KR19990060534A - Polyester yarn for seat belt and manufacturing method thereof - Google Patents

Abstract

The present invention melt-spun polyester chips having an intrinsic viscosity of 0.8 ~ 1.4 with a hollow nozzle designed under specific conditions, drawing, heat treatment 4 to 35% of hollowness, strength of more than 8.5g / d and excellent comfort It relates to a polyester hollow fiber for the belt and a method of manufacturing the same.

Description

Polyester yarn for seat belt and manufacturing method thereof

The present invention relates to a polyester yarn for seat belt with improved comfort properties and a method of manufacturing the same. More specifically, high-strength polyester chips are spun after spinning using a hollow nozzle or spin-stretched directly to spin yarn. It is about 8.5 ~ 9.0g / d level and the yarn defects to less than 1.0 per 10 km to a hollow polyester yarn for comfort improved seat belt, characterized in that the method and a manufacturing method.

In the present invention, the seat belt refers to a seat belt mounted on a car. The comfort of the seat belt refers to the property that the driver slips out smoothly and enters well when the driver pulls out the belt attached to the car by hand. In other words, when the seat belt is removed and inserted, the comfort property is determined to be good or bad according to the friction property between the belt and the plastic guide. If the friction is small, the comfort property is good, and if the friction is large, the comfort property is disadvantageous.

In addition, this comfort is related to the spring of the seat belt and the kind of softening agent that smoothes the belt surface, but the present invention focuses on the yarn-related part irrespective of this.

This seat belt composure is not required in Korea yet, but is required in recent years in Europe and America.

Therefore, the inventors found that the factors related to the comfort properties were significantly related to the bending stiffness of the yarn. In addition, this bending stiffness is different according to the yarn type, and in general, the solid type has a low value while the hollow type has a high value.

The object of the present invention is to provide a polyester yarn and a method of manufacturing the same to increase the bending stiffness of the yarn, which is a factor highly related to the comfort, in order to provide a seat belt having excellent comfort.

1 is an explanatory diagram of a hollow yarn of the present invention.

2 is a plan view of a hollow nozzle used in the present invention.

3 is a view for explaining a method for evaluating the comfort of a seat belt.

Hereinafter, the present invention will be described in detail.

Bending stiffness can be expressed as follows.

B / R = (1 × η × Ef × T ² ) / 4π × r × ρ... … … … … (One)

In the common sense

B / R = bending stiffness

η = shape factor

Ef = initial modulus of yarn

T = single yarn fine yarn

r = radius of curvature

ρ = density

In the above formula, since the size of the seat belt yarn is limited to 1000/72, 1300/96, 1500/144, etc., the T value is fixed, and the Ef value is related to the strength of the yarn. Since this decision is made, there is not much variation in the value. For example, the yarn strength of 1300/96 averages 8.8 ~ 9.0g / d, and the initial modulus (under 5% elongation) is 3.8 ~ 4.0g / d. Therefore, the change of the value is not so large.

r is the radius of curvature of the yarn on the unit structure of the fabric, and since the structure of the seat belt is usually limited, there is little variation in this value. ρ is the density of the fabric and can not be changed arbitrarily because the belt structure is set.

Therefore, it is the cross-sectional shape of the yarn that can be adjusted by the yarn company. That is, the yarn cross section can be transformed into a rectangle, a square, a hollow cone, etc. Among them, the highest form factor value is a hollow cross section yarn.

In general, solid yarns have a shape factor of 1, while hollow yarns vary in value depending on the hollow ratio, but have a shape factor of 2-5. Therefore, the high form factor makes the bending rigid box high and the comfort is good.

On the other hand, the hollow form factor η is given by the following equation, which is explained in detail in FIG.

Where Am is the area of the circle minus the hollow area.

ℓ: radius from the center of the circle

Ao: Total area of the circle, including hollow

Ai: hollow area

According to the above formula, the larger the hollow area (that is, the larger the hollowness), the higher the shape coefficient value (η).

Hollowness as referred to herein means hollow area / divisional area (FIG. 1). The strength of hollow polyester yarns that meet the required characteristics of the seat belt shall be not less than 8.5 g / d. In addition, when the hollowness is too high in the hollow fiber yarns, the elongation and yarn strength are lowered, and when the hollowness is too low, the bending rigidity value is low, and there is no effect of improving the comfort property.

The hollow polyester yarn of the present invention satisfies the following conditions.

next

Holity: 4 ~ 35%

Strength: 8 ~ 5g / d or more

Comfort

F; 1,500 g or more

F ₁ ; More than 420g

F ₁ / F × 100; 23% or more

F: Pulling the seat belt

F ₁ : The strength of the seat belt

In addition, the hollow polyester yarn of the present invention is produced by the following method.

Using a hollow nozzle that satisfies the following conditions are melt spun polyester chips of intrinsic viscosity 0.8 ~ 1.4, preferably 0.9 ~ 1.2, stretched to a total draw ratio of 5.5 ~ 6.5 and heat-treated at 180 ~ 240 ℃.

next

1 ≤ w / r ≤ 10

0.01 m ≤ w (mm) ≤ 0.5

0.1 ≤ a (mm) ≤2.0

Where r is the radius of the inner circle

w: width of slits

a: slitting interval

At this time, the melting temperature was set to 290 ~ 305 ℃, and cooled to 15 ~ 30 ℃ after melt spinning.

For concentration of the yarn, the water-soluble emulsion is tanned so that the pickup rate is 0.5 to 1.2% by weight.

Winding the yarn prepared as described above at 450 ~ 550m / min, but heat-treated at 180 ~ 240 ℃ before winding.

3 is a schematic diagram of a comfort tester.

The polyester yarn of the present invention has a low F value and a higher F ₁ value, so that the comfort is excellent. Also highly higher the hollow Fig. F ₁ / F value, the hollow detective high F ₁ / F value than the solid criminal.

EXAMPLES 1-6

A polyester hollow fiber of 1300 denier / 96 filaments was manufactured under the conditions of Table 1, with a polyester chip having an intrinsic viscosity of 0.90 at a spinning cylinder temperature of 300 ° C, a cooling temperature of 20 ° C, and a thermal setting temperature of 220 to 235 ° C. The results are shown in Table 1.

TABLE 1

As shown in the above table, the lower the hollowness, the higher the yarn strength, but the lower the comfort property, and the higher the hollowness, the lower the yarn strength and the elongation, and the better the comfort.

Example 3 The conditions showed the best physical properties, elongation and comfort.

[Comparative Examples 1-5]

Manufactured as in Example, but prepared under the conditions of Table 2 using a solid nozzle. The results were shown in Table 2.

TABLE 2

As can be seen from Table 2, the solid form does not satisfy the comfort properties compared to the hollow form under any conditions.

The present invention can easily produce a hollow polyester yarn having excellent comfort when made of a seat belt by using a hollow nozzle of a certain standard.

Claims (2)

Polyester hollow fiber for seat belts satisfying the following conditions next Holity: 4 ~ 35% Strength: 8 ~ 5g / d or more Comfort F; 1,500 g or more F ₁ ; More than 420g F ₁ / F × 100; 23% or more F: Pulling the seat belt F ₁ : The strength of the seat belt Polyester yarns for seat belts, characterized in that for manufacturing a polyester hollow fiber by melt spinning, stretching and heat-treating polyester chips having an intrinsic viscosity of 0.8 ~ 1.4 using a hollow nozzle satisfying the following conditions: Its manufacturing method. next 1 ≤ w / r ≤ 10 0.01 m ≤ w (mm) ≤ 0.5 0.1 ≤ a (mm) ≤2.0 Where r is the radius of the inner circle w: width of slits a: slitting interval