JPH0232382B2 - TOKUSHUKARYORIKAKOITONOSEIZOHOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a special false twisted yarn made of polyester fibers. More specifically, when made into a knitted fabric, the special false-twisted yarn for knitted fabrics exhibits the opacity of natural cotton or linen and a luster similar to the unique luster. Regarding the manufacturing method. Many improvements have been made in the past in attempts to produce cotton-like or linen-like knitted fabrics using certain fibers made from thermoplastic synthetic polymers. For example, examples of cotton-like processing include false twisting, fluffing, and processing of yarn with a relatively small single yarn fineness into threads with loops, and linen-like processing includes fusion false twisting. It was the main thing. However, these methods approximate the texture of the yarn in terms of its form, and are still insufficient to make it feel like cotton or linen. The current situation is that it is far from that level. In view of this situation, the present invention aims to create a yarn made of a thermoplastic synthetic polymer that can express an opaque luster and texture similar to knitted fabrics made from natural cotton or hemp. This was achieved through repeated research. That is, the present invention has a round cross-sectional shape and/or
Or, in an elliptical composite fiber in which a core component and a sheath component are arranged substantially concentrically, the core component contains at least 1% by weight of a matting agent, and the sheath component contains substantially a matting agent. This is a method for producing a special false-twisted yarn, which is characterized in that undrawn polyester multifilament yarn made of fibers that do not contain . [T]<(55000−145Te)/√ However, [T] is the number of twists inserted during false twisting (T/m) Te is the temperature of the false twisting heater (℃) D is the fineness of the yarn after false twisting (denier ) To describe the present invention in more detail, the luster of knitted fabrics made of cotton or linen, combined with their opacity, gives them a unique luster. The generation mechanism is due to the effect of the internal structure of the fiber as well as the light reflection characteristics of the fiber (surface reflected light, transmitted light, refracted light, internally reflected light, internally absorbed light, diffusely reflected light, etc.) due to its twist and cross-sectional shape. I owe a lot. After extensive research, we surmised that if we could obtain fibers made from thermoplastic synthetic polymers with optical properties similar to those described above, it would be possible to impart the special luster of cotton and linen. , which leads to the present invention. The present inventors found that in the fiber cross section, the content of matting agents such as titanium oxide was different between the sheath component and the core component, that is, the sheath component was a polymer containing no matting agent, and the core component The fiber has a core-sheath structure made of a polymer containing a matting agent, and the cross-sectional shape of the fiber is changed by false-twisting, especially by false-twisting at the same time as stretching, and the fiber has a slight cross-section in the longitudinal direction. It has been discovered that the unique opacity and luster of cotton and linen can be approximated by the synergistic effect of continuous changes. Unless the matting agent content of the core component of the core-sheath fiber in the present invention is 1% by weight or more, the unique opaque feeling described above cannot be obtained, and preferably 1.5% by weight or more is more effective. However, when the matting agent content reaches a certain amount, the opacity effect decreases, and when the amount is too high, its dispersibility decreases, which causes more clogging of the polymer overfill during spinning. It becomes difficult to perform spinning stably for a long time. The content of the matting agent is appropriately selected to be 1.0% by weight or more in view of the opacity effect and spinnability. In addition, the sheath component must be substantially free of matting agents, and the content must be
This means less than 0.30% by weight, preferably less than 0.15% by weight. In the present invention, the matting agent used can be a white pigment such as titanium oxide or barium sulfate. Also, certain colored pigments having a matte effect can also be used. The core-sheath state of the core-sheath fibers in the present invention only needs to be approximately concentric, and the core-sheath fibers do not need to be clearly separated at the interface between the core-sheath fibers, and the core-sheath components may be slightly mixed at the interface. However, the sheath component does not need to have a constant thickness in the circumferential direction, and may have some thickness unevenness. In the present invention, the fiber cross section of the undrawn yarn to be used is appropriately selected depending on the purpose and use of the resulting false twisted yarn. That is, an undrawn yarn containing only round cross-section fibers, an undrawn yarn containing only oval fibers, and an undrawn yarn containing a mixture of round cross-section fibers and oval fibers (the mixing ratio is appropriate) can be used. The present invention approximates the luster of cotton and linen through the effect of sheath components that do not substantially contain matting agents. If the sheath component is too thick, the opacity will be impaired, and if it is too thin, the gloss effect will be impaired. Therefore, the thickness of the sheath component is preferably within a range of thicknesses. A typical example of the undrawn yarn used in the present invention is shown in FIG. In the round cross-section fiber shown in FIG. 1, 1A is a sheath component, 1B is a core component, and the thickness of the sheath component 1A is preferably in the range of 5≦A-B/A×100≦45. Even if the value is within this range, if the fiber is thick, it is desirable to set it to a smaller value, and if the fiber is thin, it is desirable to set it to a larger value. The thickness of the sheath component is selected accordingly. Further, FIG. 2 shows a schematic cross-sectional view of a typical oval fiber, and in the cross-sectional view, it is preferable that the value of C/E×100 is in the range of 30 to 80. In addition, in the case of oval fibers, 1A is the sheath component and 1B is the core component, and in the same way as the round cross-section fiber, the thickness of the sheath component is the value of CD/C x 100 in Figure 2. is in the range of 5 to 45, and the thickness of the sheath component is preferably approximately the same in the circumferential direction of the ellipse. Fibers with an elliptical cross section like this are a preferable means to approximate cotton, and also to approximate the feel to the touch. The undrawn yarn having the above-mentioned special characteristics is subjected to false twisting, but it is necessary to carry out the false twisting under specific conditions. The specific conditions are defined as a range in which cross-sectional deformation of the fibers during false twisting is small and gloss is not impaired. The cross-sectional deformation during false twisting is mainly influenced by the fineness (denier) of the multifilament, the number of inserted twists (T/m), and the false twisting heater temperature (° C.). Naturally, the smaller the number of inserted twists and the lower the false-twisting heater temperature, the smaller the degree of cross-sectional deformation.
The number of inserted twists is almost determined by the fineness of each multifilament in order to make a false twisted yarn, and the smaller the fineness, the more the number of inserted twists needs to be. Formula [T] < (55100−
145Te)/√ defines the relationship between these three, and it is necessary to perform false twisting under the condition that [T] is within the range of the formula calculated by D and Te. When we try to calculate the upper limit of the range of [T] using this formula, we get the results shown in Table 1.

[Table] The ratio to the normal level [T] is calculated by assuming that the number of inserted twists at the normal level is about 3400 (T/m) for 75 ^D , and the ratio of [T] to that. This formula was determined from a method of false twisting at the same time as stretching. To measure the number of inserted twists, sample the running yarn by holding both ends of the running yarn during false twisting, set both ends on a twister, and actually measure the number of untwists. It is expressed as the number of twists. (Unit: T/m) When performing false twisting under such specific conditions, it is necessary to perform false twisting simultaneously with stretching. The method of false twisting at the same time as stretching is industrially very useful because it enables cost reduction and speeding up production by combining the two steps of stretching and false twisting into one step. Traditionally, a method of false-twisting drawn yarn, called the conventional false-twisting method, generally uses false-twisting pins, but this pin false-twisting method may cause scratches on the fiber surface and reduce luster. ), so it is not a preferred method. That is,
The false-twisting device for the simultaneous stretching and simultaneous false-twisting method is not a false-twisting pin method, but is, for example, a 3-axis circumscribed friction type device that uses a non-metallic disk (for example,
A material mainly made of polyurethane is preferred. The false-twisted yarn according to the present invention is intended to be used as a cotton or linen-like yarn, but when producing it with the aim of producing a ramie-like linen-like texture, the yarn is fused to give it a silky feel. It is preferable to create a bond, for example by increasing the temperature of the false twisting heater to such an extent that partial fusion occurs in the longitudinal and cross-sectional directions of the yarn. The temperature of the false-twisting heater depends on the ease of fusion depending on the draw ratio. In other words, when the draw ratio is low, fusion tends to occur even at a relatively low heater temperature, and when the draw ratio is high, the temperature is higher. It is set as appropriate, taking into account the need for fusion and the ease of fusion depending on the thickness of the fibers, that is, thicker fibers are more likely to be fused than thin fibers. Next, the manufacturing method of the present invention will be explained using the drawings. FIG. 3 is a diagram of one embodiment for explaining the simultaneous stretching and false twisting method of the present invention. In FIG. 3, the undrawn yarn 1 is stretched and false-twisted between the first roller 2 and the second roller 6,
Secondary heat setting is performed between the second roller 6 and third roller 8, and entangling treatment is performed between the third roller 8 and fourth roller 10. It is then shown to be oiled and wound up by the winding device 12. 3 is a false twisting heater for fixing false twisting, 4 is a yarn cooling device, 5 is a false twisting device, 7 is a secondary heat treatment device, 9 is an interlacing nozzle,
11 indicates an oil addition roller. In addition, secondary heat treatment,
The entanglement treatment and oil addition may be carried out depending on the purpose of use of the resulting false twisted yarn, and one, two or all of these treatments may be omitted. As mentioned above, the false twisting device 5 is preferably a circumscribed friction false twisting device, and for example, a circumscribed friction false twisting device equipped with a friction disk as shown in Japanese Patent Application Laid-Open No. 51-1565 is suitable. ing. The fineness of the false-twisted yarn to be obtained when false-twisting is carried out simultaneously with drawing using such a false-twisting device.
(D) and the false-twisting heater temperature (Te) determined according to the purpose of use of the false-twisted yarn, the number of inserted twists [T] satisfies the above-mentioned formula. As the friction disk of the false twisting device, it is particularly preferable to use a friction disk mainly made of a non-metallic material, such as a polyurethane rubber material, in order to avoid damaging the fiber surface as much as possible. The polyester constituting the polyester multifilament undrawn yarn in the present invention is one containing 85 mol% or more of ethylene terephthalate units. Examples of copolymerization components include dibasic acids such as adipic acid, sebacic acid, isophthalic acid, diphenyldicarboxylic acid, and naphthalene carboxylic acid, oxyacids such as oxybenzoic acid, and diethylene glycol, propylene glycol, pentaerythritol, and polyethylene glycol. Glycols such as monoether, 5-sodium sulfoisophthalic acid, etc. can be used. The combination of polyester polymers for the core component and the sheath component may be of the same or different types, but it is important that the combination does not reduce the spinning productivity of the undrawn yarn, and that it depends on the time of false twisting, knitting and weaving, dyeing, etc. From the viewpoint of preventing peeling due to physical and chemical effects, the combination is preferably of the same type of polymer. On the other hand, undrawn yarns made of composite fibers can be obtained by melt spinning using a core-sheath composite spinning machine. core,
The ratio of the sheath components can be set to a desired ratio by changing the capacity or rotational speed of the discharge pump for each of the core and sheath components of the spinning machine. Furthermore, by making the discharge hole round and/or oval, it is possible to easily obtain yarns with only round cross sections, yarns with only oval cross sections, and yarns with a mixture of round and oval cross sections. . In the present invention, the undrawn yarn used may be an undrawn yarn spun and wound at a low speed, but it is possible to use an undrawn yarn spun and wound at a low speed, but since it is false-twisted at the same time as drawing, the processability is stabilized, productivity is improved, and quality is improved. In order to improve the
It is more preferable to use an undrawn yarn spun and wound at a speed of 2500 m/min or more. The single yarn fineness of the false twisted yarn in the method of the present invention is preferably at least 4 denier, more preferably 3 denier or less, for the purpose of obtaining a high-quality knitted fabric. However, if the single yarn fineness is too small, stable spinning cannot be performed, so the lower limit of the single yarn fineness is preferably 0.7 denier or more. As detailed above, the present invention is characterized in that an undrawn yarn having special characteristics is subjected to stretching and false twisting under specific conditions, and
The knitted fabric using the obtained yarn can provide a knitted fabric that approximates the unique opacity and luster of cotton and linen. Next, a specific explanation will be given with reference to examples, but the scope is not limited to this. The intrinsic viscosity used in the examples was determined by dissolving the sample in orthochlorophenol solvent and measuring it at 25°C using an Ostwald viscometer.
Intrinsic viscosity measured at Example 1 Using a core-sheath composite spinning machine equipped with a composite spinneret with 48 round holes, polyethylene terephthalate with an intrinsic viscosity of 0.65 was used, and the titanium oxide content in the polymer was 0.
Several types of polymers in the range of ~20% by weight are used for the core component and the sheath component, respectively, and the thickness of the sheath component (A-B/A x 100 in Figure 1) is 15, and the core has a round cross section. Spinning undrawn yarn with sheath structure (level 13) at 3000
It was melt-spun and wound at a speed of m/min. These undrawn yarns were drawn and simultaneously false-twisted using the false-twisting machine shown in FIG. 3 under the following conditions to obtain false-twisted yarns of 75 ^D -48 ^fil . Next, each of the obtained false twisted yarns was knitted using a circular knitting machine, and the knitted fabric was evaluated with the naked eye. The results are shown in Table 2. <Stretching and simultaneous false-twisting processing conditions> Stretching ratio 1.75 (times), processing speed 600 (m/min), false-twisting device: 3-axis circumscribed friction false-twisting device (10 polyurethane rubber discs), false-twisting heater temperature 220 (℃), number of inserted twists 2600 (T/m)

[Table] No. 1, No. 2, No. 7, and No. 8 in Table 2 are comparative examples for clarifying the effects of the present invention. That is,
In No. 1 and No. 2, the core component did not contain 1.0% by weight or more of titanium oxide, and therefore lacked opacity. No. 8 has relatively weak luster because it contains 0.3% by weight or more of titanium oxide as a sheath component. In addition, No. 13 had a large pressure increase due to clogging of the filter material during spinning. Example 2 Example 2 is a comparative evaluation of the thickness of the sheath component. Polyethylene terephthalate with an intrinsic viscosity of 0.65 containing 2.5% by weight of titanium oxide was used as the core component polymer, and polyethylene terephthalate with an intrinsic viscosity of 0.65 without titanium oxide was used as the sheath component. Spinning and processing were carried out under the same conditions as in Example 1 except that the level was changed, and a false twisted yarn of 75 ^D -48 ^fil was obtained. The obtained false twisted yarn was knitted and evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Table] No. 14 in Table 3 has a thin sheath component and has the same luster as fibers obtained only from the core polymer.
Therefore, compared to Nos. 15 to 19, it does not approximate the luster of cotton or linen. In addition, it is difficult to adjust the core and sheath during spinning, and the thickness of the sheath component tends to be uneven. No.
No. 20 had a thick sheath component and was slightly less opaque than Nos. 15 to 19. Example 3 Example 3 is a relative evaluation of the ellipse ratio (C/E×100) of an ellipse cross section. The same polymers as in Example 2 were used for both the core component and the sheath component, and a composite spinneret having 48 various slit-shaped spinning holes was used to determine the thickness of the sheath component (CD/D in FIG. 2). Several types of undrawn yarns were spun and processed under the same conditions as in Example 1 so that the D×100) was approximately 15, to obtain false twisted yarns of 75 ^D -48 ^fil . The obtained false twisted yarn was knitted and evaluated in the same manner as in Example 1.
At the same time, the feel to the touch was also evaluated. The results are shown in Table 4.

【table】

[Table] In No. 21 in Table 4, the cross-sectional shape of the fiber was more flat than oval, and the gloss was a little poor, and the cotton-like feel was also a little bad. No. 26 has a good level of gloss, but
The cotton-like feel to the touch is slightly poor. Example 4 Using the undrawn yarn No. 5 of Example 1, the temperature of the false twisting heater during drawing and simultaneous false twisting was changed, and the number of inserted twists was changed under each false twisting heater temperature condition11 A standard textured yarn of 75 ^D -48 ^fil was produced. The processing conditions other than the false twisting heater temperature and the number of inserted twists were the same as in Example 1. The obtained false twisted yarn was prepared in Example 1.
It was organized and evaluated in the same way. The results are shown in Table 5.

[Table] No. 27, No. 29, No. 31, No. 33, and No. 36 in Table 5 are comparative examples for clarifying the effects of the present invention. In other words, these five levels are expressed by the formula [T] < (55100−
145Te)/√, and the number of insertion twists is larger than the number of insertion twists [T] calculated by the formula, the gloss of the knitted fabric decreases, and local reflected light (bright spots) ), and it could hardly be said that the luster was close to that of cotton or linen. Among the standards of the present invention, No. 37 had a ramie-like hemp-like texture with a shirring feel, with partial fused portions in the longitudinal direction and cross-sectional direction of the yarn. Example 5 Both core component polymer and sheath component polymer Example 2
Using the same polymer as in Example 1, the number of holes in the spinneret was changed to four levels, and the polymer discharge amount was changed to match the number of holes in each spinneret so that the single fiber fineness was constant. 50 ^D
False twisted yarns of 24 ^fil , 75 ^D -36 ^fil , 100 ^D -48 ^fil , and 150 ^D- 72 ^fil were obtained. The obtained false twisted yarn was knitted and evaluated in the same manner as in Example 1. The results are shown in Table 6.

[Table] No. 38, No. 40, No. 42, and No. 44 in Table 6 are comparative examples for clarifying the effects of the present invention. That is,
These four levels are the formula [T]<(55100−
145Te)/√ is not satisfied, the gloss of the knitted fabric
It was difficult to say that the luster was close to that of cotton or linen, as there were many locally reflected lights (bright spots).

[Brief explanation of drawings]

1 and 2 are enlarged views for explaining the fiber cross-sectional shape of the undrawn yarn in the present invention.
The figure shows a fiber with a round cross section, and Figure 2 shows a fiber with an oval cross section. FIG. 3 is a diagram of one embodiment for explaining the simultaneous stretching and false twisting method of the present invention. 1: undrawn yarn, 2: first roller, 3: false twisting heater, 4: cooling device, 5: false twisting device, 6: second roller, 7: secondary heat treatment device, 8: third roller,
9: Entwining nozzle, 10: Fourth roller, 11: Adding oil roller, 12: Winding device.

Claims (1)

[Scope of Claims] 1. A composite fiber having a round and/or oval cross-sectional shape and a core component and a sheath component arranged substantially concentrically, the core component containing at least 1% by weight of a matting agent. A special fabric characterized by stretching and simultaneously false-twisting polyester multifilament undrawn yarn consisting of fibers containing the above-mentioned fibers and substantially no matting agent in the sheath component under conditions that satisfy the following formula. A method for producing twisted yarn. [T]<(55100−145Te)/√ However, [T] is the number of twists inserted during false twisting (T/m) Te is the temperature of the false twisting heater (℃) D is the fineness of the yarn after false twisting (denier )