Method for preparing melt-spun phase change fibers, melt spinning apparatus, and phase change fibers

Abstract

The application discloses a melt spinning phase change fiber preparation method, a melt spinning device and a phase change fiber. The melt spinning phase change fiber preparation method comprises the following steps: S1, resin A is added to a multiple high-frequency shearing melt extrusion system for melting; S2, when resin A is in a semi-melted state, the resin A melt is mixed with a phase change modifier, the resin A melt and the phase change modifier are in a melt pipeline of the multiple high-frequency shearing melt extrusion system, the mixture is uniformly sheared at high speed to form a uniform melt, water and small molecule volatile substances volatilized from the melt are removed, the melt is pressurized by a melt pump and metered by a metering pump, and then the melt is conveyed to a spinning box; S3, resin B is conveyed to the spinning box by a single-screw extruder; and S4, resin A and resin B are extruded together to form a phase change fiber with a skin-core structure, resin A forms a core layer containing the phase change modifier, and resin B forms a skin layer.

Description

TECHNICAL FIELD

[0001] The present application relates to a method and material for preparing phase change modified resin melt and phase change fiber by using melt spinning online devolatilization technology, and belongs to the technical field of material processing and fiber preparation. BACKGROUND

[0002] Energy storage temperature regulating textiles are a new type of functional textiles made of phase change technology, which can automatically absorb or release heat to reduce the temperature fluctuation of the body surface microenvironment according to the change of the external temperature, thereby ensuring human comfort, avoiding pathological reactions caused by temperature fluctuations, and achieving energy recycling. This type of product has achieved industrialization in solution spinning at home and abroad, and the produced heat storage temperature regulating acrylic and viscose fibers have been widely used in high-end, special clothing and home textiles fields. However, this technology has not achieved industrialization breakthrough in polyester and nylon fibers which account for 70% of the market.

[0003] The existing method for preparing polyester and nylon phase change fibers by melt spinning in China mainly prepares phase change modified resin chips, and then prepares phase change fibers by melt spinning. However, the above method and process have the problems of poor chip stability, phase change material precipitation above a certain temperature, and difficulty in normal feeding and material conveying at the feeding port of the melt spinning machine. The above problems restrict the application of phase change modified materials in melt spinning fibers and greatly limit the development of polyester and nylon phase change fibers. How to prepare a high-uniform phase change melt by melt spinning process and then prepare a phase change fiber has become a difficult problem to be solved in this field. SUMMARY

[0004] The present application aims to solve the problems in the prior art, and discloses a melt spinning phase change fiber preparation method, which comprises the following steps:

[0005] S1, resin A is added to a multiple high-frequency shearing melt extrusion system for melting;

[0006] S2, resin A is mixed with a phase change modified material when resin A is in a semi-melted state. The resin A melt and the phase change modified material form a uniform mixed melt in the melt pipeline of the multiple high-frequency shearing melt extrusion system through high-speed shearing, and are pumped and metered by a melt pump and a metering pump, and then are delivered to a spinning box;

[0007] S3, resin B is delivered to the spinning box by a single screw extruder;

[0008] S4, resin A and resin B are co-extruded to form a phase change fiber with a skin-core structure, resin A forms a core layer containing a phase change modified material, and resin B forms a skin layer.

[0009] In the preferred scheme, the resin A is one or a mixture of several of polyethylene, low-melting polyester, polybutylene succinate.

[0010] In the preferred scheme, the phase change modifier is in liquid state, the melting point of the phase change material is between 30-50℃, and the molecular weight is between 20000-100000.

[0011] In the preferred scheme, the phase change modifier is selected from phase change microcapsule, polyethylene glycol PEG-2000.

[0012] In the preferred scheme, when the phase change fiber with skin-core structure is extruded, the fiber with expected fineness is formed under the cooling of side blowing, and the melt-spun phase change temperature regulating fiber with skin-core structure is prepared after oiling, hot drawing and winding.

[0013] In the preferred scheme, the melt A and the phase change modifier are sheared by kneading shear blocks and conveying thread blocks in the multiple high-frequency shear melting extrusion system, and the multiple high-frequency shear melting extrusion system is a three-screw extruder.

[0014] The application also discloses a melt spinning device for phase change fiber, which comprises the following components.

[0015] The multiple high-frequency shear melting extrusion system comprises a melt pipeline, wherein the melt pipeline is provided with thread blocks, kneading blocks, shear conveying screws, a feeding port and an online adding port.

[0016] The multiple high-frequency shear melting extrusion system further comprises a melt pump pressurizing system and a metering pump.

[0017] A single-screw extruder;

[0018] A spinning box connected with the multiple high-frequency shear melting extrusion system and the single-screw extruder.

[0019] In the preferred scheme, the multiple high-frequency shear melting extrusion system further comprises an online devolatilization port, the online devolatilization port is communicated with the melt pipeline, and the online devolatilization port is used for removing air in the melt in the melt pipeline.

[0020] The application also discloses a phase change fiber prepared by the method, which comprises a skin layer and a core layer, the skin layer wraps the core layer, and the core layer is dispersed with phase change modifiers.

[0021] This invention achieves online composite modification of phase change modified materials and resin melt through online addition and devolatilization methods, preparing a phase change modified resin melt with high uniformity, realizing stable melt spinning production of phase change temperature-regulating fibers with good mechanical properties. It solves the problems of poor slice stability, feeding difficulties, melt inhomogeneity, and poor mechanical properties in the existing technology of preparing melt-spun phase change fibers by phase change modified slices.

[0022] The phase change modified melt preparation process of this invention eliminates the drying process of the phase change components. By using a vacuum pump through a negative pressure port, the volatilized moisture and small volatile molecules in the melt can be removed, reducing energy consumption in the chip drying process and lowering production costs. Compared to solution-based phase change fiber preparation, the melt spinning process for polyester and nylon phase change fibers prepared by this invention offers advantages such as a shorter process flow, no use of organic solvents, and environmental friendliness, further expanding the application of phase change materials in the textile and new materials fields. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the device in this embodiment;

[0024] Figure 2 These are photomicrographs of phase change fibers.

[0025] The markings in the diagram are: 1. Feed inlet; 2. Online addition port; 3. Online devouring port; 4. Shearing conveyor screw; 5. Threaded block; 6. Kneading block; 7. Melt pump booster system; 8. Metering pump; 9. Spinning box; 10. Single screw extruder. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings.

[0027] like Figure 1 As shown, this embodiment discloses a melt spinning device for phase change fibers, including: a multi-frequency high-frequency shear melt extrusion system, a single screw extruder 10, and a spinning box.

[0028] like Figure 1 As shown, the multi-frequency shear melt extrusion system is a three-screw extruder, which includes a melt pipe, a threaded block 5, a kneading block 6, a shearing conveying screw 4, a feed inlet 1, and an online addition port 2. The feed inlet and the online addition port 2 are connected to the melt pipe, and the resin at the online addition port is in a semi-molten state. The multi-frequency shear melt extrusion system also includes a melt pump booster system 7 and a metering pump 8. The multi-frequency shear melt extrusion system has three screws inside, and the feed inlet 1 is located at the end of the multi-frequency shear melt extrusion system. The shape of the feed inlet 1 is a common feed inlet shape, and the feed inlet 1 can add resin material to the melt pipe.

[0029] The online addition port 2 is used to add liquid phase change modification material, and below the online addition port 2, the resin entering from the feed port 1 is just melted into a semi-melted state, which can be mixed with the phase change modification material, and sheared by the kneading block 6 in the melt pipeline, so that the resin material and the phase change modification material are better mixed, and the problems of feeding difficulty, poor blending effect, and uneven melt caused by mixing of the phase change modification material and the solid resin material are avoided.

[0030] The multiple high-frequency shearing melt extrusion system is also provided with a plurality of online devolatilization ports 3, the online devolatilization ports 3 are in communication with the melt pipeline, and at the online devolatilization ports 3, the moisture and small molecule volatiles volatilized from the melt in the melt pipeline can be removed through the online devolatilization ports 3, reducing manual operation. The online devolatilization port 3 is a channel structure, the size of which is appropriately set according to needs, and the material in the melt pipeline is sheared on one hand and mixed on the other hand, and moisture and small molecules are volatilized.

[0031] The melt pipeline is connected with a melt pump pressurization system 7 and a metering pump 8, the melt pump pressurization system 7 can increase the melt, and the metering pump 8 meters the material, which is then conveyed to the spinning beam.

[0032] The single-screw extruder 10 is a common structure, which is provided with a metering pump downstream, and can convey the material to the spinning beam.

[0033] The spinning beam is used to spin the skin-core structure phase change fiber.

[0034] Embodiment 1, a melt spinning online addition devolatilization phase change modification resin melt preparation method

[0035] First step: 5 kg of polyethylene resin chips and 5 kg of polyester chips (polyethylene terephthalate) are weighed respectively, the polyester chips are dried in a vacuum oven, the temperature is set to 120℃, and pre-crystallization is performed for 4 hours, and then the temperature is raised to 180℃ for drying for 24 hours.

[0036] Second step: as Figure 1As shown, polyethylene resin chips are fed into the inlet of the multi-frequency high-frequency shear melt extrusion system via a feeder, and dried polyester chips are added to the single-screw melt extrusion system. The heating temperatures of each zone in the multi-frequency high-frequency shear melt extrusion system are as follows: Zone 2 100℃, Zone 3 110℃, Zone 4 120℃, Zone 5 130℃, Zone 6 160℃, Zone 7 160℃, Zone 8 190℃, Zone 9 190℃, Zone 10 190℃, Zone 11 190℃, Zone 12 190℃, Die head 190℃, Melt pump 210℃, Metering pump 220℃, Pipe A temperature 220℃. The feeding temperatures of each zone of the single screw are set as follows: Zone 1 265℃, Zone 2 285℃, Zone 3 285℃, Zone 4 285℃, Zone 5 285℃, Metering pump 285℃, Pipe B temperature 285℃, Spinning box 285℃. Pipe A is the pipe connecting the multi-frequency shear melt extrusion system and the spinning box, and pipe B is the pipe connecting the single screw extruder and the spinning box.

[0037] Step 3: The phase change microcapsule dispersion is added online into the multi-frequency high-frequency shear melt extrusion system using a liquid metering device. The liquid addition rate is 30 mL / min. According to the weight, 100 parts of polyethylene resin chips require 40 parts of phase change microcapsule dispersion. The multi-screw shear speed is set to 210 r / min, and the negative pressure vacuum port pressure is set to 0.6 MPa.

[0038] Step 4: The phase change modified melt and polyester melt prepared by the above process are transported to the melt pump and metering pump for metering via the material path. The pressure of the melt pump after pressurization is 7.5 MPa. The volume ratio of the two components is set to 1:1. The speed of both metering pumps is set to 15 Hz. After metering by the metering pump, the melt is transported to the spinning box.

[0039] Step 5: Adjust the pressure of the spinning assembly by adjusting the feed rate. Adjust the component pressures of the two components to 6.9 MPa and 7.1 MPa respectively. The melt is extruded into fibers through the core-sheath assembly.

[0040] Step 6: Prepare 10% polyester spinning oil, set the oil pump speed to 10Hz, side blowing temperature to 25℃, wind speed to 0.36m / s, stretch ratio to 3.5 times, hot roller temperature: GR1 to 80℃, GR2 to 110℃, GR3 to 160℃, and winding speed to 2000m / min.

[0041] like Figure 2 As shown, the prepared melt-spun phase change fiber samples were tested. The results showed that the fiber diameter was between 15 and 20 μm, the fiber had an obvious core-sheath structure, the fiber breaking strength was 1.3 cN / dtex, the breaking elongation was 20.6%, the fiber phase change temperature range was 32 to 48℃, and the latent heat value was 22.3 J / g.

[0042] Example 2: A method for preparing a melt-spun phase change modified resin melt with on-line devolatilization and a phase change fiber

[0043] The preparation method is basically the same as that of Example 1, except that the polyester chip is replaced by nylon 6 chip, and a polyamide phase change fiber is prepared, and the proportion of the two components is 4:6 for the phase change core layer:nylon 6 skin layer. The prepared melt-spun phase change fiber sample is tested, and the breaking strength of the fiber is 2.7 cN / dtex, the elongation at break is 30.1%, the phase change temperature range of the fiber is 32-48℃, and the latent heat value is 20.9 J / g.

[0044] Example 3: A method for preparing a melt-spun phase change modified resin melt with on-line devolatilization and a phase change fiber

[0045] The preparation method is basically the same as that of Example 1, except that the polyolefin as the phase change modified substrate is replaced by low-melting-point polyester (PET), and the melting processing temperature of each heating zone is reduced by 10℃. The prepared melt-spun phase change fiber sample is tested, and the breaking strength of the fiber is 3.8 cN / dtex, the elongation at break is 33.2%, the phase change temperature range of the fiber is 32-49℃, and the latent heat value is 21.7 J / g.

Claims

1. A method for preparing melt-spun phase change fibers, characterized by, The steps are as follows: S1, resin A is added to a multiple high-frequency shearing melt extrusion system for melting; S2, when resin A is in a semi-melted state, it is mixed with a phase change modifier, the resin A melt and the phase change modifier are in the melt pipeline of the multiple high-frequency shearing melt extrusion system, form a uniform mixed melt after high-speed shearing, remove the water and small molecule volatiles volatilized from the melt, are pressurized by a melt pump and metered by a metering pump, and are transported to a spinning beam; S3, resin B is transported to the spinning beam by a single screw extruder; S4, resin A and resin B are co-extruded to form a phase change fiber with a skin-core structure, resin A forms a core layer containing a phase change modifier, and resin B forms a skin layer; The multiple high-frequency shearing melt extrusion system comprises a melt pipeline, and the melt pipeline is provided with a threaded block (5), a kneading block (6), a shearing conveying screw (4), a feeding port (1), and an online adding port (2); the feeding port is in communication with the melt pipeline; the online adding port (2) is in communication with the melt pipeline, and the resin at the online adding port is in a semi-melted state; and the multiple high-frequency shearing melt extrusion system is internally provided with three screws. The resin A is a mixture of one or more of polyethylene, low-melting-point polyester, and polybutylene succinate. The phase change modifier is in a liquid state, has a melting point of 30-50℃, and has a molecular weight of 20,000-100,000; and the phase change modifier is selected from phase change microcapsules and polyethylene glycol PEG-2000.

2. The melt spinning phase change fiber production method according to claim 1, wherein, When the phase change fiber with a skin-core structure is extruded, the fiber with an expected fineness is formed under the action of side blowing and cooling, and the melt-spun phase change temperature regulating fiber with a skin-core structure is prepared after oiling, hot drawing, and winding.

3. The method for preparing melt-spun phase change fibers according to claim 2, characterized in that, The resin A and the phase change modifier are sheared by the kneading shearing block and the conveying threaded block in the multiple high-frequency shearing melt extrusion system, and the multiple high-frequency shearing melt extrusion system is a three-screw extruder.

4. A melt spinning apparatus for phase change fibers, characterized by, It comprises: a multiple high-frequency shearing melt extrusion system comprising a melt pipeline, and the melt pipeline is provided with a threaded block (5), a kneading block (6), a shearing conveying screw (4), a feeding port (1), and an online adding port (2); the feeding port is in communication with the melt pipeline; the online adding port (2) is in communication with the melt pipeline, and the resin at the online adding port is in a semi-melted state; the multiple high-frequency shearing melt extrusion system further comprises a melt pump pressurization system (7) and a metering pump (8); a single screw extruder (10); a spinning beam connected with the multiple high-frequency shearing melt extrusion system and the single screw extruder (10).

5. The melt spinning apparatus for phase change fibers of claim 4, wherein, The multiple high-frequency shearing melt extrusion system further comprises an online devolatilization port (3), the online devolatilization port (3) is in communication with the melt pipeline, and the online devolatilization port (3) is used to remove air in the melt in the melt pipeline.

6. A phase change fiber, characterized by, The phase change fiber is prepared by the method in any one of claims 1-3, comprises a skin layer and a core layer, the skin layer wraps the core layer, and the core layer is dispersed with a phase change modifier.

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