JPH0453969B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention has intermittently thick thread parts along the longitudinal direction of the thread that can be dyed more densely and is bulkier than other parts, the thread has torque, and the winding method does not have a tension adjustment function. It can also be easily rolled up on a device. The present invention relates to a method for producing polyester thick and thin yarn. Conventionally, various attempts have been made to obtain polyester slub yarns that alternately have darkly dyed thick yarn portions and lightly dyed thin yarn portions consisting of undrawn portions along the longitudinal direction of the yarn. A method of mechanically stretching the yarn by changing the stretching ratio, a method of stretching the yarn at a stretching ratio lower than the natural stretching ratio, etc. have been proposed.
However, in the method of manufacturing slub yarn simply by drawing conditions, it is difficult to control the length and appearance frequency of the thick yarn portion, resulting in a narrow pattern range. When undrawn yarn is used, there is a drawback that the thick yarn portion becomes thermally brittle during the false twisting and crimping process, dyeing and finishing process, etc. For this reason, the present inventors first filed a patent application filed in 1983-
In No. 206718, while drawing a highly oriented undrawn polyester yarn with a birefringence of 15 to 80 x 10 ^-3 at a natural drawing ratio of 1.1 times or more, water or an aqueous liquid is intermittently applied in the drawing area. We proposed a method for producing slub yarn by heat treatment and then relaxation heat treatment under overfeed of 8% or more. According to this method, it is possible to produce a polyester slab yarn that has a large thickness/fine ratio and a large difference in dyeing, can easily adjust the length and appearance frequency of the thick yarn portion, and does not become brittle during post-processing. However, the slub yarn produced by this method has poor elasticity, so the range of winding rate that is the appropriate winding frequency when winding it onto the package cage is extremely narrow. When winding with a winding device that does not have a so-called winding tension adjustment function that rotates the package and winds it up into a square cheese shape while periodically varying only the traverse speed, there may be variations in winding hardness and problems with the edges of the cheese. However, when the traverse guide is of the slit groove type, the yarn may come off from the guide when it becomes slack, making it difficult to wind it into the package cage. It had been. As a result of intensive studies to overcome the above-mentioned problems, the present inventors have found that by applying a specific false twisting process, torque can be applied to the yarn without causing a change in the bulkiness of the yarn. The present invention was achieved based on the discovery that it is possible to easily wind up polyester thick-and-thin yarn with little heat deterioration without reducing the thickening effect or dyeing effect, even with a winding device that does not have a winding tension adjustment function. This is what I did. That is, the present invention involves stretching highly oriented undrawn polyester yarn with a birefringence of 15 to 80 x 10 ^-3 at a ratio of 1.1 times or more, while intermittently attaching water or an aqueous liquid to the yarn in the stretching region. This is a method for producing a polyester thick-and-thin yarn, which is characterized in that the yarn is heat-treated at a rate of 8% or higher, followed by relaxation heat treatment at an overflow rate of 8% or more, and then false-twisted at a temperature below the secondary transition temperature. The method of the present invention will be further explained below. In the present invention, first, a highly oriented undrawn yarn with a birefringence index of 15 to 80×10 ^-3 is stretched by a factor of 1.1 or more, and water or an aqueous liquid is intermittently applied to the yarn in the stretching region to heat-treat the yarn. . When heat treatment is performed by intermittently attaching water or an aqueous liquid to the yarn in the drawing zone, the inner structure is formed between the wetted part and the non-watered part due to the difference in drawability due to the heat receiving effect. The heat treatment effect does not reach or is extremely small on the wetted part,
This results in a cold-stretched part with low orientation and high shrinkage, while the non-wetted part has a sufficient heat treatment effect, resulting in a hot-stretched part with high orientation and low shrinkage. In the subsequent relaxation heat treatment step, the yarn in which the wetted part and the non-wetted part coexist is subjected to relaxation heat treatment under sufficient excess supply to form the wetted part into a thick yarn part. In order to stably form thick threads that are bulkier than other parts and have deep dyeing properties, the feed yarn should have a birefringence of 15 to 80x.
10 ^-3 highly oriented polyester undrawn yarn should be used. In this case, if the birefringence is less than 15×10 ^-3 , the yarn will become brittle with a slight heat treatment.
This is not preferable because it results in poor operability during stretching and post-processing. In addition, when the birefringence exceeds 80×10 ^-3 , the orientation is relatively advanced and it resembles a drawn yarn, so there are differences in the internal structure such as orientation, heat shrinkage rate, etc. between the water-wetted part and the non-watered part. It is unsuitable because the difference is small and it is impossible to form a thick-and-thin yarn with clear bulkiness and deep dyeing properties. In addition, in order to give the wetted part such a difference in internal structure that it is possible to form a thick yarn part that is bulkier and more dyed than the non-wetted part in the subsequent relaxation heat treatment,
It is necessary to stretch at a stretching ratio of 1.1 times or more. If this drawing ratio is less than 1.1 times, the difference in internal structure between the two will be small and a clear thick yarn can be formed. It is preferable to increase the stretching ratio to the extent that it does not. The stretching ratio is 1.1 which is the natural stretching ratio.
It is more effective to double or more. In order to form a thick yarn section along the longitudinal direction of the yarn, which is sufficiently bulkier than other portions and capable of deep dyeing, with an appropriate length and appearance frequency, water or an aqueous liquid is applied to the yarn in the drawing area. It is necessary to intermittently deposit them at desired intervals and heat-treat them. Here, the aqueous liquid that is intermittently attached to the yarn is water that is more than half (50% by weight) by weight.
Substances other than water include surfactants, dyeing aids, rust preventives, etc., but they do not substantially affect dyeing properties, damage fibers, or adversely affect the human body or machinery. Any aqueous liquid may be used. In addition, any method may be used to attach water or an aqueous liquid to the yarn as long as it is applied intermittently over an appropriate length.
For example, there may be a method in which the roller surface is made to adhere by using a gear-type roller with protrusions provided on the roller surface, a method in which an electromagnetic solenoid is used intermittently to reciprocate and the roller surface is brought into contact with water or aqueous liquid at an arbitrary length, and the like. In addition, heat treatment after applying water or aqueous liquid intermittently is performed in such a way that the effect of heat treatment does not reach or is extremely small on areas with water, so that the effect of heat treatment can be sufficiently applied to areas without water. The heat treatment conditions include, for example, the amount of adhesion is such that the wetted area is still in a wet state immediately after the heat treatment, and the heat treatment temperature is 200 to 250 °C.
The conditions include a heat receiving time of 0.2 to 0.8 seconds.
The heat treatment temperature is within a range where the yarn does not melt, and the higher the temperature, the higher the stretching rate, which can increase the internal structure difference between the wetted part and the non-watered part, and a non-contact heating device is used as the heat treatment method. It is preferable to use Next, the yarn having a mixture of wetted parts and non-wetted parts obtained as described above is subjected to a relaxation heat treatment at an overfeed rate of 8% or more. In this case, if the overfeed rate is less than 8%, the shrinkage of the wetted part is insufficient and only a thick thread part with poor bulkiness and deep dyeing properties can be formed, which is not preferable. In addition, the higher the overfeed rate, the more the shrinkage in the free state is promoted, and the formation of thick threads with rich dyeing properties, bulkiness, and crimpability.
% or more and within the processable range, the bulkiness and deep dyeability of the thick yarn portion can be controlled. If the tension is set to d or less, the bulkiness and deep dyeing properties of the thick yarn portion can be made even clearer. The heat treatment temperature during the above-mentioned relaxation heat treatment may be any temperature that allows the wetted part to shrink with an overfeed rate of 8% or more, but it is preferable to perform the relaxation heat treatment at a temperature exceeding 200°C to increase the bulk of the thick yarn part. It is possible to make deep dyeing clearer. Further, in order to contract the wetted portion freely, it is preferable to perform the relaxation heat treatment without bringing the yarn into contact with a heating device. Note that the overfeed rate during the relaxation heat treatment is a value (expressed as a percentage) obtained by dividing the difference between the supply speed and the take-up speed by the take-up speed. In this way, the wetted part, which has a lower orientation and higher shrinkage than the non-watered part in the drawing region, undergoes relaxation heat treatment and shrinks while the cross section of the single filament constituting the yarn becomes thicker and thinner, and becomes a single filament. It is possible to generate a crimp and form a densely dyed thick yarn section that is bulkier and deeper than the non-wetted section. Moreover, since the wetting part is a thick thread part, it is easy to adjust the length and appearance frequency of the thick thread part by changing the length and spacing of the wetting part. A thick-and-thin yarn having a pattern can be obtained, and by changing the overfeed rate during the relaxation heat treatment, the thickness of the thick yarn portion and the degree of deep dyeing can be controlled. Further, the yarn subjected to the relaxation heat treatment is subsequently subjected to a false twisting process at a temperature below the secondary transition temperature of the yarn. Here, the second-order transition temperature refers to the temperature at which when heating is started from room temperature, the thermal motion of molecules increases as the heating temperature increases, changes in the internal structure begin to occur, and an endothermic peak occurs in the differential thermal curve. When false twisting is performed immediately after heat treatment without winding, the heat remaining in the yarn can be utilized, so this also includes cases where the yarn is at room temperature and is not heated. Note that this case is economical because no particular heating device is required. In other words, when false-twisting is performed at a temperature below the secondary transition temperature, the polyester fiber becomes slightly thermoplastic even at temperatures below the secondary transition temperature, so the crimp in the thick yarn portions does not disappear and the thin yarn becomes thin. Without adding substantial bulk to the striations,
Only torque can be applied, and a yarn can be obtained that has the above-mentioned thickening effect and has elasticity due to torque in the thin yarn portion that does not have crimps.
Even if the thus obtained thick-and-thin yarn is rolled up into a square cheese shape using a winding device that does not have the above-mentioned winding tension adjustment function, the ends of the cheese will become extremely hard or the ends will become high. There is no problem of poor appearance, crossing threads, or unwinding due to the traverse guide coming off. As the twisting tension during the above-mentioned false twisting process increases, the crimp of the thick yarn portion tends to be elongated and the thick/fine ratio tends to decrease, so the twisting tension is set to 0.1.
It is preferable to set it as g/d or less. In addition, in the method of the present invention, it is better to make the overfeed rate as high as possible during the relaxation heat treatment and the running tension of the yarn as low as possible, and it is better to make the false twisting tension as low as possible during the false twisting process. Since it is effective in clarifying the striations, a guide roller that rotates passively is used as the yarn feeding means from the relaxation heat treatment zone to the false twisting zone, and the twisting from the false twisting zone is not retroactively transferred to the relaxation heat treatment zone. If only the tension in the false twisting zone is traced back and the tension in the relaxation heat treatment zone and the tension in the false twisting zone are linked, the tension fluctuations of the running yarn during the relaxation heat treatment can be compared to the tension in the false twisting zone. As a result of being able to relax by the contraction force caused by twisting and shrinking, it is possible to set the overfeed rate of the relaxation heat treatment zone and the false twisting zone to a higher overfeed rate than if each were set independently. , the thick thread portion can be made clearer. Further, when such a yarn feeding means is used, it is economical in terms of equipment because it does not require a driving device such as a nip roller that actively rotates. Further, as a twisting means during the false twisting process, it is desirable that the structure is such as an air false twisting nozzle, a belt nip type twisting body, etc. that can twist the yarn without applying tension to the running yarn as much as possible. On the other hand, when false twisting is performed by winding yarn around a spinner pin using a commonly used false twisting spindle, excessive tension is applied to the running yarn, which is undesirable. A structure in which the yarn is passed through the spinner pin without being wound around it, or the normally used spindle is made into a hollow cylindrical tube structure, and the yarn is twisted inscribed in the cylindrical tube by ballooning the yarn. In this case, by using a normal two-heater false twisting machine that performs false twisting and reheating processing in series, a guide that rotates passively is installed between the false twisting heater and the spindle, and the threading order is partially changed. In this case, it is possible to carry out the method of the present invention by simply carrying out the method, and in this case, it is possible to use a twisting equipment using an air false twisting nozzle or a so-called pirn-shaped It is economically advantageous because the method of the present invention can be carried out at low cost without requiring a special winding device such as a winding device for winding up sheets. Thus, as shown in Fig. 2, the yarn has thick yarn portions c and thin yarn portions d alternately in the longitudinal direction of the yarn, and has excellent thick and thin effects and dyeing effects, and is also given elasticity by torque. A polyester thick-and-thin yarn can be obtained that can be easily wound even in a winding device that does not have a winding tension adjustment function. FIG. 1 is a process schematic diagram showing an example of the manufacturing process of the method of the present invention. The yarn is supplied to the stretching area between the first roller 2 and the second roller 3, which rotates at a higher speed than the first roller 2, and passes through a yarn swinging width guide 6 connected to a fulcrum 5 to which the swinging motion of the electromagnetic solenoid 4 is transmitted. This leads to the fulcrum guide 7, which is the fulcrum on which the beam swings. An adhesion device for adhering water or aqueous liquid is installed between the yarn swing width guide 6 and the fulcrum guide 7, 8 is a rotating roller with a relatively small diameter for applying water, 9 is a water tank, and 10 is a water tank. Water or an aqueous liquid. Here, the yarn Y is moved from the position a where it is in contact with the water application rotating roller 8 with the fulcrum guide 7 as a fulcrum by the swinging action of an electromagnetic solenoid using a random pulse oscillator as a signal source. It is swung between a distance point b. At this time, the portion where the yarn comes into contact with the water application rotating roller 8 becomes the water application portion, and the portion where it does not come into contact becomes the non-water application portion. The length of the wetted part and the non-watered part and the ratio of the two lengths can be changed freely by using a microcomputer, film photo sensor, etc. together with a random pulse generation unit, and the length of the wetted part and the non-watered part can be changed freely along the longitudinal direction of the yarn. It is possible to form a yarn with a mixture of wetted portions and non-wetted portions at a desired and appropriate length. Then, the yarn Y passes through the fulcrum guide 7 and enters the first heater 11, where it is subjected to a heat treatment while being stretched. Next, the yarn Y is transferred to the second roller 3 and the third roller 1.
2 is subjected to a relaxing heat treatment by a second heater 13 to become a thick and thin yarn, which then passes through a third roller 12 and enters a false twisting zone, where it becomes a twisted body 1.
While being twisted at step 5, it is heat-set by a third heater 14, passed through a delivery roller 16, and then rolled up into a package 18 by a winding roller 17. The polyester in the present invention is a polymer having an ester bond in its molecular chain, and includes homopolymers typified by polyethylene terephthalate, copolymers or blend polymers thereof, and the like. The birefringence index is a value measured by interference fringe measurement using a polarizing microscope compensator. As mentioned above, the method of the present invention has a birefringence of 15 to 15.
After drawing 80×10 ^-3 highly oriented polyester end-drawn yarn by a factor of 1.1 times or more and heat-treating the yarn by intermittently attaching water or an aqueous liquid to the yarn in the drawing area, an overfeed rate of 8% or more is obtained. Since the yarn is subjected to a relaxation heat treatment at a temperature of 100 mm and then subjected to a false twisting process at a temperature below the second order dislocation temperature, the method of the present invention allows the yarn to be heated without reducing the bulkiness of the thick yarn portion formed in the yarn. It is possible to produce a polyester thick-and-thin yarn that is imparted with elasticity by torque, has excellent thickening and dyeing effects, and can be easily wound up even on a winding device that does not have a winding adjustment function. Hereinafter, the method of the present invention will be specifically explained using examples. Example Highly oriented polyester undrawn yarn 230d/48f with a birefringence index of 45×10 ^-3 obtained by high-speed spinning of polyethylene terephthalate was used as the source yarn, and processed as shown in Table 1 according to the steps shown in FIG. 1. A polyester thick-and-thin yarn (No. 1) was produced according to the conditions according to the method of the present invention. In addition, using the same supplied yarn as above, in the process shown in Fig. 1, a diameter of 10 mm was used instead of the third roller.
A rotating guide roller (grooved bearing roller) of φ is provided, and in the false twisting area, the third heater is not used and the yarn is wound around the spinner pin of the false twisting spindle as a false twisting body. Polyester thick-and-thin yarn was produced by the method of the present invention under the processing conditions shown in Table 1 using a so-called reverse twisting spindle with the spinner positioned downstream in the running direction of the yarn. (No. 2) was manufactured.

[Table] In both of the obtained thick-and-thin yarns (No. 1 and No. 2) produced by the method of the present invention, only the filaments constituting the thick thread portion have a three-dimensional crimp, and the cross section has a thick and thin filament. On the other hand, the fine thread part has torque without having any crimp, and the torque measured by the above measurement method is 50 (t/m) for sample No. 1 and 38 (t/m) for sample No. 2. t/m)
It was hot. In addition, the winding of the thick-and-thin yarn (No. 1, No. 2) into the package by the method of the present invention during manufacturing was carried out despite the fact that the winding device did not have a winding adjustment function. It was possible to do this without any problems, and even when the winding amount was increased to 2.7 kg, the package remained in shape and had a good shape. Comparative Example For comparison, a processed yarn was produced using the same supplied raw yarn as in the above example and without rotating the spindle under the processing conditions of sample No. 2 in Table 1 above, that is, without false twisting. Although the obtained processed yarn had thick and thin threads, the torque measured by the above-mentioned measurement method was 0, and the winding tension when winding the processed yarn was extremely high at both ears of the cheese ( During the false twisting process in the example, the winding tension was 10g.
20g or more), there are also frequent occurrences of "crossing threads due to surface falling" on the cheese end face, and the cheese rolls up into a gourd-like package, causing poor rotation of the cheese and breaking the threads, reducing the amount of threads rolled up. It was impossible to roll it up to more than 500g.

[Brief explanation of the drawing]

FIG. 1 is a schematic process diagram showing an example of the manufacturing process of the method of the present invention, and FIG. 2 is a schematic side view showing an example of the polyester thick-and-thin yarn obtained by the method of the present invention. 1... Highly oriented polyester undrawn yarn spool, 2
...first roller, 3...second roller, 4...electromagnetic solenoid, 5...fulcrum, 6...yarn swing width guide, 7...fulcrum guide, 8...rotating roller, 9...water tank, 10...
Water or aqueous liquid, 11...first heater, 12...third roller, 13...second heater, 14...third heater, 15...twisted body, 16...delivery roller, 17...winding up roller, 18...package ,Y
... Yarn, c... Thick thread part, d... Thin thread part.

Claims (1)

[Claims] 1 Highly oriented undrawn polyester yarn with a birefringence of 15 to 80×10 ^-3 is stretched by a factor of 1.1 or more, while water or an aqueous liquid is intermittently attached to the yarn in the stretching region. 1. A method for producing polyester thick-and-thin yarn, which comprises subjecting it to heat treatment, followed by relaxation heat treatment at an overfeed rate of 8% or more, and subsequent false twisting at a temperature below the secondary transition temperature. 2. The method for producing polyester thick-and-thin yarn according to claim 1, wherein the twisting tension during false twisting is 0.1 g/d or less.