JPH01321955A - Warp knit fabric for forming and production thereof and production of warp knit fabric form - Google Patents

Abstract

PURPOSE:To obtain the title fabric form with bulky, warm feel, excellent in light fastness, tear strength and fatigue resistance, suitable as an automobile sheet backing, cladding for musical instruments, etc., by using textured yarn of specified birefringence as a backing part. CONSTITUTION:Highly oriented polyester undrawn yarn or incompletely drawn yarn with its birefringence of pref. 0.02-0.10 is put to drawing-and-false twisting at temperatures lower than the glass transition temperature of this polyester into crimped textured yarn, which is then used as a backing part, thus making a warp knit fabric. This fabric is bonded to e.g. a plastic board 4 through an adhesive 3 followed by integral forming processing at temperatures of pref. >=100 deg.C to a solid structure, thus obtaining the objective fabric form >=100% under dry heat at 130 deg.C in the extension rate in the warp direction and 0.07-0.13 in the birefringence of the textured yarn in the backing part 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a warp knitted fabric for forming, a molded article thereof, and a method for producing the same.

[Prior art]

Warp knitted fabrics for molding are used for car seat backs, exterior coverings for door trims, musical instruments, and bottles.

It is widely used as exterior and interior lining materials for jewelry boxes, as well as wall fabrics and chair upholstery for interior decorations.

When warp knitted fabrics are used in these molded products, the degree of unevenness and curvature increases as the degree of drawing increases, making it an important condition for a high-quality product to be finished with a natural sharpness. has been done.

Conventionally, in order to meet these conditions, elastic yarns were generally used for warp knitted fabrics for high drawing, and highly oriented undrawn polyester yarns or completely undrawn yarns were used for warp knitted fabrics for medium drawing. was used, and false twisted yarn was used for warp knitted fabrics for low drawing areas.

However, among these warp knitted fabrics, those used especially for medium drawing are described in Japanese Patent Application Laid-Open No. 55-7432.
As disclosed in Japanese Utility Model Publication No. 6111264, etc., highly oriented undrawn yarns and completely undrawn yarns are used as constituent yarns of warp knitted fabrics for forming, so there are various problems as described below. was pointed out.

First, because it was made from raw silk, it lacked bulk and warmth. In addition, the dye fastness against sunlight is poor, tear strength is low, and fatigue resistance is low, so there are problems in that the fabric is easily damaged and is prone to fuzzing and pilling.

Secondly, it was susceptible to the influence of '/14 humidity during the knitting process and was likely to cause quality unevenness. In addition, bending, friction, handling, etc. caused by guides, needles, etc. can cause abnormal tension, which tends to cause warp streaks, which are the biggest drawback of warp knitted fabrics, making process control and quality control extremely difficult. That's what happened.

[Problem to be solved by the invention]

The purpose of the present invention is to provide bulky and warm texture, improve sunlight fastness and tear strength, improve fatigue resistance, and facilitate process control and quality control, especially for medium drawing. It is an object of the present invention to provide a suitable warp knitted fabric for shaping, a method for producing the same, and a method for producing a molded article of the warp knitted fabric.

[Means to solve the problem]

The warp knitted fabric for forming of the present invention which achieves the above object is composed of a front part and a back part, and at least the back part is made of a crimped polyester synthetic fiber yarn having a birefringence Δn of 0.07 to 0.13. It is a warp knitted fabric, and the warp knitted fabric is characterized by a warp direction elongation rate of 100% or more under dry heat conditions of 130°C.

In addition, the method of the present invention for producing such a warp knitted fabric for forming uses highly oriented undrawn or incompletely drawn polyester yarns having a birefringence Δn in the range of 0.02 to 0°10 at a temperature below the glass transition point. The crimped yarn is drawn and false-twisted at a temperature to form a crimped yarn, the crimped yarn is used at least in the back portion to knit a warp knitted fabric, and the warp knitted fabric is heated to a temperature higher than the glass transition point of the crimped yarn. It is characterized by being subjected to rapid heat treatment at a high temperature.

Further, according to the present invention, it is possible to provide a warp knitted fabric molded body in which the warp knitted fabric for molding is made of heath, which is temporarily bonded to plastic and integrally molded into a three-dimensional structure, and such warp knitted fabric molding is possible. The body can be manufactured by joining the warp knitted fabric for molding to a plastic plate and integrally molding it together with the plastic plate into a three-dimensional structure at a temperature of 100° C. or higher.

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

The above-mentioned warp knitted fabric has at least the back part (ground part)
It is necessary that it is made 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 texture can be bulky, soft, and warm.

The type of polyester constituting this crimped yarn is not particularly limited, but polyethylene terephthalate and polybutylene terephthalate are preferably used, with polyethylene terephthalate being particularly suitable.

The birefringence Δn of this crimped yarn must be greater than 0.07, and if it is smaller than 0.07, the sunlight fastness and tear strength will be significantly reduced, similar to conventional warp knitted fabrics using undrawn yarn. In addition, the fatigue resistance of the fabric decreases, making it more likely that the fabric will be damaged. Further, the birefringence Δn of this crimped yarn must be smaller than 0.13. If it is larger than 0.13, the elongation rate in the warp direction will decrease when it is made into a warp knitted fabric, and the drawability, which is important for the present invention, will deteriorate.

Further, the stretch recovery rate of the crimped yarn is preferably 10% or more, and if it is lower than 10%, the effect as a crimped yarn will be reduced.

When the expansion/recovery rate exceeds 30%, handling of the crimped yarn becomes somewhat difficult, but this does not pose a major problem.

Furthermore, although the crimped yarn used in the present invention is a false twisted yarn, its form does not have strong torque or snarl like normal false twisted yarn, and it does not have a crimped form like a conjugate yarn, for example. It is desirable that it be of a degree that indicates the following. Therefore, in terms of the number of twists, it is desirable that the torque is 150 cm or less twice. By reducing the number of torque twists in this way, for example, it is possible to prevent twisting or release failure during warping, and it is possible to improve process passability.

In addition, in the present invention, the torque twist number refers to the number of twists when a small load of 2 mg/d is hooked to the center of 1 meter of the test yarn, and the yarn ends are aligned, folded in half, and suspended. The number of rotations at which the load rotates is the number of torque twists.

In the warp knitted fabric of the present invention, the above-described crimping system is used at least in the back portion (ground portion). Therefore, if the crimped yarn is used only in the back part, it will be hidden inside the front part (pile part), but even if it is hidden in this way, it will not be bulky or stretchy. The effect on the texture is recognized, and there is no problem in softening the texture or increasing the bulk of the fabric.

The warp knitted fabric for molding of the present invention, which is made by using the above-mentioned polyester synthetic fiber crimped yarn at least in the puncture part (ground part), has an elongation rate of 100% in the warp direction under dry heat conditions of 130°C. It is necessary that it is at least 150%, more preferably 150% or more. The reason why the elongation rate in the warp direction was set at 130°C in dry heat is that the processing temperature during molding is generally carried out at around 130°C in dry heat. If the elongation rate in the longitudinal direction is less than 100% at a temperature close to this forming process temperature, the cross section or curved surface of the formed object will be sharp, especially when medium drawn.
Moreover, it becomes difficult to achieve a natural-looking finish.

FIG. 1 shows an example of the warp knitted fabric for molding of the present invention. ■ is the ground part of the warp knitted fabric, and 2 is the pile part. Of these, the crimped yarn Y of the present invention described above is used in the ground portion 1. On the other hand, in the pile part 2, the shrinkage rate is lower than that of the crimped yarn Y in the ground part 1.
Filament yarn or spun yarn Y' is used.

Of course, the same yarn as the crimped yarn Y of the gland section 1 may be used. In this embodiment, the pile in the pile section 2 is cut to form a cut pile.

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

As described above, the warp knitted fabric for forming of the present invention is produced by using highly oriented undrawn or incompletely drawn polyester yarns having a birefringence Δn in the range of 0.02 to 0.10 at a temperature below the glass transition point. The crimped yarn is drawn and false-twisted to form a crimped yarn, the crimped yarn is used at least in the back portion to knit a warp knitted fabric, and the warp knitted fabric is heated at a temperature equal to or higher than the glass transition point of the crimped yarn. It can be manufactured by subjecting it to rapid heat treatment.

Yarns with birefringence Δn of 0.02 to 0.10 include highly oriented undrawn yarns (PO, Y) obtained by ultra-high speed spinning,
Incompletely drawn yarn, which is obtained by drawing an undrawn yarn at a low magnification, is preferably used. In particular, highly oriented undrawn yarn (POY) is suitable as the raw yarn for producing the above-mentioned crimped yarn. Birefringence Δ
When n is smaller than 0.02, the yarn becomes more susceptible to the influence of temperature and humidity, which increases the variation in yarn quality due to changes over time. Furthermore, if the birefringence Δn is larger than 0.10, the warp knitted fabric will have a high warp direction elongation rate under dry heat conditions of 130°C because it will move from the highly oriented unstretched or incompletely stretched region to the fully stretched region. becomes difficult to do.

The method of stretch false twisting is a method of heating during stretching, heat setting below the glass transition point, and false twisting of untwisting at the same time. Any post-stretching plate-twisting process may be used, in which the sheet is once stretched and then subjected to a false-twisting process of heating, heat setting at a temperature below the glass transition point, and untwisting. However, in terms of the uniformity of the obtained yarn quality and yarn processability, the former method of drawing and twisting is more preferable.

The heating mechanism is not particularly limited and may be a friction type, spindle type, or pneumatic type. However, the friction type is the best in terms of cost and quality. In addition, the number of false twists given by this stretch false twisting process is not particularly limited, but is generally used in the range of 1500 to 5000.
A range of times/m is preferably applied. Further, the false twisting speed is preferably 100 to 900 m/min.

The draw ratio in draw false twisting processing needs to be at least the same level as when drawing and false twisting ordinary highly oriented undrawn yarns, and the higher the draw ratio, the higher the elongation rate of the warp knitted fabric after the rapid heat treatment performed in the subsequent process. can be made larger. The stretching ratio is desirably equal to or higher than the natural stretching ratio; for example, when using the same system as highly oriented unstretched polyester at a spinning speed of 3500 m/min, it is preferably about 1.8 to 2.0 times. These are favorable conditions.

In the manufacturing method of the present invention, the heat set temperature in the stretch false twisting process must be below the glass transition point.

Further, the heat treatment performed after the false twisted yarn is made into a warp knitted fabric must be performed by rapid heat treatment at a temperature equal to or higher than the glass transition point. Rapid heat treatment means that the temperature is instantaneously raised to a target glass transition point or higher by taking a process of gradually increasing the temperature after passing through an intermediate temperature.

Through such stretch false twisting processing at a heat set temperature below the glass transition point and rapid heat treatment of the warp knitted fabric at a temperature above the glass transition point, warp knitted fabric for forming purposes can be stretched in the warp direction at 130°C dry heat for the first time. This makes it possible to increase the ratio to over 100%. If the heat set temperature during stretch false twisting is set above the glass transition point or the temperature during rapid heat treatment of the warp knitted fabric is set below the glass transition point,
It is difficult to obtain the desired high longitudinal elongation rate.

In addition, in the present invention, by setting the heat setting temperature of the draw false twisting process to below the Wokara transition point, torque and snarl are not generated in the crimped yarn, and the crimped form is made to have an appearance similar to that of a conjugate yarn. be able to. This improves the process passability of the crimped yarn. Furthermore, the crimped yarn that has been drawn and false-twisted at a temperature below the glass transition temperature has the characteristic that it has almost no processing deformation in its cross section, even though it is a false-twisted yarn. Therefore, most of the luster of the original yarn is maintained, and a high-class appearance can be achieved. This effect is particularly noticeable when yarns with irregular cross-sections, such as triangular cross-sections, are used, and their luster can be further emphasized.

FIG. 2 shows the drawing and false twisting process for producing the above-mentioned crimped yarn. Reference numeral 11 denotes a pancage around which the raw yarn Yo, which is a highly oriented undrawn yarn or an incompletely drawn yarn, is wound. The raw yarn YO released from this package 11 is transferred to the feed roller 1
2 and the pre-heli roller 15, it is heated and untwisted by the rice fold 14, heat-set by the heater 13 whose heating area on the upstream side is set to a temperature below the glass transition point, and untwisted on the downstream side. Then, the crimped yarn Y is obtained. Next, this crimped yarn Y is wound up as a package 16.

In order to make the above-mentioned crimped yarn into a warp knitted fabric for forming according to the present invention, it must be used at least in the back part (ground part), but it may also be used in the front part (pile part).

This is because the back portion can have a higher shrinkage rate when subjected to rapid heat treatment than the front portion. It is preferable that the difference in shrinkage rate between the back part and the front part when subjected to this rapid heat treatment is 10% or more.

In addition, the temperature of the rapid heat treatment performed after knitting the crimped yarn into a warp knitted fabric must be higher than the glass transition point, and the higher the temperature, the better. The elongation rate in the longitudinal direction can be increased.

Further, when the front part is made into a pile part and it is made into a cant pile part, the pile cutting may be performed either before or after the rapid heat treatment. In addition, when raising the pile, the raising method is not particularly limited, and may be any of the following methods, such as loop raising by scratching the loops with a cloth cloth, cut raising by cutting the loops with a cutter, or shirring. good.

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

Generally, a vacuum forming method is preferably used as the forming method. However, other methods such as press molding and stretch molding can be used for those with small depth and sharpness of irregularities and a small squeezing effect. The temperature during this molding process is generally 100'C or higher, more preferably around 130C.

〔Example〕

A 75-denier, 36-filament highly oriented polyester undrawn yarn (POY) with a birefringence Δn of 0.09 was heated at a cent temperature of 70°C, a stretching ratio of 1°8 times, and a number of false twists of 3400 times/m.
A crimped yarn is obtained by drawing and false twisting, and this crimped yarn is used for the ground part of the pile structure, and is 75 denier.

A warp knitted fabric was knitted using easily dyeable polyester filament yarn of 24 filaments in the pile portion. When knitting this warp knitted fabric, the process passability of the crimped yarn is extremely good, and the warp knitted fabric has no warp streaks or sink marks, and is of good quality. Ta.

Next, this warp knitted fabric was rapidly heat treated in boiling water at 98°C, and then the pile portion was pile cut and further heated at 105°C.
A cut pile warp knitted fabric for molding was produced by subjecting it to high-temperature dyeing.

This warp knitted fabric had an elongation rate of 150% in the warp direction when dry heated at 130°C. Further, when the tear strength of this cut pile warp knitted fabric was examined, it was found that the weight in the warp direction was 1.5 kg, and the color fastness after being exposed to carbon light for 20 days was grade 4.

Next, a thin plastic plate (film) is attached to the ground part of this cut pile warp knitted fabric via an adhesive to make a composite sheet, and this composite sheet is then used as an automobile seat back by vacuum forming at 130°C. The molding force was increased under dry heat.

The warp knitted fabric on the surface of the formed sheet pack was extremely soft and bulky, and had a very warm texture. In addition, the molded irregularities and bends had a natural sharpness.

〔Effect of the invention〕

As mentioned above, the warp knitted fabric for forming of the present invention is composed of polyester synthetic fiber crimped yarn with a birefringence Δn of 0.07 to 0°13 at least in the back portion, so it is different from conventional highly oriented undrawn yarn. It has a softer texture, bulkiness, and warmth compared to those using completely undrawn yarn. Moreover, the sunlight fastness and tear strength are improved, and the fatigue resistance is also improved.

In addition, the warp knitted fabric has a warp direction elongation rate of 100% or more under dry heat conditions of 130°C, so it has very good formability, and in particular, it naturally reduces irregularities and bends during medium drawing. You can achieve a sharp finish.

Further, according to the manufacturing method of the present invention, it is possible to easily obtain the above-mentioned warp knitted fabric for shaping and a molded article from this warp knitted fabric. In particular, the crimped yarn used is obtained by stretching and false twisting at a heat setting temperature below the glass transition point, so it has almost no torque or snarl, making process control and quality control during knitting easier. can do. That is, warp lines and sink marks do not occur in the warp knitted fabric, and a high-quality product can be easily obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of a warp-knitted fabric for forming according to the present invention, and FIG. 2 is a process diagram of a drawing false twisting process for producing the same crimped yarn. 1...Gland part (back part), 2...Pile part (
Front part), 3...Adhesive, 4...Plastic plate, 12...Feed roller, 13...Heater, 1
4...Twister, 15...Delivery roller. Agent Patent Attorney Nobuo Ogawa −

Claims (5)

[Claims] (1) A warp-knitted fabric consisting of a front part and a back part, at least the back part being composed of crimped polyester synthetic fiber yarn with a birefringence Δn of 0.07 to 0.13,
The warp knitted fabric has a warp direction elongation rate of 1 under dry heat conditions of 130°C.
00% or more warp knitted fabric for forming. (2) The warp knitted fabric for forming according to claim 1, wherein the front part forms a pile part and the back part forms a ground part of the ground structure. (3) A highly oriented undrawn or incompletely drawn polyester yarn with a birefringence Δn in the range of 0.02 to 0.10 is drawn and false twisted at a temperature below the glass transition point to form a crimped yarn, and this A method for producing a warp knitted fabric for forming, comprising knitting a warp knitted fabric using crimped yarn at least in the back portion, and subjecting the warp knitted fabric to rapid heat treatment at a temperature equal to or higher than the glass transition point of the crimped yarn. (4) The method for producing a warp knitted fabric for forming according to claim 3, wherein the warp knitted fabric is a pile warp knitted fabric. (5) Consisting of a front part and a back part, at least the back part is made of crimped polyester synthetic fiber yarn with a birefringence Δn of 0.07 to 0.13, and a dry heat 130
Production of a warp knitted fabric molded article by joining a warp knitted fabric with a warp direction elongation rate of 100% or more under the condition of 100% or more to a plastic plate, and integrally molding the warp knitted fabric together with the plastic plate into a three-dimensional structure at a temperature of 100°C or more. Method.