KR100658090B1 - A measuring method for crimp properties of sea-island type staple, and a nonwoven fabric for artificial leather - Google Patents

Abstract

The present invention relates to a crimping characteristic measuring method of an island-in-the-sea staple characterized by using a staple tow as a sample for measurement. In another aspect, the present invention is characterized in that the non-woven fabric for artificial leather, characterized in that the crimping rate of the staple is measured 5 ~ 20%, the residual crimping rate is 3 ~ 10%, the crimp elastic modulus is 30 ~ 80% It is about. The present invention improves the reliability of the measurement results by measuring the crimp characteristics of the staples in the tow state, and as a result, it is possible to greatly improve the nonwoven fabric operability.

Crimping property, artificial leather, nonwoven fabric, measuring method, staple, island-in-sea type, tow, crimp rate, nonwoven fabric

Description

A measuring method for crimp properties of sea-island type staple, and a nonwoven fabric for artificial leather}             

1 is a schematic view of the present invention crimp characteristic measuring apparatus.

※ Code description of main part of drawing

DESCRIPTION OF SYMBOLS 1 Staple tow 2 Drive motor 3 Tensile weight mechanism

4: Sample holder 5a, 5b: Hook 6: Guide roller

7: Tension control roller 8: Frame

The present invention relates to a method for measuring the crimping characteristics of an island-in-the-sea staple used in the manufacture of nonwoven fabric for artificial leather. Nonwoven fabrics for artificial leather have been produced by opening, carding and needle punching the island-in-the-sea staples produced by composite spinning.

The items mainly measured and analyzed by the basic properties of staples are individual denier, strength, elongation, fiber length, crimp number per inch and crimp characteristics (crimp rate, residual crimp rate, crimp modulus), etc. (Hereinafter referred to as "OPU"), moisture content (hereinafter referred to as "MPU"), coefficient of friction, and the like.

Among the above properties, the crimping property is the one that has the greatest influence on the weight, thickness and density of the nonwoven fabric and is difficult to manage. For example, OPU and MPU are mainly related to stapling capacity and antistatic properties, and depend on the characteristics of the oil used.They maintain special pick-up amount and mature the staples sufficiently at a certain temperature and humidity after opening to make special The problem rarely occurs.

In addition, the basic properties of staples such as denier, strength, elongation, and fiber length are easy to measure and do not have a significant influence on the weight change of the actual nonwoven fabric. However, the crimping characteristics of the staples are very low in reliability because of the current manual measurements using one strand of staples as a sample. Therefore, it is difficult to confirm the correlation between the crimp characteristics data of staples and the nonwoven fabric operation performance, which does not help to improve the nonwoven fabric operability.

In other words, if the crimping properties of staples cannot be effectively measured and managed, raw seam-shaped staples with constant basic properties such as denier, strength, elongation, and fiber length are used as raw materials. Even if seasonal factors, nonwoven fabric facilities, and production conditions are managed in the same way, the uniformity of weight, thickness and density, which are the main quality factors of nonwoven fabrics, may occur. In this case, even cause analysis was difficult.                         

An object of the present invention is to provide a method that can reduce the measurement error and quantify the crimp characteristics by measuring the crimp characteristics of the staples for artificial leather, which has been spotlighted as an alternative to natural leather in a more improved method.

The present invention is to provide a method for measuring the crimping characteristics of the staples in the staple toe state. In another aspect, the present invention is to provide a staple crimp characteristics measuring method having a higher measurement reliability so that the crimp characteristics measurement data of the staples can be used in the actual non-woven fabric manufacturing process for artificial leather. In addition, the present invention is to provide a non-woven fabric for artificial leather composed of island-in-the-sea staples having desirable crimping properties.

In order to achieve the above object, the crimp characteristic measurement method of the island-in-the-sea staple of the present invention is characterized by using a staple tow as a sample during the measurement.

Hereinafter, the present invention will be described in detail with reference to FIG. 1. 1 is a schematic view showing a measuring method of the present invention.

First, the present invention hangs both ends of the staple toe to each of the two hooks (5a, 5b) respectively installed on the vertical surfaces facing each other, as shown in Fig. 1, then the tension adjusting roller connected to the drive motor ( 7) pulls the tow on one side and is connected to the bottom of the hook (5b) installed on the opposite vertical surface, and pulls up the tension weight mechanism (3) to the position where the sensor which operates by detecting its position is attached to the sample holder (4). A certain length is displayed on the staple tow 1 to measure the winding side characteristics of the island-in-the-sea staple.
The tensile weight mechanism (3) is an additional structure to give a load to the rod, when the tension weight mechanism (3) is raised to a predetermined position, the sensor detects this and pulls the tow of one side to the tension control device (7) The operation stops automatically.

The crimp characteristics of the staples are classified into crimp rate, residual crimp rate, and crimp elastic modulus, and they are obtained according to the Korean Industrial Standard Synthetic Fiber Staple Test Method (KS0327) as shown in Equations (I) to (III) below.

× 100 (Ⅰ)Crimp rate (%) =

× 100 (Ⅰ)

× 100 (Ⅱ)Residual crimp rate =

× 100 (Ⅱ)

× 100 (Ⅲ)Crimp modulus (%) =

× 100 (Ⅲ)

In the above formula, A is the length of 2mg / d load on the sample, B is the length measured after 30 seconds by applying a load of 50mg / d to the sample, C is 2mg / d after removing all the load and left for 2 minutes It is the length of the load.

In other words, the crimp rate is the ratio of the crimp reduced from the original length (unfolded length), that is, the crimp rate indicates the degree of crimping, and the higher the crimp rate, the stronger the binding force. In the case of island-in-the-sea staples for artificial leather manufacturing, the crimp rate is in the range of 5 to 20%.

Residual crimp ratio is the ratio of the original length (unfolded length) to the force of the crimp itself, which can be seen as the rate of contraction of the crimp itself, which is the criterion for crimp shape stability. In other words, if the residual crimp rate is high, the crimp can be well maintained by mechanical and physical forces during the opening, carding, and needle punching processes of the nonwoven fabric. In the case of the island-in-the-sea staple for artificial leather manufacturing, the residual crimp ratio is about 3 to 10%.

The crimp modulus is the ratio of the residual crimp rate to the crimp rate, which indicates the extent to which the crimp is reduced by the force of the crimp itself, which means the elastic modulus of the crimp itself.

Crimps per inch refers to the number of crimps in one inch (25.4mm) in the longitudinal direction of the staples, and is used according to the type, condition and product usage of the nonwoven fabric. The crimps per inch are given to be suitable for the purpose when producing staples and are strictly controlled by the properties of the staples, so the error is not large and by itself, the correlation with the uniformity of weight, thickness and density, which are the main quality factors of nonwoven fabrics, is not large. not.

In order to produce the island-in-the-sea staples having the above crimp characteristics, spinning and drawing process conditions are the main factors. As the spinning component, polyamide having a relative viscosity of 2.55 is used, and as the sea component, a copolymerized polyethylene terephthalate having an intrinsic viscosity of 0.55 in a 25 ° C. solution of orthochlorophenol is used. The elution of sea component is non-woven in padded non-woven fabric in 10% alkali solution, squeezed at 120% pick-up rate, and treated for 8 minutes and 30 seconds under conditions of 100% relative humidity with steam at 100 ℃. It is sufficient for the level to be completely eluted.

After drying the sea component and the island component with a vacuum dryer, the sea component is extruded with an extruder of 285-290 ° C. and the extruded component with an extruder of 250-260 ° C., respectively, and then composite spun at a spinning temperature of 280-285 ° C. and then 900 Undrawn yarn is prepared by winding at a winding speed of ˜1,000 m / min and laminated to the can. It is advisable to use a detention device for islands-in-the-sea composite fiber with 36 islands during spinning.                     

Next, the cans are arranged to draw a tow of 1.2 to 1.8 million denier at a drawing speed of 120 to 160 m / min, and a drawing ratio of 3.40 to 3.80 times, and then an emulsion is applied in a roller manner. When extending | stretching, it is preferable that the draw roller temperature is 45-95 degreeC, and the drawing duct temperature is 90-160 degreeC. Subsequently, an appropriate amount of squeegee of the oil is squeezed in the stuffing box-type crimper and the crimp is imparted. Then, heat treatment is performed at 120 to 160 ° C. for 0.5 to 2 minutes, cut and packaged to 51 mm to prepare an island-in-the-sea staple.

The physical properties of the island-in-the-sea staple prepared by the above process are 3.3-3.7 denier, the intensity is 3.7-4.3g / d, and the elongation is 60-90%. The number of crimps can vary depending on the application, but it is 15-23 mountains / inch and the fiber length is 47-54mm. The island-in-the-sea staples may be produced by adjusting physical properties according to use and product characteristics.

Crimping properties, which are the subject matter of the present invention, depend on several factors when crimping the tow in a crimper. Specifically, the main factors are the temperature and pressure of the crimper roller, the pressure of the stuffing box, and the amount of oil squeegeeing.

The compression of the crimper roller is a pressure that presses the supplied tow up and down, and may vary depending on the denier of the tow. However, when the tow is 1.2 to 1.8 million denier, 2.0 to 3.0 bar is preferable. The stuffing box pressure is preferably 1.50 to 2.50 bar, and the amount of squeegeeing of the oil is difficult to measure quantitatively, but the direction of the tow from the ground plane of the upper and lower rollers when viewed from the direction in which the tow is fed to the crimper. It is stable to squeeze within 3cm in the opposite direction.                     

In addition, it is recommended that the roller temperature, the main factor, be 20 ~ 30 ℃ so that the coolant can be continuously circulated in the upper and lower rollers to prevent overheating due to frictional heat and to prevent changes in outside temperature. If the roller temperature is out of the above range, the modulus of the tow may change and thus the crimp characteristic may become unstable.
According to the present invention, the crimping characteristics of the staples are not measured manually by hand, but mechanically measured in the staple toe state, and thus the reliability of the measurement data is very high. As a result, the measurement data can be used in the manufacturing process of the nonwoven fabric for artificial leather, so that the weight, thickness and density, which are the main quality factors of the nonwoven fabric for artificial leather, can be managed constantly.

delete

Nonwoven fabric for artificial leather of the present invention is characterized in that the crimping rate of the staple is 5 ~ 20%, the residual crimping rate is 3 ~ 10%, the crimp elastic modulus is 30 ~ 80%, characterized in that the nonwoven fabric for artificial leather is characterized by do. In addition, the density of the nonwoven fabric for artificial leather of the present invention is 0.15 ~ 0.25g / cm3.

The nonwoven fabric for artificial leather has a length change rate (hereinafter referred to as "ΔL") of 1.50 to 3.50 times of the nonwoven fabric after needle punching, and a width change rate (hereinafter referred to as "ΔW") of the nonwoven fabric after needle punching is 0.50 to 0.95 times. desirable.

The main quality factors for artificial leather nonwovens are weight per square meter, thickness of the nonwoven fabric (millimeters) and density (grams per cubic centimeter). Other factors include width (in centimeters), contamination, surface appearance, and length / width variations. In general, the weight, thickness and density of the nonwoven fabric are correlated items, and if the weight is large and the thickness is low, the density increases. High density nonwoven fabrics for artificial leather are advantageous in terms of morphological stability in post-processing and hair density in final products. The required density varies somewhat depending on the application and product type, but is usually in the range of 0.15 to 0.25 g / cm 3.

In addition, there are ΔL and ΔW as factors for measuring and managing the nonwoven fabric. [Delta] L denotes a constant distance A in the longitudinal direction of the laminated web coming out through the cross wrapper after opening and carding, and after measuring the gap B when the final winding is performed after needle punching, ) Is a measure of how much is increased, and ΔW measures the width (A) of the laminated web coming out through the cross-wrapper after opening and carding, and after measuring the width (B) when the final winding after needle punching This is an estimate of how much (B) is reduced compared to (A).

If ΔL decreases and ΔW increases, that is, if the length decreases less and the width decreases less, the density of the nonwoven fabric increases. It is easy to increase the density by decreasing the volume in the width direction, but the excessive shrinkage in the width direction means that the needle punching requires a lot of staples, so the entanglement caused by the needle punching is low. In other words, the density becomes low.

Therefore, the researchers of the present invention have analyzed the correlation between the crimp characteristics of the staples and the nonwoven fabrics ΔL and ΔW and obtained the following results. If the crimp rate is low (high crimp modulus is high), ΔL decreases and ΔW increases, resulting in an increase in density. Therefore, the crimp rate can be judged as the most important factor to be managed.                     

In the case of artificial leather island-in-the-sea staples, ΔL ranges from 1.50 to 3.50, preferably 1.90 to 3.00. ΔW is in the range of 0.50 to 0.95 and preferably in the range of 0.60 to 0.80. In the case of the island-in-the-sea staple for artificial leather manufacturing, the crimp rate measured by the method of the present invention is 5 to 20%, more preferably 10 to 17%. The crimp modulus is 30 to 80%, more preferably 35 to 70% in the case of island-in-the-sea staples as a ratio of the residual crimp rate and the crimp rate.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

Example 1 to Example 3

The polyamide having a relative viscosity of 2.55 is used as the island component, and the copolymerized polyethylene terephthalate having an insoluble viscosity of 0.55 and an intrinsic viscosity of 0.55 in an orthochlorophenol solution at 25 ° C is used as a sea component. The weight ratio of sea component to island component is shown in Table 1. The sea component was extruded with an extruder at 290 ° C and extruded with an extruder at 260 ° C, and then spun at a spinning temperature of 285 ° C with a spinner for 36 islands-in-the-sea composite fiber, and spun at 900 m / min. Undrawn yarn is produced at a winding speed, drawn at a draw ratio of 3.50, a drawing roller temperature of 80 ° C., and a drawing ductor temperature of 120 ° C., a crimper roller pressure of 2.8 bar, a temperature of 27 ° C., and a stuffing box pressure of 2.0 bar. After applying a low crimp and heat-treated at 140 ° C. for 1 minute with hot air to prepare a staple tow having a staple fineness of 3.5 denier and a total fineness of 1.5 million denier. Take 2m of the staple tow and leave it in the analysis room at 20 ° C. and 65% relative humidity for 12 hours, and then measure the number of crimps, crimp rate, residual crimp rate and crimp modulus 10 times using the crimp rate measuring device of the present invention. The standard deviation is shown in Table 1.

Comparative Example 1 to Comparative Example 3

One strand of the drawn staples prepared in Examples 1 to 3 was 51 mm long, and the average number and standard deviation of the crimp number, the crimp rate, the residual crimp rate, and the crimp modulus were measured ten times using the conventional KS0327 method. same.

Measurement result division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Sea component / island component weight ratio (%) 30/70 40/60 50/50 30/70 40/60 50/50 Crimp Average 18.5 18.3 18.0 18.7 19.2 19.6 Deviation 1.49 1.21 1.38 2.42 1.95 2.78 Crimp rate Average 10.4 10.7 11.1 5.8 6.7 7.9 Deviation 1.75 2.13 1.68 3.21 4.08 2.74 Residual crimp rate Average 6.4 6.1 5.9 3.2 2.8 2.7 Deviation 0.56 0.75 0.68 1.54 1.32 1.89 Crimp modulus Average 61.5 57.0 53.2 55.2 41.8 34.2 Deviation 7.56 9.77 8.38 12.64 13.47 16.80

In the present invention, since the crimping property of the staple is measured by the measuring apparatus of the present invention in the staple toe state, the measurement reliability is very high compared with the prior art. As a result, the measurement data of staple crimp characteristics can be used in the manufacturing process of nonwoven fabric for artificial leather, and as a result, changes in weight, density, and thickness of the nonwoven fabric for artificial leather can be minimized.

Claims (3)

delete Hook both ends of the staple toe to each of the two hooks 5a and 5b respectively installed on the vertical surfaces facing each other, and then pull the tow on one side with the tension adjusting roller 7 connected to the drive motor 2 and install it on the opposite vertical surface. Measurement method connected to the bottom of the hook (5b) to pull up the tensile weight mechanism (3) to the position attached to the sensor to detect the position of the operation, and then display a certain length on the staple toe (1) with the sample holder (4) Non-woven fabric for artificial leather, characterized in that consists of a seam-type staple with a crimp ratio of 5 to 20%, a residual crimp ratio of 3 to 10%, and a crimp elastic modulus of 30 to 80%. The nonwoven fabric for artificial leather according to claim 2, wherein the length change ratio (ΔL) of the nonwoven fabric after needle punching is 1.50 to 3.50 times, and the width change rate (ΔW) of the nonwoven fabric after needle punching is 0.50 to 0.95 times.

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