EP3012356A1

EP3012356A1 - Spun yarn drawing apparatus

Info

Publication number: EP3012356A1
Application number: EP15190362.2A
Authority: EP
Inventors: Kinzo Hashimoto; Kenji Sugiyama; Yasuhiro Yamashita; Iwao Kubo
Original assignee: TMT Machinery Inc
Current assignee: TMT Machinery Inc
Priority date: 2014-10-21
Filing date: 2015-10-19
Publication date: 2016-04-27
Anticipated expiration: 2035-10-19
Also published as: CN105525372B; JP6484425B2; CN105525372A; EP3012356B1; JP2016079539A

Abstract

A spun yarn drawing apparatus by which yarns with a low boiling water shrinkage are obtained while surface temperatures of heat-setting heating rollers are restrained to be low is provided. The spun yarn drawing apparatus includes preliminary heating godet rollers 14 and 15 and heat-setting godet rollers 16 to 18 which are heating rollers rotating at higher yarn feeding speeds than the godet rollers 14 and 15. Onto each of these godet rollers 14 to 18, the yarns are wound at a winding angle of smaller than 270 degrees. In the heat-setting godet rollers 16 to 18, the yarn feeding speed of a roller on the downstream side is equal to or lower than the yarn feeding speed of a roller on the upstream side. Furthermore, the deceleration rate between the yarn feeding speed of the most upstream godet roller 16 in the yarn running direction and the yarn feeding speed of the most downstream godet roller 18 in the yarn running direction is 2% or higher.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a spun yarn drawing apparatus configured to draw yarns spun out from a spinning apparatus.
A spun yarn drawing apparatus which includes rollers by which yarns spun out from a spinning apparatus are drawn and thermally set has been known.
Patent Literature 1 (Japanese Unexamined Patent Publication No. 2011-122276 ) discloses such a spun yarn drawing apparatus. This spun yarn drawing apparatus is provided with plural heating rollers (pre-heating rollers) for preliminary heating and heating rollers (heat-set rollers) for heat-setting. In this spun yarn drawing apparatus, yarns are wound onto the heating rollers for preliminary heating, and are then wound onto the heating rollers for heat-setting, which are provided above the heating rollers for preliminary heating. The surface of each heating roller for preliminary heating is set at a temperature with which the yarns are drawable. The surface of each heating roller for heat-setting is set at a temperature which is higher than the temperature of each heating roller for preliminary heating and at which the drawn yarns are thermally settable. Furthermore, the yarn feeding speed of each heating roller for heat-setting is higher than the yarn feeding speed of each heating roller for preliminary heating. The yarn preliminarily heated by the heating rollers for preliminary heating are drawn between the most downstream one in the yarn running direction of the heating rollers for preliminary heating and the most upstream one in the yarn running direction of the heating rollers for heat-setting. The drawn yarns are thermally set by the heating rollers for heat-setting.
Patent Literature 2 (Japanese Unexamined Patent Publication No. 2003-105628 ) recites a spun yarn drawing apparatus which is able to produce yarns with a predetermined boiling water shrinkage by setting the heating temperature of heat-setting heating rollers for thermally setting the yarns at a predetermined temperature. Patent Literature 2 further recites that the boiling water shrinkage of the produced yarns decreases as the surface temperature of the heat-setting heating rollers in contact with the yarns increases.

SUMMARY OF THE INVENTION

In regard to the above, because a heat radiation amount from the heat-setting heating rollers increases as the surface temperature of these rollers increases, the heat energy is wasted. Furthermore, because the heated yarns having a large heat amount are sent out together with a heated accompanying airflow from a thermal insulation box housing the rollers, the heat energy is further wasted. On this account, in view of the energy saving, the surface temperature of the heat-setting heating rollers is required to be restrained as low as possible, even when yarns with a low boiling water shrinkage are produced.
However, in the spun yarn winding apparatus recited in Patent Literature 2, the surface temperature of the heat-setting heating rollers must be high to obtain the yarns with a low boiling water shrinkage, and hence the energy loss is significant.
The present invention was done to solve the problem above, and an object of the present invention is to provide a spun yarn drawing apparatus which is able to produce yarns with a low boiling water shrinkage while surface temperatures of heat-setting heating rollers are restrained to be low.
According to the first aspect of the invention, a spun yarn drawing apparatus includes: rollers which are provided along a yarn path to draw yarns spun out from a spinning apparatus; and a speed controller configured to control yarn feeding speeds of the rollers, wherein, the yarns are wound onto each of the rollers at a winding angle of smaller than 270 degrees, and the rollers include at least one first roller and second rollers on which the yarns supplied from the at least one first roller are wound and which are heating rollers having higher yarn feeding speeds than the at least one first roller.
The speed controller causes the yarn feeding speed of a roller on the downstream in a yarn running direction among neighboring two of the second rollers to be equal to or lower than the yarn feeding speed of a roller on the upstream in the yarn running direction among the neighboring two of the second rollers, and a deceleration rate between the yarn feeding speeds of the most upstream and the most downstream ones in the yarn running direction of the second rollers to be 2% or higher.
In the present invention, onto each of the rollers including the second rollers, the yarns are wound at a winding angle of smaller than 270 degrees. In an arrangement in which yarns are wound onto the second rollers more than once, the surface speeds of these rollers are required to be identical. In this regard, in the present invention, because the yarns are partially wound onto each of the second rollers, the yarn feeding speed of each of the second rollers is freely settable.
In the present invention, in regard to the second rollers, the controller adjusts the yarn feeding speed of the roller provided on the downstream side in the yarn running direction to be equal to or lower than the yarn feeding speed of the roller on the upstream side in the yarn running direction. On this account, the drawn yarns are relaxed and contract at the heat-setting second rollers, with the result that the produced yarns have a small boiling water shrinkage. In addition to the above, in the present invention, the deceleration rate between the yarn feeding speeds of the most upstream second roller in the yarn running direction and the most downstream second roller in the yarn running direction is 2% or higher. As such, because the deceleration rate between the yarn feeding speeds of the most upstream second roller in the yarn running direction and the most downstream second roller in the yarn running direction (i.e. the total deceleration rate of the second rollers) is arranged to be high, i.e., 2% or higher, the yarns are sufficiently relaxed and thermally set at the second rollers. Therefore the yarns with a small boiling water shrinkage are obtained while the surface temperatures of the second rollers are restrained to be low.
According to the second aspect of the invention, the spun yarn drawing apparatus of the first aspect is arranged such that the speed controller causes a deceleration rate between the yarn feeding speeds of two of the second rollers neighboring each other in the yarn running direction to be lower than 5%.
In this regard, when the deceleration rate between the yarn feeding speeds of two rollers neighboring each other in the yarn running direction is too high, the yarns are significantly relaxed and the yarn path becomes unstable. When the yarn path is unstable, the yarns may be unnecessarily wound onto the rollers.
In the present invention, the deceleration rate between the yarn feeding speeds of two of the second rollers neighboring each other in the yarn running direction is smaller than 5%. On this account, in regard to the two second rollers neighboring each other in the yarn running direction, the arrangement above restrains the yarn path from becoming unstable on account of the relaxation of the yarns due to the deceleration of the downstream second roller with respect to the upstream second roller. On this account, unnecessary winding of the yarns onto the second rollers, yarn cutting, or the like are restrained.
According to the third aspect of the invention, the spun yarn drawing apparatus of the first or second aspect is arranged such that the number of the second rollers is three or more, and the speed controller causes a deceleration rate between the yarn feeding speeds of each neighboring pair of the second rollers neighboring each other in the yarn running direction to be 1% or higher.
When the number of the second rollers is three or more, there are plural yarn running intervals in the second rollers. In the present invention, in all of the yarn running intervals in the second rollers, the deceleration rate between the yarn feeding speeds is arranged to be 1% or higher. As such, the total deceleration rate is increased by suitably increasing the deceleration rates in the plural intervals rather than particularly increasing the deceleration rate of a particular interval. With this, yarns with a small boiling water shrinkage are obtained while the surface temperatures of the second rollers are restrained to be low.
According to the fourth aspect of the invention, the spun yarn drawing apparatus of the third aspect is arranged such that the number of the second rollers is three or more, and the speed controller causes the deceleration rates between the yarn feeding speeds of the neighboring pairs of the second rollers in the yarn running direction to be identical between plural intervals.
In the present invention, there are the plural yarn running intervals in the second rollers, and the deceleration rate between the yarn feeding speeds is identical between these intervals. With this, the deceleration rates in the plural intervals are uniformized while the total deceleration rate is maximized. Therefore the yarns with a small boiling water shrinkage are obtained while the surface temperatures of plural second rollers are restrained to be low. In the present invention, when the deceleration rate between the yarn feeding speeds is identical between the plural intervals, the deceleration rates are not only completely identical with each other but also are slightly different from each other to the extent that the boiling water shrinkage is not affected.
According to the fifth aspect of the invention, the spun yarn drawing apparatus of any one of the first to fourth aspects further includes a temperature controller configured to control a temperature of each of the second rollers.
In the present invention, because the temperature of each of the second rollers are freely settable and controllable by the temperature controller, yarns with a low boiling water shrinkage are easily obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of a spun yarn take-up machine of an embodiment of the present invention.
FIG. 2 is a profile of the spun yarn take-up machine of the embodiment of the present invention.
FIG. 3 is an enlarged front elevation of a spun yarn drawing apparatus.
FIG. 4(a) is a table showing the relationship between a temperature of heat-setting godet rollers and a boiling water shrinkage when the deceleration of the heat-setting godet rollers is not performed, FIG. 4(b) is a table showing the relationship between a deceleration rate of the heat-setting godet rollers and a boiling water shrinkage when the temperature of the heat-setting godet rollers is fixed at 160 degrees centigrade, and FIG. 4(c) is a table showing examples of conditions of roller temperatures and deceleration rates when yarns with a boiling water shrinkage of 11% are produced.
FIG. 5(a) is a graph showing the relationship between a surface temperature of the heat-setting godet rollers and the boiling water shrinkage obtained from the data of FIG. 4(a), whereas FIG. 5(b) is a graph showing the relationship between the deceleration rate of the heat-setting godet rollers and the boiling water shrinkage obtained from the data of FIG. 4(b).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following will describe an embodiment of the present invention with reference to figures.
FIG. 1 is a front elevation of a spun yarn take-up machine including a spun yarn drawing apparatus of an embodiment of the present invention. FIG. 2 is a profile of the spun yarn take-up machine. Hereinafter, the directions shown in FIG. 1 and FIG. 2 will be referred to as an up-down direction, a left-right direction, and a front-back direction. As shown in FIGs. 1 and 2, a spun yarn take-up machine 1 includes a spun yarn drawing apparatus 2 and a take-up winder 3. The spun yarn take-up machine 1 is configured so that, yarns Y spun out and continuously supplied from a spinning apparatus 4 located above the spun yarn drawing apparatus 2 are drawn by the spun yarn drawing apparatus 2, and the yarns Y are fed to the take-up winder 3 to be wound up by the take-up winder 3. The yarns Y are, for example, made of polyester or nylon.
The spun yarn drawing apparatus 2 is provided with members such as godet rollers 14 to 18 (rollers) for drawing the yarns Y spun out from the spinning apparatus 4. A specific arrangement of the spun yarn drawing apparatus 2 will be detailed later.
The take-up winder 3 is provided below the spinning apparatus 4. The take-up winder 3 is configured to wind the yarns Y, which are drawn by the spun yarn drawing apparatus 2, on respective bobbins B so as to form packages P. The take-up winder 3 includes: guide rollers 5 and 6; a plurality of fulcrum guides 7; and two winding units 8.
Each of the guide rollers 5 and 6 is a drive roller rotationally driven by a motor which is not illustrated. The guide rollers 5 and 6 are disposed to be axially in parallel to the left-right direction. The guide roller 6 is provided behind and above the guide roller 5. The yarns Y supplied from the spun yarn drawing apparatus 2 are sent to the fulcrum guides 7 below by the guide rollers 5 and 6.
The fulcrum guides 7 are provided below the guide roller 6, above traverse guides 12 of a later-described winding unit 8, and immediately above the traverse guides 12 and the bobbins B attached to a bobbin holder 11, respectively. The fulcrum guides 7 are lined up in the front-back direction at the same intervals as the bobbins B.
Each winding unit 8 includes members such as a main body frame 9, a disc-shaped turret 10 rotatably attached to the main body frame 9, the two bobbin holders 11 each of which is cantilevered by the turret 10 and has a horizontally-extending winding axis and to each of which the bobbins B are attached in series along the winding axis, the traverse guides 12 configured to traverse the yarns Y, and a contact roller 13 which makes contact with and is detached from the bobbins B attached to the bobbin holder 11.
In the winding unit 8, one of the bobbin holders 11 is rotated by an unillustrated motor, to rotate the bobbins B attached onto this bobbin holder 11, and thereby the yarns Y are wound on the rotating bobbins B. In this process, the yarns Y to be wound on the bobbins B are traversed about the respective fulcrum guides 7 in the axial direction of the bobbins B by the respective traverse guides 12 located above the bobbins B.
Then, the yarns Y having been traversed about the respective fulcrum guides 7 by the respective traverse guides 12 are wound on the respective bobbins B, to form the packages P. While the yarns Y are thus wound on the respective bobbins B, the contact roller 13 comes into contact with outer circumferential surfaces of the package P, and rotates while applying a predetermined contact pressure to the packages P, to properly shape the packages P. When the formation of packages P on the bobbins B attached to the bobbin holder 11 is completed, the turret 10 is rotated by an unillustrated driving unit so that the bobbin holder 11 which supports the fully-wound packages P and is at the winding position is switched to the standby position whereas the bobbin holder 11 at the standby position is switched to the winding position. Furthermore, the yarns Y having formed the fully-wound packages P are switched to the bobbins B at the winding position as an unillustrated yarn switching unit operates, and the winding of the yarns Y is continued. The fully-wound packages P are pushed toward the front by a not-illustrated pusher, to be detached from the bobbin holder 11.
Now, a specific configuration of the spun yarn drawing apparatus 2 will be described. The spun yarn drawing apparatus 2 is provided below the spinning apparatus 4. As shown in FIG. 1 to FIG. 3, the spun yarn drawing apparatus 2 includes the godet rollers 14 to 18 (rollers), a thermal insulation box 19, guide rollers 20 and 21, guides 25 and 26, and a controller 27. FIG. 1 and FIG. 3 show the inside of the thermal insulation box 19.
The godet rollers 14 to 18 are provided along a yarn path, and are configured to draw the yarns Y spun out from the spinning apparatus 4 and thermally set the yarns Y. Each of the godet rollers 14 to 18 is a drive roller rotated by an unillustrated drive motor which is cantilevered by an unillustrated frame. Furthermore, each of the godet rollers 14 to 18 is a heating roller having an unillustrated heater therein. The surface temperature of each of the godet rollers 14 to 18 is maintained at a predetermined temperature as the later-described controller 27 controls the heaters.
The godet rollers 14 and 15 (first rollers) on which the yarns Y before drawn run are preliminary heating godet rollers for heating the yarns Y before drawn. In this regard, to draw yarns Y made of resin such as polyester having a glass transition temperature higher than room temperatures, the surface of each godet roller in contact with the yarns Y must be heated to a temperature equal to or higher than the glass transition temperature. On this account, the surface temperatures of the godet rollers 14 and 15 which are in contact with the yarns Y are maintained at the glass transition temperature or higher by the unillustrated heaters provided in the godet rollers 14 and 15. In the meanwhile, when the yarns Y made of resin such as nylon having a glass transition temperature which is close to room temperatures as described below are drawn, the preliminary heating before the yarn drawing is not prerequisite. In this case, the godet rollers 14 and 15 may be non-heating rollers.
In addition to the above, the godet rollers 14 and 15 are substantially identical with each other in the speed of rotation (yarn feeding speed). The yarn feeding speeds of the preliminary heating godet rollers 14 and 15 may be different from each other.
The godet rollers 16 to 18 (second rollers) are heat-setting godet rollers for thermally setting the drawn yarns Y. The surface temperatures of the godet rollers 16 to 18 which are in contact with the yarns Y are maintained at a temperature higher than the surface temperatures of the preliminary heating godet rollers 14 and 15, by the unillustrated heater provided in each of the godet rollers 16 to 18. When the yarns Y having a glass transition temperature close to room temperatures are drawn, preliminary heating before the yarns Y are drawn is not prerequisite. However, when preliminary heating godet rollers each including a heater are employed, the surface temperatures of the godet rollers 16 to 18 are arranged to be higher than the glass transition temperature. For example, when the yarns Y are made of polyester, the surface temperatures of the preliminary heating godet rollers 14 and 15 are set at a temperature of 80 degrees centigrade or higher. When the yarns Y are made of nylon, the surface temperatures of the preliminary heating godet rollers 14 and 15 are set at a temperature of 50 degrees centigrade or higher. The godet rollers 16 to 18 are substantially identical with one another in surface temperature.
By the later-described controller, the yarn feeding speeds of the godet rollers 16 to 18 are arranged such that the yarn feeding speed of a roller on the downstream in the yarn running direction is equal to or lower than the yarn feeding speed of a roller on the upstream in the yarn running direction. In other words, the godet rollers 16 to 18 are arranged such that the yarn feeding speed of the godet roller 16 is identical with or higher than that of the godet roller 17, and the yarn feeding speed of the godet roller 17 is identical with or higher than that of the godet roller 18. To be more specific, the yarn feeding speed of the most upstream godet roller 16 in the yarn running direction and the yarn feeding speed of the most downstream godet roller 18 in the yarn running direction are the highest and lowest among the yarn feeding speeds of the godet rollers 16, 17, and 18. The total deceleration rate of the yarn feeding speeds of the godet rollers 16 and 18 is at least 2%. The total deceleration rate (%) of the yarn feeding speeds of the heat-setting godet rollers 16 to 18 is a value represented by 100x(Va-Vb)/Va, assuming that the yarn feeding speed of the most upstream godet roller 16 is Va and the yarn feeding speed of the most downstream godet roller 18 is Vb.
Between the neighboring two godet rollers 16 and 17, the deceleration rate between the yarn feeding speeds of the upstream godet roller 16 and the downstream godet roller 17 is not lower than 1% and lower than 5%. In regard to the two godet rollers 17 and 18, the deceleration rate between the yarn feeding speeds of the upstream godet roller 17 and the downstream godet roller 18 is likewise not lower than 1% and lower than 5%. The deceleration rate between the yarn feeding speeds of the godet rollers 16 and 17 is identical with the deceleration rate between the yarn feeding speeds of the godet rollers 17 and 18. The deceleration rate (%) between two neighboring godet rollers is a value represented by 100x(V1-V2)/V1, assuming that the yarn feeding speed of the upstream godet roller is V1 whereas the yarn feeding speed of the downstream godet roller is V2. When the deceleration rate between the godet rollers 16 and 17 is "identical" with the deceleration rate between the godet rollers 17 and 18, these deceleration rates are not only completely identical with each other but also are slightly different from each other to the extent that the physical properties of the yarns are not affected.
The following will describe an example in which the deceleration rate between the godet rollers 16 and 17 and the deceleration rate between the godet rollers 17 and 18 are deemed to be identical even if they are actually slightly different from each other. Typically, in the speed control of the godet rollers 14 to 18 by the controller 27, a target yarn feeding speed is set for each of the rollers 14 to 18. In other words, in the heat-setting godet rollers 16 to 18 , the deceleration rates are not directly set. The deceleration rate between the godet rollers 16 and 17 and the deceleration rate between the godet rollers 17 and 18 are automatically determined as a result of the setting of the target yarn feeding speeds for the respective rollers 16 to 18.
Assume that the deceleration by 2% is performed between the godet rollers 16 and 17 and the deceleration by 2% is performed between the godet rollers 17 and 18, with the result that the deceleration by 4% is performed in total in the godet rollers 16 to 18. To be more specific, the yarn feeding speed of the godet roller 16 is set at 5000 m/min, the yarn feeding speed of the godet roller 17 is set at 4900 m/min, and the yarn feeding speed of the godet roller 18 is set at 4800 m/min. In this case, in the entirety of the godet rollers 16 to 18 , 5000 m/min is changed to 4800 m/min, and hence the total deceleration rate is 4%. However, in each of the two intervals of the rollers, while the deceleration rate is 2% as the yarn feeding speed is changed from 5000 m/min to 4900 m/min between the godet rollers 16 and 17, the deceleration rate is 2.04% as the yarn feeding speed is changed from 4900 m/min to 4800 m/min between the godet rollers 17 and 18. In the present embodiment, the expression that the deceleration rate between the godet rollers 16 and 17 is identical with the deceleration rate between the godet rollers 17 and 18 encompasses cases where a slight difference exists between the rates as above.
The godet rollers 14 to 18 are axially in parallel to one another and the rotation shafts thereof extend away from the viewer of each of FIG. 1 and FIG. 3. The godet rollers 14 to 18 are substantially identical with one another in diameter. The diameters of the godet rollers 14 to 18 fall within the range of 220 to 300mm. The godet rollers 14 to 18 are disposed such that the heat-setting godet rollers 16 to 18 are above the preliminary heating godet rollers 14 and 15. The godet rollers 14 to 18 are disposed upward in a staggered manner so that the godet roller 14 is the lowest, the godet roller 15 is the second lowest, the godet roller 16 is the third lowest, the godet roller 17 is the second highest, and the godet roller 18 is the highest.
As indicated by the arrows in FIG. 1 and FIG. 3, the godet rollers 14, 16, and 18 rotate clockwise. As indicated by the arrows in FIG. 1 and FIG. 3, the godet rollers 15 and 17 rotate counterclockwise. To put it differently, in each pair of godet rollers neighboring each other in the running direction of the yarns Y, i.e., each of the pair of the godet rollers 14 and 15, the pair of the godet rollers 15 and 16, the pair of the godet rollers 16 and 17, and the pair of the godet rollers 17 and 18, the godet rollers in the pair rotate in opposite directions.
Onto each of the godet rollers 14 to 18, the yarns Y are partially wound upward along the rotational direction of each roller, at a winding angle of smaller than 270 degrees (the angle θ shown in FIG. 3). The yarns Y are wound onto the godet rollers 14, 15, 16, 17, and 18 in this order. To put it differently, onto the pair of the two godet rollers neighboring each other in the running direction of the yarns Y, i.e., godet rollers 14 and 15, godet rollers 15 and 16, the godet rollers 16 and 17, and the godet rollers 17 and 18, the yarns Y are partially wound to form an S shape. On this account, between the two godet rollers neighboring each other in the running direction of the yarns Y, i.e., godet rollers 14 and 15, godet rollers 15 and 16, the godet rollers 16 and 17, and the godet rollers 17 and 18, the yarns Y run in the direction of the inner common tangent of the neighboring godet rollers.
The thermal insulation box 19 is provided for housing the godet rollers 14 to 18. The thermal insulation box 19 is a substantially rectangular parallelepiped box. The thermal insulation box 19 is made of a heat insulating material. On this account, heat generated from the godet rollers 14 to 18 does not escape from the thermal insulation box 19 to the outside, and the temperature in the box is maintained. Inside the thermal insulation box 19, the upper part of the box is higher in temperature than the lower part because the heat-setting godet rollers 16 to 18 having high surface temperatures are provided in the upper part and due to heat convection. Inside the thermal insulation box 19, partitions 24 are provided to prevent the surface temperatures of the godet rollers 14 to 18 from influencing on one another. To be more specific, each of the partitions 24 is provided, for example, between two godet rollers to separate the godet rollers lined up in the up-down direction from each other.
In addition to the above, the thermal insulation box 19 has two slits 22 and 23 at an upper part and a lower part of a single side surface (right side surface in the figure). The yarns Y spun out from the spinning apparatus 4 and guided to the guide roller 20 by the later-described guides 25 and 26 are introduced into the thermal insulation box 19 through the lower slit 22. Thereafter, as described above, the yarns Y are wound onto the godet rollers 14 to 18 and introduced to the outside of the thermal insulation box 19 through the upper slit 23.
Each of the guide rollers 20 and 21 is a drive roller rotated by a dedicated drive motor which is not illustrated. The guide rollers 20 and 21 are non-heating rollers.
The guide roller 20 is provided outside the thermal insulation box 19 and is deviated from the slit 22 of the thermal insulation box 19 in the left-right direction (i.e., provided on the right side in the figure). The guide roller 20 changes the yarn path of the yarns Y spun out downward from the spinning apparatus 4 by using the later-descried guides 25 and 26, and guides the yarns Y to the slit 22 which is formed through the thermal insulation box 19.
The guide roller 21 is provided outside the thermal insulation box 19 and is deviated from the slit 23 of the thermal insulation box 19 in the left-right direction (i.e., provided on the right side in the figure). Onto the guide roller 21, the yarns Y supplied from the most downstream godet roller 18 in the yarn running direction among the godet rollers 14 to 18 are wound. The guide roller 21 changes the yarn path of the yarns Y which have been guided to the outside of the thermal insulation box 19 through the slit 23 of the thermal insulation box 19, and guides the yarns Y to the guide roller 5.
The guide 25 is provided below the spinning apparatus 4. The guide 25 is provided for bending frontward the yarns Y spun out downward from the spinning apparatus 4. The bended yarns Y are guided to the guide 26.
The guide 26 is provided in the vicinity of the guide roller 20. The guide 26 is provided for bending the yarns Y downward. The bended yarns Y are guided to the guide roller 20.
The controller 27 (which is equivalent to a speed controller and a temperature controller of the present invention) is connected with drive units of the spun yarn drawing apparatus 2, such as the unillustrated drive motor driving each of the godet rollers 14 to 18, the unillustrated heater for heating the surface of each of the godet rollers 14 to 18 in contact with the yarns Y, and the unillustrated drive motor driving each of the guide rollers 20 and 21.
The controller 27 individually controls the unillustrated drive motors driving the respective godet rollers 14 to 18 so as to adjust the yarn feeding speed of each godet roller to a predetermined speed. Furthermore, the controller 27 individually controls the unillustrated heaters heating the surfaces of the godet rollers 14 to 18 in contact with the yarns Y so as to adjust the surface temperature of each godet roller to a predetermined temperature. Furthermore, the controller 27 individually controls the drive motors driving the respective guide rollers 20 and 21 so as to adjust the yarn feeding speed of each godet roller to a predetermined speed.
Now, a process of drawing the yarns Y by the godet rollers 14 to 18 will be described.
To begin with, when the yarns Y guided into the thermal insulation box 19 through the slit 22 are, for example, made of polyester, the yarns Y are preliminarily heated to a temperature equal to or higher than the glass transition temperature as the yarns Y make contact with the surfaces of the preliminary heating godet rollers 14 and 15. The yarns Y having been preliminarily heated are sent to the heat-setting godet rollers 16 to 18 which are on the downstream in the yarn running direction, by the rotational driving of the preliminary heating godet rollers 14 and 15. In this regard, as described above, the heat-setting godet rollers 16 to 18 on the downstream in the yarn running direction rotate at higher yarn feeding speeds than the preliminary heating godet rollers 14 and 15. On this account, the yarns Y are accelerated between the preliminary heating godet roller 15 and the heat-setting godet roller 16. With this, the yarns Y are drawn. When the yarns Y have a glass transition temperature close to room temperatures as in the case of nylon, the preliminary heating godet rollers 14 and 15 may be non-heating rollers.
The drawn yarns Y are thermally set as they make contact with the heat-setting godet rollers 16 to 18. On the godet rollers 16 to 18, the yarns Y are partially wound upward along the rotational direction of each roller, at a winding angle of smaller than 270 degrees. The yarns Y are wound onto the godet rollers 16, 17, and 18 in this order. In a well-known arrangement in which yarns are wound onto godet rollers more than once, the surface speeds of these rollers are required to be identical. In the present embodiment, because the yarns are partially wound onto each of the godet rollers 16 to 18, the yarn feeding speed of each of the godet rollers 16 to 18 is freely settable.
Based on the above, in regard to the heat-setting godet rollers 16 to 18 neighboring one another in the yarn running direction, the controller 27 adjusts the yarn feeding speed of the roller provided on the downstream side in the yarn running direction to be equal to or lower than the yarn feeding speed of the roller on the upstream side in the yarn running direction. On this account, the yarns Y drawn between the godet rollers 15 and 16 are relaxed and contract at the three godet rollers 16 to 18 for heat-setting, with the result that the yarns Y having a small boiling water shrinkage are obtained.
In addition to the above, in the present embodiment, the controller 27 arranges the deceleration rate between the yarn feeding speeds of the most upstream godet roller 16 in the yarn running direction and the most downstream godet roller 18 in the yarn running direction to be 2% or higher, among the three heat-setting godet rollers 16 to 18. As such, because the deceleration rate between the yarn feeding speeds of the most upstream godet roller 16 in the yarn running direction and the most downstream godet roller 18 in the yarn running direction (i.e. the total deceleration rate of the three godet rollers 16 to 18) is arranged to be high, i.e., 2% or higher, the yarns Y are sufficiently relaxed and thermally set at the three godet rollers 16 to 18. Therefore the yarns Y with a small boiling water shrinkage are obtained while the surface temperatures of the godet rollers 16 to 18 are restrained to be low.
In addition to the above, in the spun yarn drawing apparatus 2 of the present embodiment, the deceleration rates of the godet rollers 16 to 18 are suitably changeable in accordance with a desired boiling water shrinkage. For example, when yarns Y with a small boiling water shrinkage are produced, the total deceleration rate of the yarn feeding speeds of the heat-setting godet rollers 16 to 18 is arranged to be high by means of an input from a unillustrated setting unit. In the meanwhile, when yarns Y with a large boiling water shrinkage are produced, the total deceleration rate of the yarn feeding speeds of the heat-setting godet rollers 16 to 18 is arranged to be low by means of an input from the unillustrated setting unit. To be more specific, based on information input by the setting unit, the controller 27 controls the unillustrated drive motors provided for the godet rollers 16 to 18 so as to individually adjust the yarn feeding speeds of the godet rollers 16 to 18 and suitably change the deceleration rates of the yarn feeding speeds of the godet rollers 16 to 18.
The roller surface temperatures of the godet rollers 16 to 18 are also individually adjustable as the controller 27 controls the unillustrated heaters. That is to say, as the controller 27 controls the yarn feeding speed and the roller surface temperature of each of the godet rollers 16 to 18, yarns Y with a desired boiling water shrinkage are easily obtained.
In regard to the above, when the deceleration rate between the yarn feeding speeds of two godet rollers neighboring each other in the yarn running direction is too high, the yarns Y are significantly relaxed and the yarn path becomes unstable. When the yarn path is unstable, the yarns may be unnecessarily wound onto the rollers. In this connection, in the present embodiment, the deceleration rate between the yarn feeding speeds of the two heat-setting godet rollers neighboring each other in the yarn running direction, i.e., the deceleration rates between the yarn feeding speeds of the heat-setting godet rollers 16 and 17 and between the yarn feeding speeds of the godet rollers 17 and 18, are less than 5%. This restrains the yarn path from becoming unstable on account of the relaxation of the yarns Y due to the deceleration of the downstream godet roller with respect to the upstream godet roller. On this account, unnecessary winding of the yarns Y onto the heat-setting godet rollers 16 to 18, yarn cutting, or the like is restrained.
In addition to the above, in the present embodiment, three heat-setting godet rollers are provided, and two yarn running intervals in which the yarns Y run exist in these three godet rollers 16 to 18. In the present embodiment, in these two running intervals, the deceleration rate between the yarn feeding speeds is arranged to be 1% or higher. That is to say, the total deceleration rate is increased by suitably increasing the deceleration rates in two intervals rather than particularly increasing the deceleration rate of a particular interval. With this, yarns with a small boiling water shrinkage are obtained while the surface temperatures of the heat-setting godet rollers 16 to 18 are restrained to be low.
In addition to the above, because the deceleration rate between two neighboring heat-setting godet rollers is arranged to be high, i.e., 1% or higher, the required number of heat-setting godet rollers for realizing the required total deceleration rate is small (e.g., three). This reduces the equipment cost.
In addition to the above, the two yarn running intervals in the three godet rollers 16 to 18 are identical with each other in the deceleration rate between the yarn feeding speeds of two godet rollers neighboring each other in the yarn running direction. With this, the deceleration rates in plural intervals are uniformized while the total deceleration rate is maximized. Therefore the yarns with the small boiling water shrinkage are obtained while the surface temperatures of plural second rollers are restrained to be low.

(Details of Examples)

Now, deceleration rates of heat-setting godet rollers and a boiling water shrinkage of produced yarns will be described based on specific examples. In the following examples, yarns to be produced are made of nylon (PA6: 78dtex/24f). The number of the heat-setting godet rollers is three, and the yarn feeding speeds of these three heat-setting godet rollers are individually changeable. In the examples, the surface temperatures of the three heat-setting godet rollers are identical with one another. Under these conditions, how the shrinkage of yarns was varied when the yarn feeding speeds and the roller surface temperatures of the three heat-setting godet rollers were changed was studied.
In FIG. 4, (a) is a table showing the relationship between temperatures of the heat-setting godet rollers and a boiling water shrinkage when the deceleration of the heat-setting godet rollers was not performed. (b) is a table showing the relationship between temperatures of the heat-setting godet rollers and a boiling water shrinkage when the temperatures of the heat-setting godet roller were fixed at 160 degrees centigrade. (c) is a table showing an example of a roller temperature and a deceleration rate when yarns with a boiling water shrinkage of 11% were produced. In FIG. 4, "A/B" is recited in the column "deceleration rate between neighboring rollers". In this regard, "A" indicates a deceleration rate in the first one of the two yarn running intervals in the three heat-setting godet rollers, whereas "B" indicates a deceleration rate in the second one of the two yarn running intervals. FIG. 5(a) is a graph obtained by plotting the data in the table of FIG. 4(a), indicating the relationship between the surface temperatures of the heat-setting godet rollers and the boiling water shrinkage. FIG. 5(b) is a graph obtained by plotting the data in the table of FIG. 4(b), indicating the relationship between the deceleration rates of the heat-setting godet rollers and the boiling water shrinkage.
First of all, to produce yarns with a low boiling water shrinkage without changing the yarn feeding speeds of the heat-setting godet rollers (i.e., while maintaining the total deceleration rate to be zero), it is necessary to set the temperatures of the heat-setting godet rollers to be significantly high as shown in FIG. 4(a) and FIG. 5(a). For example, while the required roller temperature is 150 degrees centigrade when the boiling water shrinkage of the yarns is 12% as shown in Comparative Example 5, the roller temperature must be maintained at 180 degrees centigrade which is higher than the temperature in Comparative Example 5 by 30 degrees centigrade when the boiling water shrinkage of the yarns Y is lower than the above by 1%, i.e., 11% in Comparative Example 2.
In this regard, when the yarn feeding speed of the heat-setting godet rollers decelerates as in the present invention, yarns with a low boiling water shrinkage are produced without requiring a high roller temperature. As shown in FIG. 4(b) and FIG. 5(b), even when the surface temperatures of the rollers are 160 degrees centigrade, yarns with a boiling water shrinkage about 11% were produced by setting the total deceleration rate of the heat-setting godet rollers to be 2% or higher as in Examples 1 to 3.
On the contrary to the above, how the roller temperature and the deceleration rate should be set to produce the yarns with a boiling water shrinkage of 11% was also studied. As mentioned above, as shown in FIG. 4(c), to produce yarns with a boiling water shrinkage of 11% when the yarn feeding speeds of the heat-setting godet rollers are not decelerated (i.e., the total deceleration rate is zero), as shown in Comparative Example 2, it is necessary to increase the roller temperatures to 180 degrees centigrade. In the meanwhile, in Examples 4 to 9 in which the yarn feeding speeds were decelerated, yarns with a boiling water shrinkage of 11% were produced at lower roller temperatures than in Comparative Example 2. Furthermore, as clearly understood from FIG. 4(c), provided that yarns with the same boiling water shrinkage are produced, the roller temperature is further restrained to be low as the total deceleration rate of the heat-setting godet rollers is increased.
While a preferred embodiment of the invention has been described, the present invention is not limited to the embodiment above, and it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art, within the scope of the claims.
While in the present embodiment the deceleration rate between the yarn feeding speeds of the heat-setting godet rollers is identical between the pair of the godet rollers 16 and 17 and the pair of the godet rollers 17 and 18, the deceleration rate between the yarn feeding speeds may be different between the pair of the godet rollers 16 and 17 and the pair of the godet rollers 17 and 18, on condition that the maximum deceleration rate of the yarn feeding speed is less than 5% as shown in some of the examples in FIG. 4(c), for example.
Furthermore, on condition that the total deceleration rate remains the same, the deceleration rates of the two neighboring heat-setting godet rollers may be variously arranged.
While in the present embodiment the surface temperatures of the heat-setting godet rollers 16 to 18 are substantially identical with one another, the surface temperatures of the godet rollers 16 to 18 may be different from one another. To be more specific, for example, the surface temperatures may be arranged to increase from the godet roller 18 to the godet roller 16, i.e., the surface temperature of the most upstream godet roller 16 among the heat-setting godet rollers may be arranged to be highest.
While in the present embodiment the number of the heat-setting godet rollers 16 to 18 is three in total, the number of the heat-setting godet rollers may be two or more, on condition that the number of the heat-setting godet rollers is sufficient to thermally set the yarns Y.
While in the present embodiment the number of the preliminary heating godet rollers 14 and 15 is two in total, the number of the preliminary heating godet rollers may be arbitrarily set on condition that the number of the preliminary heating godet rollers is sufficient to preliminarily heat the yarns Y.
In the present embodiment, the preliminary heating godet rollers 14 and 15 on which the yarns Y before drawn run are heating rollers. In this regard, when the yarns Y are made of resin such as nylon having a glass transition temperature close to room temperatures, preliminary heating is not always necessary. On this account, at least one of the preliminary heating godet rollers 14 and 15 may be a non-heating roller which is not provided with a heater. Alternatively, when each of the preliminary heating godet rollers 14 and 15 includes a heater, at least one of the heaters may be powered off and at least one of the preliminary heating godet rollers may be used in a non-heated state.
In the present embodiment, each of the godet rollers 14 to 18 is 220 to 300mm in diameter and the godet rollers 14, 15, 16, 17, and 18 are disposed upward in this order and in a staggered manner. In this regard, the diameter, arrangement, and the winding angle of the yarns on each of the godet rollers 14 to 18 may be suitably changed in accordance with the type of the yarns Y to be produced, the heating temperature of the yarns Y, or the like.

Claims

A spun yarn drawing apparatus comprising:
rollers which are provided along a yarn path to draw yarns spun out from a spinning apparatus; and a speed controller configured to control yarn feeding speeds of the rollers, wherein,

the yarns are wound onto each of the rollers at a winding angle of smaller than 270 degrees,

the rollers include at least one first roller and second rollers on which the yarns supplied from the at least one first roller are wound and which are heating rollers having higher yarn feeding speeds than the at least one first roller, and

the speed controller causes

the yarn feeding speed of a roller on the downstream in a yarn running direction among neighboring two of the second rollers to be equal to or lower than the yarn feeding speed of a roller on the upstream in the yarn running direction among the neighboring two of the second rollers, and

a deceleration rate between the yarn feeding speeds of the most upstream and the most downstream ones in the yarn running direction of the second rollers to be 2% or higher.
The spun yarn drawing apparatus according to claim 1, wherein,
the speed controller causes
a deceleration rate between the yarn feeding speeds of two of the second rollers neighboring each other in the yarn running direction to be lower than 5%.
The spun yarn drawing apparatus according to claim 1 or 2, wherein,
the number of the second rollers is three or more, and
the speed controller causes a deceleration rate between the yarn feeding speeds of each neighboring pair of the second rollers neighboring each other in the yarn running direction to be 1% or higher.
The spun yarn drawing apparatus according to claim 3, wherein,
the number of the second rollers is three or more, and
the speed controller causes the deceleration rates between the yarn feeding speeds of the neighboring pairs of the second rollers in the yarn running direction to be identical between plural intervals.
The spun yarn drawing apparatus according to any one of claims 1 to 4, further comprising
a temperature controller configured to control a temperature of each of the second rollers.