JPH038852A - Fabric for forming - Google Patents

Abstract

PURPOSE:To obtain a fabric for forming, capable of readily carrying out three- dimensional heat forming and having excellent appearance after the forming by arranging a specific polyester multifilament yarn in a ground part or the back side and placing fiber having higher resistance than that of the aforementioned filament yarn in pile parts or the right side. CONSTITUTION:Polyester multifilament yarn, composed of polyethylene terephthalate homopolymer and having >=4.0g/d strength, <=50% breaking elongation, >=70g/d initial Young's modulus, >=0.5g/d peak stress of thermal stress and >=20% shrinkage factor in boiling water is arranged in a ground part or the back side and fiber (e.g. drawn polyester yarn, polyamide or wool) having higher heat resistance than that of the aforementioned filament yarn is arranged in pile parts or the light side and woven to afford a fabric for forming suitable for automotive internal trim, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a molding fabric for automobile interiors, etc., which has a three-dimensionally complex curved surface, and includes processes ranging from knitting and weaving to thermoforming. The present invention relates to a warp knitted fabric for molding that causes fewer troubles during molding and has good appearance quality after molding.

[Conventional technology]

Conventionally, a method for thermoforming fabrics such as woven or knitted fabrics into a curved shape such as a hat is disclosed in Japanese Patent Application Laid-Open No. 15698/1982, and a method for thermoforming fabrics for use in automobiles or along the unevenness of buildings is disclosed. It is known from Japanese Patent Publication No. 59-1811. In other words, the former has a birefringence (Δn) of 0.0.
By using a fabric such as a woven or knitted fabric made of undrawn polyester yarn with a diameter of 2 to 0.10, it is possible to easily form the woven or knitted fabric without applying undue stress even in the mountain area where the maximum deformation occurs during thermoforming. In the latter, a highly oriented undrawn polyester yarn with a birefringence index (△n) of 0.02 to 0.08 is arranged in the ground part, and a fiber having a higher softening point than the fiber is arranged in the pile part. It is disclosed that thermoforming into a three-dimensional shape is possible by using a moldable fiber sheet arranged in a three-dimensional shape.

[Problem to be solved by the invention]

However, in both methods, the birefringence index (Δn) of the yarn
Because we use undrawn yarn with a diameter of 0.02 to 0.10,
It has the following drawbacks.

In other words, an undrawn yarn with a birefringence index (Δn) of 0.02 to 0.10 has an initial Young's modulus of 70 g/d or less, and a large elongation at break of 70% or more, which is added to the yarn in the knitting and weaving process. Recovery from repeated elongation stress is poor, and the threads are partially elongated, resulting in uneven stitches and textures. Furthermore, although the boiling shrinkage rate of the yarn is high, the shrinkage stress against heat (thermal stress) is as low as 0.3 g/d, so it cannot be sufficiently shrunk in a restricted fabric state such as a knitted or woven fabric. For this reason, there is a drawback that there is little room for the fabric to stretch during thermoforming, and it is difficult to obtain a molded product that conforms to the irregularities of a complex curved surface.

In order to solve these problems, Japanese Patent Application Laid-Open No. 63-165560
In this case, the average birefringence (Δn) is larger than 0.08.
A warp knitted fabric for forming is disclosed in which low orientation drawn yarns of 15 or less are arranged in the ground portion.

However, this yarn is obtained by cold-drawing a low-oriented undrawn yarn at room temperature below 25°C, and the resulting yarn has low thermal stress, and although it shrinks when the yarn is under no tension or restraint. ,
When it becomes a fabric and there is dye liquid resistance in the dyeing machine, etc.
Sufficient shrinkage cannot be obtained when the yarn is under tension, and the dyed finished product has poor formability, especially in the second corner with a complex curved surface, which may tear, and the weave eyelets may become uneven. There was a problem.

[Means for Solving the Problems] The present inventors have discovered that it is possible to easily thermoform three-dimensional shapes having various curved surfaces, and that it is possible to easily thermoform a three-dimensional object having various curved surfaces. It can be handled in the same way as conventional drawn yarn, has fewer fabric defects, and shrinks sufficiently during the dyeing and finishing process, allowing the fabric to stretch evenly over some of the complexly uneven corners during molding. The present invention was developed as a result of extensive research aimed at obtaining a molding fabric with a good raised appearance.

That is, the present invention is made of a polyethylene terephthalate homopolymer having a strength of 4.0 g/d or more, a breaking elongation of 50% or less, an initial Young's modulus of 70 g/d or more, a thermal stress peak stress of 0.5 g/d or more, A molding fabric characterized in that a polyester multifilament yarn having a boiling water shrinkage rate of 20% or more is arranged on the ground part or mainly on the back surface, and fibers having higher heat resistance than the fibers are arranged on the pile part or mainly on the surface. The main points are as follows.

The quality of the yarn constituting the gland portion of the molding fabric of the present invention requires a strength of 4.0 g/d or more.

If the strength is less than 4.0 g/d, the bursting strength of the fabric will be low and the fabric will be prone to tearing and forming holes at some corners of irregularities during molding, that is, at areas where stress is concentrated.

Next, the elongation at break is 50% or less, and the initial Young's modulus is 70 g/d.
It is necessary to satisfy the above requirements, and yarns with an elongation at break of 50% or more and an initial Young's modulus of 70 g/d or less have a low recovery rate of 70% or less at the 10th time of repeated 3% constant elongation. This is undesirable because the repeated elongation in the weaving and knitting process causes the yarn to partially elongate, which tends to cause problems such as slack in the yarn, uneven stitches and weaves, and uneven density.

Next, it is essential that the thermal stress peak stress is 0.5 g/d or more; if it is less than 0.5 g/d, sufficient shrinkage cannot be obtained in a restrained state such as a knitted or woven fabric; The fabric weight (fabric weight) is large, and the thermal stress needs to be 0.5 g/d or more in order to overcome the heat and weight in the heated dyeing machine and cause the fabric to shrink.

Next, it is essential that the boiling water shrinkage rate is 20% or more.

If it is less than 20%, the amount of shrinkage of the fabric after dyeing is insufficient,
The elongation rate of the article in three-dimensional molding, especially the fabric elongation rate in the warp direction, is less than 150% when measured at room temperature, resulting in insufficient moldability. If a fabric with low modulus and high elongation is not used at the corners of a complex uneven surface, the fabric will not be able to be formed smoothly, resulting in uneven stretching of the fabric and uneven pile density, which will deteriorate the quality of the molded product.

The yarn used in the ground part of the present invention has a spinning speed of 2000
Preferably used is an undrawn yarn spun at a high speed of from m/min to 4,500 m/min and drawn at a temperature of from 50'C to 80'C.

Next, the pile part of the present invention has many features such as being stable against molding temperatures and retaining excellent appearance and texture even after molding by using fibers that have higher heat resistance than the ground part. have As the highly heat-resistant fibers, ordinary polyester drawn yarns, polyester ultra-high-speed spun fibers (spinning winding speed of 7000 m/min or more), and natural or regenerated fibers such as polyamide, cotton, rayon, and wool can be used.

[For production]

The reason why the raised fabric for molding of the present invention is suitable for molding fabrics for automobile interiors, etc. that have three-dimensional complex curved surfaces is that the threads constituting the ground part have a high initial Young's modulus, and in the uneven weaving process. It has small deformation due to repeated stretching action, has durability against abrasion and bending, and eliminates density unevenness and
There are almost no problems such as thread breakage or uneven texture.

Furthermore, since the yarn used for the ground section is a yarn with high thermal stress and high shrinkage rate, the yarn can overcome the constrained state of the fabric and the heat and gravity of the dyeing process of raised cloth with a large basis weight. The strips shrink well. The greater the shrinkage of the ground yarn and the greater the shrinkage of the fabric, the greater its elongation ability during thermoforming, making it possible to mold objects with complex curved surfaces.

In addition, the ground yarn is a low modulus and high elongation yarn, which distributes stress evenly during molding and does not have built-in distortion.
There are no defects such as deformation after molding or peeling between the eyebrows when laminated with a plastic sheet and integrally molded.

The molding fabric of the present invention can be obtained, for example, by the following method.

A tricot pile knitted fabric was knitted using a sinker with a structure of 1-0/1-2 for the ground part and 1-2/1-0 for the pile part, and the cough rope was shirred with a shearing machine → dry heat. (130°C x 40 seconds) → Relaxation treatment in boiling bath → Using a jet dyeing machine (130°C x 30 seconds)
Minutes) Width extension 140'CX 30 seconds) → Raised processing → Shirring → Finishing set (150°C x 30 seconds) to perform dyeing and finishing treatment.

The breaking elongation of the molding fabric obtained by the above method was measured at room temperature and at 1
As a result of measurement using Tensilon under 50°C dry heat,
At room temperature, 140% or more in longitudinal direction, 130% or more in latitude, 150
It showed a high elongation rate of 185% or more in the warp direction and 180% or more in the weft direction under dry heat at °C, and when the fabric was thermoformed,
A molded product with low deformation stress, smooth, and no uneven pile density or holes in the corners of a complex curved surface, no internal distortion, excellent stability over time, and good appearance quality was obtained. .

A more preferred method for dyeing and finishing in the present invention is a relaxing method before dyeing the fabric. The purpose of this is to fully relax the fabric after knitting and weaving.As shown in Figure 1, the key point in the relaxing treatment method is the temperature at which the fabric is placed in hot water at 95°C x 30°C.
During the relaxing treatment, the temperature of the hot water was 60°C.
Put the fabric at below °C, raise the temperature to 95 °C, and then
For fabrics treated for 0 minutes, the shrinkage of the fabric is small, and the fabric should be placed in hot water at a temperature of 60°C or higher, preferably at 80°C.
The shrinkage ability of the ground yarn can be fully brought out by relaxing the fabric by placing it in hot water at a temperature of 100°C or higher, and the fabric should be relaxed in a state as close to zero tension as possible. To this end, relaxing equipment can be spread out,
Moreover, it is preferable to use equipment that can feed the fabric even at a temperature of 60° C. or higher.

In this way, the fabric is sufficiently relaxed in the first relaxing process, and once preset is applied, the fabric is not stretched in the next dyeing process, and a good fabric for molding can be obtained.

(Example) Polyethylene terephthalate with an intrinsic viscosity of 0.69 was used as the first
The undrawn system was spun at the spinning speed shown in the table, and the yarn for ground yarn was produced under the drawing conditions shown in Table 2. The yarn after drawing is 100 denier/24 filament.
The spinning conditions were adjusted.

Next, the drawn yarn shown in Table 2 was arranged in the ground part, and the pile part was made of polyester drawn yarn 150 denier/48 filament yarn, and the structure of the ground part was 1-0/
1-2. A tricot pile knitted fabric was knitted using a sinker with a 1-2/1-0 texture as the texture of the pile portion. Subsequently, processing was performed using the processing steps shown below.

Gray machine → shearing, raising treatment → preset (150°C x 30
seconds) → Relaxation treatment (95°C x 180 seconds) → Staining (
130°C x 40 seconds) → Offer set (140°C x 3
0 seconds) → Raised processing → Finishing set (160°C x 30 seconds)
The breaking elongation of the obtained molding fabric was measured at room temperature and at 150"C.
The moldability was evaluated using Tensilon.

In Examples 1 to 4 and Comparative Examples 1 to 2, the spinning winding speed was 1500.
~5000 m 7 minutes of undrawn yarn drawn at 75°C1
The stretching ratio was varied, and the stretching ratio was large and the moldability was good.

As shown in Examples 5-6 and Comparative Examples 3-5, the spinning speed was 40.
As a result of using an undrawn yarn of 00m 7 minutes and processing the stretching temperature and stretching ratio as shown in Table 2, in Comparative Example 3, the thermal stress peak stress of the obtained yarn was less than 0.50 g/d, and the relaxation process The fabric shrinkage was insufficient and the moldability was also poor. In addition, the yarns obtained in Comparative Examples 4 and 5 have a high thermal peak stress, but a very low fresh water shrinkage rate, a low fabric shrinkage rate in the relaxing process, and poor formability.
Holes occurred in some corners where the stretch was large.

As shown in Examples 7 to 10, stretching was performed under the conditions of the stretching ratio. The fresh water shrinkage rate of the threads of Comparative Examples 1 and 2 was less than 20%, and those using these threads for the ground system had a small fabric elongation rate and poor formability. On the other hand, when the threads of Examples 1 to 4 were used as ground yarns, the fabric shrinkage was large during the relaxing process, and if the shrinkage was maintained even after dyeing, the thermal stress value would be high, but the boiling shrinkage The stretching ratio tends to decrease, and it is desirable to carry out the stretching at a stretching ratio determined from the formula for calculating the stretching ratio, or at a lower range of about 0.2.

In addition, Comparative Example 6 is an ordinary drawn yarn that is currently commercially available, Comparative Example 7 is an undrawn yarn at a spinning winding speed of 4000 m 7 minutes, and Comparative Example 6 is an undrawn yarn with a small fresh water shrinkage rate of the yarn. The yarn used in the ground yarn has small fabric shrinkage and fabric elongation.The yarn in Comparative Example 7 that uses the yarn as the ground yarn has sufficient shrinkage, but it shrinks when the fabric is restrained. The stitching rate was low, the texture was stiff, the stretch of the fabric was low, the stitches were uneven, and the quality was poor.

Table 2 Table 3 Example 11 Using the yarn of Example 7 as a ground yarn, the pile part was 150
A pile knitted fabric with a velor texture of 500 g/r+ (area weight) is knitted using a single circular knitting machine using a polyester processed yarn dyed with loop fluff interlaced yarn using denier/48 filament fluid jet processing. Then shearing treatment → pre-cera) (130”CX 40 seconds) → relaxing treatment (95°CX 180 seconds) → proposal set (140°
C x 30 seconds) - → Hair raising process (200°C) → Hair shearing process →
Finishing was performed using (150"CX 30 seconds).

A 0.7 ta thick ABS resin plate coated with an adhesive consisting of a saturated polyester resin and a curing agent to a solid content of 20 μm was laminated onto this knitted fabric, and dried to obtain a laminated sheet. After heating this laminated sheet to 170°C, vacuum forming was performed using a vacuum forming mold having a curved surface shape. The ground fiber has extremely low elongation stress and can be molded uniformly even on curved surfaces, and a high-quality molded product with no distortion or uneven pile density after molding was obtained. The physical properties measured in the examples were evaluated by the method described below.

(1) Strength and elongation of yarn, Young's modulus Toyo Baldwin type Tenshiro 207M-4-100
It was determined from the average value of n-10 using a mold with a sample length of 10 cm and a tensile speed of 10 cm/min.

(2) Thermal stress Using a thermal stress tester manufactured by Kanebo Engineering, sample length: 100 bars, initial load: 0.1 g/d, heating rate: 300
"C/180 seconds, and the peak stress and peak temperature of thermal stress were determined from the average value of n=5.

(3) Voile shrinkage rate: Mark a length of 50 cm on the yarn with an initial load of 0.1 g/d, put it into a boil bath in a load-free state, process for 30 minutes, and measure the length between the marks after air drying. The shrinkage rate with respect to the original sample length was determined.

(4) Elongation rate of fabric Using Tensilon UTM-4-100 manufactured by Toyo Baldwin, sample length 10, tensile speed 10 cm/min, 5 in sample.
The elongation rate at room temperature and under heating at 150°C was determined from the average value of n-5.

〔Effect of the invention〕

The present invention has the above-mentioned configuration, and has the disadvantages of the conventional methods, such as yarn slack, stitches, etc., in the process up to thermoforming.
There are no problems such as uneven texture, and it has sufficient shrinkage ability during the dyeing process.As a result, it can be easily molded in the thermoforming process without requiring excessive pressure, and even three-dimensional structures can be easily molded without distortion. It is possible to obtain a laminated fabric product with good surface quality without any internalization, and it can be widely used in the field of molded products with many uneven parts such as automobile interior parts, buildings, upholstery, and bags.

[Brief explanation of drawings]

FIG. 1 shows the relationship between the temperature at which the fabric is placed in hot water and the shrinkage rate of the fabric during the relaxing treatment method for fabrics for molding of the present invention.

Claims (1)

[Claims] Made of homopolymer of polyethylene terephthalate, the strength is 4.0 g/d or more, the elongation at break is 50% or less, the initial Young's modulus is 70 g/d or more, and the thermal stress peak stress is 0.5 g.
polyester multifilament yarn with boiling water shrinkage of 20% or more is arranged on the ground part or mainly on the back surface, and fibers with higher heat resistance than the fibers are arranged on the pile part or mainly on the surface. fabric for molding