EP2329071B1

EP2329071B1 - Machine and method for mercerizing threads or yarns

Info

Publication number: EP2329071B1
Application number: EP09780810.9A
Authority: EP
Inventors: Antonio Riva; Roberto De Mattia
Original assignee: Ricambi Tessili Rite - SpA
Current assignee: Ricambi Tessili-Rite Srl
Priority date: 2008-07-21
Filing date: 2009-07-20
Publication date: 2013-10-23
Anticipated expiration: 2029-07-20
Also published as: WO2010010054A1; EP2329071B8; IT1391695B1; EP2329071A1; ITUD20080171A1

Description

FIELD OF THE INVENTION

The present invention concerns a machine and the relative method for mercerizing threads or yarns wound in skeins. In particular, the present invention concerns the uniform tensioning of the skeins during the immersion of the threads in caustic soda. Hereafter in the description by the term thread we shall mean both threads or yarns, natural or synthetic.

BACKGROUND OF THE INVENTION

It is known that mercerization means a treatment in which the threads are immersed under tension in a bath of caustic soda.
Machines and methods are known for discontinuous mercerization in skeins, in which the threads are grouped together in skeins and threaded on two rolls, to be immersed in a mercerizing tank filled with caustic soda.
In known machines, at least one of the two rolls can be selectively distanced with respect to the other, so as to impart to the threads in the skeins a desired tension, characteristic of the mercerizing process.
A first type of machine is known in the state of the art (see for example DE 14 60 425 B1 and DE 558 235 C ) in which the skeins of threads to be subjected to mercerization are wound on a pair of rolls mounted cantilevered, aligned with each other on a substantially vertical plane. The rolls can assume a first position, close to each other, in order to allow and facilitate the insertion on them of the skeins of threads, and a second position, distanced from each other, in order to put the threads under tension before they are immersed in the processing tank.
The solution that uses cantilevered rolls does not allow to obtain great tensioning forces of the skeins, and therefore this solution is limited to small skeins, with a reduced load of threads and with low maximum tensions that can be exerted.
Furthermore, this solution with cantilevered rolls allows to load a very limited number of skeins for each roll, normally not more than two, to prevent the roll from bending.
Another solution is known in the state of the art in which the rolls are mounted supported on both their ends by suitable support means. This solution is applied in machines used for working a much larger number of skeins simultaneously, with a much higher quantity of yarn to be worked for every cycle and with a greater capacity of supporting drawing actions.
In this type of machine, the movement of one of the two rolls is normally achieved by means of a plurality of movement members distributed and constrained, normally equidistant, on the length of the roll.
Movement members of a mechanical type are known, in which each member is controlled and commanded individually, although synchronized with the others, in order to move the mobile roll and keep it substantially parallel with the other, fixed roll.
In this solution, to guarantee an effective uniform tension of the threads, also given the possible different behaviors of the different skeins, very complex coordination kinematisms are provided, with consequent high costs of both manufacture, management and maintenance.
Furthermore, the mechanical conformation of the movement members has a great operating rigidity, and therefore only a predetermined number of operations can be performed, without allowing the user to vary the operating conditions as desired.
Machines are also known in which the movement members are of the electromechanical type, and therefore controlled and managed electronically, one by one, by means of specific transducers, electro valves or other.
These known machines require sophisticated electronic plants to control and coordinate the movement members; such plans are not only very costly and complex, but also are not always completely reliable, and entail frequent stoppages of the machine.
Furthermore, the normal workplaces where mercerizing machines are installed, and the substances used in the production steps, for example caustic soda, determine frequent malfunctions of the electronics with a consequent reduction in the reliability of the machine, low quality of the product obtained and low productivity.
One purpose of the present invention is to achieve a machine, and perfect a method, for mercerizing threads in skeins which allow to obtain, with good repeatability and reliability, a high-quality mercerized thread, and which allow good productive flexibility so as to vary the operating conditions as desired.
Another purpose is to obtain a machine that allows to obtain a very high productivity, allowing to load on the rolls a large number of skeins for every mercerizing cycle, and allowing high drawing forces, up to 70 tonnes and more.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with the above purposes, a machine and method for mercerizing threads or yarns according to the present invention comprises the features according to claims 1 and 4.
With the present invention, a sole movement actuator can therefore determine the selective movement of the single mobile structure which, being associated with the attachment members that support each mobile roll at the respective ends, conditions the movement of the mobile roll with respect to the fixed roll of the pair.
In this way, the same tension is applied substantially on the whole roll, so as to apply a uniform mercerizing tension on all the skeins loaded on the rolls.
Furthermore, the sole movement actuator can be adjusted and driven simply and as desired, substantially without any operating constraints, and it is therefore possible to establish, on each occasion, the desired tensions, or tensioning cycles, of the skeins of threads.
With the present invention therefore it is possible to obtain, simply and economically, both a good operating reliability, typical of known machines with mechanical members, and also a good operating flexibility, typical of known machines with electromechanical members.
At the same time, the present invention allows to avoid frequent interruptions in production and high costs for the design and manufacture of the command and control components.
Furthermore, the structure of the machine according to the present invention, with rolls supported at both their ends, allows to load a high number of skeins, normally up to 6 and more, without any risk of the roll bending.
Moreover, the structure of the machine allows to exert very high traction forces, up to 70 tonnes and more, values that cannot be obtained with cantilevered rolls without risks of structural yielding or deformations, and therefore guaranteeing that good quality results are obtained in the mercerizing step.
The movement of the mobile structure and the rolls, with consequent drawing of the skeins, is exerted with the rolls adjacent on a first substantially horizontal plane, using one or more actuators lying and operating on a substantially horizontal plane.
According to a variant, the mobile structure is mounted on a fixed frame, on which the tank is made. In particular, the movement of the mobile structure with respect to the frame is coordinated by a plurality of reaction elements sliding with respect to suitable guides.
The reaction elements contrast potential lateral and/or rotary slipping of the mobile structure due, for example, to different lengths, lack of uniformity or defects of some of the skeins, or other.
The reaction elements allow to keep the mobile roll perfectly aligned with the fixed roll when it is moving.
In this way, a uniform tensioning of the skeins is guaranteed, substantially in every operating condition.
This advantage allows a high repeatability of the quality of the mercerized yam.
According to a variant the movement actuator comprises an oil-dynamic cylinder commanded and controlled by a single group of electro valves. This solution of the invention allows to simplify to the utmost the configuration of the control unit, if provided, that governs the mercerizing steps.
According to the invention, the attachment members solid with the mobile structure comprise at least two hooks constrained to the ends of each mobile roll, so as to move the latter in coordination with the mobile structure and, at the same time, to allow the free axial rotation thereof.
In other words, since two pairs of rolls are provided, the mobile structure comprises a number of attachment members coordinated with the number of the pairs of rolls, so as to constrain the ends of each mobile roll and move all the mobile rolls of each pair in coordination and uniformly.
According to the invention the mobile structure is conformed as a slider.
According to another variant the mobile structure comprises a lattice-type frame.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

fig. 1 is a three-dimensional view of a machine for mercerizing threads according to the present invention, in a first operating condition;
fig. 2 is a three-dimensional view of the machine in fig. 1, in a second operating condition;
fig. 3 is an exploded view of the machine in fig. 1 with a mobile structure in the tilted condition.

DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT

With reference to figs. 1 and 2, a machine 10 according to the present invention comprises a frame 11 defining a tank 12 which is filled during use with caustic soda, in order to mercerize the threads.
The machine 10 comprises in the case shown in the drawings, two pairs of rolls, each of which comprises a fixed roll 13, motorized, and a mobile roll 15, idle. The pairs of rolls 13, 15, in the case shown, are adjacent to each other longitudinally on a substantially horizontal plane. The threads to be mercerized are threaded in skeins 14 on each pair of rolls 13, 15. In the case shown five skeins 14 are provided for each pair of rolls 13, 15.
Both the pairs of rolls 13, 15 are commonly mounted on a mobile turret, of which a pin 21 is indicated in fig. 3, able to selectively take the rolls 13, 15, rotating around a fulcrum 27, between a raised loading position, in which they are outside the tank 12, and a lowered mercerizing position, in which they are at least partly immersed in the tank 12, in order to keep the skeins 14 at least partly immersed in the caustic soda.
In the attached drawings, the machine 10 according to the present invention is always shown in the lowered mercerizing position.
The machine 10 also comprises a movement mechanism 16 mounted sliding on the frame 11 and constrained, at least in the lowered position, to the mobile rolls 15 of each pair.
The movement mechanism 16 comprises a mobile structure, in this case a slider 17, provided at the front with a plurality of hooks 19, in this case four, respectively two internal and two external, each able to be constrained to a respective end of the corresponding mobile roll 15, to support said mobile roll 15 from both sides.
In this case, the slider 17 lies on a substantially horizontal plane and extends longitudinally so as to cover the entire longitudinal extension of the rolls 13, 15. Substantially from the ends of said slider 17 the external hooks 19 extend, on which the external ends of the respective rolls 13, 15 are mounted, whereas the internal hooks 19 are disposed in a substantially central position of the slider 17 and are associated with the internal ends of the mobile rolls 15.
The slider 17 is selectively movable by means of a linear actuator 22, in this case on a substantially horizontal plane, between an inactive position near the tank 12 (fig. 1), and a tensioning position, in which it is slightly distanced from the tank 12 (fig. 2), and distances the mobile roll 15 with respect to the fixed roll 13, imparting a desired mercerizing tension on the skeins 14.
The linear actuator 22 in this case is of the oil-dynamic type, electronically controlled by a single group of electro valves, of a traditional type and not shown in the drawings, which determine the actuation thereof between one and the other of its operating conditions.
In this case, a single linear actuator 22 is provided, disposed in a substantially central position and symmetrical with respect to the slider 17, in an intermediate position between the two internal ends of the rolls 13, 15.
According to a variant, not shown, two oil-dynamic actuators are provided, disposed close and symmetrical to the median axis of the slider 17. In this solution, the actuators are coordinated with each other to effect a common action to move the slider 17.
According to other variant embodiments, several actuators may be provided, which in any case cooperate with a mobile structure of the same type as the slider 17.
Furthermore, the slider 17 is associated with the frame 11 by means of a plurality of reaction runners 23 mounted on a bottom surface of the slider 17, and able to slide with respect to coordinated guides 24 mounted on the frame 11.
In particular, the cooperation between the reaction runners 23 and the guides 24 is such as to contrast any possible lateral and/or rotary movements of the slider, due for example to different lengths, lack of uniformity or defects of some of the skeins 14, or other.
Thanks also to the fact that the movement of the two rolls 13, 15 takes place on a substantially horizontal plane, and it is therefore possible to exploit said cooperation between runners 23 and guides 24, it is therefore possible to keep the mobile roll 15 perfectly aligned with the fixed roll 13 during the movement, thus guaranteeing a uniform tensioning of the skeins 14, improving the quality of the finished product.
The hooks 19 are conformed so that the ends of the mobile rolls 15 are automatically positioned in cooperation with the hooks 19 when the rolls 15 are taken to the lowered mercerizing position. Moreover, the conformation of the hooks 19 is such as to allow the rolls 15 to freely detach from the hooks 19 when the rolls 15 are returned to the raised loading position.
In particular, the constraint established between the hook 19 and the end of the mobile roll 15 in the lowered position of the rolls 13, 15 is such that said mobile roll 15 is free to rotate around its own axis and is constrained to the slider 17 in a substantially transverse direction, and is subjected to the possible movement thereof imparted by the linear actuator 22.
The machine 10 according to the present invention functions as follows.
Initially the pairs of rolls 13, 15 are in the raised loading position and, by means of a device for loading the skeins 14, not shown, a plurality of skeins 14 of thread are inserted upon them. The number of skeins 14 obviously depends on the length of the rolls 13, 15 and the width of the skeins 14, however the solution described here allows to load the whole length of the roll 13, 15 with the skeins 14, without any risk of bending or longitudinal deformation, thanks to the support given at both ends.
Once loading is terminated, the rolls 13, 15 are taken to the lowered mercerizing position, so that the skeins 14 are at least partly soaking in the caustic soda.
The mobile rolls 15 automatically move to the condition of constraint with the hooks 19, whereas the fixed rolls 13 are made to rotate in order to make the whole skein 14 pass into the caustic soda.
Then the linear actuator 22 is driven, to take the slider 17 into its tensioning position, distancing the mobile rolls 15 from the relative fixed rolls 13 with a single uniform traction action.
The traction of the rolls 13, 15 is thus achieved on a horizontal plane, allowing to exert an extremely high force, up to 70 tonnes, and extremely uniform, so as to guarantee maximum effectiveness in the mercerizing process.
Once mercerizing is complete, the sole linear actuator 22 returns the slider 17 to the inactive position, and consequently the rolls 13 and 15 are brought near to each other and the tensioning of the yarn is released.
The rolls 13, 15 are then raised, acting by means of the cylinder 26, the shaft 25 of which is solid with the pin 21, and rotating around the fulcrum 27 (fig. 3), and returned to the loading position, so as to replace the skeins 14 of mercerized thread with other skeins of thread to be mercerized.
It is clear that modifications and/or additions of parts or respectively of steps may be made to the mercerizing machine 10 and method as described heretofore, without departing from the field and scope of the present invention.
For example, more than one actuator may be used to move a single mobile structure, or a single actuator and a single mobile structure can be used to move three or more pairs of rolls adjacent longitudinally with each other on a substantially horizontal plane.
It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of machine and method for mercerizing threads or yarns, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

Machine for mercerizing threads or yarns, comprising a fixed frame (11), two pairs of rolls (13, 15) each pair of rolls (13, 15) comprising an idle mobile roll (15) and a motorized fixed roll (13) on which are able to be disposed, in a threaded condition, a plurality of skeins (14) of thread, a mercerizing tank (12), at least partly filled with caustic soda and in which said pairs of rolls (13, 15) are able to be at least partly immersed in order to take said skeins (14) at least partly to soak, and movement means (16) mounted sliding on the frame (11) and able to move said idle mobile rolls (15) of each pair with respect to said motorized fixed rolls (13), so as to effect a tensioning of said skeins (14) when they are soaking in said mercerizing tank (12), whereby said movement means (16) comprises a single slider (17) associated with a movement actuator (22) disposed in a substantially central position and symmetrical with respect to the slider (17), in an intermediate position between the two internal ends of said rolls (13, 15) wherein said slider (17), said movement actuator (22) and said rolls (13, 15) lie and move, during the reciprocal movement of the rolls (13, 15) to effect the tensioning of said skeins (14), on a substantially horizontal plane, and wherein said slider (17) extends longitudinally for the entire longitudinal extension of said pairs of rolls (13, 15) and is provided at the front side facing said rolls (13,15) with a first and a second hook (19) on which a corresponding first and second end of each mobile roll (15) of said pairs is constrained.
Machine as in claim 1, characterized in that said slider (17) comprises a plurality of reaction elements (23) mounted on the bottom surface of the slider (17) and running in a parallel direction to the movement direction, able to slide with respect to coordinated guides (24) mounted on said frame (11) and able to contrast potential lateral and/or rotary movements of said slider (17), so as to keep said mobile roll (15) aligned with said fixed roll (13) of each pair during the movement thereof.
Machine as in any claim hereinbefore, characterized in that said movement actuator comprises an oil-dynamic cylinder (22) commanded and controlled by a control unit.
Method for mercerizing threads or yarns, comprising at least a mercerizing step in which, by means of two pairs of rolls (13, 15) each pair of rolls (13, 15) comprising an idle mobile roll (15) and a motorized fixed roll (13) on which a plurality of skeins (14) of thread are able to be disposed, in a threaded condition, said skeins (14) are taken at least partly to soak in a mercerizing tank (12) at least partly filled with caustic soda and in which, when they are soaking in said mercerizing tank (12), the skeins (14) are tensioned by means of movement, actuated by relative movement means (16), of said idle mobile roll (15) of each pair with respect to said fixed motorized roll (13), of each pair, whereby in said mercerizing step, said movement of each idle mobile roll (15) is made in a coordinated manner by a single slider (17) associated with at least a movement actuator (22) disposed in a substantially central position and symmetrical with respect to the slider (17) in an intermediate position between the two internal ends of said rolls (13, 15) said slider (17), said actuator (22) and said rolls (13, 15) being provided to lie and move, during the reciprocal movement of the rolls (13, 15) to effect the tensioning of said skeins (14), on a substantially horizontal plane, and wherein said slider (17) extends longitudinally for the entire longitudinal extension of said pairs of rolls (13, 15) and being provided at the front side facing said rolls (13, 15) with a first and a second hook (19) on which a corresponding first and second end of each mobile roll (15) of said pairs is constrained.