JPH07216676A - Polypropylene-based bulky composite yarn and its production - Google Patents

Abstract

PURPOSE:To produce a polypropylene-based bulky composite yarn having a strength elongation equal to that of a stretched filament yarn of a general polypropylene fiber and a high bulkiness. CONSTITUTION:This polypropylene-based bulky composite yarn composed of a stretched filament of an ethylene propylene copolymer fiber and a stretched filament of a polypropylene fiber and having 40% heat shrinkage factor at 130 deg.C dry heat temperature is produced by drawing and stretching unstretched filament yarns of an ethylene propylene copolymer fiber composed of an ethylene propylene random copolymer having 5 to 30g/10min melt index and unstretched filament yarns of a polypropylene fiber or drawing and stretching them while simultaneously applying an air treatment thereto under conditions of 3 to 6 draw ratio, 65 to 100 deg.C drawing temperature and 90 to 130 deg.C heat setting temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene bulky composite yarn and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, it has been known from JP-A-5-44108 that fibers made of an ethylene-propylene random copolymer containing a small amount of ethylene exhibit high shrinkability. However, all the known fibers are limited to short fibers or spun yarns thereof, and compounding with other fibers is also limited to mixed spinning.

[0003]

DISCLOSURE OF THE INVENTION The present invention is equivalent to a drawn filament yarn of a normal polypropylene fiber if an undrawn filament of a fiber made of an ethylene-propylene random copolymer is simultaneously drawn with an undrawn filament of a normal polypropylene fiber. This is due to the finding that a composite filament yarn having high bulkiness can be obtained while having the same strength and elongation, and an object of the present invention is to provide a filament having a strength and elongation equivalent to that of a normal polypropylene fiber stretched filament yarn. And a polypropylene bulky composite yarn having high bulkiness.

[0004]

Means for Solving the Problems That is, the present invention is as follows: 1) Melt index 5 to 30 g / 10 min (23
(Measured at 0 ° C.), a polypropylene-based bulky composite yarn composed of an ethylene propylene random copolymer having a heat shrinkage of 40% or more at a dry heat temperature of 130 ° C. and a polypropylene fiber drawn filament, and 2. ) Melt index 5 to 30 g / 10 min (23
(Measured at 0 ° C.), an undrawn filament yarn of ethylene propylene copolymer fiber consisting of an ethylene propylene random copolymer and an undrawn filament yarn of polypropylene fiber are drawn at a draw ratio of 3 to 6 and a drawing temperature of 65 to 100 ° C.
A method for producing a polypropylene-based bulky composite yarn, which is characterized in that a heat-setting temperature of 90 to 130 ° C. is used for parallel drawing and simultaneous air drawing and drawing.

The polypropylene bulky composite yarn of the present invention comprises an ethylene propylene copolymer fiber stretched filament and a polypropylene fiber stretched filament. One of the ethylene propylene copolymer fiber drawn filaments constituting the composite yarn is ethylene propylene containing 3 to 7% by weight of ethylene having a melt index (hereinafter referred to as MI) of 5 to 30 g / 10 min measured (230 ° C.) according to JIS K7210. It consists of a random copolymer. The other polypropylene fiber stretched filament is not particularly limited and is made of polypropylene having MI of about 10 g / 10 min, which is used for ordinary polypropylene fibers.

If the MI of the ethylene-propylene random copolymer is less than 5 g / 10 min, the melting temperature must be set to a high temperature during the spinning of the undrawn filament yarn, which deteriorates the spinning stability and pigment colorability, and the MI of 30 g / min. 1
If it exceeds 0 min, the spinning stability is deteriorated, but the fiber strength of the drawn filament yarn is lowered.

Further, in the polypropylene bulky composite yarn of the present invention, the ethylene propylene copolymer fiber stretched filament which is a constituent component of the polypropylene bulky composite yarn is 4 at a dry heat temperature of 130 ° C.
It has a heat shrinkage rate of 0% or more.

The ethylene propylene copolymer fiber drawn filament and the polypropylene fiber drawn filament are
The single fiber fineness is not limited and may be any fineness, and the fiber cross section may be a circular cross section, a modified cross section such as a triangle, or a primary dye fiber containing a coloring pigment. Good.

In the production of the polypropylene bulky composite yarn of the present invention, the unstretched filament yarn of ethylene-propylene copolymer fiber has MI of 5 to 30 g / 10 min.
The ethylene propylene random copolymer (measured at 230 ° C.) is extruded at a temperature of 230 to 285 ° C. and the spinning speed is 300 m.
It is obtained by melt-spinning at a speed of not less than / min and taking it up. The undrawn filament yarn of polypropylene fiber can be obtained under any known condition.

In the present invention, it is essential that undrawn filament yarn of ethylene-propylene copolymer fiber and undrawn filament yarn of polypropylene fiber are aligned and drawn. Alignment stretching is performed at a stretching ratio of 3 to 6 times, a stretching temperature of 65 to 100 ° C, and heat setting at a temperature of 90 to 130 ° C.

When the draw ratio is less than 3 times, the strength and elongation of the obtained composite yarn are lowered, and when it exceeds 6 times, the stability of yarn making is lowered. If the drawing temperature is less than 65 ° C, high-strength drawing cannot be performed, and the strength of the composite yarn is lowered, and the spinning stability is also lowered. If the stretching temperature is more than 100 ° C, the spinning stability is lowered.
Further, as the heat setting, any method such as a hot plate method and a roller method is used, but if the heat setting temperature is lower than 90 ° C., the obtained composite yarn shrinks with time even at room temperature, and the weather resistance is lowered. If it exceeds 130 ° C., the stability of yarn production decreases.

By the above-mentioned drawing and stretching, the unstretched filament yarn of polypropylene fiber is simultaneously stretched, and at the same time, the unstretched filament yarn of ethylene propylene copolymer fiber is stretched, and the stretched filament of polypropylene fiber is given ordinary heat shrinkability. However, the drawn filament of ethylene propylene copolymer fiber has a dry heat temperature of 13
Thermal shrinkage at 0 ° C is 40% or more, preferably 50%
The heat shrinkability described above is imparted, and high bulkiness is imparted to the composite yarn due to the high shrinkability of one of the constituent components.

In the present invention, the unstretched filament yarn of the ethylene-propylene copolymer fiber and the unstretched filament yarn of the polypropylene fiber can also be air-processed by blowing hot air at the same time as drawing and stretching. By such simultaneous air drawing and drawing, it is possible to obtain a bulky composite yarn having a worsted appearance. Further, in air processing, it is possible to serve both as heating during stretching and heating as a heat set.

The polypropylene-based bulky composite yarn of the present invention has a high bulkiness while having the same strength and elongation as a filament yarn made only of ordinary polypropylene fibers, and has a high component of ethylene propylene by heat treatment. The stretched filament of the copolymer fiber contracts, the stretched filament of the polypropylene fiber becomes a loop, and the bulkiness is developed. The loft can be expressed in the state of yarn, but if the woven or knitted woven fabric or knit is subjected to heat treatment, the loft is expressed in the constitution of the woven or knitted fabric. As the heat treatment for expressing the bulkiness, a dry heat treatment at a temperature of 110 to 130 ° C. is preferably applied.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples. The bulkiness of the fabric and the composite yarn was measured as follows.

Bulkiness of the fabric: The thickness of the fabric was measured and shown by the bulk increase rate of the following formula. Bulk increase rate (%) = (fabric thickness after heat treatment / fabric thickness before heat treatment−
1) x 100

Bulkiness of the composite yarn: A skeleton-shaped sample is placed on a measuring table having a width of 1 cm and a length of 4 cm, and a load of 20 g is placed on the sample. After 1 minute, the height H (cm) of the sample is read. The sample protruding from the measuring table was cut off, the weight X (g) of the sample on the measuring table was measured, and it was shown by the bulk volume and the rate of increase in volume of the following formulas. Bulk volume V (cm ³ / g) = 4H / X Bulk increase rate (%) = (V _S / V _O −1) × 100 V _S : Inventive yarn bulk volume, V _O : Standard yarn bulk volume Standard yarn: Polypropylene fiber Unstretched filament Aligned drawn yarn

(Example 1) Using an ethylene-propylene random copolymer having MI of 10 g / 10 min, a melt extruder was used to extrude temperature 1st zone 240 ° C, 2nd-4th zone 2.
70 ° C., spinning temperature 270 ° C., spinning speed 300 m / min
To obtain 550 denier (d) / 80 filaments (f) of undrawn yarn of ethylene propylene copolymer (EP) fiber. On the other hand, using polypropylene of MI10g / 10min, the extrusion temperature in the first zone 2 by the melt extruder.
40 ° C, second to fourth zones 270 ° C, spinning temperature 270 ° C,
Spinning was performed at a spinning speed of 300 m / min to obtain 680 d / 120 f undrawn yarn of polypropylene (PP) fiber.
These two types of undrawn yarns were aligned and drawn at a draw ratio of 4.72 times, a drawing temperature of 70 ° C and a heat setting temperature of 115 ° C to obtain a composite yarn. The drawn filament of EP fiber of the obtained composite yarn had a strength of 4.72 g / d, an elongation of 47.1%, and a heat shrinkage ratio of 66.9% (130 ° C. × 15 min). A knitted fabric knitted using this composite yarn is dried at 120
Table 1 shows the bulkiness of the knitted fabric obtained by heat treatment at ℃. In addition, 680 d / 120 f undrawn yarns of PP fiber were aligned and drawn under the same conditions to obtain standard yarns, and similarly knitted fabrics, and their bulkiness are shown in Table 1.

[0019]

[Table 1]

(Example 2) 5 of the EP fiber obtained in Example 1
50d / 80f undrawn yarn and PP fiber 680d / 12
The undrawn yarn of 0f was subjected to simultaneous drawing and air processing at a drawing ratio of 3.88 times and a hot air temperature of 100 ° C. by a simultaneous drawing air processing machine to obtain a composite yarn. The obtained composite yarn was a worsted composite processed yarn having a crimped loop. The bulkiness of the obtained composite yarn is shown in Table 2. Also, 68 of PP fiber
The unstretched yarns of 0d / 120f were aligned and drawn and air-processed simultaneously under the same conditions to obtain standard processed yarns, and the bulkiness thereof is shown in Table 2.

[0021]

EFFECTS OF THE INVENTION The polypropylene bulky composite yarn according to the present invention has high bulkiness while having the same strength and elongation as the stretched filament yarn of ordinary polypropylene fiber only. When the composite yarn of the present invention is used, for example, bulkiness is exhibited when heat treatment is applied, and for example,
It is suitable as a material in various fields including industrial material fields, such as a high-density woven or knitted fabric that can be used for a filter or the like, and a woven or knitted fabric that can be applied to a carpet or the like and has a volume feeling.

[Table 2]

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Claims (2)

[Claims] 1. A melt index of 5 to 30 g / 10 m
A polypropylene-based bulky composite yarn made of in-ethylene random copolymer (measured at 230 ° C.) and having a heat shrinkage ratio of 40% or more at a dry heat temperature of 130 ° C. and polypropylene polypropylene drawn filament. 2. A melt index of 5 to 30 g / 10 m
An unstretched filament yarn of ethylene-propylene copolymer fiber made of in-ethylene random copolymer (measured at 230 ° C.) and an unstretched filament yarn of polypropylene fiber were drawn at a draw ratio of 3 to 6 and a drawing temperature of 65 to 5.
A method for producing a polypropylene-based bulky composite yarn, which comprises performing parallel drawing and simultaneous parallel drawing and air processing at 100 ° C. and a heat setting temperature of 90 to 130 ° C.