JPH0617338A - Polyamide piled yarn for artificial turf its production - Google Patents

Abstract

PURPOSE:To provide the polyamide piled yarn used for artificial turfs and excellent in the balance of the tufting property (collecting property), the crimping property and the durability (strengthretaining rate), and to provide the method for effectively producing the same. CONSTITUTION:A process for melt-spinning nylon 6 into filaments each having a flat cross section, a process for cooling the spun filaments in a 2-60 deg.C medium and subsequently drawing the cooled filaments into a 2.5-4.5 times length in a 40-90 deg.C hot medium, and a process for feeding the drawn filaments into a thermal treatment machine and into an air false-twisting nozzle disposed behind the thermal treatment machine and subsequently subjecting the fed filaments to an air false-twisting crimping treatment under dry-heating conditions comprising an air pressure of 1-7kg/cm<2>, a temperature of 120-220 deg.C, and a relaxation degree of 0.95-0.80 are continuously and consistently performed. The obtained pile yarn comprises multifilaments having a single filament fineness of 100-700d and a total fineness of 1000-5000d, and has characteristics comprising an alternating twist number of 30-200 times per 1 meter of the single filament, an elastic recovery measured by the JISL 1090, and a strength retention constant of >=40% after an outdoor water-immersed exposure test is performed for 3 months.

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 raw yarn for artificial grass made of nylon 6 is originally excellent in bundling property and crimping property, in order to further improve its sag resistance,
It was necessary to manufacture by the above-mentioned wet heat treatment method. However, the nylon 6-based raw yarn obtained by this wet heat treatment method has a problem that its weather fastness is inferior and strength cannot be maintained well.

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 having excellent tufting property (bunching property), crimping property and durability (strength retention ratio), and an efficient method for producing the same. To provide.

[0013]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have conducted a crimping process on a polycaproamide-based 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 having excellent properties that has not been obtained can be efficiently produced by continuously and consistently performing false twist 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 700 denier (d), and a total fineness of 1000 to 5.
6,000 denier (D) polycaproamide-based multifilament, the number of alternating twists per meter of single yarn:
It is characterized by having characteristics of 30 to 200 times, expansion and contraction recovery rate measured by JISL1090: 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-based pile yarn for artificial grass of the present invention comprises a step of melt-spinning a polycaproamide-based resin as a flat cross-section yarn using a nozzle having slit-shaped spinning holes, and a spun yarn. The strip 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 hours.
˜4.5 times drawing process, 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, compressed air pressure is 1 to 7 kg / cm ² , temperature: 120 to 220 ° C., relaxation rate: It is characterized in that the step of applying false false twist crimps under dry heat conditions of 0.95 to 0.80 is performed continuously and consistently.

Nylon 6 is mainly used as the polyamide resin for forming the raw yarn for artificial lawn of the present invention. Nylon 6 and nylon 12 are contained in a small proportion as long as the object of the present invention is not impaired. It may be a copolymer or polymer blend containing.

The nylon 6 used may contain usual additives such as weathering agents, light resistance agents, heat resistance agents, coloring agents, 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.

In producing the polyamide-based pile yarn for artificial lawn of the present invention, crimping of nylon 6 multifilament having a flat cross section is performed by a consistent combination of air false twisting and dry heat crimping. This is very important.

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 6 is first subjected to a 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 700 denier (d) is preferable, and the total fineness of multifilament is , 1000 ~
A range of 5000 denier (D) is preferable.

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 , especially ² to 5 kg / cm ² , temperature: 12
0-220 ° C, especially 160-205 ° 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 Nl / min, especially 50 to 130 Nl / 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.

Further, the temperature in the crimping process is 120
When the temperature is lower than 0 ° C, the expansion / recovery rate becomes low, and when the temperature exceeds 220 ° 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 Nl / min.

The space temperature in the dry heat treatment machine 10 is 12
It is desirable to maintain a constant temperature in the range of 0 to 220 ° 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 very good tufting property to the base fabric, and also has very good settling resistance due to the characteristic that the expansion and recovery rate is 1 to 5%.

In addition, since the strength retention rate after 40 months of the outdoor water immersion exposure test is 40% or more, the weather resistance is excellent and the pile may fall off even if it is used for a long time. You can get no artificial grass.

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 the original green master chip and Nylon 6 of No. 4 was supplied to a melt spinning machine, melted at 270 ° C., extruded from a substantially flat spinneret nozzle, and cooled in a cooling bath at 20 ° 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. After that, 10 drawn yarns are continuously bundled and the space dry heat temperature is set to 180.
It is introduced into a heat treatment machine having a relaxation rate 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 this 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) on which alternate twisting was performed.

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 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.

Table 1 also shows the results of measuring the number of alternating twists, the expansion recovery ratio and the tenacity retention ratio of the 10 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 all day and night. 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 strength retention was calculated from the results of the tenacity (JIS L 1013) before and after this treatment. .

[0044]

[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 are tufting property (bunching property), crimp property and durability (strength retention ratio). Is balanced and excellent.

On the other hand, according to the wet heat treatment method (Comparative Example 1), only pile yarn having extremely poor durability can be obtained.

[0047]

As described in detail above, the polyamide-based pile yarn for artificial grass of the present invention has excellent tufting property (bunching property), crimpability and durability (strength retention rate), and is excellent. ing. Further, according to the manufacturing method of the present invention, the pile yarn having the above-mentioned performance can be efficiently manufactured 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 the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location D02J 1/22 RE0C 13/00 B 7322-2D

Claims (2)

[Claims] 1. A single yarn fineness of 100 to 700 denier (d) and a total fineness of 1000 to 50 having a substantially flat cross-sectional shape.
It consists of polycaproamide-based multifilament of 00 denier (D), and the number of alternating twists per meter of length of single yarn: 3
Polyamide system for artificial lawn, which has characteristics of 0 to 200 times, expansion and recovery rate measured by JISL1090: 1 to 5%, strength retention rate after 3 months of outdoor water immersion exposure test: 40% or more. Pile yarn. 2. A step of melt spinning a polycaproamide-based resin as a flat cross section yarn using a nozzle having slit-shaped spinning holes, cooling the spun yarn in a refrigerant at 2 to 60 ° C.,
Immediately after that, in a heat medium of 40 to 90 ° C, 2.5 to 4.5.
The step of drawing twice, 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 1
~ 7 Kg / cm ² , temperature: 120-220 ° C, relaxation rate: 0.
The step of applying the false false twist crimp under a dry heat condition of 95 to 0.80 is continuously and consistently performed.
A method for producing a polyamide-based pile yarn for artificial grass having the characteristics described in 1.