JPH06207337A - Polyamide pile yarn for artificial lawn and its production - Google Patents

Abstract

PURPOSE:To provide a polyamide pile yarn for artificial lawn having excellent and balanced tufting property (collectability), crimpness, durability (strength retention) and settling resistance (decrease in thickness) and provide a process for the production of the yarn in high efficiency. CONSTITUTION:The objective pile yarn is produced by continuously and successively carrying out a step for the melt-spinning of nylon 66 in the form of a yarn having flat cross-section, a step to cool the spun yarn in a cold medium of 2-60 deg.C and immediately draw 2.5-4.5 times in a thermal medium of 40-90 deg.C and a step to transfer the drawn yarn to a heat-setting machine and a pneumatic false-twisting nozzle placed at the back of the heat-setting machine and subject the yarn to pneumatic false-twisting and crimping under dry-heat condition under an air pressure of 1-7kg/cm<2> at 150-250 deg.C and a relaxation ratio of 0.95-0.80. The obtained pile yarn is composed of a multifilament yarn having a single fiber fineness of 100-1,000d and a total fineness of 1,000-8,000D. The number of twist per 1m of the single yarn is 30-200, the shrink restoration ratio measured in conformity to JIS L1090 is 1-5% and the strength retention is >=40% after 3 months outdoor water-immersion exposure test.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide pile yarn having suitable properties for artificial grass and an efficient method for producing the same.

[0002]

2. Description of the Related Art Recently, as various sports have become active, the frequency of use of the stadium has increased. Therefore, a stadium that is easy to maintain and is not easily affected by the weather has been demanded. In fields such as tennis courts, soccer fields, hockey fields, golf fields and gateball courts, artificial grass has become popular as a substitute for natural grass or clay court.

Conventionally, artificial lawns have been produced by using synthetic resin such as polyamide, polypropylene and polyvinylidene chloride as a desired green-colored resin material, which is melt-spun to form a flat yarn or a film.
It is manufactured by cutting a tape or splitting split yarn into a pile yarn and tufting the pile yarn on a base fabric by an appropriate method.

Among them, artificial grass using flat yarns made of polyamide resin such as polycaproamide (hereinafter referred to as nylon 6) and polyhexamethylene adipamide (hereinafter referred to as nylon 66) has a feeling. It is suitable for stadiums and widely used because of its excellent resistance to settling.

[0005] Since the pile yarn as the artificial yarn for the artificial lawn is required to have a covering property with respect to the base fabric, it is made into a plurality of aggregates, which are crimped for practical use. Is customary.

[0006] By the way, as a crimping method of the above-mentioned raw yarn for artificial lawn, for example, a wet heat treatment method using steam is generally adopted, such as a method described in Japanese Patent Publication No. 62-14659 or a processing method using a stuffer box. However, in most of these methods, a two-step twisting method that is offline is used, and there is a problem that the manufacturing process is complicated and the cost is increased.

Further, as an important characteristic required for the crimped pile yarn, there is a focusing property when tufting the base fabric. That is, if the pile yarn does not have a good binding property, the single yarns are separated during tufting, and troubles such as disengagement from the looper of the tuft machine and miscuts of the single yarns occur. Therefore, it is necessary to add more sufficient entanglement to obtain a pile yarn having excellent sizing properties.

However, although the conventional yarn for artificial grass made of polyamide resin originally has excellent sizing and crimping properties, in order to further improve the sag resistance thereof, the above-mentioned wet heat treatment method is used. Had to be manufactured by. However, the nylon 6-based raw yarn for artificial grass obtained by this moist heat treatment method has a problem that its weather fastness is inferior and strength cannot be maintained satisfactorily. In the field where weather fastness is required, nylon 66 is used. It was customary to use raw yarns for artificial grass made from.

In other words, artificial lawns are often attached to the outside in general, and are easily deteriorated by light or the like due to constant exposure to sunlight and severe weather.
Even if it is an artificial lawn using flat pile yarn made of nylon 6 type resin with excellent fatigue resistance, its characteristics will gradually deteriorate due to changes with time since it was attached to the stadium, and the original strength and texture etc. It included the drawback of being hindered.

Therefore, in the field where weather fastness is particularly required, a raw yarn made of nylon 66 is actually used. However, nylon 66 has a higher spinning temperature than nylon 6 and is a polymer. Since the gelation of (3) is likely to occur, the spinnability is inferior, which causes a problem of increasing cost.

[0011]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of investigations to solve the problems of the conventional polyamide-based pile yarns for artificial grass made of the above-mentioned polyamide-based resin.

Therefore, an object of the present invention is to provide a polyamide-based pile yarn for artificial lawn which is excellent in balance of tufting property (bunching property), crimpability and durability (strength retention rate), and this polyamide for artificial grass. An object of the present invention is to provide a method for efficiently producing a system pile yarn with excellent productivity.

[0013]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have conducted a crimping process on a nylon 66 type multifilament having a flat cross section by air-drying under dry heat conditions. The present inventors have found that a polyamide-based pile yarn for artificial grass, which has excellent properties that have never been obtained before, can be efficiently produced by continuously and consistently twisting and crimping, and arrived at the present invention.

That is, the polyamide-based pile yarn for artificial grass of the present invention has a substantially flat cross-sectional shape, a single yarn fineness of 100 to 1000 denier (d), and a total fineness of 1000 to.
Consisting of 8000 denier (D) nylon 66 multifilament, the number of alternating twists per meter of single yarn: 3
It is characterized in that it has characteristics of 0 to 200 times, expansion and contraction recovery rate measured by JIS L1090: 1 to 5%, and strength retention rate after 40 months of outdoor water immersion exposure test: 40% or more.

Further, the method for producing a polyamide pile yarn for artificial lawn of the present invention comprises the steps of melt-spinning nylon 66 resin as a flat cross section yarn using a nozzle having slit-shaped spinning holes, and spun yarn. Is cooled in a refrigerant of 2 to 60 ° C., and then immediately in a heating medium of 40 to 90 ° C. for 2.5 to
The step of drawing 4.5 times, the drawn yarn is subjected to a heat treatment machine and an air false twisting nozzle provided in the latter stage of this heat treatment machine, and compressed air pressure is 1 to 7 kg / cm ² , temperature is 150 to 250 ° C., and relaxation rate is 0. It is characterized in that the step of imparting the false false twist crimps is continuously and consistently performed under a dry heat condition of 0.95 to 0.80.

Nylon 66 is mainly used as the polyamide resin for forming the raw yarn for artificial grass of the present invention. Nylon 66, nylon 12 and the like are contained in a small proportion within a range not impairing the object of the present invention. It may be a copolymer or polymer blend containing.

The nylon 66 used is a weather resistant agent,
It may contain conventional additives such as light fastness agents, heat resistance agents, colorants, plasticizers, flame retardants and lubricants.

Next, the constitution and effect of the present invention will be described in detail. First, the method for producing the polyamide-based pile yarn for artificial lawn of the present invention will be explained, and then the characteristics of the obtained polyamide-based pile yarn for artificial lawn will be explained. To do.

When the polyamide pile yarn for artificial grass of the present invention is manufactured, nylon 66 having a flat cross section is used.
It is important to perform the crimping process for multifilaments by a consistent combination of air false twisting and dry heat crimping.

This manufacturing method will be described below with reference to FIG. FIG. 1 is a schematic explanatory view showing the manufacturing process of the present invention.

In FIG. 1, 1 is a melt spinning machine, 2 is a nozzle, 3 is a cooling bath, 4 is a first drawing roller, 5 is a second drawing roller, 6 is a third drawing roller, 7 is a take-up roller, and 8 is a drawing roller. First
A drawing bath, 9 is a second drawing bath, 10 is a heat treatment machine, 11 is a false twist nozzle, and 12 is a winding machine.

When the polyamide pile yarn for artificial grass of the present invention is manufactured by the process shown in FIG. 1, nylon 66 is first subjected to the melt spinning machine 1 and melt kneaded to have slit-shaped spinning holes. Melt-spun as a multifilament using the flat cross-section yarn A as a single yarn by using the nozzle 2, cool in a cooling bath 3 containing a refrigerant of 2 to 60 ° C., and then immediately draw a heating medium of 40 to 90 ° C. The first drawing roller 4, the second drawing roller 5, and the third drawing roller 6 draw in the baths 8 and 9 by a factor of 2.5 to 4.5 to obtain a drawn yarn B.

In this case, since the pile yarn has a texture close to that of natural grass, the spun yarn needs to be a flat cross-section yarn A having a cross-section ratio of about 5 to 20, and the drawn stretched yarn B is drawn. The monofilament fineness of No. 1 differs depending on the use of artificial grass, for example, the type of stadium such as tennis, gateball, baseball and soccer, but the range of 100 to 1000 denier (d) is preferable, and the total fineness of multifilament is , 1000
It is preferably in the range of ˜8000 denier (D).

Next, the stretched drawn yarn B is crimped in order to satisfy the tufting property (bunching property) and the sag resistance against the base fabric.

In this crimping process, the drawn yarn B drawn immediately is immediately followed by the heat treatment machine 10 and the heat treatment machine 1.
0 to the air false twisting nozzle 11 provided in the latter stage, and the compressed air pressure is 1 to 7 kg / cm ² , particularly ² to 5 kg / cm ² , temperature: 15
0-250 ° C, especially 180-220 ° C, relaxation rate: 0.
It is carried out by continuously and consistently performing the step of applying false false twist crimps under dry heat conditions of 95 to 0.80, particularly 0.90 to 0.85.

That is, in this crimping process,
At the same time that the plurality of drawn yarns B discharged from the heat treatment machine 10 are twisted by the air false twisting nozzle 11,
It is heat set by the heat treatment machine 10. More specifically, the twist applied to the drawn yarn B by the air false twisting nozzle 11 is propagated and goes back through the heat treatment machine 10 to reach the third drawing roller 6, and the drawn yarn B passing through the heat treatment machine 10 is Here, it is heat-fixed in a single twist state. And
The plurality of drawn yarns B to which the single twist is applied are untwisted in the opposite twist direction when passing through the air false twist nozzle 11.
The pile yarn C is alternately twisted, and this pile yarn C
Is then wound onto the bobbin via the take-up roller 7.

The degree of crimping in this crimping process is
It is desirable that the number of alternating twists per 1 m of the length of the single yarn is in the range of 30 to 200 times, preferably 40 to 100 times,
Further, the air flow rate from the false-twisting air nozzle 9 is 20 to 17
0 n · l / min, particularly 50 to 130 n · l / min is preferred.

The compressed air pressure in the crimping process is 1 kg / cm.
^If it is less than ² , the crimp is weak and the expansion and contraction recovery rate is low.
If it exceeds / cm ² , the process loss increases, which is not preferable.

The temperature in the crimping process is 150
When the temperature is lower than 0 ° C, the expansion / recovery rate is low, and when the temperature is higher than 250 ° C, the filaments tend to be fused, which is not preferable.

Further, when the relaxation rate in the crimping step exceeds 0.95 and is less than 0.80,
This is not preferable because the number of alternating twists becomes low.

It should be noted that the above-mentioned degree of the alternating twist number is the third.
It can be adjusted by the rotation ratio of the stretching roller 6 and the take-up roller 7, the air pressure of the false-twisting air nozzle 11, the air flow rate, and the like. For example, the number of alternating twists is 30 to 200 times /
To obtain m, the rotation ratio of the third stretching roller 6 and the take-up roller 7 is 1.0: 0.95 to 0.80, and the air pressure is 1 to 7 kg.
/ Cm ² , and the air flow rate is preferably 20 to 170 n · l / min.

The space temperature in the dry heat treatment machine 10 is 15
It is desirable to maintain a constant temperature in the range of 0 to 250 ° C.

Thus, the polyamide-based pile yarn for artificial lawn of the present invention obtained by an efficient dry heat treatment method is cut into an appropriate length and is flocked to a base cloth by a usual method, but crimped. Number of alternating twists 30 to 20 suitable for the flexibility and the focusing property
Since it has a characteristic of 0 times / m, it has excellent tufting properties to the base fabric and has an excellent expansion and recovery rate of 1 to 5%.

Further, it has a high weather resistance with a strength retention of 40% or more after 3 months of an outdoor water immersion exposure test, and more preferably has a sag resistance (thickness reduction rate measured by the method of JIS L1021). ) Also has a characteristic of not more than 60%, it is possible to obtain an artificial lawn which is excellent in weather resistance and does not cause falling of pile even after long-term use.

The constitution and effects of the polyamide-based pile yarn for artificial grass of the present invention will be further described below with reference to examples.

[0036]

Example: The relative viscosity ηr measured by the 98% sulfuric acid method was 3.
A mixture of Nylon 66 of No. 2 and green master chips for shaving was supplied to a melt spinning machine, melted at 290 ° C., extruded from a substantially flat spinneret nozzle, and cooled in a cooling bath of 40 ° C.

Then, the spun yarn was immediately drawn 3.0 times in a first drawing bath consisting of a hot water bath at 70 ° C. and 1.3 times in a second drawing bath consisting of a hot water bath at 90 ° C. Then, subsequently, 10 drawn yarns were bundled, and this was dried at a space dry heat temperature of 200
It is introduced into a heat treatment machine having a relaxation rate of 0.9 at a temperature of 0.9 ° C., and air having a compressed air pressure of 5 kg / cm ² is blown from an air false twisting nozzle provided in the latter stage of the heat treatment machine, at a speed of 180 m / min to about 1. Dry heat relaxation heat treatment was performed for 3 seconds to obtain a pile yarn (single yarn fineness 300d, total fineness 3000D) that was alternately twisted (Example 1).

In the above method, the dry heat temperature in the heat treatment machine, the relaxation rate, and the pneumatic pressure from the air false twist nozzle were changed as shown in Table 1 to further increase the temperature.
A variety of pile yarns (Examples 2-6 and Comparative Examples 2-4) were produced.

A pile yarn (Comparative Example 1) was manufactured by a wet heat treatment method using a wet heat treatment machine consisting of a steam atmosphere having a steam pressure of 2 kg / cm ² instead of the above heat treatment machine.

In the same manner, using nylon 6 having a relative viscosity ηr of 3.4, two types of pile yarns (Comparative Examples 5 to 6) were produced under substantially the same conditions as above.

Table 1 also shows the results obtained by measuring the number of alternating twists, the expansion recovery ratio, the tenacity retention ratio, and the sag resistance of the 12 types of pile yarns obtained above by the following methods.

Number of alternating twists: The false twisted yarn is formed into a skein shape, treated in boiling water for 30 minutes, and air-dried for 24 hours. Next, one air-dried single yarn was taken out and fixed with a tension of 2 mg / denier applied, and an S-shape per unit length and Z
The number of alternate twists in a letter shape is read and the number of alternate twists per 1 m is calculated.

Stretch recovery rate: Measured according to the method of JIS L1090.

Tensile strength retention: After the pile yarn was immersed in a water tank and exposed to outdoor sunlight for 3 months, the tenacity retention was calculated from the strength (JIS L 1013) measurement results before and after this treatment. .

Sag resistance: Measured according to JIS L1021 test item (11) Method A (thickness reduction rate by dynamic load).

[0046]

[Table 1]

As is clear from the results shown in Table 1, all of the polyamide-based pile yarns for artificial grass obtained by the method of the present invention have tufting property (bunching property), crimp property and durability (strength retention rate). Well balanced and even nylon 6
It has very good sag resistance (thickness reduction rate) compared to the series pile yarn.

[0048]

As described in detail above, the polyamide-based pile yarn for artificial grass of the present invention has tufting property (bunching property), crimp property, durability (strength retention rate) and sag resistance ( The thickness reduction rate is balanced and excellent. Further, according to the manufacturing method of the present invention, the pile yarn having the above performance can be efficiently manufactured with excellent productivity by the dry heat treatment method which is processally advantageous.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a manufacturing process of the present invention.

[Explanation of symbols]

 1 Melt Spinner 2 Nozzle 3 Cooling Bath 4 First Stretching Roller 5 Second Stretching Roller 6 Third Stretching Roller 7 Take-up Roller 8 First Stretching Bath 9 Second Stretching Bath 10 Heat Treatment Machine 11 False Twisting Nozzle 12 Winder

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area D02J 1/22 L

Claims (2)

[Claims] 1. A single yarn fineness of 100 to 1000 denier (d) and a total fineness of 1000 to 1000 having a substantially flat cross-sectional shape.
Consisting of 8000 denier (D) polyhexamethylene adipamide-based multifilament, the number of alternating twists per 1 m of single yarn: 30 to 200 times, expansion and recovery rate measured by JISL1090: 1 to 5%, outdoor water Immersion exposure test 3
Strength retention after a lapse of months: A polyamide pile yarn for artificial grass, which has characteristics of 40% or more. 2. A step of melt spinning a polyhexamethylene adipamide resin as a flat cross-section yarn using a nozzle having slit-shaped spinning holes, and cooling the spun yarn in a refrigerant at 2 to 60 ° C. Then, a step of immediately drawing 2.5 to 4.5 times in a heat medium at 40 to 90 ° C., the drawn yarn is subjected to a heat treatment machine and an air false twisting nozzle provided in a subsequent stage of the heat treatment machine, and compressed air pressure 1 to 7 kg / cm ² , temperature: 150-250
The artificial having the characteristics according to claim 1, wherein the step of applying the false-twisted air crimp is continuously and consistently performed under dry heat conditions of ° C and a relaxation rate of 0.95 to 0.80. Method for manufacturing polyamide-based pile yarn for lawn.