JP2611339B2 - Warp knitted fabric for molding, method for producing the same, and method for producing warp knitted fabric - Google Patents

Description

The present invention relates to a knitted fabric for molding, a method for producing the same, and a method for producing a warp-knitted fabric.

(Prior art)

The warp knitted fabric for molding is widely used as an outer material for automobile seat backs and door trims, or as an outer material and lining material for musical instruments, bottles and jewelry boxes, and as a wall material for interior use as a chair material. I have. When warp knitted fabrics are used in these molded products, it becomes important conditions for high quality products to be able to finish with natural sharpness as the degree of unevenness and bending becomes higher as the degree of drawing becomes higher. Have been.

Conventionally, in order to meet such conditions, elastic yarns are generally used for warp knitted fabrics for high drawing, and highly oriented undrawn yarns or completely undrawn yarns of polyester are used for warp knitted fabrics for medium drawing. And warp knitted fabrics for low drawing use false twisted yarns.

However, among these warp knitted fabrics, sometimes used for middle drawing, as described above, and as disclosed in JP-A-55-7432 and JP-B-61-11264,
Since highly oriented undrawn yarn or completely undrawn yarn is used as a constituent yarn of the warp knitted fabric for molding, various problems as described below have been pointed out.

First of all, because of the use of raw silk, there was no bulk or warmth in the hand. In addition, the dyeing resistance to sunlight is poor, the tear strength is low, and the fatigue resistance is low. Therefore, there is a problem that the fabric is easily damaged, and fluff and pilling are easily generated.

Secondly, during the knitting process, it was easily affected by temperature and humidity, and quality unevenness was easily generated. In addition, there is a problem in that process control and quality control are extremely difficult because abnormal tension is caused by bending, friction, handling, etc., caused by guides, needles, etc., and it is easy to generate “warp streaks” which is the largest defect of warp knitted fabrics. That is.

(Problems to be Solved by the Invention) An object of the present invention is to improve bulkiness and warmth, to improve sunlight fastness and tear strength, to improve fatigue resistance, and to improve process control and quality control. An object of the present invention is to provide a warp-knitted fabric for molding, which is suitable for medium drawing, and a method for manufacturing the same, and a method for manufacturing a warp-knitted fabric.

[Means for solving the problem]

The warp knitted fabric for molding of the present invention that achieves the above object comprises a front portion and a back portion, and at least the back portion has a birefringence Δn of 0.07 to 0.13 and a twist number of twists of 2 polyester fibers of 50 cm or less. A warp knitted fabric composed of a fiber crimped yarn, characterized in that the warp knitted fabric has a warp elongation of 100% or more under a dry heat condition of 130 ° C.

Further, the method of the present invention for producing such a warp knitted fabric for molding comprises the steps of drawing a polyester highly oriented undrawn yarn or incompletely drawn yarn having a birefringence Δn in the range of 0.02 to 0.10 at a temperature not higher than the glass transition point. Twisting to form a crimped yarn having a number of twists of 2 times / 50 cm or less, knitting a warp knitted fabric by using the crimped yarn at least in the back portion, and applying the warped knitted fabric to the crimped yarn Characterized by being subjected to rapid heat treatment at a temperature not lower than the glass transition point.

Further, according to the present invention, it is possible to provide a warp knitted fabric which is based on the above-described warp knitted fabric, is adhered to a plastic plate, and is integrally formed into a three-dimensional structure. A molded article can be produced by joining the above-mentioned warp knitted fabric to a plastic plate and integrally molding it with the plastic plate into a three-dimensional structure at a temperature of 100 ° C. or higher.

The warp knitted fabric for molding in the present invention preferably comprises a front portion and a back portion, and more preferably has a structure in which the front portion forms a pile portion and the back portion forms a ground portion of a ground structure. More preferably, the pile portion has a cut pile structure in which the pile portion is further cut.

The warp knitted fabric has at least a back portion (ground portion)
However, it is necessary to be composed of a crimped polyester synthetic fiber yarn having a birefringence Δn in the range of 0.07 to 0.13. By using such a crimped yarn, the hand can be made bulky and soft and warm.

The type of polyester constituting the crimped yarn is not particularly limited, but polyethylene terephthalate,
Polybutylene terephthalate is preferably used, and especially polyethylene terephthalate is the most suitable material.

The birefringence Δn of this crimped yarn needs to be larger than 0.07, and if it is smaller than 0.07, the sunlight fastness and tear strength are significantly reduced, as in the case of a warp knitted fabric using a conventional undrawn yarn, and Since the fatigue resistance is reduced, the fabric is likely to be damaged. Further, the birefringence Δn of the crimped yarn must be smaller than 0.13. When it is larger than 0.13, the warp elongation rate when the warp knitted fabric is formed is reduced, and the drawability important for the present invention is deteriorated.

Moreover, the expansion / contraction restoration ratio of the crimped yarn is preferably 10% or more, and if it is lower than 10%, the effect as the crimped yarn is reduced. When the expansion / contraction restoration rate is 30% or more, it becomes difficult to handle the crimped yarn,
There is no big trouble.

In addition, the crimped yarn used in the present invention is a false twisted yarn, but the form does not have a strong torque or snare like a normal false twisted yarn, and is a crimped form such as a conjugate yarn. Is desirable. The false twisted yarn used in the present invention has a torque twist number of 2 times.
/ 50 cm or less, and is characterized by a very small number of twists in this way, so that, for example, it is possible to prevent twisting or release failure during aging and improve process passability. .

In the present invention, the number of twists is defined as a value obtained when a small load of 2 mg / d is hooked at the center of 1 m of a test yarn, and both yarn ends are aligned and folded in two. The number of twists is determined by the number of rotations at which the load rotates.

In the warp knitted fabric of the present invention, the above-described crimped yarn is used at least for the back portion (ground portion). Therefore, when the crimped yarn is used only for the back portion, the crimped yarn is hidden inside the front portion (pile portion). The effect on the combination is recognized, and there is no problem in trying to soften the texture and enhance the fabric.

The above-mentioned polyester synthetic fiber crimped yarn is used at least in the back part (ground part), and the warp knitted fabric for molding of the present invention has a warp elongation of 100% under the condition of dry heat of 130 ° C. It is necessary that the temperature be at least 150 ° C., and more preferably at least 150 ° C. The reason why the warp elongation rate is set at a dry heat of 130 ° C. is that the processing temperature during the forming process is generally performed at about 130 ° C. of the dry heat. If the elongation ratio in the warp direction at a temperature close to this molding temperature is less than 100%, the cross-section or bent surface of the molded body, especially when subjected to medium drawing, has a sharp and natural finish. It becomes difficult.

FIG. 1 shows an example of the warp knitted fabric for molding of the present invention. 1 is a ground portion of the warp knitted fabric, and 2 is a pile portion.
The ground portion 1 uses the above-described crimped yarn Y of the present invention. On the other hand, the pile portion 2 has a lower crimping rate than the crimped yarn Y of the ground portion 1,
Filament or spun yarn Y 'is used.
Of course, the same yarn as the crimped yarn Y of the ground portion 1 may be used. In this embodiment, the pile of the pile section 2 is cut to form a cut pile.

When the warp knitted fabric having such a structure is formed, a plastic plate 4 is bonded to the back surface of the ground portion 1 via an adhesive 3 and is integrally formed with the plastic plate 4. .

The warp knitted fabric for molding of the present invention described above, as described above,
Polyester highly oriented undrawn yarn or incompletely drawn yarn having a birefringence Δn in the range of 0.02 to 0.10 is drawn false twisted at a temperature not higher than the glass transition point, and a crimped yarn having a torque twist number of 2 times / 50 cm or less. The warp knitted fabric is knitted using at least the back portion of the crimped yarn, and the warp knitted fabric is subjected to rapid heat treatment at a temperature equal to or higher than the glass transition point of the crimped yarn. it can.

As the yarn having a birefringence Δn of 0.02 to 0.10, a highly oriented undrawn yarn (POY) obtained by ultra-high speed spinning, an incompletely drawn yarn obtained by drawing an undrawn yarn at a low magnification, and the like are preferably used. In particular, highly oriented undrawn yarn (POY) is suitable as a raw yarn for producing the crimped yarn. If the birefringence Δn is smaller than 0.02, the yarn becomes more susceptible to the influence of temperature and humidity, so that the variation of the yarn quality due to the daily change becomes large. Further, when the birefringence Δn is greater than 0.10, since the highly oriented unstretched or incompletely stretched region enters the completely stretched region,
It becomes difficult to increase the warp elongation ratio of the warp knitted fabric under the condition of dry heat of 130 ° C.

The method of the stretch false twisting is a twisting during stretching, in which the twisting-heat setting below the glass transition point is performed simultaneously with the stretching while performing the false twisting of the untwisting, or the glass transition point or less. After the drawing is performed once, any of the twisting, the heat setting below the glass transition point, and the false twisting after drawing in which the false twisting is performed. However, from the viewpoint of uniformity of the obtained yarn quality and yarn processability, the former false twisting during stretching is more preferable.

The twisting mechanism may be any of a friction type, a spindle type, and a pneumatic type, and is not particularly limited. However, the friction type is the best in terms of cost and quality. The number of false twists to be given in this stretch false twisting is not particularly limited, but a generally used range of 1500 to 5000 times / m is preferably applied. The false twist speed is 10
0-900 m / min is preferably used.

The draw ratio in the draw false twisting process is required to be equal to or higher than that in the case of drawing false twist of a normal highly oriented drawn yarn, and the higher the draw ratio, the more the elongation rate of the warp knitted fabric after the rapid heat treatment performed in the subsequent process. Can be bigger. The stretching ratio is desirably equal to or higher than the natural stretching ratio. For example, when a polyester highly oriented undrawn yarn having a spinning speed of 3500 m / min is used, the condition is preferably approximately 1.8 to 2.0 times.

In the production method of the present invention, the heat setting temperature in the above-described draw false twist processing must be equal to or lower than the glass transition point. Further, the heat treatment performed after the false twisted yarn is formed into a warp knitted fabric must be performed by a rapid heat treatment at a temperature equal to or higher than the glass transition point. The rapid heat treatment means that the temperature is instantaneously raised to a temperature equal to or higher than a target glass transition point without taking a process of gradually increasing the temperature through an intermediate temperature.

For the first time, the warp knitted fabric for forming is subjected to the warp elongation at 130 ° C dry heat by drawing false twisting at a heat setting temperature below the glass transition temperature and rapid heat treatment of the warp knitted fabric at a temperature above the glass transition temperature. Can be over 100%. If the heat setting temperature in the stretch false twisting is set to be equal to or higher than the glass transition point or the temperature of the rapid heat treatment of the warp knitted fabric is set to be equal to or lower than the glass transition point, it is difficult to obtain a target high elongation in the warp direction.

In addition, in the present invention, by setting the heat setting temperature of the draw false twisting process to be equal to or lower than the glass transition point, torque or snare is not generated in the crimped yarn, and the crimped form has an appearance close to that of the conjugate yarn. can do. This improves the processability of the crimped yarn. Also,
The crimped yarn drawn and false twisted below the glass transition point is
Although it is a false twisted yarn, it has the feature that it has almost no deformation in the cross section. For this reason, the luster of the original yarn is almost maintained, and a high-grade appearance can be exhibited. In particular, this effect is remarkable when a yarn having a modified cross section such as a triangular cross section is used, and its gloss can be further emphasized.

FIG. 2 shows a draw false twisting process for producing the above-described crimped yarn. Reference numeral 11 denotes a package in which a raw yarn Yo of a highly oriented undrawn yarn or an incompletely drawn yarn is wound. The raw yarn Yo released from the package 11 is twisted and untwisted by the twister 14 while being stretched between the feed roller 12 and the delivery roller 15, and the twisted area on the upstream side is reduced to a glass transition point or lower. Heat set by the heater 13 with the temperature of
It is untwisted on the downstream side to form a crimped yarn Y. Next, the crimped yarn Y is wound up as a package 16.

To make the crimped yarn into the warp knitted fabric for molding of the present invention,
It must be used at least for the back part (ground part), but may be used for the front part (pile part). This is because the back portion can have a higher shrinkage ratio when subjected to rapid heat treatment than the front portion. It is preferable that the difference in shrinkage between the back portion and the front portion after the rapid heat treatment be 10% or more.

In addition, the temperature of the rapid heat treatment performed after knitting the crimped yarn into a warp knitted fabric needs to be equal to or higher than the glass transition point, and the higher the temperature is, the more preferable it is. The longitudinal elongation rate can be increased.

When the front portion is a pile portion and it is a cut pile, the pile cutting may be performed before or after the rapid heat treatment. In the case of raising the pile, the raising means is not particularly limited, and may be, for example, any of a loop raising that scratches the loop with a needle cloth or the like, a cut raising that cuts the loop with a cutter, and a shirring. .

When the warp knitted fabric of the present invention obtained as described above is subjected to molding processing, as shown in FIG. 1 described above, a plastic plate is bonded to the back portion thereof with an adhesive or the like. Integrally into a desired three-dimensional shape by a simple molding method. As the plastic plate, a relatively thin film or sheet is used.

In general, a vacuum forming method is preferably used as the forming method. However, for those having a small drawing effect with a small depth and sharpness of the unevenness, other methods such as press molding and stretch molding can be used. Generally, a temperature of 100 ° C. or higher is used as the temperature at the time of the molding, and a temperature of about 130 ° C. is more preferably employed.

〔Example〕

A 75-denier, 36-filament polyester highly oriented undrawn yarn (POY) having a birefringence Δn of 0.09 was set at a set temperature of 70
℃, draw ratio 1.8 times, draw false twisting at a false twist number of 3400 times / m to obtain a crimped yarn with a torque twist number of 1 / 50cm, and apply this crimped yarn to the ground part of the pile structure. 75 to use
A warp knitted fabric using a denier, 24 filament easily dyeable polyester filament yarn in the pile portion was knitted. The processability of the crimped yarn at the time of knitting the warp knitted fabric was extremely good, and no warp streaks or sink marks were generated on the warp knitted fabric and the quality was good. .

Next, the warp knitted fabric was subjected to rapid heat treatment in boiling water at 98 ° C., and then the pile portion was pile-cut and further subjected to high-temperature dyeing at 105 ° C. to produce a cut pile warp knitted fabric for molding.

This warp knitted fabric has a warp elongation of 1 at 130 ° C dry heat.
50%. Further, when the tear strength of the cut pile warp knitted fabric was examined, it was 1.5 kg in the warp direction, and the dyeing fastness after being exposed to carbon light for 20 days was class 4.

Next, the cut pile warp knitted fabric is laminated to a ground portion with a thin plastic plate (film) via an adhesive to form a composite sheet. The composite sheet is then used as a seat back of an automobile and dried at 130 ° C. by a vacuum forming method. Molded under heat.

The warp knitted fabric on the surface of the formed seat back was extremely soft and sublime, and had a very warm feeling. Moreover, the formed unevenness and bending were finished to a natural sharpness.

〔The invention's effect〕

As described above, the warp knitted fabric for molding of the present invention has at least a back portion made of a polyester synthetic fiber crimped yarn having a birefringence Δn of 0.07 to 0.13. Compared to those using undrawn yarns, the texture is soft, sublime and warm. In addition, sunlight fastness and tear strength are improved, and fatigue resistance is improved.

In addition, the warp knitted fabric has a characteristic that the elongation in the warp direction at a dry heat temperature of 130 ° C is 100% or more, so the formability is very good. The sharpness can be finished.

Further, according to the production method of the present invention, the above-described warp-knitted fabric for molding and a molded article from this warp-knitted fabric can be easily obtained.
In particular, since the crimped yarn used is obtained by drawing false twisting at a heat setting temperature below the glass transition point, the number of twists of the twist is 2 times / 50 cm or less, and it has almost no torque or snare. In addition, process management and quality control during knitting can be facilitated. That is, it is possible to easily obtain a high-quality product without generating warp streaks or sink marks on the warp knitted fabric.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a warp knitted fabric for molding according to the present invention, and FIG. 2 is a process chart of a stretch false twisting process for producing the crimped yarn. 1 ... ground part (back part), 2 ... pile part (front part), 3 ... adhesive, 4 ... plastic plate, 12 ...
… Feed roller, 13… heater, 14… twister, 15
…… Delivery roller.

Claims (5)

(57) [Claims] 1. A warp comprising a front portion and a back portion, wherein at least the back portion is formed of a crimped polyester synthetic fiber yarn having a birefringence Δn of 0.07 to 0.13 and a torque twist number of 2 times / 50 cm or less. A warp-knitted fabric, wherein the warp-knitted fabric has a warp elongation of 100% or more under dry heat conditions of 130 ° C. 2. The warp knitted fabric according to claim 1, wherein the front portion forms a pile portion, and the back portion forms a ground portion of a ground structure. 3. Polyester highly oriented undrawn yarn or incompletely drawn yarn having a birefringence Δn in the range of 0.02 to 0.10 is subjected to drawing false twisting at a temperature not higher than the glass transition point, and the number of torque twists is 2 turns / 50 c.
m or less, and a knitted fabric is knitted using at least the back portion of the crimped yarn, and the warp knitted fabric is subjected to rapid heat treatment at a temperature equal to or higher than the glass transition point of the crimped yarn. A method for producing a warp knitted fabric to be provided. 4. The method for producing a warp knitted fabric according to claim 3, wherein the warp knitted fabric is a pile warp knitted fabric. 5. A polyester synthetic fiber crimped yarn comprising a front portion and a back portion, wherein at least the back portion has a birefringence Δn of 0.07 to 0.13 and a torque twist number of 2 times / 50 cm or less, and A warp knitted fabric is formed by joining a warp knitted fabric having a warp elongation of 100% or more under dry heat conditions of 130 ° C to a plastic plate and integrally forming a three-dimensional structure with the plastic plate at a temperature of 100 ° C or more. How to make the body.