Patent Application
20200086779
The present invention relates to a polyethylene terephthalate bulked continuous filament suitable for use in automobiles and a tufted carpet including the same.
Generally, nylon 6, nylon 66, polypropylene, polyethylene terephthalate, and the like are used as a synthetic fiber material of a bulk continuous filament (BCF) as a material for a tufted carpet. Among them, nylon is the most suitable material for carpet, but it has a disadvantage of high price, so low-priced polypropylene is used as a substitute.
However, since polypropylene is not suitable for use in automobile carpets that are molded at high temperatures due to its low heat resistance, non-woven type needle punches of low quality but inexpensive prices are often used. However, since the needle punch nonwoven fabric has a disadvantage in that the quality of the appearance is lower than that of the tufted carpet and the abrasion resistance is poor, development of a tufted carpet material of a low price is demanded.
In recent years, in order to solve the above problems, attempts have been made to use BCF as a carpet for automobiles, the BCF made by using a polyethylene terephthalate material having excellent characteristics in comparison with other materials in terms of economy and having a high heat resistance, but polyethylene terephthalate has a high weight relative to nylon, so it has a disadvantage in terms of price because it has to increase the weight of yarn planted per unit area in order to produce the same appearance. In addition, since the bulk stability of the yarn is lower than that of nylon, there is a problem that the yarn is pressed after molding, and the feeling of volume is lowered.
An object of the present invention is to provide a polyethylene terephthalate bulked continuous filament which has an improved crimp ratio and is suitable for use as an automobile carpet, and a method for producing the same.
Another object of the present invention is to provide a tufted carpet including the polyethylene terephthalate bulked continuous filament, which is improved in the sense of volume of the outer appearance and in the quality of abrasion resistance.
According to an aspect of the present invention, there is provided a tufted carpet for automobiles including: a pile layer including polyethylene terephthalate (PET) bulked continuous filament (BCF); and at least one backing layer, in which the bulked continuous filament has a crimp ratio of 14% or more and a cross-sectional modification ratio of 1.9 to 3.4.
Herein, the diameter of the bulked continuous filament may be 6 to 20 dpf, and the bulked continuous filament may have a fineness of 700 to 1500 denier.
Further, wherein the pile layer may weigh 180 gsm to 700 gsm.
Further, a wear resistance level according to MS343-15 standard may be grade 3 or more.
In the method of manufacturing a polyethylene terephthalate bulked continuous filament according to an example of the present invention, the filament is passed through a texturing nozzle to quench the filament, thereby lowering the heat shrinkage of the filament, thereby improving the crimp ratio, compared to the conventional level.
Further, by adjusting the cross-sectional profile of the filament to a specific range, the sense of volume of the filament can be increased, and the tufted carpet to which such a filament is applied can also improve the sense of volume and the quality of wear resistance of the appearance.
The present invention is capable of various modifications and various forms, and specific examples are described in detail in the following description. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
In this application, the terms “include” or “having”, etc., are used to specify that there is a feature, figure, step, operation, element, part or combination thereof which is stated in the specification, and that it should not be construed to preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, when a part such as a layer, film, region, plate, or the like is referred to as being “on” another part, this includes not only the case where it is “directly over” another part, but also a case where there is another part therebetween. On the contrary, when a part such as a layer, film, region, plate or the like is referred to as being “under” another part, it includes not only the case where it is “directly under” another part, but also the case where there is another part in the middle.
Hereinafter, examples of the present invention will be described in detail.
Hereinafter, a method for producing a polyethylene terephthalate bulked continuous filament according to an example of the present invention will be described with reference to the drawings.
A method of producing polyethylene terephthalate bulked continuous filaments according to an example may include melt spinning a polyethylene terephthalate chip.
The polyethylene terephthalate chip is preferably prepared by liquid phase polymerization or solid phase polymerization. At this time, it is preferable to use a batch or continuous polymerization method for the solid phase polymerization, but the present invention is not limited to this example. More specifically, the solid phase polymerization is carried out under vacuum conditions at 110 to 170° C. for 4 to 6 hours to remove moisture, and the temperature is raised from 235 to 255° C. for 4 to 6 hours, and the solid phase polymerization time is preferably 20 to 30 hours.
As described above, the liquid phase polymerization or solid phase polymerized polyethylene terephthalate chips are melt-spun at 245-335° C. and passed through a spinneret 1.
The polyethylene terephthalate resin that is the basis of the present invention preferably contains at least 90 mol % of repeating units of ethylene terephthalate.
Alternatively, the polyethylene terephthalate may include a small amount of units derived from ethylene glycol and terephthalenedicarboxylic acid or derivatives thereof and one or more ester-forming components as copolymer units. Examples of other ester forming components copolymerizable with the polyethylene terephthalate unit include glycols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and the like, and dicarboxylic acid such as terephthalic acid, isophthalic acid, hexahydroterephthalic acid, stilbene dicarboxylic acid, bibenzoic acid, adipic acid, sebacic acid, and azelaic acid.
The fineness of the polyethylene terephthalate yarn thus produced is preferably 700 to 1500 denier and more preferably 850 to 1350 denier. The diameter of the polyethylene terephthalate yarn is preferably 6 to 20 dpf, more preferably 10 to 15 dpf.
When the fineness of the yarn is less than 700 denier and the diameter is less than 6 dpf, the uprightness of the fabric pile is lowered when the carpet is formed, resulting in poor abrasion resistance, molding restorability and appearance, and when the fineness exceeds 1500 denier or the diameter exceeds 20 dpf, the density of the carpet fabric is lowered, resulting in poor abrasion resistance and restoring force.
Thereafter, the step of cooling the spun polyethylene terephthalate yarn may be performed. At this time, the cooling step may be a step of cooling the yarn at the cooling zone 3 with air at a speed of 0.2 to 1.0 m/sec. The cooling temperature is preferably adjusted to 10 to 30° C., and if the cooling temperature is less than 10° C., it is disadvantageous from the economical point of view. If the cooling air speed is less than 0.2 m/sec, the cooling effect is insufficient. If the cooling air speed is more than 1.0 m/sec, the shaking of the yarn is excessive, which will cause a problem in the spinning workability, and thus it is preferable that the speed of the cooling air is 0.2 to 1.0 m/sec.
After the cooling, a spin finish step of performing oiling is carried out. In a finishing applicator 4, oil is firstly and secondarily lubricated by using a neat type emulsion or a water-soluble emulsion, thereby increasing rolling speed, lubricity and smoothness of the yarn.
Thereafter, the filament is fed to a stretching roller 6 at a speed of 300 to 1,200 m/min, preferably 500 to 800 m/min, on the feed roller 5. At this time, the stretching roller 6 is stretched at a speed of 2.0 to 5.0 times the feed roller 5 speed, preferably 2.5 to 4.5 times. If the stretching speed is less than 2.0 times, the stretching cannot be performed sufficiently. If the stretching speed is more than 5.0 times, the polyethylene terephthalate may not be stretched due to the nature of the material.
The filament that has passed through the stretching roller 6 passes through a texturing unit 7 having a texturing nozzle for imparting a bulking property. At this time, a heating fluid of 150 to 270° C. is sprayed in the texturing unit 7 with a pressure of 3 to 10 kg/cm2 to thereby cause the filament to crimp irregularly in three dimensions.
In this case, the temperature of the heating fluid is preferably 150 to 250° C., and when the temperature is lower than 150° C., the texturing effect is lowered. If the temperature exceeds 250° C., the filament is damaged. In addition, the pressure of the heating fluid is preferably 3 to 10 kg/cm2, and if less than 3 kg/cm2, the texturing effect is lowered, and if it exceeds 10 kg/cm2, the filament is damaged.
On the other hand, the crimp ratio is preferably 14% or more, and more preferably 16% or more. Polyethylene terephthalate has a high specific gravity, which causes a problem that the weight of yarn becomes higher than that of nylon which is generally used as a material of BCF per unit area of carpet. In order to solve this problem, the present invention increases the crimp ratio of the polyethylene terephthalate BCF yarn from the existing 10% level to 14% or more, more preferably 16% or more, thereby improving the sense of volume. In addition, when the crimp ratio of the BCF yarn is increased, the bulkiness of the yarn itself is increased, so that the yarn can have a rich appearance and sense of volume even with a small yarn weight.
However, polyethylene terephthalate has a problem that it is difficult to increase the crimp ratio because the polymer is hard compared to nylon.
As described above, the yarn, which has passed through the stretching roller 6 having a high speed, is wound on the final winder via a texturing nozzle which gives a crimp through a relax roller 9 to be described later. At this time, the difference between the speed V1 of the stretching roller and the speed V2 of the relax roller is referred to as an over feed rate. This rate of overfeed is the source of the crimp and can be expressed as:
Over Feed rate (%)=(V1−V2)/V1*100=Heat shrinkage rate+crimp ratio [Formula]
As described above, the yarn supplied from the stretching roller to the texturing nozzle is softened and compressed by the high-temperature, high-pressure air to have a sinuous crimp shape at the outlet of the texturing nozzle. Therefore, in order to increase the crimp ratio, the temperature and pressure of the air must be high, and in particular, polyethylene terephthalate has a higher melting point (Tm) than nylon, and thus a higher temperature is required. If the over feed rate is increased, it is possible to increase the crimp ratio. However, if the over feed rate is increased, the truncation occurs and the workability becomes poor. Therefore, it is not preferable to increase the over feed rate to increase the crimp ratio. In order to increase the crimp ratio at the same level over feed rate, the heat shrinkage should be lowered. Since the yarn whose temperature has been raised by passing through the texturing unit continually shrinks until being sufficiently cooled, cooling should be performed as fast as possible in order to lower the heat shrinkage.
Therefore, the present invention is characterized in that the thermal shrinkage of the yarn is lowered to increase the crimp ratio by quenching by cooling water or cooling air at the outlet of the texturing nozzle or by sucking air through the cooling drum located at the lower end of the texturing nozzle.
More specifically, the filament that has passed through the texturing unit 7 is cooled through the cooling section. The cooling section may be a section where the filament passing through the texturing unit is quenched with cooling water or cooling air. At this time, the temperature of the cooling water and the cooling air is preferably 5 to 10° C. and the pressure is preferably 3 to 10 kgf, and the desired quenching effect can be obtained within the above range, thereby lowering the heat shrinkage rate of the yarn, thereby increasing the crimp ratio to 14% or more.
Meanwhile, the cooling section may be a cooling drum 8 disposed at the lower end of the texturing nozzle, and may be a section for sucking air to quench the air. At this time, it is preferable that the cooling drum 8 is arranged to be separated from the texturing nozzle by less than 1 cm. In this case, the desired quenching effect can be obtained, thereby lowering the heat shrinkage rate of the yarn and increasing the crimp ratio to 14% or more.
The cooled raw yarn is passed through the relax roller 9 at a speed of 0.65 to 0.95 times the drawing roller speed to give an over feed rate of 5 to 35%. At this time, if the speed of the relax roller is less than 0.65 times the speed of the stretching roller, the paper is not wound. If the speed exceeds 0.95 times, the bulkiness is reduced, the shrinkage of the yarn is significantly increased, and high tension is caused, thereby interfering with the job. The yarn passed through the relax roller 9 passes through a collator 10. In this part, a slight twist and a knot are given at a pressure of 2.0 to 8.0 kg/m2 in order to improve the rolling speed of the yarn, and it is given in the range of 0 to 40 times/m, preferably 10 to 25 times/m. In case of exceeding 40 times of being interlaced, even after dyeing and post-processing, the interlaced state is maintained and the appearance of the carpet is damaged. The yarn passed through the collator 10 is wound in the final winder 11.
The speed of the winder is preferably adjusted so that the tension of the yarn usually ranges from 50 to 350 g. At this time, if the tension is less than 50 g in the winder, the winding is impossible, and if it exceeds 350 g, the bulkiness is decreased and the contraction of the yarn is largely caused and the high tension is generated.
On the other hand, in order to improve the carpet covering property by using a yarn with a small weight, the cross section of the yarn is made into a trilobate shape (Y-shaped cross section), and this cross section shape is also important. The index that evaluates the cross-sectional shape is the modification ratio, the ratio of the circumscribed circle (Y2) to the inscribed circle (Y2), that is, Y2/Y1. If the modification ratio is too high, the abrasion resistance will be disadvantageous. On the contrary, if the modification ratio is low, the volume feeling of the yarn will be low. Therefore, a proper degree of the modification ratio should be set. The modification ratio of the cross section is preferably between 1.9 to 3.4.
The above method relates to a BCF produced only from a polyethylene terephthalate resin, and the stepwise process is the same as that described above in the case of producing a dope-dyed yarn according to the carpet use. However, it is also possible to manufacture a dope-dyed yarn by feeding a certain amount of coloring agents into the base chip input amount in the supply of the raw material and spinning it.
As described above, the polyethylene terephthalate multifilament prepared according to the present invention is manufactured as a carpet for automobiles through a post-process. Carpets made from the BCF yarns of the present invention can be prepared in any manner known to those skilled in the art.
Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.
A slurry prepared by mixing 50 parts by weight of ethylene glycol with 100 parts by weight of terephthalic acid was added into an esterification reactor and pressurized at 250° C. for 4 hours under a pressure of 0.5 torr to allow water to flow out of the reactor and allow the esterification reaction to be performed, to thereby prepare (2-hydroxyethyl) terephthalate. At this time, 300 ppm of a phosphorus heat stabilizer was added at the end of the esterification reaction. After the esterification reaction, 300 ppm of the antimony catalyst was added as an polymerization catalyst at the beginning of the polycondensation reaction, the temperature was raised from 250° C. to 285° C. at 60° C./hr, and the pressure was reduced to 0.5 torr. Solid phase polymerization is carried out to increase the viscosity of the liquid polymer. During the process of solid phase polymerization in general, the batch solid phase polymerizer is used to dry for 4 hours at 140° C. under vacuum condition. The temperature is raised from 235° C. to 245° C. for 4 hours to 6 hours until reaching the final target viscosity.
The polyethylene terephthalate polymer produced through the spinneret having 128 holes and a Y-shaped cross-section is melt-spun at 290° C. The polymer exiting the spinneret is cooled by cooling air at 20° C. at the bottom of the nozzle at 0.5 m/s, and then passes through the emulsion feeder. The yarn to which the emulsion has been applied passes through a feed roller maintained at a temperature of 90° C. at a speed of 598 m/min and then stretched at a rate of 2,840 m/min at 190° C. on the stretching roller. The yarn passed through the stretching roller passes the texturing nozzle and is given a crimp. At this time, the hot air temperature is 200° C., the pressure is 7 kg/cm2, and the back pressure is 5 kg/cm2. Thereafter, the yarn was rapidly cooled with cooling air at the outlet of the texturing nozzle at the temperature and pressure shown in the following Table 1, and relaxed by about 21% after passing the relax roller at 2250 m/min. After being interlaced at a pressure of 4.0 kg/m2, it is wound in a winding machine.
Polyethylene terephthalate BCF yarn was prepared through the same procedure as in Example 1, except that the yarn was rapidly cooled with cooling air or cooling water at the temperature and pressure shown in Table 1 at the outlet of the texturing nozzle.
Except that instead of cooling the yarn with cooling air at the outlet of the texturing nozzle, air was sucked through a cooling drum disposed within 1 cm immediately below the texturing nozzle to quench the air, polyethylene terephthalate BCF yarn was prepared through the same process as in Example 1.
Polyethylene terephthalate BCF yarn was produced in the same manner as in Example 1, except that the yarn was cooled with cooling air at the temperature and pressure shown in Table 1 at the outlet of the texturing nozzle.
A nylon BCF yarn was produced in the same manner as in Example 1 except that nylon was used in place of the polyethylene terephthalate polymer and the yarn was cooled with cooling air at the outlet of the texturing nozzle at the temperature and pressure shown in Table 1 below.
The crimp ratios of the polyethylene terephthalate and nylon BCF prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were measured by the following methods, and the results are shown in Table 1 below.
A skein was made by winding the yarn once around a reel of 1 m in circumference.
Next, the yarn is dipped in a boiling water at 100° C. for 5 minutes, then the yarn is conditioned for 20 minutes after taking the yarn out from the oven. After that, the length L0 was measured 60 seconds after hanging the weight of the additional load (Denier*0.1 g), then the weight of the old load (Denier*0.01 g) was hung after the additional load was removed, and the length L1 was measured after 60 seconds, then the crimp ratio (%) was calculated by the following formula.
Crimp Ratio (%)={(L0−L1)/L0}×100
Referring to Table 1, it can be seen that the polyethylene terephthalate BCF produced according to the example is manufactured by cooling the yarn having a higher temperature by passing through the texturing unit as quickly as possible, thereby lowering the heat shrinkage rate of the yarn and improving the crimp ratio. Further, as the crimp ratio is improved, the bulkiness of the yarn itself is increased, so that the yarn can have a rich feeling of appearance and a volume feeling even with a small yarn weight.
On the other hand, in the case of the BCF produced according to the comparative example, the yarn passed through the texturing unit was not rapidly cooled, and the shrinkage progressed continuously until the temperature became high enough to cool, and the crimp ratio decreased as the heat shrinkage ratio increased.
A polyethylene terephthalate BCF yarn was obtained through the same procedure as in Example 1 except that the modification ratio of the yarn (the ratio of the circumscribed circle (Y2) to the inscribed circle (Y2)=Y2/Y1) is adjusted, respectively, as in Table 2, to thereby prepare a tufted carpet. The abrasion resistance of each prepared tufted carpet was measured as follows, and the results are shown in Table 2 below.
Related test method Specification: ASTM D3884
Test method: Hyundai Motor MS300-35
Test equipment: Taber abrasion tester
Sample size: 130 mm diameter circular sample
Exam conditions
1) Wear wheel: H-18
2) Rotation speed: 70 times/minute
3) Load: 1000 g
4) Number of revolutions: 1000
5) Evaluation method: Appearance evaluation 1st to 5th grade (Passed grade 3 or higher (3, 4, 5 grade) of MS343-15 of Hyundai Motor Company)
6) Evaluation criteria: At grade 5, no abrasion is observed, at grade 4, abrasion is slightly visible or almost inconspicuous, at grade 3, abrasion is visible, at grade 2, abrasion is slightly severe, and at grade 1, abrasion is fairly severe.
Referring to Table 2, it can be seen that when the cross-sectional modification ratio is controlled in the range of 1.9 to 3.4 according to the present invention (Examples 5 to 7), the volume feeling and wear resistance of the outer appearance are excellent. On the other hand, in the case of the cross-sectional modification ratio lower than the above range (Comparative Example 3), the volume feeling of the yarn is lowered, and when it exceeds the above range (Comparative Example 4), the wear resistance is lowered.
Therefore, when the carpet is produced using the polyethylene terephthalate BCF according to the present invention, the volume feeling and the quality of the abrasion resistance of the outer appearance can be improved even with a yarn having the same weight as that of nylon.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2018-0092998 | Aug 2018 | KR | national |
