low spinning processing efficiency.

[0003] Therefore, how to synchronously produce two fibers with different shrinkage rates using different processes is the key to realizing the one-step production process of differential shrinkage conjugated yarn. It is necessary to focus on breaking through the key technical bottlenecks such as the control of spinning stability and the regulation of fiber differential shrinkage rate for the current technical difficulties in the one-step spinning and blending process, and develop a new generation of one-step production process equipment technology to achieve the industrial production of one-step differential shrinkage conjugated yarn and its application in high-grade chemical fiber fabrics. Summary of the Invention

[0004] To solve certain technical problems existing in the prior art, one of the purposes of this application is to provide a one-step processing technology for differential shrinkage mixed-fiber polyester, which can solve the problems in the prior art that are likely to cause large differences in the uniformity of monofilament fineness and, due to the excessive span between spinnerets, a maximum of only 24 filaments can be produced at a single spinning position. It has significant advantages such as a short process flow, low energy consumption, high production efficiency, uniform and stable quality, and high added value. The differential shrinkage rate of the product can be flexibly adjusted, making it suitable for processing high-grade products and having good development prospects.

[0005] Another purpose of this application is to provide a production equipment for differential shrinkage mixed-fiber polyester, which can prevent problems such as difficulties in regulating the fiber aggregation structure, unstable differential shrinkage indicators, high production difficulty for fine denier filaments and high F filaments, and low processing efficiency and easy hairiness during weaving when processing polyester POY / FDY mixed-fiber filaments by the one-step method, and achieve the stable industrial production of one-step differential shrinkage mixed-fiber filaments.

[0006] To solve the above-mentioned existing technical problems, one of the purposes of this application is achieved by adopting the following technical solutions:

[0007] A one-step processing technology for differential shrinkage mixed-fiber polyester, the processing technology steps include:

[0008] S1. After the PET polyester melt is finally condensed and formed through the polyester final condensation kettle, it sequentially passes through a melt filter, a booster pump, a melt conveying pipeline, a cooler, and a static mixer and is injected into the spinning box.

[0009] S2. After being distributed in the spinning box, it is respectively branched into the first metering pump and the second metering pump, and the corresponding spinning components are fed through the first metering pump and the second metering pump respectively.

[0010] S3. After the filaments discharged from the spinning component connected to the first metering pump in step S2 pass through ring blowing cooling and oiling on the oil nozzle, they enter the IBox five-roll hot drawing through the GR0 godet to form an FDY filament bundle, and the FDY filament bundle enters the pre-network through the GR1 godet.

[0011] S4. After the filaments discharged from the spinning component connected to the second metering pump in step S2 pass through ring blowing cooling and oiling on the oil nozzle, a POY filament bundle is formed, and the POY filament bundle directly enters the pre-network.

[0012] S5. The FDY filament bundle formed in step S3 and the POY filament bundle formed in step S4 enter the pre-network simultaneously for network mixing to form a preformed ITY filament bundle, and then sequentially enter the GR2 godet, the main network, the GR3 godet, fully automatic integrated winding, and bobbin winding to form an ITY filament bundle, and finally undergo quality inspection, packaging, and warehousing.

[0013] Preferably, the different shrinkage rate of the ITY tow is controlled by the difference in the boiling water shrinkage rate of the POY tow and the FDY tow. The calculation formula for the different shrinkage rate of the ITY tow is: ΔS = S1 - S2; where: S1 is the boiling water shrinkage rate of the POY in the mixed fiber tow, and S2 is the boiling water shrinkage rate of the FDY in the mixed fiber tow.

[0014] Preferably, the five hot rollers of the IBox in step S3 include HR1 - HR5. HR1 - HR3 are used for stretching and heating, and HR4 - HR5 are used for setting and heating. The fiber stretching is completed between the HR1 - HR4 hot rollers.

[0015] Preferably, based on the traditional melt spinning kinetics, considering the influence of fiber crystallinity and orientation degree introduced during the spinning process, the melt spinning processes of POY and FDY in the one-step POY / FDY polyester different shrinkage mixed fiber tow are simulated, and a process technology model for controllable different shrinkage rate of one-step polyester is established. Among them,

[0016] The orientation degree model equation is:

[0017] The crystallinity model equation is:

[0018]

[0019] where: Δn is the birefringence, Aop is the stress - optical coefficient, E is the modulus, v is the axial spinning speed, τ is the relaxation time, θ’ is the relative crystallinity, n is the Avrami index, K is the crystallization rate constant, t is the average temperature of the tow, f is the orientation factor of the amorphous region part of the polymer, Kmax is the maximum crystallization rate constant, tmax is the maximum crystallization rate temperature, D1 / 2 is the half - width at half - maximum of crystallization kinetics, and A is a constant.

[0020] Preferably, the mixing point tensions GR0, GR1, GR2, GR3 of the pre - network and the main network are adjusted and controlled by the speed differences. Among them, the speed difference between the GR2 guide disk and the GR3 guide disk is 30 - 60 m / min. The PO tow and the FDY tow are mixed by the pre - network device and then enter the main network through the GR2 guide disk; the draw ratio of the FDY tow after being stretched by the five hot rollers of the IBox is 2.8 - 3.5.

[0021] Preferably, the fully automatic integrated winding and bobbin - changing device adopts a constant - tension winding control system, and all the winding heads adopt grease - lubricated bearings.

[0022] Preferably, the opening time of the A - plate rod in the fully automatic integrated winding and bobbin - changing device reaches more than twice the original effect.

[0023] Preferably, the oil content of the POY tow is 0.3-0.6%, the oil content of the FDY tow is 0.8-1.2%, and the comprehensive oil content of the mixed fiber tow is 0.6-1.0%.

[0024] The second object of the present application is achieved by the following technical solutions:

[0025] A production device for different shrinkage mixed fiber polyester, characterized in that it includes a polyester final condensation kettle, a melt filter, a booster pump, a melt conveying pipeline, a cooler, a static mixer, a spinning box, a GR0 godet wheel, an IBox five-roll hot roller, a GR1 godet wheel, a pre-network, a GR2 godet wheel, a main network, a GR3 godet wheel, a fully automatic integrated winding and bobbin-changing device arranged in sequence. A first metering pump and a second metering pump are arranged inside the top of the spinning box. A plurality of spinning components respectively communicated with the first metering pump and the second metering pump are further arranged on the top of the spinning box. A ring blowing cooling device and an oiling device are successively arranged below the spinning components. A spinning hot air recovery device is arranged between the ring blowing cooling air box and the IBox five-roll hot roller. The hot air blown out by the ring blowing cooling air box is injected into the IBox five-roll hot roller through the spinning hot air recovery device for heat setting.

[0026] Preferably, the spinning hot air recovery device includes a hot air recovery cover, a first hot air pipe, a blower, a second hot air pipe, a feeding box, a third hot air pipe, and a heat setting box. The IBox five-roll hot roller is located inside the heat setting box. The hot air recovery cover is communicated with the ring blowing cooling device through a pipeline. The hot air recovery cover is communicated with the blower through the first hot air pipe. The feeding box is communicated with the blower through the second hot air pipe. The heat setting box is communicated with the feeding box through the third hot air pipe.

[0027] Preferably, the oiling device includes 64 oiling nozzles. Half of the oiling nozzles use emulsion oiling, and the other half of the oiling nozzles use high antistatic crude oil oiling.

[0028] Preferably, the silk holes on the spinning components are circular silk plates arranged in a rectangular pattern and are staggeredly arranged, and the number of components per position is 16.

[0029] Preferably, the ring blowing cooling device includes an air box and a ring blowing air cylinder communicated with the air box. Two groups of ring blowing air cylinders are used. Control valves for adjusting the air speed are arranged on the air inlet pipelines of the two groups of ring blowing air cylinders.

[0030] Preferably, all porcelain parts on the fully automatic integrated winding and bobbin-changing device are installed through bearing bases.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] At present, the equipment for producing FDY only produces FDY filaments and cannot achieve the production of mixed-fiber polyester. After adding a set of metering pumps, oil pumps and corresponding frequency converters, based on the characteristics of POY and FDY fibers respectively, and on the basis of the process model, mathematical modeling is carried out for the spinning processes of POY and FDY, the hot-roll stretching process of FDY, the hot-roll heat setting process of FDY, etc., to break through the difficulties of the spinning process of POY / FDY different-shrinkage mixed-fiber filaments, develop a melt direct spinning one-step process for polyester with controllable different shrinkage rates, and through the control of the silk path, realize the quantitative control of the stress matching and internal structure (crystallinity, orientation degree, etc.) of POY and FDY at the mixing point; enable the FDY production equipment to achieve the purpose of separately feeding and controlling POY filaments and FDY filaments through system setting parameters; ultimately realize the development and industrial application of the one-step short process, high-efficiency and green processing technology and equipment for different-shrinkage mixed-fiber polyester. Brief Description of the Drawings

[0033] Figure 1 is the process flow chart of the present invention;

[0034] Figure 2 is the orientation and crystallization distribution curve of POY of the present invention along the spinning direction;

[0035] Figure 3 is the orientation and crystallization distribution curve of FDY of the present invention along the spinning direction;

[0036] Figure 4 is the influence of the stretching temperature of the present invention on the different shrinkage rate of the mixed-fiber filaments;

[0037] Figure 5 is the influence of the heat setting temperature of the present invention on the different shrinkage rate of the mixed-fiber filaments;

[0038] Figure 6 is the influence of the air temperature cooling condition of the present invention on the different shrinkage rate of the mixed-fiber filaments;

[0039] Figure 7 is the influence of the air pressure cooling condition of the present invention on the different shrinkage rate of the mixed-fiber filaments;

[0040] Figure 8 is the structural schematic diagram of the present invention;

[0041] In the figure: 1. GR0 wire guide disk; 2. IBox five-roll hot roller; 3. Wire hot air recovery device; 31. Heat setting box; 32. Third hot air pipe; 33. Feeding box; 34. Second hot air pipe; 35. Blower; 36. First hot air pipe; 37. Hot air recovery hood; 4. Ring blowing cooling device; 41. Control valve; 42. Air box; 43. Ring blowing air cylinder; 5. Ester final condensation kettle; 6. Melt filter; 7. First metering pump; 8. Booster pump; 9. Cooler; 10. Melt conveying pipeline; 11. Static mixer; 12. Second metering pump; 13. Spinning box; 14. Spinning pack; 15. Oil application device; 16. GR3 wire guide disk; 17. Main network; 18. Full-automatic integrated winding and bobbin-changing device; 19. GR2 wire guide disk; 20. Pre-network; 21. GR1 wire guide disk; Detailed implementation manners

[0042] Next, in combination with the accompanying drawings and specific implementation manners, the present application will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be combined arbitrarily to form new embodiments.

[0043] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0044] The terms "first", "second", etc. in the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or multiple. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.

[0045] Embodiment 1:

[0046] As Figure 1 shown, a one-step processing process for differential shrinkage mixed fiber polyester, the processing process steps include:

[0047] S1. After the PET polyester melt is finally condensed and formed through the polyester final condensation kettle, it passes through the melt filter, booster pump, melt conveying pipeline, cooler, and static mixer in sequence and is injected into the spinning box.

[0048] S2. After being distributed by the melt in the spinning box, it is respectively shunted into the first metering pump and the second metering pump, and the corresponding spinning components are fed through the first metering pump and the second metering pump respectively;

[0049] S3. After the filaments are discharged from the spinning component connected to the first metering pump in step S2, they are cooled by ring blowing and oiled by an oil nozzle, and then enter the IBox five-roll hot drawing through the GR0 godet to form a FDY filament bundle. The FDY filament bundle enters the pre-network through the GR1 godet;

[0050] S4. After the filaments are discharged from the spinning component connected to the second metering pump in step S2, they are cooled by ring blowing and oiled by an oil nozzle to form a POY filament bundle. The POY filament bundle directly enters the pre-network;

[0051] S5. The FDY filament bundle formed in step S3 and the POY filament bundle formed in step S4 are simultaneously fed into the pre-network for network mixing and fiber blending to form a preformed ITY filament bundle, and then sequentially enter the GR2 godet, the main network, the GR3 godet, the fully automatic integrated winding, and the bobbin winding to form an ITY filament bundle. Finally, quality inspection, packaging, and warehousing are carried out.

[0052] The POY / FDY differential shrinkage mixed fiber yarn is produced by direct spinning of polyester (PET) melt under the condition of a spinning speed of 3000 - 4000 m / min. After the POY and FDY raw materials are injected into the spinning box through a static mixer, they are split in the spinning box and then respectively injected into the first metering pump and the second metering pump. Through the first metering pump and the second metering pump, half of the spinning components are respectively fed. After being stretched, cooled and shaped by the spinneret of the spinning component and oiled by the oil nozzle, the FDY is thermally drawn and heat set through five hot rollers of the IBox in the winding section. After the drawing is completed, it enters the pre-network through the GR1 godet wheel, while the POY directly enters the pre-network. After being mixed by the networker, it forms an ITY mixed fiber bundle in one step. When spinning the ITY differential shrinkage mixed fiber yarn, by adding an inverter for an independent metering pump and an oil agent pump in the spinning box, the spinning components on the spinning box are respectively fed and extruded and oiled through two metering pumps and oil nozzles. The left half of the same spinning position is used to produce FDY, and the right half is used to produce POY. The independent metering and spinning of POY and FDY are matched with DIO components, ring blowing cooling and spinning forming, which can achieve the purpose of independent metering and fine spinning. The spun fiber bundle is significantly improved in terms of uniformity and consistency. Compared with the traditional process of using the 1-in-2 technology on the spinneret plate, it can solve the problems in the existing technology that are prone to large differences in the uniformity of single fiber fineness and, due to the too large span between spinneret plates, the maximum number of yarn heads that can be produced by a single spinning position is only 24. The FDY yarn is oiled with crude oil and is produced by the process route with the most energy-saving consumption during the heat drawing and setting process of the fiber bundle. After passing through two networkers, it reaches sufficient network point fastness, which can ensure slurry-free weaving. At the same time, it can also produce strongly twisted products according to different supporting facilities, providing support for personalized customization of high-end warp knitting, circular knitting and doubling twisting. The made polyester mixed fiber yarn has different differential shrinkage rates and produces a micro-crimping effect to a certain extent. The product is woven by means of post-doubling twisting and setting or direct warping, etc. Through the flexibility of high-F POY and the low shrinkage characteristics of FDY, the high-shrinkage POY is in the middle of the fiber, and the low-shrinkage FDY floats on the surface, making the woven fabric take into account the wool feeling and drapability.

[0053] When producing POY / FDY differential shrinkage conjugate filaments, the FDY part first goes through pre-networking, and then is mixed with the POY part in the main network. The physical properties such as the tension and oil content of the two parts should be as close as possible to be well combined into one. How to effectively make the two different fibers fully hold together to achieve the physical properties required for weaving is very important. Therefore, how to set the network, the level and quantity of network points are the key factors. The establishment of network nodes between fibers strengthens the macroscopic morphological structure between the fibers through the torsion and wrapping of the fibers on the nodes, and to a certain extent, it will hinder the change of the fiber morphological structure (elongation or shrinkage). Therefore, generally, the more network points, the lower the differential shrinkage rate of the conjugate filaments. Therefore, first, a pre-network is configured for FDY. Firstly, it serves the purpose of uniform oiling on FDY, and secondly, it adds network points to the FDY filaments. Then, a main network is set between GR2 and GR3. After the POY and FDY pass through GR2 together, they achieve the purpose of complete mixing in the main network. For thick-denier conjugate fibers, such as products like 195dtex / 108F, 135dtex / 108F, 150dtex / 108F, etc., compressed air not lower than 0.4MPa is used to ensure that the number of network points is not less than 20. This not only facilitates the processing of downstream customers and reduces the occurrence of fuzz and broken filaments, but also improves the processing stability, efficiency, and the woolly feeling of the fiber fabric.

[0054] Among them, the table shows the influence of the network point setting on the differential shrinkage performance of the conjugate filaments (195dtex / 108f).

[0055] Table 1

[0056]

[0057] This innovative technology has significant advantages over the original one-step conjugate filament products, including a short process flow, low energy consumption, high production efficiency, uniform and stable quality, and high added value. The differential shrinkage rate of the products of this project can be flexibly adjusted, and the production cost has strong competitiveness. It is a substitute product that can replace the low-speed two-step production process, is suitable for processing high-grade products, and has good development prospects.

[0058] Further improvement is as follows Figure 4 and Figure 5 As shown, the differential shrinkage rate of the ITY filament bundle is controlled by the difference in the boiling water shrinkage rate between the POY filament bundle and the FDY filament bundle. The calculation formula for the differential shrinkage rate of the ITY filament bundle is: ΔS = S1 - S2; where: S1 is the boiling water shrinkage rate of POY in the conjugate filaments, and S2 is the boiling water shrinkage rate of FDY in the conjugate filaments.

[0059] In the ITY tow, FDY is a low-shrinkage fiber, and its boiling water shrinkage rate is relatively fixed. The boiling water shrinkage rate of POY fiber varies greatly. The fineness of FDY and POY in ITY is not evenly distributed, and the fineness of POY plays a key role in the differential shrinkage rate. By adjusting the fineness of POY fiber, the differential shrinkage rate of ITY tow can be controlled, resulting in a large range of differential shrinkage deviation for each batch of products. The thermal shrinkage rate in the fiber is related to fiber crystallization and orientation. POY has a low crystallinity and orientation degree, and the stability of the macromolecular network structure is poor, resulting in a high thermal shrinkage rate. During the processing of the blended fiber tow, FDY undergoes hot roll drawing and setting, and both the fiber orientation degree and crystallinity are significantly improved, the fiber structure is stable, and the thermal shrinkage rate decreases. The differential shrinkage of ITY tow is caused by the difference in the boiling water shrinkage rate between POY and FDY, and the calculation formula is ΔS = S1 - S2. The differential shrinkage rate of ITY blended fiber tow can be adjusted through process conditions such as spinning speed, the blending ratio of POY and FDY, the drawing ratio of FDY, and setting temperature. By simulating the molecular orientation and crystallinity of the fiber to optimize the spinning process, the differential shrinkage rate can be precisely controlled, and the physical index fluctuations are small. Among them, the stretching temperature has little effect on the differential shrinkage rate of the blended fiber tow, while with the increase of the setting temperature, the differential shrinkage rate will increase significantly because the increase in crystallinity has a greater impact on the boiling water shrinkage rate of the blended fiber tow than on the orientation degree. Compared with the original one-step blended fiber tow product, it has significant advantages such as a short process flow, low energy consumption, high production efficiency, uniform and stable quality, and high added value. The differential shrinkage rate of this product can be flexibly adjusted, and the production cost has strong competitiveness. It is a substitute product that can replace the low-speed two-step production process, is suitable for processing high-grade products, and has good development prospects.

[0060] Further improvement is that the five hot rolls of IBox in step S3 include HR1-HR5. HRl-HR3 are used for stretching and heating, and HR4-HR5 are used for setting and heating. The fiber stretching is completed between the hot rolls of HR1-HR4.

[0061] In the production process of one-step POY / FDY polyester differential shrinkage conjugate fiber, a crucial step is the production of FDY. In traditional FDY production, the methods of multi-loop winding on hot rollers for drawing and emulsion oiling are adopted, which increases the friction between the tow and the hot rollers, and the evaporation of moisture in the emulsion significantly increases the energy consumption of the hot rollers. The five-zone hot roller of the IBox used in this project's differential shrinkage conjugate fiber consists of HR1 - HR5. Among them, the FDY spinning and drawing are carried out continuously. The fiber undergoes drawing through five hot rollers: HR1 - HR5 during the drawing process. The tow is rapidly heated on the surface of the hot rollers and then drawn, making full use of the waste heat of the tow and the low heat consumption mode of crude oil oiling. Each roller has 2 / 3 turns of winding, which is conducive to increasing the contact area between the fiber and the roller, equivalent to increasing the heating time, reducing the process temperature of the hot rollers, minimizing the damage to the surface of the fine denier fiber caused by friction with the tow, and significantly reducing the electricity cost of the current production method with the same output. In the five-zone hot rollers, HR1 - HR3 are used for drawing and heating, and HR4 - HR5 are used for setting and heating. The fiber drawing is completed between the two hot rollers HR1 - HR4. The speed difference between HR1 - HR3 and HR4 - HR5 is relatively large. The speed of HR1 - HR3 is less than that of HR4 - HR5. The temperature of HR1 - HR3 is the drawing temperature, which heats the fiber, intensifies the movement of macromolecules in the fiber, enabling the fiber to be drawn smoothly. The temperature of HR4 - HR5 is the setting temperature, which stabilizes the internal structural changes generated during the drawing process of the fiber. According to the new three-zone drawing process method, the phenomenon of hairy filaments during the drawing process is avoided, which is more advantageous than the original production method with two pairs of hot rollers, especially for the quality of fine denier products. The temperature of HR1 - HR3 should be selected above the glass transition temperature of the polymer. The movement time of the fiber between hot rollers HR3 and HR4 is extremely short. Therefore, the drawing model of the hot roller can be simplified to the drawing and setting of the fiber at a certain specific temperature.

[0062] Furthermore, based on the traditional melt spinning kinetics, the influence of fiber crystallinity and orientation on the spinning process is introduced, and the melt spinning processes of POY and FDY in one-step POY / FDY polyester differential shrinkage conjugate fiber are simulated to establish a process technology model for controllable differential shrinkage rate of one-step polyester, where,

[0063] The orientation model equation is:

[0064] The crystallinity model equation is:

[0065]

[0066] Where: Δn is the birefringence, Aop is the stress-optical coefficient, E is the modulus, v is the axial spinning speed, τ is the relaxation time, θ’ is the relative crystallinity, n is the Avrami exponent, K is the crystallization rate constant, t is the average temperature of the tow, f is the orientation factor of the amorphous region of the polymer, Kmax is the maximum crystallization rate constant, tmax is the maximum crystallization rate temperature, D1 / 2 is the full width at half maximum of the crystallization kinetics, and A is a constant.

[0067] The traditional processing technology of differential shrinkage conjugate fiber cannot quantitatively control the internal structure (crystallinity, orientation degree, etc.) of the fiber, which will lead to unstable differential shrinkage indexes. According to the process characteristics of pre-oriented yarn POY and fully drawn yarn FDY, based on the process model, mathematical modeling is carried out for the spinning process of POY and FDY, the hot roll stretching process of FDY, and the hot roll heat setting process of FDY respectively, to establish a controllable process technology model for one-step polyester differential shrinkage rate, so as to realize the stress matching and quantitative control of the internal structure (crystallinity, orientation degree, etc.) of POY and FDY at the mixing point, laying a theoretical foundation for the industrial production of one-step polyester differential shrinkage conjugate fiber. Computer simulation based on the PET physical property parameters can obtain the orientation and crystallization distribution curves of the tow along the spinning process. It can be seen from the curves in Figure 2 and Figure 3 that after the draw reaches a certain length, the crystallization of the fiber has tended to be stable, which is consistent with the fiber orientation and crystallization situation in the actual fiber processing process.

[0068] Furthermore, it is improved that the mixing point tensions GR0, GR1, GR2, GR3 of the pre-network and the main network are adjusted and controlled by the speed difference, wherein the speed difference between the GR2 godet and the GR3 godet is 30-60 m / min, the PO tow and the FDY tow are mixed by the pre-network device, and then enter the main network through the GR2 godet; the draw ratio of the FDY tow after being drawn by the five hot rolls of the IBox is 2.8-3.5.

[0069] POY is spun at a medium speed, and FDY is spun at a high speed with an unconventional draw ratio, so that the FDY yarn and the POY yarn have different tension points respectively. The internal stresses and tensions of the two different fibers are greatly affected by the speeds of the moving parts in the spinning process. Therefore, the tension matching and stable control at the mixing point are the key to the production of differential shrinkage fibers.

[0070] The tension control of the mixing point is adjusted by the speed difference of the four wire guides GR0, GR1, GR2, and GR3. The winding tension of the two fibers along the spinning process should be as uniform as possible to avoid the POY yarn and FDY yarn from forming a winding roller due to tension fluctuations and failing to produce normally. In the production mode where the independent POY part and the FDY part are sent to the main network and the yarn is combined, the POY part is the same as the conventional polyester POY production process. After passing through the two wire guides GR2 and GR3, the speed difference between the two wire guides is 30-60m / min, which plays a role in conveying and adjusting the yarn tension. After passing through the GR2 guide, the POY yarn is combined with the FDY yarn and enters the main network. The FDY part is the same as the normal polyester FDY. It passes through 5 hot rollers with a stretching ratio of 2.8-3.5, and then it is combined with the POY yarn through the GR2 wire guide and enters the main network. After the two yarns are combined through the main network, they enter the winding machine for winding and forming.

[0071] A further improvement is that the fully automatic integrated winding and doffing device adopts a constant tension winding control system, and all winding heads adopt grease-lubricated bearings.

[0072] The 32-head mixed fiber yarn with different shrinkage has a large tension deviation due to the large strength difference between POY and FDY tows, which makes it easier to break when switching full rolls. Therefore, the full process control of the fully automatic winding head is adjusted, and a constant tension winding control system is added, and all winding heads use grease lubricated bearings; the constant tension winding control system can reduce the tension fluctuation during the winding process, so that the package has a good shape; and all winding heads use grease lubricated bearings, and the lubrication method is safe and reliable; the winding head switching is fast and reliable, and the switching success rate is over 99%.

[0073] A further improvement is that the opening time of the A-plate rod in the fully automatic integrated winding and doffing device is more than twice the original effect.

[0074] Optimize and improve the winding equipment to improve the quality of the bottom layer of silk. During the production process, according to the characteristics of the product, it is necessary to adjust the height of the A-plate rod of the winding machine, and set the opening time of the A-plate to more than twice the original effect (when the set winding diameter is 165mm, the opening time is about 7-9 minutes. If the opening time exceeds 9 minutes, the distance between the bottom layer of the silk cake and the A-plate is too close, which will cause the bottom layer of silk to be rubbed or the production part to be broken), and the situation of rubbing and breaking of silk is significantly reduced.

[0075] Further improvement is that the oil content of the POY tow is 0.3-0.6%, the oil content of the FDY tow is 0.8-1.2%, and the comprehensive oil content of the mixed fiber is 0.6-1.0%.

[0076] The first 64-head differentiated oiling rack. According to the characteristics of the different-shrinkage blended polyester products, innovations were made on the original 32-head FDY spinning equipment. By designing a set of micro-atomized oil pump control systems, FDY and POY can be oiled using different processes respectively, and the layout of the oil nozzles is reasonably designed. On the basis of the original 32 oil nozzles, 64 oil nozzles are added to meet the independent oiling of 32 bundles of FDY yarns and 32 bundles of POY yarns at the same spinning position, achieving the purpose of oiling POY yarns and FDY yarns with different oils and oil concentrations. Among them, the oil content of the POY tow is 0.3-0.6%, the oil content of the FDY tow is 0.8-1.2%, and the comprehensive oil content of the blended yarn is 0.6-1.0%, which can ensure smooth post-processing of the product.

[0077] For example, POY / FDY heterogeneous shrinkage blended yarn is produced by direct spinning of polyester (PET) melt at a spinning speed of 3000-4000m / min. After the POY and FDY tows are stretched, cooled and formed by different spinning assembly nozzles, and oiled by different oil nozzles, the FDY is hot-drawn and heat-set in the winding section. After the stretching is completed, it is mixed and formed in one step by a network device. FDY yarn is oiled with crude oil. During the heat stretching and shaping process of the tow, it is produced using the most energy-saving process route. After passing through the second network device, it reaches sufficient network point firmness, which can ensure pulp-free weaving. At the same time, it can also produce strong twist products according to different needs, supporting the personalized customization of high-end warp knitting, circular knitting machines and two-for-one twisting manufacturing. The polyester blended yarn has different shrinkage rates and produces a micro-curl effect to a certain extent. The product is woven by post-twisting shaping or direct warp drawing. Through the high F flexibility of POY and the low shrinkage characteristics of FDY, the high shrinkage POY is in the middle of the fiber and the low shrinkage FDY floats on the surface, so that the woven fabric has both wool feel and drape.

[0078] Compared with the original one-step mixed fiber products, this innovative technology has the significant advantages of short process flow, low energy consumption, high production efficiency, uniform and stable quality and high added value. The product shrinkage rate of this project can be flexibly adjusted, and the production cost is highly competitive. It is an alternative product that can replace the low-speed two-step production process, suitable for processing high-end products, and has good development prospects.

[0079] Among them, Table 2 shows the effect of improved spacing between winding equipment partitions on rubbing and end breakage:

[0080] Table 2

[0081]

[0082]

[0083] By establishing a one-step polyester differential shrinkage control technology model, quantitative control of the fiber internal structure (crystallinity and orientation, etc.) is achieved, and independent control systems for POY and FDY yarns at the same spinning position, spinning oil racks for double differential oiling, crude oil oiling and drafting technology, and mixing point tension control technology are developed to achieve the industrial development of efficient and energy-saving 32-spindle one-step polyester blended yarn. The difficulties of the POY / FDY differential shrinkage blended yarn spinning process have been broken through, and a one-step polyester differential shrinkage control process for melt direct spinning has been developed. Integrate and innovate the upper and lower coordinated integration technologies such as separate drawing, cooling and molding, separate nozzle oiling, stretching and shaping, and mixed fiber point netting, and finally achieve the development and industrial application of one-step short-process efficient and green processing technology and equipment for differential shrinkage blended polyester.

[0084] Embodiment 2:

[0085] like Figure 8 As shown, a production equipment for different shrinkage blended polyester fiber includes a polyester final shrinking reactor 5, a melt filter 6, a booster pump 8, a melt conveying pipeline 10, a cooler 9, a static mixer 11, a spinning manifold 13, a GR0 godet 1, an IBox five-pass hot roller 2, a GR1 godet 21, a pre-network 20, a GR2 godet 19, a main network 17, a GR3 godet 16, and a fully automatic integrated winding and doffing device. The top of the spinning manifold 13 is provided with a first metering pump 7 and a second metering pump 8. The metering pump 12 is inside, and the top of the spinning box 13 is also provided with a plurality of spinning components 14 which are respectively connected with the first metering pump 7 and the second metering pump 12; a ring-blowing cooling blowing device 4 and an oiling device 15 are arranged in sequence below the spinning components 14; a spinning hot air recovery device 3 is arranged between the ring-blowing cooling wind box 42 and the IBox five-pass hot roller 2; the hot air blown out by the ring-blowing cooling wind box 42 is injected into the IBox five-pass hot roller 2 through the spinning hot air recovery device 3 for heating and shaping.

[0086] Improve the existing equipment. Connect the spinning box 13 to the fully automatic integrated winding and bobbin-changing device through the guide roller 1 of GR0, the five-roll hot roller 2 of IBox, the guide roller 21 of GR1, the pre-network 20, the guide roller 19 of GR2, the main network 17, and the guide roller 16 of GR3. And install the first metering pump 7 and the second metering pump 12 on the top of the spinning box 13 to supply materials to different spinning components 14 respectively. At the same time, install a spinning hot air recovery device 3 between the ring blowing cooling air box 42 and the five-roll hot roller 2 of IBox. The hot air blown out by the ring blowing cooling air box 42 is injected into the five-roll hot roller 2 of IBox through the spinning hot air recovery device 3 for heat setting. It can enable the spinning box 13 to form fiber bundles with different properties through different combinations of spinning components 14 and metering pumps. After the different fiber bundles are connected in series through the guide roller 1 of GR0, the five-roll hot roller 2 of IBox, the guide roller 21 of GR1, and the pre-network 20, FDY fiber bundles and POY fiber bundles can be formed. Finally, through the connection and transportation of the guide roller 19 of GR2, the main network 17, and the guide roller 16 of GR3, an ITY mixed fiber bundle can be formed. During the production process, the area where the five-roll hot roller 2 of IBox is located can be heated by the hot air introduced by the spinning hot air recovery device 3, enabling it to have a refined configuration when producing differential shrinkage fiber spinning, and the equipment performance is correspondingly improved. With the adjustment of the process requirements for FDY fiber and POY fiber, differential shrinkage fibers with different characteristics can be produced, and products can be customized according to different customer needs. By upgrading and transforming the traditional FDY spinning equipment, it has the ability to spin high-strength differential shrinkage mixed fibers, extending the function of the equipment and facilitating the adjustment of the spinning process. It meets the refined requirements of the FDY and POY spinning processes in aspects such as cooling and forming, tension control, and network mixing, expanding the spinning range and improving the product quality at the same time. Through the optimization of the fiber path in the technical upgrade of the drawing and winding part, the spinning varieties are broadened, achieving the effect of multi-purpose use of one machine.

[0087] Further improvement is made as follows. The spinning hot air recovery device 3 includes a hot air recovery cover 37, a first hot air pipe 36, a blower 35, a second hot air pipe 34, a feeding box 33, a third hot air pipe 32, and a heat setting box 31. The five-roll hot roller 2 of IBox is located inside the heat setting box 31. The hot air recovery cover 37 is connected to the ring blowing cooling and blowing device 4 through a pipeline. The hot air recovery cover 37 is connected to the blower 35 through the first hot air pipe 36. The feeding box 33 is connected to the blower 35 through the second hot air pipe 34. The heat setting box 31 is connected to the feeding box 33 through the third hot air pipe 32.

[0088] The instability of the cooling conditions also directly affects the evenness variation of the filaments, causing fluctuations in the differential shrinkage rate, thus making it impossible to ensure the use in post-processing. With the change of the monofilament linear density of different products, the corresponding specific surface area of the filament bundle also changes. The difference in heat dissipation speed will cause the solidification point to change during the cooling of the filament. At the same time, the temperature difference between the surface layer and the inner layer of the filament is relatively large, which may lead to changes in the linear density in the longitudinal direction during the fiber stretching process. For the production of high-shrinkage filaments, it is necessary to increase the cooling air temperature or reduce the wind speed to lower the cooling speed and extend the plastic zone, which is beneficial to the formation of the low-orientation structural morphology of the nascent fiber. However, it also slows down the solidification of the melt stream. Under the action of surface tension, shrinkage occurs on the surface of the stream, and at the same time, the solidification point moves downward, which is also prone to cause filament doubling and fuzzing. Therefore, a spinning hot air recovery device 3 is added. First, the cooling air cools the filament bundle in the ring blowing cooling device 4. After heat exchange, the temperature of the cooling air rises, enters the hot air recovery hood 37 through the channel of the annular cooler 9, is then sucked by the blower 35 through the first hot air pipe 36, blown into the feed box 33 through the second hot air pipe 34, and finally blown into the heat setting box 31 through the third hot air pipe 32 to conduct ambient heating and insulation for the five heat rollers 2 of the IBox, thereby reducing the energy consumption required for the heat setting rollers to generate heat, making the heat insulation effect of the heat setting box 31 good, and greatly improving the thermal setting stability of the product. The products produced by this process and device have greatly improved breaking strength and boiling water differential shrinkage rate compared with the products produced by traditional equipment and processes, so that their fabric dyeing is more uniform and the quality is more stable. From the relationship between the cooling conditions and the differential shrinkage rate of the conjugate fiber, as shown in Figure 6 and Figure 7 shown: Strengthening the cooling conditions is beneficial to improving the differential shrinkage rate of the conjugate fiber, achieving a win-win situation of controllable differential shrinkage rate and quality improvement.

[0089] Further improved, the oiling device 15 includes 64 oiling nozzles, and half of the oiling nozzles use emulsion oiling, and the other half of the oiling nozzles use high antistatic crude oil for oiling.

[0090] Based on the original 32 oil nozzles, the number is increased to 64 oil nozzles to meet the independent oiling of 32 FDY yarn bundles and 32 POY yarn bundles at the same spinning position, and realize the oiling of POY yarn and FDY yarn with different oil agents and oil agent concentrations. According to the characteristics of FDY and POY products, POY uses emulsion oiling to improve the oiling uniformity; while FDY yarn uses high antistatic crude oil for oiling, reducing the heat consumption of the hot roller caused by water evaporation during emulsion oiling, and can avoid winding and reduce the stretching path through multi-roller winding, thereby reducing the production energy consumption of one-step polyester differential shrinkage fiber. After the FDY yarn bundle is oiled through the oil nozzle, it undergoes a drawing process through 5 hot rollers, and can complete stretching and shaping within a short residence time, and the product quality and physical properties are controlled. The double-different oiling process makes the rigid FDY crude oil more prominent in the yarn bundle, and the emulsion oiling of POY also reduces the generation of static electricity, which is more conducive to the uniformity of oiling of high-F products. Different oil contents are also significantly reflected in the fabric style. Due to the characteristic of deep color absorption of POY, the finally woven fabric has a unique style.

[0091] Further improvement is that the silk holes on the spinning component 14 are circular silk plates arranged in a rectangular pattern and are staggeredly arranged, and the number of components per position is 16.

[0092] The existing one-step ITY preparation process can only produce 24 spindles. There is also a two-step preparation process of spinning first and then mixing fibers, which has low production efficiency, low equipment automation, large floor area in the workshop, high energy and raw material consumption. At the same time, the spinning box adopts an energy-saving type. To reduce the position distance and improve the tension difference between yarn bundles, the one-step 32-spindle has a higher unit output, so it is called high-efficiency energy-saving. The spinning component 14 uses a circular silk plate with a rectangular arrangement of silk holes and is staggeredly arranged, and the number of components per position is 16, ensuring sufficient cooling space at a reasonable position distance and between yarn bundles, and ensuring the evenness of the strand and tension between yarn bundles. Compared with the traditional fiber splitting technology of only splitting 1 into 2 on the spinneret plate, the number of yarn spindles per spinning position is increased from the original maximum of 24 to 32, and the production efficiency is increased by more than 25%.

[0093] Even further improvement is that the ring blowing cooling air device 4 includes an air box 42 and a ring blowing air cylinder 43 communicated with the air box 42. Two groups of the ring blowing air cylinders 43 are adopted, and control valves 41 for adjusting the wind speed are provided on the air inlet pipes of the two groups of the ring blowing air cylinders 43.

[0094] For the convenience of process adjustment, an annular blow cooling device 4 composed of two groups of annular blow air cylinders 43 is installed on each spinning box 13. The device is arranged separately on the left and right. The air speed can be adjusted separately through a control valve 41, and the annular blow cooling for cooling the FDY and POY tow can be set separately, which is beneficial to adopting different cooling air volumes for the FDY and POY tow due to different fineness, and realizing the complete independent spinning process adjustment of FDY and POY. After being combined with the spinning hot air recovery device 3, the melt heat preservation effect is improved, and the process energy consumption is further reduced.

[0095] Furthermore, it is improved that all the porcelain parts on the fully automatic integrated winding and bobbin changing device 18 are installed through bearing bases.

[0096] At the mixing point, the tension difference after the mixing of FDY and POY is highly relevant to the dyeing of the product. Especially, the tension of the tow before combination determines the influence degree of the friction force of the tow on the guide disk and the porcelain parts. Excessive friction force is likely to cause the tow to get hot and generate hairiness, which easily leads to the problem of white appearance on the fabric surface after weaving. To completely solve this problem, all the porcelain parts on the automatic integrated winding equipment are installed through bearing bases, so that the porcelain parts rotate through bearings, effectively avoiding the problem of excessive friction force of the tow on the guide disk and the porcelain parts.

[0097] The above embodiments are only the preferred embodiments of the present application, and the protection scope of the present application cannot be limited thereby. Any non-substantial changes and substitutions made by those skilled in the art based on the present application belong to the protection scope required by the present application.

Claims

1. A one-step processing technology for differential shrinkage mixed fiber polyester, characterized in that: The processing process steps include: S1. After the PET polyester melt is finally condensed and formed in the polyester finisher, it is successively injected into the spinning box through a melt filter, a booster pump, a melt conveying pipeline, a cooler, and a static mixer; S2. After being distributed by the melt in the spinning box, it is respectively shunted into the first metering pump and the second metering pump, and the corresponding spinning components are fed through the first metering pump and the second metering pump respectively; S3. After the filaments discharged from the spinning component connected to the first metering pump in step S2 are cooled by ring blowing and oiled by an oil nozzle, they enter the IBox five-roll hot drawing through the GR0 godet to form a FDY filament bundle, and the FDY filament bundle enters the pre-network through the GR1 godet; S4. After the filaments discharged from the spinning component connected to the second metering pump in step S2 are cooled by ring blowing and oiled by an oil nozzle, a POY filament bundle is formed, and the POY filament bundle directly enters the pre-network; S5. The FDY filament bundle formed in step S3 and the POY filament bundle formed in step S4 enter the pre-network simultaneously for network mixing and fibrillation to form a preformed ITY filament bundle, and then successively enter the GR2 godet, the main network, the GR3 godet, the fully automatic integrated winding, and the bobbin winding to form an ITY filament bundle, and finally quality inspection, packaging, and warehousing are carried out.

2. The one-step processing technology of differential shrinkage mixed fiber polyester according to claim 1, characterized in that: The differential shrinkage rate of the ITY filament bundle is controlled by the difference in the boiling water shrinkage rate between the POY filament bundle and the FDY filament bundle. The calculation formula for the differential shrinkage rate of the ITY filament bundle is: ΔS = S1 - S2; where: S1 is the boiling water shrinkage rate of the POY in the mixed fiber filament, and S2 is the boiling water shrinkage rate of the FDY in the mixed fiber filament.

3. The one-step processing technology of differential shrinkage mixed fiber polyester according to claim 1, characterized in that: The IBox five-roll hot drawing in step S3 includes HR1-HR5, and HRl-HR3 are used for stretching and heating, HR4-HR5 are used for setting and heating, and the fiber stretching is completed between the HR1-HR4 hot rolls.

4. A one-step processing process for differential shrinkage mixed fiber polyester according to claim 3, characterized in that: The mixing point tension of the pre-network and the main network is adjusted and controlled by the speed difference of GR0, GR1, GR2, and GR3. Among them, the speed difference between the GR2 godet and the GR3 godet is 30-60 m / min. The PO filament bundle and the FDY filament bundle are fibrillated through the pre-network device and then enter the main network through the GR2 godet; the draw ratio of the FDY filament bundle after being stretched by the IBox five-roll hot drawing is 2.8-3.

5.

5. The one-step processing technology for differential shrinkage mixed fiber polyester according to claim 1, characterized in that: The opening time of the A-plate rod in the fully automatic integrated winding and bobbin winding device is more than twice the original effect.

6. A production device for differential shrinkage conjugated polyester fibers, characterized in that: It includes a polyester finisher (5), a melt filter (6), a booster pump (8), a melt conveying pipeline (10), a cooler (9), a static mixer (11), a spinning box (13), a GR0 godet wheel (1), an IBox five-roll hot roller (2), a GR1 godet wheel (21), a pre-network (20), a GR2 godet wheel (19), a main network (17), a GR3 godet wheel (16), and a fully automatic integrated winding and bobbin-changing device (18) arranged in sequence as described in any one of claims 1 to 6. A first metering pump (7) and a second metering pump (12) are provided inside the top of the spinning box (13). A number of spinning components (14) respectively communicating with the first metering pump (7) and the second metering pump (12) are further provided on the top of the spinning box (13). An annular blow cooling air blowing device (4) and an oiling device (15) are sequentially arranged below the spinning components (14). A spinning hot air recovery device (3) is provided between the annular blow cooling air box (42) and the IBox five-roll hot roller (2). The hot air blown out by the annular blow cooling air box (42) is injected into the IBox five-roll hot roller (2) through the spinning hot air recovery device (3) for heat setting.

7. The production equipment of a differential shrinkage mixed fiber polyester according to claim 6, characterized in that: The spinning hot air recovery device (3) includes a hot air recovery cover (37), a first hot air pipe (36), a blower (35), a second hot air pipe (34), a feeding box (33), a third hot air pipe (32), and a heat setting box (31). The IBox five-roll hot roller (2) is located inside the heat setting box (31). The hot air recovery cover (37) is communicated with the annular blow cooling air blowing device (4) through a pipeline. The hot air recovery cover (37) is communicated with the blower (35) through the first hot air pipe (36). The feeding box (33) is communicated with the blower (35) through the second hot air pipe (34). The heat setting box (31) is communicated with the feeding box (33) through the third hot air pipe (32).

8. The production equipment of a differential shrinkage mixed fiber polyester according to claim 6, characterized in that: The oiling device (15) includes 64 oiling nozzles. Half of the oiling nozzles use emulsion oiling, and the other half of the oiling nozzles use high antistatic crude oil for oiling.

9. The production equipment of a differential - shrinkage mixed - fiber polyester according to claim 7, characterized in that: The annular blow cooling air blowing device (4) includes an air box (42) and an annular blow air cylinder (43) communicated with the air box (42). Two groups of the annular blow air cylinders (43) are used. Control valves (41) for adjusting the air speed are provided on the air inlet pipelines of the two groups of the annular blow air cylinders (43).

10. The production equipment of a differential - shrinkage conjugated polyester fiber according to claim 6, characterized in that: All porcelain parts on the fully automatic integrated winding and bobbin-changing device (18) are installed through bearing bases.

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