JPH10273834A - Polyamide crimped yarn, its production and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject crimped yarn having excellent durability, bulkiness, antifouling property and fastness to crimp in dyeing by drawing melt-spun polyamide multifilament yarn, subjecting the yarn to crimping processing, cooling and heat-setting the yarn, applying water content to yarn and winding the yarn. SOLUTION: Melt-spun polyamide multifilament yarn is drawn to 2-6 times at 150-195 deg.C and successively, subjected to crimp processing with a fluid heated at 120-250 deg.C and cooled. Then, the yarn is heat-set at 60-90 deg.C and 3-5 wt.% water content is applied to yarn and yarn is wound to provide the objective crimped yarn of polyamide filament having hollow cross section, simultaneously satisfying that a peak of wet heat shrinkage factor (FTA value) measured under conditions of 10 m/min raw yarn transfer rate and 1 sec hot water bath treating time under 2 mg/d load tension by a continuous shrinkage measuring machine exists at >=80 deg.C wet heat temperature and FTA value in 30-50 deg.C low temperature region is <=30% based on FTA peak value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide crimped yarn having excellent durability, bulkiness and antifouling property, and having improved crimp fastness during dyeing, and efficient production of the polyamide crimped yarn. And a carpet face yarn which is less likely to cause wrinkles and streak defects due to crimp set during dyeing.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for improved quality and cost reduction of carpets using crimped yarns made of synthetic multifilaments as face yarns. In particular, in the field of tile carpets and roll carpets, supply of inexpensive face yarns that are excellent in durability, bulkiness and antifouling property has been strongly desired.

[0003] As a known technique that meets the above demand, a crimped yarn made of a polyamide filament having a hollow cross section has been proposed in Japanese Patent Publication No. 61-83307. Further, as a method for producing a crimped yarn that meets the above demand, a method using a crimping device using a heating fluid, for example, a method described in US Pat. No. 4,526,808 is known.

[0004]

However, it is not possible to provide a carpet having excellent durability, bulkiness and antifouling property by using a crimped yarn obtained by the above-mentioned prior art in a face yarn. However, since the hollow section yarn has a larger second moment of area than the non-hollow cross section yarn, it is easy to crimp (elongate) at the time of dyeing, which causes wrinkles and streak defects in the carpet.

[0005] Therefore, in order to prevent the above crimp set, it is necessary to cope by applying undesired conditions in the process of lowering the dyeing temperature or reducing the amount of dyeing per batch. There was no state.

Accordingly, the present invention solves the above-mentioned problems in the prior art, and is excellent in durability, bulkiness and antifouling property, and has improved crimp fastness during dyeing. A main object of the present invention is to provide a method for efficiently producing a crimped yarn, and to provide a carpet face yarn in which wrinkles and streak defects due to crimping set during dyeing are unlikely to occur.

[0007]

In order to achieve the above object, the present invention provides a polyamide crimped yarn comprising a plurality of hollow-section polyamide filaments and having a crimp. Yarn moving speed 1 under tension of 2mg / d load by continuous shrinkage measuring machine
The wet heat shrinkage rate (FTA value) measured under the conditions of 0 m / min and a hot water bath treatment time of 1 second, the peak of the FTA value is a wet heat temperature of 8
0 ° C. or more, FTA value in a low temperature range of 30 to 50 ° C. is 30% or less of the FTA peak value,
Are simultaneously satisfied.

[0008] The polyamide crimped yarn of the present invention has a polyamide filament whose cross section has an outer shape composed of 3 to 5 peaks and 3 to 5 valleys projecting to the outside, and
Being a cross-sectional shape having 1 to 3 hollow portions, in particular,
It is preferable to have a Y-shaped hollow cross-section having a Y-shaped outer cross-section and having one hollow portion. Further, the hollow ratio in the cross section of the polyamide filament is preferably 5 to 20%, the crimp elongation is preferably 15% or more, and the total fineness is preferably 500 to 5000 denier. If the conditions are satisfied, more excellent effects can be obtained. This polyamide crimped yarn is suitable for carpet face yarn.

Further, the method for producing a polyamide crimped yarn of the present invention is a method for producing a polyamide crimped yarn comprising a plurality of hollow cross-section polyamide filaments and having crimps, wherein the melt-spun multifilament yarn is produced by a method comprising the steps of:
Stretching 2 to 6 times at a stretching temperature of １９195 ° C.
After crimping with a heating fluid of 0 to 250 ° C and cooling, 6
Heat set at a temperature of 0-90 ° C. and then 3-5
The method according to claim 1, wherein the film is wound after being provided with a water content of 1% by weight.
It is characterized by producing the polyamide crimped yarn described above.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION First, the polyamide crimped yarn of the present invention will be described, and then a method for producing the crimped yarn and its use will be described.

[0011] The polyamide crimped yarn of the present invention comprises:
An aggregate (multifilament) comprising a plurality of polyamide filaments having a hollow cross-sectional shape and having crimps.

Examples of the polyamide include polycapramide, polyhexamethylene adipamide, polytetramethylene adipamide, and the like.
It may be a copolymer containing the following other copolymer components.
Examples of the copolymer component referred to here include amides such as ε-caproamide, tetramethylene adipamide, hexamethylene sebacamide, hexamethylene isophthalamide, tetramethylene terephthalamide, and xylylene phthalamide. .

[0013] The polyamide multifilament of the present invention may be an aggregate of single dyeable filaments made of a single polyamide material, or an aggregate of different polyamide single yarns potentially having different dyeability. It may be.

For example, an aggregate of filaments made of polyamide having many NH ₂ terminal groups easily dyeable in an acid dye, and an aggregate of filaments made of polyamide having many SO ₃ H end groups easily dyeable in a basic dye. When used in combination, dyes of two colors can be dyed in subtle shades by using two different dyes in combination.

The area occupation ratio (hollow ratio) of the hollow portion in the cross section of the polyamide filament is not particularly limited, but is 5 to 20% in consideration of weight reduction and matting effect.
Is preferable.

The polyamide filament is not limited in its outer shape as long as it has a hollow cross section. In particular, in order to further improve its bulkiness, 3 to 5 peaks projecting to the outside are required. And a modified hollow cross section yarn having an outer shape consisting of 3 to 5 valleys and having 1 to 3 hollows, among which 3 ridges and 3 valleys projecting to the outside It is desirable that the yarn is a Y-shaped cross-section hollow cross-section yarn having a Y-shaped cross-section outer shape formed of a hollow portion and having one hollow portion. The use of a Y-shaped hollow cross section yarn improves the ease of spinning when the polyamide is melted to form a modified cross section yarn. The degree of deformation is preferably from 2 to 7.

FIG. 1 shows an example of a yarn having a hollow cross section having a Y-shaped cross section. In FIG. 1, C represents a hollow portion, D represents three peaks, and E represents a ridge.
Indicates three valleys. The presence of the peaks D and the valleys E increases the second moment of area of the polyamide filament, thereby improving the recovery from bending and increasing the area occupied by each filament. A carpet face yarn with excellent covering properties is obtained.

The polyamide crimped yarn of the present invention has a wet heat shrinkage rate (measured by a continuous shrinkage measuring machine under tension of 2 mg / d load, under the conditions of an original yarn moving speed of 10 m / min and a warm water bath treatment time of 1 second ( It is important to satisfy at the same time that the peak of the FTA value is above 80 ° C. of the wet heat temperature and that the FTA value in the low temperature range of 30 to 50 ° C. is 30% or less of the FTA peak value. It is.

In other words, the crimping during the dyeing process is severe (elongation).
The conventional polyamide crimped yarn which easily causes wrinkles and streak defects of the carpet develops a high crimp under low-temperature dyeing conditions such as 60 ° C. or less, but is unwound under high-temperature dyeing conditions (normal dyeing conditions) of 80 ° C. or more. Shrinkage is easy to settle (elongate). This is considered because the shrinkage ratio shows a peak value at 60 ° C.

However, the polyamide crimped yarn obtained under specific production conditions different from the conventional one has a peak value of shrinkage of as high as 80 ° C. or more, and the crimp of the polyamide crimped yarn has the highest dyeing temperature ( (80 ° C. or higher), so that high crimping can be achieved. As a result, even during dyeing, crimping is hard to occur (elongation), and carpet wrinkles and streaks are not induced, thereby achieving the object of the present invention. be able to.

Such a difference in the shrinkage ratio characteristics is caused by the value of the wet heat shrinkage ratio (FTA) obtained by a continuous shrinkage measuring device that measures the shrinkage ratio when a moist heat treatment is performed for a certain period of time under a constrained load using the processing temperature as a variable. Value), that is, it can be represented by whether or not the above condition is satisfied.

In other words, when one or both of the above conditions are lacking, the crimp fastness of the polyamide crimped yarn at the time of dyeing is inferior. And wrinkles and streak defects occur on the carpet.

The crimped polyamide yarn of the present invention has a crimp elongation of preferably 15% or more, particularly preferably 20% or more, from the viewpoint of handling at the time of high-order processing using this as a carpet face yarn. The total fineness is preferably 500 to 5000 denier, particularly preferably 700 to 4000 denier.

That is, if the crimp elongation is less than 15%, after processing as a carpet, the surface covering property cannot be sufficiently satisfied, and it is difficult to obtain a high-grade carpet, which is not desirable. Further, if the total fineness is less than 500 denier, it is necessary to increase the basis weight of the tuft, and the processing cost becomes high. Conversely, if it exceeds 5,000 denier,
It is not desirable because the handling at the time of tufting becomes complicated and practicality is reduced.

Next, an example of a method for producing a polyamide crimped yarn of the present invention will be described with reference to FIG.

In producing the polyamide crimped yarn of the present invention, first, the polyamide chip is supplied to a melt extruder to be melted and then melt-spun from a spinneret, which may be carried out in a conventional manner. The melt-spun polyamide filament yarn is cooled and solidified by cold air, and subsequently, after an oil agent is attached thereto, is taken up by the take-up roll 1 at about 300 to 1200 m / min. In FIG. 2, illustration of the steps up to the attachment of the oil agent is omitted.

Subsequently, the undrawn yarn that has been cooled and taken off is led to a drawing step, and is drawn by a drawing roll 2 to 150 to 150 mm.
The film is stretched 2 to 6 times at a temperature of 195 ° C., and then introduced into a crimping device 3 using a heating fluid. Here, the reason for setting the stretching temperature to 150 to 195 ° C. is that if the drawing temperature is lower than 150 ° C., sufficient properties as a carpet crimped yarn cannot be obtained, and
If the temperature exceeds 95 ° C., fusion of the polyamide is likely to occur. The reason for setting the stretching ratio to 2 to 6 times is as follows.
If it is less than 2 times, the crimp elongation rate, which is important in crimping properties, will be small, and if it exceeds 6 times, single yarn breakage will occur frequently during stretching, and the yarn formability will be poor. The stretching conditions are, among others, 1
A range of 3.0 to 4.0 times at a temperature of 60 to 190 ° C is preferable.

In the crimping device 3, crimp is applied to the polyamide filament yarn by a heating fluid (120 to 250 ° C.) such as heated air or heated steam. The crimping device 3 is not particularly limited as long as it can be crimped by a heating fluid. For example, Japanese Patent Publication No. 58-1214 and Japanese Patent Application Laid-Open No. 56-101925
And a crimping apparatus using a heating fluid as described in US Pat. No. 4,526,808 and the like.

The polyamide filament yarn crimped by the heating fluid is then cooled by the cooling rotary drum 4,
After being thermally set at a temperature of 60 to 90 ° C. through the pin 5 and the take-off roller 6, the crimp is unraveled. Finally, after the water application device 7 applies 3 to 5% of water, It is wound on the bobbin 9 by the winding device 8. Note that the tension at the time of applying the water content may be such that the crimp is not reduced.

In the above-mentioned steps, the filament may be wound once at an arbitrary portion, but it is preferable to continuously perform the winding.

In the crimping step in the method of the present invention, (1) the fluid temperature at the time of crimping, (2) the heat setting temperature at which the crimp is released after cooling by the rotating drum 4, and
(3) It is important to set the following conditions as the amount of water provided by the water supply device 7.

That is, the first condition for maximizing the crimp of the polyamide filament yarn at the highest dyeing temperature in the dyeing step is to set the fluid temperature at the time of crimping in the above (1) to 120 ° C.
By setting the temperature to about 250 ° C., the heat treatment during crimping is strengthened.

Here, the fluid temperature during crimping is 120 ° C.
If the temperature is less than 250 ° C., the desired polyamide crimped yarn cannot be obtained, and if the temperature exceeds 250 ° C., the cut yarn in the course of the production is fused to the yarn path, so that the productivity is deteriorated.

The first condition for maximizing the crimp of the polyamide multifilament at the highest dyeing temperature in the dyeing step is the heat setting temperature of the above (2), that is, crimping and cooling, followed by crimping. By setting the heat setting temperature in the step of releasing the shrinkage to 60 to 90 ° C., the fiber structural strain is reduced. Here, when the heat setting temperature exceeds 90 ° C., the latent crimp developing power of the polyamide raw yarn is lost, and the crimp does not appear during dyeing. If the heat setting temperature is lower than 60 ° C., the relaxation of the fiber structural strain is small, and it is not possible to suppress the development of crimp of the original yarn in the medium temperature dyeing region (40 to 85 ° C.).

Further, the second condition for maximizing the crimp of the polyamide multifilament at the highest dyeing temperature in the dyeing step is the amount of water given in the above (3), that is, the polyamide crimp immediately before the final winding. The amount of water applied to the yarn is 3 ~
By setting the content to 5%, the expression of crimp during low-temperature dyeing of the polyamide yarn is suppressed, and the fiber structural distortion in the amorphous region is alleviated.

Here, when the amount of water added is less than 3%,
The effect of relaxing the fiber structure strain in the amorphous region is reduced, and the crimping of the original yarn in the low temperature region (40 ° C. or lower) cannot be suppressed. If the amount of water added exceeds 5%, the wound shape of the raw yarn cheese is significantly deteriorated.

The polyamide crimped yarn obtained by the method of the present invention satisfies the conditions (1) and (2) simultaneously, has excellent durability, bulkiness and antifouling properties, and has improved crimp fastness during dyeing. Therefore, the carpet face yarn obtained by using this crimped yarn does not generate wrinkles or streak defects due to crimping during dyeing, and is of extremely high quality.

The carpet face yarn is a fiber material which is planted on a carpet base material (base cloth) and appears on the surface of the carpet. The carpet face yarn of the present invention comprises:
It is composed of the polyamide crimped yarn of the present invention obtained by the above method.

Here, the form of the face yarn is not particularly limited, and may be, for example, a cut pile, a loop pile, or a combination thereof. Further, the polyamide crimped yarn of the present invention may be used by blending a plurality of yarns and then twisting the yarns. In this case, a plurality of differently dyed crimped yarns may be blended. As long as the effect of the polyamide crimped yarn is not impaired, it may be combined with another crimped yarn or material.

The carpet face yarn is set on a tufting machine, tufted on a primary base fabric such as a polyester nonwoven fabric, and then lining the carpet to make a carpet. If necessary, processing such as steaming, brushing, spraying, dyeing, shearing, and polisher can be performed in the middle.

The resulting carpet is durable, bulky,
Since the face yarn has excellent antifouling properties, it meets the market requirements as a tile carpet or roll carpet.

[0042]

EXAMPLES Hereinafter, the structure and effects of the present invention will be further described with reference to examples. The physical property values in the present invention are values obtained as follows.

[Deformation Degree] The ratio R / r of the diameter (R) of the circumscribed circle and the diameter (r) of the inscribed circle of the outer periphery of the polyamide filament cross section is defined as the degree of deformation.

[Hollow ratio] The area occupancy of the hollow portion occupying the filament cross section of the irregular shaped hollow cross-section polyamide filament is defined as the hollow ratio.

[Crimping Elongation] The polyamide crimped yarn was subjected to boiling water treatment at 98 ° C. for 5 minutes without load, and then air-dried.
The length (L1) is measured by applying an initial load (2 mg / d). Next, a constant load (100 mg / d) was applied and the length (L
2) is measured and calculated by the following equation. Crimp elongation (%) = 100 × (L2−L1) / (L1)

[Strength and elongation of raw yarn] Measured using a Tensilon tensile tester manufactured by Orientec Co., Ltd. under the conditions of a test length of 250 mm and a tensile speed of 300 mm / min.

[Heat Shrinkage (FTA)] "FTA-500" (manufactured by Toray Engineering Co., Ltd.)
And the yarn moving speed is 10 under the tension of 2 mg / d load.
The measurement is performed under the conditions of m / min and a warm water bath treatment time of 1 second.

[Model Evaluation of Crimp Set in Dyeing] A tuft greige machine prepared by tufting a polyamide crimp yarn on a base cloth was cut into a square of 25 cm × 25 cm, folded in two, and piled together. The top was treated in boiling water with a load of 10 g / cm ² or 100 g / cm ² for 10 minutes. After air-drying for one day, the state of occurrence of creasing due to crimping was determined. 4 best products depending on the degree of crease
Grade, the worst product was class 1. In addition, the class 3 or higher was judged as passing.

[Evaluation of actual crimping set at the time of dyeing] Three polyamide crimped yarns were mixed and mixed to obtain a raw yarn.
A tuft greige was manufactured by tufting a base cloth with a gauge of 1/10 inch and a basis weight of 450 g / m ² . The tufted greige was dyed with a rope win dyeing machine (maximum dyeing temperature: 90 ° C.), air-dried for one day, and the state of occurrence of creasing due to crimping was examined. According to the degree of the wrinkles, the best product was classified as grade 4 and the worst product was classified as grade 1. In addition, the grade 3 or higher was considered as a pass.

[Durability and antifouling property of carpet] The durability and antifouling property of the carpet product after 10 normal monitors have been used for one year are visually judged.
Grade, the worst product was class 1. In addition, the class 3 or higher was judged as passing.

[Carpet bulkiness] The bulkiness of carpet products was relatively determined based on the tactile sensation of the hands and feet of 10 monitors, and the best product was classified as Class 4 and the worst product was classified as Class 1. In addition, the class 3 or higher was judged as passing.

[Tufting property of carpet] The tuft machine stoppage rate due to defective yarn at the time of tufting is 0.5% or less, good, 0.5 to 1.0% slightly poor, 1.0% The case where it exceeded was evaluated as bad.

[Examples 1 to 4] Three types of nylon 6 (SO ₃ H terminal group having 5 × 10 ⁻⁵ mol / g) having different dyeing performance
Of the basic dye-dyable nylon 6, unmodified nylon 6 (regular), and acid dye-dyeable nylon 6 having an NH ₂ terminal group of 7 × 10 ⁻⁵ mol / g by an extruder spinning machine. , And melt-spun from a Y-shaped hollow section die.

An oil agent is first adhered to the melt-spun, cooled and solidified yarn, subsequently taken up by a take-up roll, and drawn by a hot draw roll at the temperature shown in Table 1.
A multifilament was obtained.

Further, continuous with the stretching, US Pat.
220 ° C. using a crimping apparatus described in 6808
After the crimp is applied by the heated steam of the above, the crimp is unraveled at the heat setting temperature shown in Table 1 to the extent that the crimp is not loosened, and then 3.8% by weight of water is polyamide-wound with a fixed water application device. After being applied to the crimped yarn, it was wound up to obtain three types of crimped yarns shown in Table 1 (approximately Y-type having a degree of deformation of 3 and a Y-type hollow cross-section having a hollow ratio of 12%) (implementation). Examples 1-3).

The polyamide crimped yarn obtained above was tufted onto a polyester non-woven fabric to give a basis weight of 450 g / m 2.
The loop pile carpet of No. ² was used. Table 1 also shows the results obtained by measuring the characteristics of the obtained carpet according to the above criteria.

Further, after the three types of polyamide crimped yarns obtained above were mixed and mixed to obtain a heat-treated yarn, the heat-treated yarn was tufted onto a polyester non-woven fabric to obtain a basis weight of 450 g / m 2.
The loop pile carpet of No. ² was used. The results of measuring the characteristics of the obtained carpet according to the above criteria are also shown in Table 1 (Example 4).

As shown in Table 1, the carpets produced by using the polyamide crimped yarns of Examples 1 to 4 for face yarns have excellent durability, bulkiness and antifouling properties, Excellent quality without wrinkles or streak defects due to crimping settling.

[0059]

[Table 1]

[Examples 5 to 8] Using unmodified nylon 6 (regular), melt-spinning was performed in the same manner as in Example 2, and the drawing temperature, heat setting temperature, and water application amount were set to the conditions shown in Table 2.
The other conditions were the same as in Example 2, and the film was stretched and crimped to obtain four types of polyamide crimped yarn.

Using the obtained polyamide crimped yarn, a pile carpet was prepared in the same manner as in Example 2, and the characteristics of the obtained carpet were measured according to the above criteria. The results are also shown in Table 2. Was.

As shown in Table 2, the carpets produced by using the polyamide crimped yarns of Examples 5 to 8 for face yarns were also excellent in durability, bulkiness and antifouling property, as well as at the time of dyeing. Excellent quality without wrinkles or streak defects due to crimping settling.

[0063]

[Table 2]

[Comparative Examples 1-3] Using unmodified nylon 6 (regular), melt-spinning was performed in the same manner as in Example 2, and the drawing temperature, heat setting temperature, and water application amount were set to the conditions shown in Table 3.
The other conditions were the same as in Example 2 and the film was stretched and crimped to give three types of polyamide crimped yarn.

Using the obtained polyamide crimped yarn, a pile carpet was prepared in the same manner as in Example 2, and the characteristics of the obtained carpet were similarly measured. The results are shown in Table 2. .

As shown in Table 3, in Comparative Example 1, since the heat setting temperature was too low and the amount of water applied was too small, the FTA peak temperature was as low as 60 ° C., and crimping settling occurred during dyeing and the carpet was broken. Wrinkles were poor. In Comparative Example 2, the amount of water applied was too small, so that the crimp development in the low-temperature region became large,
It was difficult for the yarn to pass through the tuft needle, and the tuft performance was poor. In Comparative Example 3, the temperature during stretching was too low.
The crimp elongation rate of the raw yarn was low, and the durability and bulkiness of the carpet were poor.

[0067]

[Table 3]

[0068]

The crimped polyamide yarn of the present invention has excellent durability, bulkiness and antifouling property, and has improved crimp fastness during dyeing.

Further, according to the method of the present invention, a crimped polyamide yarn having the above characteristics can be efficiently produced.

Further, the carpet of the present invention does not generate wrinkles or streak defects due to crimp set during dyeing, and is of extremely high quality.

[Brief description of the drawings]

FIG. 1 illustrates a cross section of a hollow cross-section polyamide filament used in a polyamide crimped yarn of the present invention.

FIG. 2 is a process schematic diagram showing a main part of a process for producing a polyamide crimped yarn of the present invention.

[Explanation of symbols]

1: take-up roller, 2: stretching roller, 3: crimping device, 4: cooling rotary drum, 5: fixing pin, 6:
Take-up roller, 7: water application device, 8: take-up device,
9: bobbin, C: hollow, D: mountain, E: valley

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI D02G 3/22 D02G 3/22 D02J 1/00 D02J 1/00 K

Claims (7)

[Claims] 1. A polyamide crimped yarn comprising a plurality of hollow-section polyamide filaments and having a crimp, the polyamide crimped yarn is measured for 2 m by a continuous shrinkage measuring machine.
Wet heat shrinkage (FTA value) measured under the conditions of a yarn moving speed of 10 m / min and a warm water bath treatment time of 1 second under a g / d load tension
A polyamide characterized by simultaneously satisfying that the peak of the FTA value exists at a wet heat temperature of 80 ° C. or higher, and that the FTA value in a low temperature range of 30 to 50 ° C. is 30% or less of the FTA peak value. Crimped yarn. 2. The polyamide filament having a cross section of:
2. A cross-sectional shape having an outer shape consisting of 3 to 5 peaks and 3 to 5 valleys projecting to the outside, and having 1 to 3 hollows. Polyamide crimped yarn according to the above. 3. The polyamide crimped yarn according to claim 2, wherein the polyamide filament has a Y-shaped outer cross section and a Y-shaped hollow cross section having one hollow portion. 4. The polyamide crimped yarn according to claim 1, wherein the hollow ratio of the polyamide filament in the cross section is 5 to 20%. 5. The polyamide crimped yarn according to claim 1, wherein the crimp elongation is 15% or more, and the total fineness is 500 to 5000 denier. 6. A method for producing a polyamide crimped yarn comprising a plurality of hollow cross-section polyamide filaments and having a crimp, wherein the melt-spun multifilament yarn is stretched 2 to 6 times at a drawing temperature of 150 to 195 ° C. Stretch,
Subsequently, by crimping with a heating fluid of 120 to 250 ° C, cooling, heat setting at a temperature of 60 to 90 ° C, and then winding the yarn after imparting 3 to 5% by weight of moisture to the yarn. A method for producing a polyamide crimped yarn, comprising producing the polyamide crimped yarn according to claim 1. 7. A carpet face yarn comprising the polyamide crimped yarn according to claim 1.