KR20030046109A - Method for alkaline weight loss of polyester fiber by applying ultrasonic wave - Google Patents

Abstract

PURPOSE: An alkali weight loss finishing method of polyester fiber using ultrasonic wave is capable of increasing velocity of weight loss, reducing troubles of post-process and increasing productivity. The polyester fiber is characterized by increasing drapability, repulsive elasticity, bulkiness and soft feeling. CONSTITUTION: The alkali weight loss finishing method of the polyester fiber is as follows: preparing textile; applying ultrasonic wave having 15-30KHz of frequency on the textile with a magnetostrictive sonicator to dissolve or to elute; and then drying. The alkali weight loss finishing method is useful for producing superfine yarn by alkali dissolving/eluting polyester-based dissolution/elution type conjugate fiber, producing modified polyester fiber, producing polyester hollow fiber or dying polyester fiber.

Description

Method for alkaline weight loss of polyester fiber by applying ultrasonic wave

The present invention relates to a method for reducing alkali of polyester fibers, and more particularly, to produce an ultrafine fiber from polyester-based melted / dissolved composite fibers or to reduce the alkali for an other purpose, an ultrasonic wave is applied to reduce the alkali loss rate. A method for achieving quality homogenization of improved and reduced fibers.

Attempts have been made to apply ultrasonic technology to each process in the textile industry. However, until now, ultrasonic application technology is on a laboratory scale and some of them have been put to practical use, but most of them have not been generalized. However, since applied research is being attempted in the textile field of ultrasonic waves at universities and research institutes, and the effects thereof have been reported, the results of these studies and their practical applications are listed here. Ultrasonic waves for the stability of resin emulsions during resin processing in the textile industry are listed. The method of dispersing by using the ultrasonic wave, the method of using ultrasonic wave for the callout of cotton fabric, the method of using ultrasonic wave for refining, bleaching, the method of using ultrasonic wave for dyeing, the method of using ultrasonic wave for water repellent work, and the like.

On the other hand, the weight loss of alkali may be reduced when polyester microfibers, such as polyester fibers or the like, are used to produce microfibers from soluble composite fibers such as sea-island type composite fibers or eluted composite fibers such as split type composite fibers. It is used for modifying the surface feel, for producing hollow fibers, and the like.

In particular, in the manufacture of highly sensitive, expensive artificial suede materials that outperform natural fibers by alkali-reducing composite fibers, there are many difficulties in homogeneous fine-graining technology, and when the fine-graining of constituent monofilaments is uneven, the post-process Many problems are caused, such as uniformity and lot differences.

Therefore, an object of the present invention is to produce a high quality fiber with high productivity by effectively alkali reducing the fiber.

In the study of the present inventors to achieve the above object, the application of ultrasonic waves to the alkali reduction of the fiber can not only improve the alkali reduction rate, but also realize that the quality of the reduced fiber becomes uniform. will be.

The accompanying drawings show the results of experiments in the case of application of ultrasonic wave (Ultrasonic ON) and non-application (Ultrasonic OFF) to reduce alkali of dissolved / dissolved composite fiber.

1 to 4 is a graph showing the change in weight loss with treatment time,

5 to 8 is a graph showing the change in the reduction rate according to the treatment temperature,

9 to 12 is a graph showing the change in weight loss according to the treatment concentration,

13 to 18 are photographs taken with a scanning electron microscope of the surface shape change according to the reduction ratio,

19 to 20 are photographs taken with a scanning electron microscope of the cross-sectional shape change according to the reduction ratio,

21 to 22 is a graph showing the change in air permeability according to the reduction rate,

23 to 24 is a graph showing the change in tensile strength according to the weight loss rate,

25 to 26 is a graph showing a change in K / S according to the reduction rate,

27 to 34 are graphs showing a change in bending characteristics according to a reduction ratio;

35 to 40 are graphs showing surface characteristic changes according to a reduction ratio,

41 to 22 are graphs of dyeing curves of dissolved / eluted microfine fabrics.

Therefore, according to the present invention, an alkali reduction method of polyester fiber is provided by applying ultrasonic waves at the time of alkali reduction in alkali reduction of polyester fiber.

Hereinafter, the present invention will be described in more detail.

In general, alkali reduction of polyester fibers such as polyethylene terephthalate is used for various purposes by dissolving alkali-soluble (hydrolyzable) components contained in the fibers. For example, in the case of producing an ultrafine fiber by alkali dissolving / dissolving polyester-based dissolution / elution composite fiber, in the case of producing a fiber having modified surface properties, in the case of manufacturing a hollow fiber, it is used for dyeing and the like. The present invention can be used for the production of all fibers in which alkali reduction processes are required, including these cases.

The application of ultrasonic waves according to the present invention can effectively achieve the reduction of alkali, which causes cavitation when the ultrasonic wave is radiated into the alkaline reducing liquid, which causes violent vibrations in the water by ultrasonic vibration. It is considered that bubbles are generated when the vibration reaches its limit, and high pressure is generated when the bubbles collide with each other and are destroyed again.

In particular, the present invention is very effective in the case of producing an ultrafine fiber by alkali dissolving / eluting the dissolved / eluted composite fiber.

For example, when ultrasonication is applied to the splitting of soluble composite fiber fabrics using co-polyester (Co-PET), troubles of the post-process can be eliminated by the complete removal of the decomposed Co-PET or oligomer in the splitting process. It is possible to reduce and to achieve more homogeneous fineness, and to improve the drapery, rebound elasticity, bulky and soft touch of the obtained ultrafine fabric.

In general, in reducing the fineness of the composite fiber by alkali-reducing textile products such as woven / knitted fabrics, knitted fabrics, and nonwoven fabrics containing dissolved / dissolved composite fibers, the reduction ratio varies depending on the type of the constituent fibers, but it is generally reduced by 23.0-27.0%. have. When ultrasonication is applied when the microfibers of such composite fibers are applied according to the present invention, the removal rate of the dissolved / dissolved components of the composite fibers is increased by 25 to 30% in the case of the dissolution type and in the case of the dissolution type when the ultrasonic wave is not applied. It is increased by about 15 to 20%, and microfine fibers of uniform quality can be obtained.

In the present invention, the ultrasonic generator may be installed so as to impart ultrasonic waves to the alkali reducing liquid, but there is no particular limitation on the method of installing the ultrasonic generating device.

In addition, the ultrasonic generator is not particularly limited as long as it can generate ultrasonic waves, but it is effective to use a magnetostrictive ultrasonic apparatus capable of emitting a frequency of 15 to 30 kHz.

Features and other advantages of the present invention as described above will become more apparent from the following examples.

[Examples and Comparative Examples]

The sample used for the experiment was a satin (FTR) composite yarn of Samyang Co., Ltd. (split type: PET / CDP = 7/3, 8 segment, 290g / yd). satin) [Weft: SDY SD 150/96, warp density 203 picks / inch, weft density 68picks / inch] and MEG composite yarn (sea-island type: PET / Co-PET = 7/3, 37) segment, 315g / yd) PET island-in-the-sea composite yarn) Satin fabric woven using 170d / 48f as a warp [weft: SDY SD 150/96, warp density 183 picks / inch, weft density 68picks / inch] The application was used for the split test.

The reagents used for alkali dissolution / elution of microfibers were 50% NaOH (Samgwang Co., Ltd.), emulsion dispersion refiner (SNOGEN RE-50: British Emulsifier), hobbing agent (SNOGEN DZ-705DN: British Emulsifier), acetic acid (Samsung BP). As a chemical company), a dispersant (SUNSLOT RM-800: Korea Fine Chemical), and Na ₂ S ₂ O ₄ (Hansol Chemical Co., Ltd.), commercially available unrefined commercial products were used as they were.

Bath ratio 1: 160, emulsified dispersion refiner 2g / L, derivatizer by using high temperature and high pressure mini dyeing machine equipped with 4 sets of magnetic distortion type ultrasonic generator capable of emitting 15 ~ 30KHz frequency for dissolution / dissolution split experiment Add 2g / L, and change the temperature (95, 105, 115 ℃), alkali (NaOH) concentration (0.6, 0.8, 1.1, 1.4%), and treatment time (10, 20, 30, 40, 50, 60 minutes) And dissolution / elution of the dissolution / elution component by application / non-application of ultrasonic waves. After dissolution, washing with water was carried out under the same conditions (90 ° C., 10 minutes) and then naturally dried.

The buffing of alkali-dissolved / eluted microfibers was carried out using a Kook Jae buffing m / c (buffing conditions: sand paper: P180, speed 13yds / min, SP rpm 1500, angle 19 °, tension s, m, w).

The weight loss of the ultrafine fabrics was calculated by the equation (1) from the weight (Wo) before the alkali dissolution / elution treatment and the weight (W) after the treatment. Type) and calculated weights were applied.

Dyeing was cut to a certain size in the ultra-fine sample dissolved / eluted by ultrasonic application / non-application conditions and dyed for 20 minutes at 90 ℃ using a high-temperature, high-pressure dyeing machine (PYROTEC-S: Roaches International Ltd., England). : Dye (Foron D. Blue RD-PNP) 0.5 owf, bath ratio 1: 100, dispersant (SUNSLOT RM-800) 1 g / L, pH (acetic acid) 4.0]. After washing three times with reduced washing (NaOH 1g / L, Na ₂ S ₂ O ₄ 2g / L) and drying at 80 ° C. for 60 minutes in a drying oven.

Determination of dyeing: After dyeing the microfibers using CCM (Data Match Spectroflash 50, Data color International, USA), measure the surface reflectivity of the sample before and after buffing three times, and then average the Kubelka-Munk. The K / S value was calculated according to the formula.

Dyeing curve measurement: The dyeing curve which can measure the dyeing speed of dye in real time was used by the salt circulation type dyeing machine (Roaches International Ltd., England) and ultraviolet-visible spectroscopy (UV-Vis No. 8453, Hewlett Packard). Dyeing conditions: dye (Foron D. Blue RD-PNP) 0.4 owf, bath ratio 1:50, dispersant (SUNSLOT RM-800) 0.3 owf, pH (acetic acid) 4.5].

Determination of protection rate: The protection rate of the sample is placed in a beaker according to JIS L 1095 9.27 (C method: sodium carbonate method), and after 10 minutes of hot water treatment, anhydrous sodium carbonate 5g / L, nonionic surfactant 2g / L solution (bath ratio 1: 100, a temperature of 80 ~ 90 ℃) After 1 hour was sufficiently washed in warm water and dried at 110 ℃ for 100 minutes, the protection ratio (S,%) was measured according to the formula 2 before and after dry weight. In Equation 2, w is the arc dry dry weight, and w 'is the dry dry weight after the firing.

Tensile strength measurement: Using a tensile strength tester (M500PCX-10, Testomatric Co., England) according to KS K 0520 (Ravelled Strip) method, with elution split yarn and melted ultrafine fiber The test was performed five times on each of the inclined slopes to obtain an average value.

Surface and Sectional Measurements: Alkali-dissolved / eluted ultrafine samples were Au-coated under 102 mmHg reduced pressure, and then the surface and cross-sectional shapes before and after buffing were observed using a Hitachi Corporation Scanning Electron Microscope (S-2500C).

Wash fastness: Measured using an Atlas Rounder-O-M (Atlas Electronic Devices Co., LAS / EF, USA) according to A-2 method of KS K 0430 (Dyeing fastness test method for washing).

Daylight fastness: Dry and wet test using a crock meter (crock meter: James H. Heal & Co., Ltd., 255A, England) according to the carbon arc method of KS K 0700 (Daylight Fastness Test Method of Dyes). It was.

Sublimation fastness: measured using a WFO-600ND dry oven (EYELA CO., LTD., Japan) according to the glass plate method of KS K 0651 (Sublimation fastness test method of the dye).

Mechanical characteristics: KES-FB system (KATO TECH CO., LTD., Japan) was used to measure the flexural and surface characteristics of 1 block and 5 items separately for the weft direction under standard measurement conditions.

Thickness measurement: The thickness of the alkali dissolved / eluted fabric was measured five times using a teakness gauge (No.6003, Daiei Kagakuseiki Seisakusho Ltd., Japan) according to KS K 0506 It was set as the average value.

Air permeability measurement: The air permeability of alkali dissolved / elution fabric was five times using the air permeability tester (FX 3300, Testest AG Co., Ltd., Switzerland) according to KS K 0570 (Testing method for air permeability of fabric). It was set as the average value of the measured result.

result

1. Change in weight loss rate according to treatment time

Hydrolysis of PET fabrics by NaOH is a nucleophilic ester hydrolysis reaction of OH ^- in which alkaline OH attacks the carbonyl carbon of PET and cleaves ester bonds, producing soluble ethylene glycol and disodium terephthalate. Figures 1 to 4 show the reduction rate according to the treatment time when the sample is reduced by alkali application / non-applied ultrasonic application, Figures 1 to 2 are dissolved samples and FIGS. 3 to 4 are for the eluted samples. As can be seen in Figures 1 to 4 in general, as the treatment time increases, the reduction rate increases slightly linearly, and when the application is reduced by 40% treatment than when not using the ultrasonic melt type The reduction rate of the sample was 1% at 105 ℃ and 2.5% at 115 ℃, and 0.5-1.0% increase in the eluted sample, indicating that the effect of ultrasonic wave on the weight loss was greater than that of the eluted microfabric. Can be.

In FIG. 1, the slope of the melting rate of the melted sample was 0.3639-0.4920, whereas in FIG. 2, the slope was 0.4244-0.6080, indicating that the reduction rate was 14-23% faster. At 0.1763-0.2308, whereas at 115 ° C it was 0.1980-0.2810, 12-23% faster.

Increasing the reduction rate with increasing treatment time causes nucleophilic OH ^- ions dissociated in NaOH to attack the carbon of the carbonyl group having the partial bipolarity of the ester group forming the Co-PET polymer. Since terephthalate anion, an alkali reduction product, is combined with sodium ions and is removed from the reaction system in the form of a salt, the reaction is considered to be because the reaction does not reach equilibrium and continues from the surface to the inside over time.

In addition, the reduction rate by application of ultrasonic wave increased 2.5% in melt type and 1.0% in elution type at 115 ° C than non-application of ultrasonic wave. Nucleophilic OH ^- attacking ester group by ultrasonic cavitation phenomenon It is considered that the activation of the ions is increased.

Assuming that the water-soluble Co-PET component of the dissolving and eluting type accounts for about 15.0-17.0% of the total fabric weight, and that only the Co-PET component is hydrolyzed, the loss of the dissolving and dissolving types during ultrasonic application An increase of about 2.5% and 1.0%, respectively, means that the Co-PET component will increase by 37.5-42.5% and 15.0-17.0%, respectively. Assuming that it is fast, it can be predicted that when ultrasonic application is applied, 25.0-28.3% of the dissolved Co-PET component and 10.0-11.3% of the eluted Co-PET component are hydrolyzed. It can be seen that it is useful.

Table 1 shows the loss ratios of the dissolved and eluted samples when the NaOH concentration was decreased at 115 ° C. at different temperatures of 1.1%. When the weight loss under the same conditions, it can be seen that the reduction rate is 63.8-63.9% higher than the dissolution type microfine fabric.

Processing time (minutes) Melt type (A) Elution type (B) (A-B) / B × 100 (%) Ultrasound Not Applied Ultrasonic Application Ultrasound Not Applied Ultrasonic Application Ultrasound Not Applied Ultrasonic Application 0 22.6 23.4 13.8 14.3 63.8 63.6 10 25.4 27.4 15.5 16.7 63.9 64.1 20 29.0 31.1 17.7 19.0 63.8 63.7 30 32.0 33.7 19.5 20.6 64.1 63.6 40 34.2 37.3 20.9 22.8 63.6 63.6 50 38.1 41.0 23.2 25.0 64.2 64.0 60 41.0 43.0 25.0 26.2 64.0 64.1 Average 63.9 63.8

2. Change in weight loss rate according to treatment temperature

5 to 8 show the loss ratio according to the treatment temperature when the polyester microfine fabrics are alkali-reduced by ultrasonic application / non-application, and FIGS. 5 to 6 are sea-island type microfine fabrics. 7 to 8 show a split type microfine fabric.

As can be seen in Figures 5 to 8, it can be seen that the reduction rate increases linearly as the treatment temperature increases, and the reduction rate is higher when the ultrasonic wave is applied in the Doyle condition than when the ultrasonic wave is not applied. It can be seen that this is finely high.

The reduction rate increases with increasing processing temperature because the matrix degree of freedom of the Co-PET polymer chain increases with increasing temperature, and the hydrolysis of the Co-PET molecular chain is activated by ultrasonic cavitation. It is thought that the area exchange of the decomposer was active and the reduction rate was increased in the ultrasonic application.

3. Change in weight loss rate according to treatment concentration

9 to 12 show the loss ratio according to the treatment concentration (0.6, 0.8, 1.1, 1.4%) when the dissolved / dissolved ultrafine fabrics were alkali-reduced by ultrasonic application / non-application. Is a loss rate of a sea-island type microfine fabric, and FIGS. 11 to 12 show a loss rate of a split type microfine fabric.

As can be seen in Figures 9 to 12, it can be seen that the loss ratio increases exponentially as the alkali concentration increases, and the application of ultrasonic waves under the same conditions is more effective than the application of ultrasonic waves. It can be seen that the rate is slightly high.

It is thought that the reduction rate increases as the alkali concentration increases because the nucleophilic OH- ion capable of hydrolyzing the ester group of the Co-PET polymer chain increases.

4. Surface shape change according to weight loss rate

13 to 16 show the change in surface shape according to the reduction rate when the dissolved / dissolved ultrafine fabrics are reduced by alkali application / non-application, and FIGS. 13 to 14 are sea-island types. It is the surface shape of an ultrafine fabric, and FIGS. 15-16 are the surface shape of the split type ultrafine fabric. (A)-(f) is a MEGARON photograph of a melt type microfine fabric, FIG. 14 (a)-(f) is a melted type micro fabric buffed, and FIG. 15 (a)-( f) is an inclination (FTR) photograph of the eluted microfine fabric, and FIGS. 16A to 16F show the surface of the eluted microfiber buffed. In these photographs, (a)-(c) is a case where alkali reduction is carried out by ultrasonic non-application, and (d)-(f) is a case where alkali reduction is carried out by ultrasonic application.

As can be seen in FIG. 13, the sea-island type 130/36 degree (island) component is 37 segments as the loss ratio increases, and the inclination of monofilament number (1,332 pieces) and high shrinkage yarn 40/12 is obtained. MEG) 170/48 shows that the degree of freedom increases as the concentration of monofilaments decreases as the alkali hydrolysis increases.Increasing the angularness of monofilaments increases when the weight is reduced by applying ultrasonic waves. It was found that the high shrinkage yarn composed of / 12 was less exposed to the surface.

FIG. 14 is a photo buffing an alkali hydrolyzed dissolved microfine fabric for tactile feel and appearance improvement. FIGS. 14 (a), 14 (b) and 14 (c) show weight loss as an alkali-reduced sample without applying ultrasonic waves. 17.2%, 28.6%, 37.3%, and Figures 14 (d), (e) and (f) show the weight loss rates of 18.9%, 29.8%, and 38.1%, respectively. In the case of buffing in the state, high shrinkage yarns are drawn between the buffing microfibers, which may damage the high shrinking yarns when buffing.

On the other hand, as can be seen in Figure 15, as the reduction ratio increases, the slope consisting of split type 100/48 (384 monofilaments when fully dissolved in 8 segment PET) and high shrinkage SDY SD 40/12 (FTR ), 140/60 was found to have a high degree of freedom of spatial placement of undissolved monofilaments as alkali hydrolysis increased. When the loss rate is low, co-PET is eluted on the surface of the FTR yarn, and a ditch appears in the direction of the fiber axis, and it is observed that the microfibers are restrained at the original position where the FTR yarn is placed. There are many independent batches, and the loss ratio is almost independent at 28.2% and 31.1%.

In addition, when the ultrasonic wave was applied at similar reduction rate, the microfibers which were not eluted were located more independently than the sample without the ultrasonic wave.

FIG. 16 is a photograph of buffing microfibers having different weight loss rates, and the buffing direction was not remarkably higher than that of molten microfibers, and a very high weight loss rate sample showed high damage of high shrink yarns.

5. Cross-sectional shape change according to the reduction ratio

Fig. 17 is a cross-sectional view of a dissolution type microfiber, in which (a), (b), and (c) are alkali-reduced samples without applying ultrasonic waves, and the reduction ratios were 17.2%, 28.6%, 37.3%, and (d). (e) · (f) are samples that were applied by applying ultrasonic waves, and the loss ratios were 18.9%, 29.8%, and 38.1%. The microfibers (MEGs) at were observed with less splitting, and the monofilament, or island component, on the outer layer of the microfibers was split, but not fully internally, and in the sample without ultrasonic application. More phenomena were observed.

In addition, as shown in FIG. 18, when the loss ratio was low, the PET microfiber which was not eluted near the spot where Co-PET was eluted was visually constrained to the original position as shown in the picture, but as the loss ratio increased It can be seen that the Filament is mixed independently of each other and it is unknown to which FTR the monofilament is divided.

6. Change in the thickness of the fabric according to the weight loss rate

19 and 20 show the change in the thickness of the fabric according to the increase in the reduction rate when reducing the alkali. Fig. 19 is a melt type micro fabric, and Fig. 20 is an eluted type micro fabric.

As can be seen in FIG. 19, it can be seen that the thickness decreases as the reduction ratio increases, and the thickness of the buffed sample is about 0.04 mm lower than that of the non-buffered sample. It can be seen that the thickness is dependent on the weight loss type regardless of the application, and the thickness of the eluted microfiber of FIG. 20 is about 0.04 mm lower than that of the non-buffered sample. .

In general, the thickness decreases as the weight loss rate increases, because the fineness of the constituent yarns decreases rapidly as the water-soluble Co-PET component, which accounts for about 30% of the dissolved / dissolved microfibers, decreases due to alkali reduction. It is thought that the thickness has been reduced since the space for the dissolved / eluted portion is filled with micronized yarn which is not dissolved / eluted.

7. Change of air permeability according to the reduction rate

Figure 21 and Figure 22 shows the change in air permeability of the fabric according to the increase in the weight loss rate of alkali reduction, dissolving micro-fabric and eluting micro-fabric.

As can be seen in FIG. 21, when the soluble microfine fabric was not buffed, the air permeability was slightly increased as the weight loss rate was increased, but the air permeability was decreased as the weight loss rate was increased. It was. Regardless of the application / non-application of ultrasonic waves, air permeability was highly dependent on the reduction rate.

As the weight loss rate increased, the air permeability of the buffed sample and the buffed sample showed a great difference. At the initial loss rate of about 16%, the air permeability of the buffed sample was about 30 cm 2 / cm 2 / sec. However, the air permeability of the buffed sample was about 8 cm 3 / cm 2 / sec., Which was about 22 cm 3 / cm 2 / sec., And the difference in air permeability increased as the reduction rate increased. The small increase in air permeability of the unbuffered sample with the increase in the reduction rate is thought to be due to the small voids and the filling density of the constituent yarns.

On the other hand, the eluted microfiber of FIG. 22 also showed a similar tendency to the molten microfiber, but the buffing sample showed that the decrease in air permeability was greater than that of the molten microfiber as the reduction rate increased. The permeability was about 30cm2 / cm2 / sec., And the eluted microfine fabric was about 19cm2 / cm2 / sec., Almost unaffected by the reduction rate, and the difference was about 11cm2 / cm2 / sec. In the case of buffing, the air permeability decreased as the weight loss rate increased, and when the weight loss rate was about 16%, the difference between the air permeability before and after buffing of the melted and eluted microfine fabric was about 20㎠ / ㎠ / sec. And 10 Cm 2 / cm 2 / sec.

8. Change in tensile strength according to weight loss rate

Figures 23 and 24 show the change in tensile strength of the fabric (inclined direction) according to the increase in the reduction rate during alkali reduction. Fig. 23 is a melt type micro fabric, and Fig. 24 is an eluted type micro fabric.

As can be seen in Figure 23, it can be seen that the tensile strength decreases linearly as the reduction rate increases, regardless of the buffing, and the buffing sample and the buffing at the initial reduction rate of about 16% can be seen. Tensile strength of the sample that did not show a difference of 15㎏, but as the weight loss rate increased the difference was about 20㎏.

It is considered that the decrease in tensile strength as the weight loss rate increases is because the resistance to fineness due to dissolution / dissolution decreases in tensile stress, and that the tensile strength of the buffed sample is smaller than that of the buffed sample. It is believed that this is because the fined monofilaments are cut.

On the other hand, the dissolution type microfine fabric of FIG. 24 also showed a similar tendency to the dissolution type microfine fabric, and the tensile strength of the buffed sample and the non-buffed sample showed a difference of about 15 kg, and there was little effect of the tensile strength by ultrasonic wave. .

9. Change in K / S according to the reduction rate

25 and 26 show the change in the K / S value with the increase in the reduction rate during alkali reduction, Figure 25 is the K / S value of the dissolved micro-fine fabrics, Figure 26 is K / S of the eluted micro-fine fabrics Value.

As can be seen in Figure 25 it can be seen that the K / S value decreases as the weight loss rate is increased, the buffing sample was not significantly changed even if the weight loss rate is increased. At the initial loss rate of about 17%, the K / S value of the unbuffered sample was about 1.8, but the K / S value of the buffed sample was about 1.2 to 0.6, but the difference was increased as the loss rate increased. When the loss ratio was about 25%, the K / S values of the samples before and after the buffing were almost the same, and the change in dyeability was almost the same at the loss ratio above.

In general, it is considered that the decrease in K / S value as the weight loss rate increases is because the fabric density becomes higher due to the increase in packing density due to fine graining, and thus the apparent concentration of the stain is lowered.

In addition, the K / S value is slightly higher than the sample without the ultrasonic wave at the same weight loss rate because of the high angular reflection of the fine-grained yarns.

It can be seen that the dissolution type microfiber fabric of FIG. 26 also shows the same tendency as the dissolution type microfiber fabric.

10. Changes in bending characteristics according to weight loss rate

27 to 30 show the bending stiffness according to the increase of the approximate rate during alkali reduction. 27 and 28 are the bending stiffness of the melt type microfiber, Fig. 27 is inclined, Fig. 28 is the bending stiffness of the weft, Figs. 29 and 30 are the bending stiffness of the eluting ultrafine fabric, Fig. 29 is the slope, Fig. 30 The bending stiffness of the weft.

As can be seen in FIGS. 27 and 28, as the weight loss ratio was increased, the bending stiffness of both hard and weft yarns decreased, and the test bending stiffness of the untreated (dough) sample was about 0.75 f · cm 2 / cm, and the weight loss ratio was about 14.7. In%, bending rigidity was about 0.2 gf * cm <2> / cm, and it turned out that the bending rigidity is insignificant. In addition, the bending stiffness of the buffing sample was slightly higher than that of the buffing sample. However, the bending stiffness of the weft showed almost the same level of bending stiffness at the same reduction ratio, with or without buffing.

In general, it is believed that the decrease in bending stiffness as the weight loss rate increases is because the resistance to bending during bending decreases due to the fineness of the constituent yarn after melting.

The elution microfibers of FIGS. 29 and 30 also had a lower bending stiffness as the reduction rate increased, and showed a similar tendency to the bending behavior of the dissolution microfiber.

31 to 34 show the bending history according to the increase of the reduction rate during the alkali reduction. 31 and 32 are the bending history of the melt-type microfine fabric, Figure 31 is the inclination, Figure 32 is the bending history of the weft.

As can be seen in FIGS. 31 and 32, as the weight loss rate is increased, the bending history of both the light and weft yarns decreases, and the reduction of the bending history is large at the beginning of weight loss. In the bending history of the bevel, the bending history was about 0.2 gf · cm / cm higher than that of the non-buffing sample, which showed that the resistance to recovery to the initial position after bending deformation was high. The bending history of the weft showed almost the same behavior before and after buffing, and the dissolution type microfibers of FIGS. 33 and 34 also showed the same bending history behavior as that of the dissolution type microfiber, and the buffed sample did not buff in the bending history of the warp yarn. It was found that about 0.15 gf · cm / cm higher than the sample that did not.

11. Change of surface characteristics according to the reduction ratio

35 and 36 show the coefficient of friction in the inclined direction according to the increase in the weight loss rate of alkali reduction, Figure 35 shows the dissolution type microfine fabric, Figure 36 shows the dissolution type microfine fabric.

As can be seen in FIG. 35, the coefficient of friction of the melted microfine fabric before buffing was 2.8, and there was almost no change in the coefficient of friction as the weight loss rate increased, and the coefficient of friction of the buffed fabric was very low, about 0.2, before and after buffing. The difference in friction coefficient was about 2.6.

However, in the case of the eluted microfine fabric of FIG. 36, the initial friction loss factor was about 4 before buffing, but the friction coefficient decreased to about 3 at the loss ratio of 35%, and the buffing sample had a friction coefficient of about 2.7 regardless of the loss ratio. Almost no change was found.

On the other hand, Fig. 37 to Fig. 40 show the average deviation and the surface roughness of the friction coefficient (Fig. 37 is a melt-type MMD, Fig. 38 is a dissolution type MMD, Fig. 39 is a melt type SMD, Fig. 40 is a dissolution type SMD) and dissolution-type microfine fabrics showed the same behavior with or without weight loss, and exhibited behaviors with or without buffing.

12. Color fastness according to weight loss rate

Table 2 shows the dyeing fastness of the dissolved micro-fine fabrics with the increase of the reduction rate during alkali reduction. As can be seen from Table 1, the laundry fastness is 4-5 grade, the sublimation fastness is about 3-4, but the daylight fastness and friction fastness are as low as the third level.

In general, buffed microfiber fabrics are considered to have low light and friction fastness due to their large surface area. The dissolution type microfine fabrics of Table 3 showed almost the same tendency as the dissolution type microfine fabrics.

Color fastness ultrasonic wave Unapplied Applications Reduction rate (%) 17.2 28.6 37.3 18.9 29.8 38.1 Color fastness discoloration 4-5 4-5 4-5 4-5 4-5 4-5 pollution if 4-5 4-5 4 4-5 4 4 PET 4-5 4 4-5 4 4-5 4-5 Friction fastness dry 3-4 3-4 3-4 3-4 3-4 3-4 Wetting 3 3 3 3 3 3 Daylight fastness discoloration 3 3 W 3 3 3 Sublimation fastness discoloration 3-4 4 4 3-4 3-4 4 pollution 3-4 4 3-4 4 3-4 4

Color fastness ultrasonic wave Unapplied Applications Reduction rate (%) 0.5 17.4 28.2 11.5 18.2 31.1 Color fastness discoloration 4-5 4-5 4-5 4 4-5 4-5 pollution if 4-5 4-5 4 4-5 4 4-4 PET 4-5 4-4 4-5 4 4-5 4-5 Friction fastness dry 3-4 3-4 3-4 3-4 4 3-4 Wetting 3 3 3 3 3 3 Daylight fastness discoloration 3 3 2 2 2 3 Sublimation fastness discoloration 4 3-4 3-4 4 3-4 4 pollution 3-4 4 3-4 3-4 3-4 4

13. Dyeing curves of eluted / dissolved ultrafine fabrics

41 and 42 show the dyeing curves for the ultra-fine fabrics having different alkali elution / dissolution loss ratios, and are samples without buffing.

Fig. 41 is a melt type micro fabric, and Fig. 42 is an eluted type micro fabric.

As can be seen in FIG. 41, the dye adsorption rate was increased as the dyeing time elapsed, and the sample was dissolved by applying ultrasonic waves, but the equilibrium dye amount increased as the weight loss rate increased. The higher the value of parallel adsorption was, the more unusual the trend tended to be.

In addition, the equilibrium dye amount at the similar reduction rate was found to be slightly higher in the sample applied with ultrasonic waves, and the difference was about 5%. This is considered to be due to the fact that finesse was prominent by the complete removal of the Co-PET component when combined with ultrasonic waves during alkali dissolution.

It can be seen that the same trend is observed in the eluted ultrafine fabric of FIG. 42.

conclusion

As a result of the alkaline liquid distillation (micronization) using the cavitation combined with the ultrasonic wave for the microfabric fabric produced by inclining the eluted microfiber FETHERON 140/60 and the microfiber fabric fabricated by dissolving the microfiber MEGARON 170/48 inclined, The following conclusions were made.

1. When ultrasonication was applied at 115 ℃, alkali concentration of 0.8% and 1.1%, irrespective of treatment time, the reduction rate of 2.5% for dissolved microfibers and 1.0% for eluted microfine fabrics was increased. The weight loss rate was about 64% higher than the eluting type.

2. During surface observation, the sample applied with ultrasonic wave had high independence of the divided (fine-sized) monofilaments, which made it more entangled and covered the high shrink yarn evenly. The appearance of severe exposure and damage to buffing was observed.

3. The air permeability of the dissolved microfine fabric was about 30 cm 3 / cm 2 / sec., And the eluted micro fabric was about 19 cm 3 / cm 2 / sec., Almost unaffected by the reduction rate, and the difference was about 11 cm 3. / Cm2 / sec., But when buffing, the air permeability decreased with the increase of the reduction rate.When the reduction rate was about 16%, the difference between the air permeability before and after buffing of the melted and eluted ultrafine fabric was about 20 Cm 3 / cm 2 / sec and 10 cm 3 / cm 2 / sec.

4. The sloped bending stiffness of the melted and eluted molds was about 0.2gf · cm 2 / cm and 0.1gf · cm 2 / cm, respectively. After buffing, the bending stiffness was slightly higher than before buffing. Was more pronounced than the bending stiffness, and the difference between the dissolution type and the dissolution type was about 0.1 gf · cm / cm.

5. Soluble and Dissolved Type Soluble Co-PET component accounts for about 15.0 ~ 17.0% of the total fabric weight and purely Co-PET component hydrolysis occurs. Increasing the reduction rate of about 2.5% and 1.0% respectively means that the Co-PET component has increased 37.5 ~ 42.5% and 15.0 ~ 17.0%, respectively. Assuming that is 3 times faster, it can be predicted that when ultrasonics are applied, the dissolution type Co-PET component is 25.0 to 28.3 and the dissolution type Co-PET component is 10.0 to 11.3% more hydrolyzed. It can be judged that the possibility of practical use is great.

As described above, the application of ultrasonic waves during the alkali reduction of the fiber according to the present invention can improve the alkali reduction rate. In particular, when applied to the fineness of the composite fiber, it is possible to completely remove the polymer or oligomer decomposed in the splitting process. It is possible to reduce the trouble of the post-process and to achieve more homogeneous fineness, and to improve the draperiness, resilience, bulkiness and soft touch of the obtained ultrafine fabric.

Claims (4)

In alkali reduction of polyester fiber, the ultrasonic reduction is applied at the time of alkali reduction, The alkali reduction method of polyester fiber characterized by the above-mentioned. 2. A method according to claim 1, wherein a magnetic distortion device type ultrasonic wave generator capable of radiating a frequency of 15 to 30 kHz is used as a device for applying ultrasonic waves when reducing alkali. The method according to claim 1, wherein the alkali weight loss of the polyester-based dissolved / eluted composite fibers by the alkali dissolution / elution of the ultrafine fibers, the production of polyester fibers having modified surface properties, polyester hollow fiber Alkali treatment at the time of manufacture or dyeing of polyester fiber. The method according to claim 1, wherein the polyester fiber is a melted / dissolved composite fiber for producing ultrafine fibers.