Monofilament and preparation method thereof

Abstract

The invention belongs to the technical field of monofilament spinning, and particularly relates to a monofilament and a preparation method thereof. The monofilament is prepared from the following raw materials in percentage by weight: 93.00 wt% to 98.90 wt% of polyphenyl ether sulfur resin, 0.50 wt% to 5.00 wt% of polyester, 0.30 wt% to 1.00 wt% of a nucleating agent and 0.30 wt% to 1.00 wt% of a crystallization accelerant. According to the monofilament provided by the invention, the polyphenylene ether sulfur resin is adopted as a main raw material, the nucleating agent and the crystallization accelerant are added for blending granulation to form a PPS modified polymer, micro-crosslinking is formed through a double-screw hot shearing effect, the melt strength is improved, and the flow stability is improved for single-screw spinning in the next step; meanwhile, the polyester blend is added, so that the fluidity during spinning is remarkably improved, the stability and efficiency of the production process are improved, the adhesion between PPS and a mold is reduced, and the abrasion of equipment is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of monofilament spinning, and in particular relates to a monofilament and a preparation method thereof. Background Art

[0002] PPS material has natural properties such as high rigidity, high creep resistance, good dimensional stability, good insulation, high flame retardancy, corrosion resistance, hydrolysis resistance, UV resistance, and high heat resistance. Therefore, the monofilaments spun from PPS also have similar excellent properties and are widely used in aerospace, electronics, automobiles, military, medical and other fields. However, due to the high viscosity of PPS in the molten state and easy cross-linking at high temperatures, the spinning yarn is extremely difficult to control, and the crystallization rate of PPS raw materials is very fast, which causes micro-area cooling and shaping on the surface of the monofilament at the outlet of the spinneret, resulting in rough surface of the monofilament. And because of the fast crystallization rate, it is difficult to achieve high-multiple stretching of PPS monofilaments. In addition, the domestic PPS raw material synthesis technology is inferior to that of foreign countries, and the melt stability is poor. Based on the coexistence of multiple problems and the high price of raw materials, there is currently no mature technical solution for high-performance PPS monofilaments in China. Only a few domestic companies can achieve mass production of PPS monofilaments, and they cannot meet our production index requirements. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned shortcomings and provide a monofilament and a preparation method thereof.

[0004] In the first aspect, a monofilament adopts the following technical solution:

[0005] A monofilament, wherein the raw materials for spinning the monofilament include 93.00wt% to 98.90wt% of polyphenylene ether sulfide resin, 0.50wt% to 5.00wt% of polyester, 0.30wt% to 1.00wt% of nucleating agent and 0.30wt% to 1.00wt% of crystallization accelerator.

[0006] Furthermore, the polyester includes one or more of polybutylene terephthalate and polyethylene terephthalate.

[0007] Furthermore, the nucleating agent includes calcium stearate, magnesium stearate, sodium benzoate, C 28 ~C 32 One or more of sodium alkyl salts.

[0008] Furthermore, the crystallization accelerator includes one or more of polyethylene wax, ethylene glycol, polyethylene glycol, and glycidyl methacrylate.

[0009] In a second aspect, a method for preparing a monofilament adopts the following technical solution:

[0010] A method for preparing a monofilament comprises the following steps: blending and granulating a polyphenylene ether sulfide resin, a nucleating agent and a crystallization accelerator through a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer; melt-mixing the polyphenylene ether sulfide resin modified polymer and a polyester chip, extruding the polyphenylene ether sulfide resin modified polymer through a screw spinneret, cooling and shaping the polyphenylene ether sulfide resin, and performing traction stretching and hot-air shaping to obtain the monofilament.

[0011] Furthermore, the extrusion temperature is 280° C. to 310° C., the screw aspect ratio is 25:1 to 35:1, the rotation speed is 300 rpm to 350 rpm, and the feeding rate is 30 kg / h to 50 kg / h.

[0012] Further, the extrusion temperature is seven zone temperatures, zone one temperature is 270°C to 290°C, zone two temperature is 275°C to 295°C, zone three temperature is 280°C to 300°C, zone four temperature is 285°C to 305°C, zone five temperature is 290°C to 310°C, zone six temperature is 300°C to 320°C, and zone seven temperature is 300°C to 320°C.

[0013] Furthermore, the traction and stretching process specifically includes a first traction speed of 18m / min to 22m / min, a second traction speed of 55m / min to 65m / min, a third traction speed of 70m / min to 74m / min, and a fourth traction speed of 60m / min to 65m / min.

[0014] Further, the hot air setting process includes a first hot air setting process, a second hot air setting process and a third hot air setting process;

[0015] The first hot air setting has a hot air temperature of 180°C to 220°C and a length of 3.0m to 3.5m;

[0016] The second hot air setting and the third hot air setting have a hot air temperature of 220-260° C. and a length of 6.5 m-7.5 m.

[0017] Beneficial effects of the present invention:

[0018] The present invention provides a monofilament, which adopts polyphenylene ether sulfide resin as the main raw material, adds a nucleating agent and a crystallization accelerator to blend and granulate to form a PPS modified polymer, forms micro-crosslinking through the thermal shearing action of a twin-screw to improve the melt strength, and improves the flow stability for the next single-screw spinning; the nucleating agent can accelerate the crystallization process of PPS, form a uniform microcrystalline structure, avoid the formation of large spherulites, thereby improving the tensile strength and wear resistance of the monofilament; the crystallization accelerator can further improve the dimensional stability of the monofilament, prevent uneven shrinkage and deformation; and improve the stability of the melt during the spinning process; at the same time, the polyester blend is added to significantly improve the fluidity during spinning, improve the stability and efficiency of the production process, and reduce the adhesion of PPS to the mold, thereby reducing equipment wear. DETAILED DESCRIPTION

[0019] The following is a further detailed description of a monofilament and a preparation method thereof described in the present invention in conjunction with an embodiment. For the sake of simplicity of description, this document cannot list all the alternative technical features and implementation schemes included in the present invention. Therefore, those skilled in the art should be aware that any technical features and implementation schemes in this embodiment do not limit the scope of protection of the present invention, which includes any alternative technical features and implementation schemes adopted by all those skilled in the art without creative work. Specifically, the implementation schemes obtained by replacing any technical feature in the present invention or combining any two or more technical features provided by the present invention should be within the scope of protection of the present invention.

[0020] Example

[0021] Example 1

[0022] Example 1 provides a monofilament, the raw materials of which include 93wt% PPS, 5wt% PBT, 1wt% sodium benzoate and 1wt% polyethylene glycol.

[0023] Embodiment 1 also provides a method for preparing a monofilament, comprising the following steps:

[0024] The polyphenylene ether sulfide resin, sodium benzoate and polyethylene glycol are blended and granulated by a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer. The polyphenylene ether sulfide resin modified polymer and PBT are uniformly mixed and melted, and extruded through a screw spinneret. The extrusion temperature is seven zone temperatures, the temperature of zone one is 270°C, the temperature of zone two is 275°C, the temperature of zone three is 280°C, the temperature of zone four is 285°C, the temperature of zone five is 290°C, the temperature of zone six is ​​300°C, the temperature of zone seven is 300°C, the aspect ratio of the screw is 30:1, and the rotation speed is 300rpm, feeding speed is 30kg / h, cooling in a cold water tank at 60℃, shaping in a hot water tank at 94℃, and then traction and stretching, the first traction machine speed is 18m / min, the second traction machine speed is 55m / min, the third traction machine speed is 70m / min, the fourth traction machine speed is 60m / min, hot air shaping, the first hot air box temperature is 200℃, the length is 3.5 meters, the second and third hot air boxes temperature are 240℃, the length is 7 meters, and the monofilament is obtained.

[0025] Example 2

[0026] Example 2 provides a monofilament, the raw materials of which include 98.90wt% PPS, 0.50wt% PBT, 0.30wt% sodium benzoate and 0.30wt% polyethylene glycol.

[0027] Embodiment 2 also provides a method for preparing a monofilament, comprising the following steps:

[0028] The polyphenylene ether sulfide resin, sodium benzoate and polyethylene glycol are blended and granulated by a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer. The polyphenylene ether sulfide resin modified polymer and PBT are uniformly mixed and melted, and extruded through a screw spinneret. The extrusion temperature is seven zone temperatures, the temperature of zone one is 290°C, the temperature of zone two is 295°C, the temperature of zone three is 300°C, the temperature of zone four is 305°C, the temperature of zone five is 310°C, the temperature of zone six is ​​320°C, the temperature of zone seven is 320°C, the aspect ratio of the screw is 35:1, and the rotation speed is 3 50rpm, feeding speed is 50kg / h, cooled in a cold water tank at 60℃, shaped in a hot water tank at 94℃, and then drawn and stretched, the first traction machine speed is 22m / min, the second traction machine speed is 65m / min, the third traction machine speed is 74m / min, the fourth traction machine speed is 65m / min, hot air shaping, the first hot air box temperature is 180℃, the length is 3.0 meters, the second and third hot air boxes temperature are 220℃, the length is 7.5 meters, and the monofilament is obtained.

[0029] Example 3

[0030] Example 3 provides a monofilament, the raw materials of which include 93.50wt% PPS, 5.00wt% PBT, 0.50wt% sodium benzoate and 1.00wt% polyethylene glycol.

[0031] Embodiment 3 also provides a method for preparing a monofilament, comprising the following steps:

[0032] The polyphenylene ether sulfide resin, sodium benzoate and polyethylene glycol are blended and granulated by a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer. The polyphenylene ether sulfide resin modified polymer and PBT are uniformly mixed and melted, and extruded through a screw spinneret. The extrusion temperature is seven zone temperatures, the temperature of zone one is 280°C, the temperature of zone two is 285°C, the temperature of zone three is 290°C, the temperature of zone four is 295°C, the temperature of zone five is 300°C, the temperature of zone six is ​​310°C, the temperature of zone seven is 310°C, the aspect ratio of the screw is 30:1, and the rotation speed is 3 25rpm, feeding speed is 40kg / h, cooled in a cold water tank at 60℃, shaped in a hot water tank at 94℃, and then drawn and stretched, the first traction machine speed is 20m / min, the second traction machine speed is 60m / min, the third traction machine speed is 72m / min, the fourth traction machine speed is 63m / min, hot air shaping, the first hot air box temperature is 200℃, the length is 3.5 meters, the second and third hot air boxes temperature are 240℃, the length is 7.0 meters, and the monofilament is obtained.

[0033] Example 4

[0034] Example 4 provides a monofilament, the raw materials of which include 96.00wt% PPS, 3.00wt% PBT, 0.50wt% magnesium stearate and 0.50wt% polyethylene glycol.

[0035] Embodiment 4 also provides a method for preparing a monofilament, comprising the following steps:

[0036] The polyphenylene ether sulfide resin, magnesium stearate and polyethylene glycol are blended and granulated by a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer. The polyphenylene ether sulfide resin modified polymer and PBT are uniformly mixed and melted, and extruded through a screw spinneret. The extrusion temperature is seven zone temperatures, the temperature of zone one is 280°C, the temperature of zone two is 285°C, the temperature of zone three is 290°C, the temperature of zone four is 295°C, the temperature of zone five is 300°C, the temperature of zone six is ​​310°C, the temperature of zone seven is 310°C, the aspect ratio of the screw is 25:1, and the rotation speed is 3 00rpm, feeding speed is 30kg / h, cooled in a cold water tank at 60℃, shaped in a hot water tank at 94℃, and then drawn and stretched, the first traction machine speed is 18m / min, the second traction machine speed is 55m / min, the third traction machine speed is 70m / min, the fourth traction machine speed is 60m / min, hot air shaping, the first hot air box temperature is 180℃, the length is 3.0 meters, the second and third hot air boxes temperature are 220℃, the length is 6.5 meters, and the monofilament is obtained.

[0037] Example 5

[0038] Example 5 provides a monofilament, the raw materials of which include 94.00wt% PPS, 5.00wt% PBT, 1.00wt% sodium benzoate and 1.00wt% polyethylene glycol.

[0039] Embodiment 5 also provides a method for preparing a monofilament, comprising the following steps:

[0040] The polyphenylene ether sulfide resin, sodium benzoate and polyethylene glycol are blended and granulated by a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer. The polyphenylene ether sulfide resin modified polymer and PBT are uniformly mixed and melted, and extruded through a screw spinneret. The extrusion temperature is seven zone temperatures, the temperature of zone one is 280°C, the temperature of zone two is 285°C, the temperature of zone three is 290°C, the temperature of zone four is 295°C, the temperature of zone five is 300°C, the temperature of zone six is ​​310°C, the temperature of zone seven is 310°C, the aspect ratio of the screw is 30:1, and the rotation speed is 3 50rpm, feeding speed is 45kg / h, cooled in a cold water tank at 60℃, shaped in a hot water tank at 94℃, and then drawn and stretched, the first traction machine speed is 20m / min, the second traction machine speed is 60m / min, the third traction machine speed is 72m / min, the fourth traction machine speed is 65m / min, hot air shaping, the first hot air box temperature is 200℃, the length is 3.5 meters, the second and third hot air boxes temperature are 240℃, the length is 7.0 meters, and the monofilament is obtained.

[0041] Performance Testing

[0042] The following performance index tests were performed on the monofilaments provided in Examples 1 to 5.

[0043] 1. Tensile strength and elongation at break test

[0044] Equipment: Universal material testing machine

[0045] Standard: ASTM D638

[0046] Sample preparation: The monofilament was made into a standard dumbbell-shaped specimen, and the length and thickness were in accordance with the requirements of ASTM D638. The width of the specimen was 13 mm and the thickness was 3.2 mm.

[0047] Test conditions:

[0048] Clamp spacing: 50mm

[0049] Stretching speed: 50mm / min

[0050] Test steps:

[0051] Fix the prepared dumbbell-shaped specimen between the two clamps of the universal materials testing machine, making sure that the specimen is centered.

[0052] Start the testing machine and apply tension to stretch the sample at a constant speed.

[0053] The maximum load when the sample breaks was recorded and the tensile strength (unit: MPa) was calculated.

[0054] At the same time, the displacement before fracture was recorded and the elongation at fracture (%) was calculated.

[0055] 2. Thermal shrinkage test

[0056] Equipment: High temperature oven (temperature control accuracy ±1°C)

[0057] Standard: ASTM D2732

[0058] Sample preparation: Cut out monofilament samples with a length of 100 mm and prepare at least 3 specimens for each group.

[0059] Test conditions:

[0060] The temperature was set at 100°C and 150°C.

[0061] The oven was kept at a constant temperature and the test time was 30 minutes.

[0062] Test steps:

[0063] Measure and record the initial length (L0) of each specimen, ensuring the measurement is accurate to 0.01 mm.

[0064] The sample was placed horizontally in an oven preheated to 100°C for 30 minutes.

[0065] Remove the sample from the oven and allow to cool to room temperature.

[0066] Measure the length (L1) of the sample after cooling.

[0067] The test was repeated, changing the oven temperature to 150°C.

[0068] 3. Melting point test

[0069] Equipment: Differential Scanning Calorimeter

[0070] Standard: ASTM D3418

[0071] Sample preparation: Take 2-5 mg of monofilament sample.

[0072] Test conditions:

[0073] Heating rate: 10℃ / min

[0074] Temperature range: from room temperature to 350°C

[0075] Nitrogen protection environment, flow rate is 50ml / min

[0076] Test steps:

[0077] Place the sample into the DSC sample chamber, ensuring that the sample is evenly distributed and in good contact with the sensor.

[0078] The heating rate was set at 10°C / min, and the temperature was gradually increased from room temperature to 350°C.

[0079] Observe the melting process and record the melting peak that appears on the DSC curve. The melting peak temperature is the melting point of the sample.

[0080] 4. Crystallinity test

[0081] Equipment: Differential Scanning Calorimeter (DSC)

[0082] Standard: Crystallinity was also measured using the DSC method.

[0083] Sample preparation: 2-5 mg monofilament sample

[0084] Test conditions:

[0085] Heating rate: 10℃ / min

[0086] Temperature range: from room temperature to 350°C

[0087] Test steps:

[0088] Place the sample into the DSC sample chamber.

[0089] A temperature rising program was set to heat the sample under a nitrogen atmosphere and the melting enthalpy of the sample was recorded.

[0090] The crystallinity of the samples was calculated by the melting enthalpy (ΔH_m) in the DSC curve.

[0091] The monofilament test data provided in Examples 1 to 5 are shown in Table 1 below.

[0092] Table 1

[0093] index Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength(MPa) 90.5 88.2 92.1 89.0 91.7 Elongation at break (%) 20.4 18.7 21.2 19.5 20.8 Thermal shrinkage (%) 1.5 1.6 1.4 1.7 1.5 Melting point(℃) 280.5 279.8 280.7 280.0 280.6 Crystallinity(%) 40.8 39.2 41.5 39.8 41.0

[0094] Wire diameter and tolerance characterization

[0095] The wire diameter and tolerance of the monofilaments provided in Examples 1 to 5 were measured by laser diameter measurement, as follows:

[0096] Laser Measurement Method

[0097] Laser diameter measurement is a commonly used and accurate non-contact measurement method, especially suitable for continuous online detection of single wires or thin wires in high-speed production lines. This method calculates the wire diameter by scanning the sample with a laser beam and measuring the change in reflected light. It can measure the wire diameter and characterize the tolerance in real time and accurately.

[0098] principle

[0099] The laser diameter measurement method uses a laser beam to irradiate the single wire vertically. The reflection and refraction characteristics of the laser are captured by a photoelectric sensor and converted into an electrical signal. After the electrical signal is processed, the wire diameter of the sample is obtained, and the tolerance of the wire diameter is evaluated by calculating the change in the reflected light. The advantage of this method is its non-contact measurement characteristics, which can avoid deformation or errors caused by contact with the sample.

[0100] Equipment and Materials

[0101] Equipment: Laser diameter measuring instrument (such as Keyence's LS-9000 series laser measurement system)

[0102] Sample: The single yarn to be tested, the sample length must be at least 50mm and the diameter must be within the measuring range of the instrument.

[0103] Photoelectric sensor: used to capture reflected laser light and generate corresponding electrical signals.

[0104] Measurement steps

[0105] Equipment preparation:

[0106] Start the laser measurement system and make sure the instrument is calibrated. When calibrating, you can use a standard monofilament of known diameter as a reference to ensure the accuracy of the measurement.

[0107] Set appropriate measurement conditions such as measurement accuracy, scanning frequency, and sensitivity.

[0108] Sample placement:

[0109] Place the monofilament sample in the measurement area of ​​the laser measurement system. The laser beam should be perpendicular to the monofilament to ensure that the laser can evenly irradiate the sample surface.

[0110] If it is an application in a continuous production line, the single wire will be continuously fed into the laser measuring instrument.

[0111] Measurement operation:

[0112] When the laser measurement system is activated, the laser beam will scan the filament. The instrument's sensor will capture the changes in the laser beam after it reflects off the sample surface.

[0113] The system calculates the reflection changes in real time and generates wire diameter data.

[0114] Data recording and calculation:

[0115] The measuring system will automatically record the wire diameter data and calculate the average diameter of the single wire.

[0116] While completing the wire diameter measurement, the instrument will automatically calculate the wire diameter tolerance range (for example, ±0.01mm) and display its deviation data.

[0117] Data from multiple measurement points are often averaged to reduce errors and improve measurement accuracy.

[0118] Data output and analysis:

[0119] The measurement results will be displayed on a digital display or computer interface. The data includes the actual value of the wire diameter, tolerance range (maximum / minimum value), and standard deviation.

[0120] Data files can also be exported for subsequent analysis and recording.

[0121] Characterization methods:

[0122] Average wire diameter: The average wire diameter of a single wire is calculated through multi-point measurement.

[0123] Tolerance range: Tolerance is expressed by setting the maximum allowed deviation range (e.g. ±0.01mm), which can be calculated by comparing the difference between the measured value and the standard value.

[0124] Standard Deviation: Standard deviation is used to characterize the uniformity of wire diameter. The standard deviation value is obtained by calculating the deviation of wire diameter values ​​at multiple measurement points. The smaller the standard deviation, the more stable the production process and the more consistent the quality of the monofilament.

[0125] The wire diameters and tolerances of the monofilaments provided in Examples 1 to 5 are shown in Table 2 below.

[0126] Table 2

[0127]

[0128]

[0129] For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived from them are still within the scope of protection of the claims of the invention.

Claims

1. A monofilament, characterized in that: The raw materials for spinning the monofilament include 93.00 wt% to 98.90 wt% of polyphenylene ether sulfide resin, 0.50 wt% to 5.00 wt% of polyester, 0.30 wt% to 1.00 wt% of nucleating agent and 0.30 wt% to 1.00 wt% of crystallization accelerator.

2. A monofilament according to claim 1, characterized in that: The polyester includes one or more of polybutylene terephthalate and polyethylene terephthalate.

3. A monofilament according to claim 1, characterized in that: The nucleating agent includes calcium stearate, magnesium stearate, sodium benzoate, C 28 ~C 32 One or more of sodium alkyl salts.

4. A monofilament according to claim 1, characterized in that: The crystallization accelerator includes one or more of polyethylene wax, ethylene glycol, polyethylene glycol, and glycidyl methacrylate.

5. A method for preparing a monofilament, characterized in that: The following steps are involved: The polyphenylene ether sulfide resin, a nucleating agent and a crystallization accelerator are blended and granulated by a twin-screw extruder to obtain a polyphenylene ether sulfide resin modified polymer; the polyphenylene ether sulfide resin modified polymer is melt-mixed with polyester chips, extruded through a screw spinneret, shaped after cooling, and subjected to traction stretching and hot-air shaping to obtain the monofilament.

6. A method for preparing a monofilament according to claim 5, characterized in that: The extrusion temperature is 280°C to 310°C, the screw aspect ratio is 25:1 to 35:1, the rotation speed is 300rpm to 350rpm, and the feeding speed is 30kg / h to 50kg / h.

7. The method for preparing a monofilament according to claim 5, characterized in that: The extrusion temperature is seven zone temperatures, zone one temperature is 270°C to 290°C, zone two temperature is 275°C to 295°C, zone three temperature is 280°C to 300°C, zone four temperature is 285°C to 305°C, zone five temperature is 290°C to 310°C, zone six temperature is 300°C to 320°C, and zone seven temperature is 300°C to 320°C.

8. The method for preparing a monofilament according to claim 5, characterized in that: The traction and stretching process specifically includes a first traction speed of 18m / min to 22m / min, a second traction speed of 55m / min to 65m / min, a third traction speed of 70m / min to 74m / min, and a fourth traction speed of 60m / min to 65m / min.

9. The method for preparing a monofilament according to claim 5, characterized in that: The hot air setting process includes a first hot air setting process, a second hot air setting process and a third hot air setting process; The first hot air setting has a hot air temperature of 180°C to 220°C and a length of 3.0m to 3.5m; The second hot air setting and the third hot air setting have a hot air temperature of 220-260° C. and a length of 6.5 m-7.5 m.

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