Research on Far-infrared Denier Polypropylene High-speed Spinning and Deformation Technology

In recent years, far-infrared fibers and their fabrics have become popular in the domestic market. Various scientific researches have rushed to research and develop far-infrared fibers and fabrics. This is mainly related to the special health care functions of far-infrared textiles, but far-infrared polypropylene, The study of spinning and post-processing of fine-strand far-infrared polypropylene filaments with high-speed spinning far-infrared polypropylene filaments, especially single-filament linear filaments with a density of 1 dtex, has not been reported yet. To fill this gap National Engineering Research Center for Synthetic Fibres conducted research on this project in 1999. In 2000, the project passed the appraisal of new products in Shanghai. Currently, it has the capability of mass production. Functional textiles made of 82/72fDTY are put on the market. Afterwards, it was welcomed by a large number of users. The study selected high-efficiency far infrared masterbatch and temperature-reducing masterbatch. Using the whole granulation method, far-infrared PP was first prepared, and then the spinning process and deformation process were mainly discussed. 1 Experiment 1.1 Raw materials Propylene Y2600, Plastics Division of Shanghai Petrochemical Co., Ltd.; Far-infrared masterbatch 1; Masterbatch A; Oil agent, Henkel, Germany A-2 type of special polypropylene spinning oil 1.2 pelletizing equipment and process GH-10 high-speed mixer, Beijing Plastic Machinery Plant; SH-35 type twin-screw kneading extruder, Shanghai Chemical Machinery four plants.

Granulation temperature 190 ~ 210C, the process flow is as follows: Polypropylene far-infrared masterbatch (20%)> Mixer> Twin-screw extruder cooling masterbatch (3%)? Order is a> granulator -> dry one> Far Infrared PP 13 Spinning Deformation Equipment Filament, SW46 SSD Winder; Spinneret: 0.72f, Spinning Speed ​​FK6V-900MF216 Ingot Texturing Machine 14 Testing Crystallinity Japan Science 3134 X-ray Diffraction Apparatus, Cu Target , Working voltage 35kV, Propagation speed Cs in 20, Acoustic velocity orientation factor of the sample is obtained by the formula fs=1-(G/Cs)2, Cu is taken 1.45km/s Birefringence Japan Nikon Polarized light microscope Density Germany Textechno Fiber Test CYC Extensibility Germany's Textechno Corp. Statimat's Full-Automated Extensometer Tester Twisted Germany's Textechno's Fully Automated Condenser 2 Results and Discussion 2.1 Effect of spinning temperature on fiber structure performance Known from the fact that the addition of cooling master batch far-infrared PP Although the viscous flow activation energy is slightly lower, it is still higher, and the viscous flow activation energy is one of the signs that the viscosity of the spinning melt is sensitive to temperature. The higher the viscous flow activation energy is, the narrower the control range of the spinning temperature is. , especially spinning fine denier polypropylene, even tiny temperature waves It is also likely to affect the performance and stability of spinning fibers, so far infrared PP during high speed spinning, the spinning temperature should be strictly controlled.

The physical properties of far-infrared polypropylene were spun at 500m/min. From Table 1, it can be seen that with the addition of spinning temperature, the far-infrared PP-POY strength decreases, the elongation increases, the unevenness of the stem first decreases, then rises, and the birefringence value also decreases slightly. The spinning principle is basically the same. Because 250C is close to the boiling point temperature of the biphenyl diphenyl ether, the stability of the temperature control system is poor, the phenomenon of floating monofilament during spinning is more, and the spinnability is poor. The temperature above 265C is prone to thermal degradation, resulting in a decrease in strength, and the floating monofilament phenomenon is also gradually increased with the increase of the spinning temperature, so the general spinning temperature is controlled at about 258C. Table 1 Spinning temperature POY can be Spinning. Structural properties affect the dry U value, 厶nX spinnability difference is better poor worse poor 2.2 spinning speed on the structure of far infrared fiber performance Table 2 lists the spinning temperature spinning at 258C far infrared polypropylene spinning The impact of speed on its structural performance data.

Table 2 Effect of spinning speed on fiber structure performance V/linear density/large stretch of nozzle, large axial velocity gradient on spinning, increased spinning tension, resulting in increased fiber orientation, and orientation induced further crystallization, resulting in mechanical properties The spinning speed increases and monotonously transfers (within the test speed range), which is consistent with the principle of conventional melt spinning. Polypropylene has a variety of crystal forms such as a, YS, and quasi-hexagonal. , often with the processing conditions change to get different crystal structure, different spinning speed far-infrared POY X-ray diffraction pattern seen from Table 2 can be seen, with the increase in spinning speed, far-infrared fiber strength elongation Drop, crystallinity increase, birefringence plus orientation increase. This is due to the fact that with spinning speed, as the spinning speed increases, the crystal shape of the fiber gradually changes as the crystallinity increases. The content of the quasi-hexagonal crystal form gradually decreases, and the content of a crystalline form gradually increases. At a spinning speed of 2700 m/min, the crystal form has completely changed into the T crystal form. Although the spinning speed is high at 2700 m/min, the spinning tension is large, and the cake unwinding is difficult. Further post-processing studies show that: a crystal form is relatively stable, which is not conducive to post-processing, and the resulting final product The mechanical properties are poor. The quasi-hexagonal crystal form is a relatively complex and incomplete crystal form, easy to process, and gradually transformed into a more stable a crystal form during processing. See the guarantee that the far-infrared PP-POY crystal form is a quasi-hexagonal crystal form ( Mainly, it is recommended that the spinning speed should not exceed 2500m/min. 2.3 Effect of cooling forming conditions on the fiber structure performance When the polypropylene is spun at high speed, even if the temperature reducing masterbatch is added, the spinning temperature is still higher than the melting point of 90C or even 10C. Above, in the cooling forming stage, more heat is released than polyester. If it is difficult to smoothly cool and form under the cooling conditions of polyester spinning, the length of the spun channel during the molding of polypropylene is generally larger than that of polyester but due to the use of spinning Silk device is mainly for polyester varieties, it is difficult to meet the need for high-speed polypropylene fiber spinning from the length of the spinneret. Practice has proved that it is feasible to adopt appropriate methods to reduce the side blowing temperature. The results of the tests are shown in Table 3 and Table 3: Effect of blowing temperature on the structural properties of the fiber. 4 Effect of bundled oil placement on fiber structure performance Far-infrared PP spinning at high speed At the same time, because the spinning tension is higher than polyester, and the excessive spinning tension is not conducive to the roll forming of the fiber, the yarn is generally bundled and oiled in advance to reduce the spinning tension, which is favorable for the winding of the fiber. , improve the quality of the cake, but the bundle location should not be too high, otherwise the fiber coagulation is not enough, easy to produce silk, wool and other undesirable phenomena, resulting in dry fiber rose. See Table 5 for the research results of spinning at different oiling positions. Table 5 Effect of bundled oiling position on fiber structure properties Stripe U value,% bundled oiling position/mm dry U value, spinning tension/Note: bundled The oiling position refers to the distance of the cluster point from the spinneret.

It is known from Table 3 that as the side blowing temperature is increased from 15C to 21C, the far-infrared pY elongation increases and the birefringence decreases, which is related to the lowering of the fiber freezing point and the decrease of the spinning tension. If the side blowing temperature is lower than 15C, the fiber If the cooling rate is too fast, the tensile stress of the nozzle will be high, and the filaments will be prone to have high filaments. On the contrary, if the temperature is higher than 21C, the cooling effect of the fibers will be poor, and the filaments may become even higher, which will also cause the stems to rise. Generally, the side blowing temperature is about 18C. From the perspective of cooling effect, lowering the side blowing temperature is more effective than the larger one, but the side blowing speed is too large not only to affect the fiber properties but also the spinning stability. The stems are also easy to cause the floating monofilament phenomenon under the premise of selecting the side blowing temperature. In the experiment, the influence of the wind speed on the structural performance of the fiber structure was studied. The results are shown in Table 4 and Table 4: The effect of wind speed on the fiber structure performance. Dry U, from Table 4, we can see that the side blowing speed is too high or too low, all result in high fiber dry value, the side blowing speed is about 0.4m/s, and the far-infrared PP-POY has the lowest dry value, therefore, It is advisable to use Q 4m/s as the side blowing speed From Table 5, it can be seen that as the bundle oiling position moves down, the fiber strength slightly increases, the elongation decreases, the spinning tension gradually increases, and the dry value is the smallest at 920 mm. Considering the above factors, the bundle is When the oil position is about 920mm away from the spinneret, the most éš¹25 stretched false-twisting deformation process has two factors: temperature, D/Y ratio, draw ratio, and processing speed. Far-infrared polypropylene fine denier filaments have small denier per filament, and even small structural defects can easily be enlarged and deteriorated during deformation processing. In addition, the far-infrared PP-POY has higher strips than polyester, and the breakage rate caused by shotcreting is low. With less wool, you must choose a relatively low processing speed. In addition, because far-infrared fine-denier polypropylene has low bending strength, it can only be fully deformed under low tension. Therefore, the stretching ratio should not be chosen too large. In a word, a reasonable deformation process should ensure that the resulting DTY is substantially free from naps and filaments. , tight point of silk, and head, rewind easily, the production process is stable, low breakage rate.

Based on the above considerations, the far-infrared POY tensile false twisting process was determined. See Table 6. The quality indexes of the obtained DTY are shown in Table 7. The far-infrared DTY developed by the weaving unit test has good weaving performance and is fully consistent with the requirements. Post processing requirements Table 6 Far-infrared PP-POY main deformation process conditions Fiber specifications Tensile ratio False tension deformation speed / Table 7 Far-infrared PP-DTY Fiber quality index Tah7ThequalityindexofFIPP-DTY Fiber specifications Line density / linear density e / intensity is not Uniform X, % elongation uneven KE,%KB,% (dtex 3 Conclusion High-speed spinning process to develop far-infrared denier polypropylene, the spinning temperature range is narrow, the temperature control needs to be more stringent, the spinning temperature should be controlled About 258C, the crystal structure should be mainly quasi-hexagonal. It is recommended that the spinning speed should not exceed 2. The far-infrared polypropylene should be developed on the non-polypropylene special spinning equipment. The temperature of the side blowing should be reduced accordingly. It is suitable for the research system. Cooling conditions: side blowing temperature 18C, speed 0. 4m / s or so appropriate to increase the location of the bundling oil is conducive to reduce the spinning tension, improve the quality of the package, the best bundle oiling position is 920mm left from the spinneret e system of the present study, the deformation process is preferred: The first

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