GB2165558A - Processing a thread or the like made of synthetic fibers - Google Patents

Abstract

From a freshly dyed and centrifuged or spun dyeing package (12) a thread (16) is withdrawn via a thread brake (18) and a thread monitor (20) by a first godet roll (22). In a stretching zone (36) which is located between the first godet roll (22) and a second godet roll (32) there is arranged a stationary heating element (26) around which the thread (16) is wound a number of times for drying and thermofixing the thread. After the second godet roll (32), the still warm, stretched and fixed thread passes through a finishing or avivage device (42) and thereafter is wound-up to form a precision-wound package (54) ready-for-delivery. <IMAGE>

Description

SPECIFICATION Apparatus for processing a thread or the like made of synthetic fibers, method of using such apparatus, and method of manufacturing a ready-for-use sewing thread Background of the invention The present invention relates to apparatus for processing a thread or the like made of synthetic fibers. The present invention further relates to a method of manufacturing from a raw yarn made of synthetic fibers, especially polyester fibers, a readyfor-use dyed sewing thread. The present invention still further relates to a method using apparatus of the present invention.

A qualitatively optimum sewing thread made of synthetic fibers must possess a faultless sewing quality and ensure for an undistorted or unwarped seam. The sewing quality is essentially determined by the stress-strain characteristic of the sewing thread and by a finishing or avivage application. The quality of the seam is especially dependent upon the boiling shrinkage value, which should correspond to that of the fabric to be sewn.

In order to achieve an optimum stress-strain characteristic, stretching of the thread is necessary for reducing its elongatability during sewing. The longitudinal displacement of the thread molecules which occurs during stretching, requires that these molecules are fixed or set in this condition so that the shrinkage characteristic of the finished yarn or thread can be maintained within predetermined limits.

For stretching, the thread conventionally runs over at least one withdrawal roll which is designated as a godet roll. The circumferential speed of such godet roll is greater than the supply or infeed speed of the yarn or thread. The subsequent fixing operation is achieved by means of a heat treatment.

The sewing quality is further determined by the slidability of the sewing thread, wherefore this sewing thread is treated with a finishing or avivage medium or agent, for example, with a silicon oil.

In a prior art apparatus as known, for example, from German Patent No. 1,660,481, granted December 4, 1975, the thread is pulled over a stretching pin between a pair of infeed rolls and a godet roll and is thereby stretched. After leaving the godet roll the thread is relaxed and fixed. Therefore the thread is pulled in direct contact over a stationary heating element. In a variant embodiment, a further godet roll is arranged sequentially after the heating element for positive delivery of the thread to a ringtwisting spindle. Since this known apparatus only serves for stretching, relaxing and fixing the thread, additional operational steps and apparatuses are required for further operations like, for example, finishing. The thread has to be rewound on such further apparatuses.

Afurther apparatus known, for example, from German Patent No. 2,149,793, granted March 10, 1977, serves for sequentially finishing and stretching the thread. For the finishing operation two baths are required with water containing a finishing or avivage medium or agent. The first bath is a wetting bath and the second bath is a temperature-controlled bath. A set of infeed rolls is arranged in the thread-running path between the two baths and requires a squeeze roll to squeeze excess water out of the thread. The second bath is followed in the thread-running path by two stretching regions. In the second stretching region the thread passes to a steam chamber in which the thread is subjected to post-stretching by performing a warm stretching operation.It cannot be ascertained from the abovementioned patent whether this warm stretching operation also serves for fixing the thread. It is a particular disadvantage of this known apparatus that there are required two baths for finishing, two stretching regions for stretching, as well as a multiple number of rolls.

A further apparatus for stretching and heattreat- ing a polyester yarn or thread, is known, for example, from German Patent Publication No.

2,416,927, published October 1974, possessing two successive stretching zones. After such stretching zone, a heated stretching or drawing roll is arranged. Between the second heated stretching or drawing roll and a subsequent non-heated take-up roll there is carried out shrinkage of the yarn or thread. Such apparatus is afflicted with the hard-tosolve problem of maintaining in the most precise possible manner the temperature of the rotating elements, namely the heated stretching or drawing rolls. In the present case, as also in the first mentioned prior art apparatus, further means or devices, for example, forfinishing are required and at such further means or devices, rewinding operations must be carried out.

Conventionally, for example, the following operational steps were required for manufacturing a high-quality polyester sewing thread: a) twisting, b) winding-up upon fixing drums under thread tension, c) fixing, d) winding-up dyeing packages, e) dyeing, f) centrifuging or spinning, g) drying, h) rewinding including finishing or avivage application, and i) winding-up the final make-up or product.

In contrast to the process steps performed in the conventional previously mentioned apparatus, the fixing of the thread in the above-mentioned process step c) on the fixing drum is performed in an oven or furnace which hardly caused problems with respect to maintaining a predetermined temperature.

As will be recognized for the apparatuses discussed hereinbefore, attempts have already been made, for example, to carry out the fixing operation during a rewinding step so as to shorten the processing time.

According to the present invention there is provided an apparatus for processing a thread made of synthetic fibers along a predetermined thread running path in order to produce a yarn or thread, especially a sewing thread, that is ready for use, comprising: a heating element for thermofixing said thread; a first godet roll arranged rearwardly of said heating element in said predetermined thread running path; a second godet roll arranged forwardly of said heating element in said predetermined thread running path; a stretching zone for stretching said thread and arranged in said predetermined thread running path; said stretching zone being located intermediate said first godet roll and said second godet roll and in a region defined by said heating element; finishing means arranged forwardly of said second godet roll in said predetermined thread running path; and winding means for winding-up said thread and arranged in said predetermined thread running path.

Also according to the present invention there is provided a method of manufacturing from a raw yarn made of synthetic fibers, especially polyester fibers, a read-for-use dyed sewing thread, said method comprising the steps of: winding-up said raw yarn on a dyeing spool in order to form a yarn package; dyeing and thereafter centrifuging said yarn package and thereby obtaining a package of moist yarn; and sequentially subjecting, in a singlepassage operation, said package of still moist yarn to the steps of: withdrawing said still moist yarn from said package; stretching said still moist yarn withdrawn from said package; simultaneously with said stretching operation, thermofixing said still moist yarn; and winding-up said stretched and thermofixed yarn in order to thereby obtain a precisionwound package.

In the method of the invention, said step of sequentially subjecting in a single-passage operation said package of still moist yarn may include subjecting said still moist yarn to the further step of finishing said yarn following said simultaneous stretching and thermofixing operation and prior to the step of winding-up said stretched and thermofixed yarn.

Thus, the present invention includes the use of an apparatus of the invention for the production of a sewing thread ready for use, starting from a still moist, dyed yarn withdrawn from a centrifuged dyeing bobbin.

in accordance with the invention there is provided an apparatus for, and a method of, processing a thread orthe like made of synthetic fibers along a predetermined thread travel or running path in order to produce a ready-for-use yarn or thread, especially sewing thread, and which allow all of the operational steps which were previously carried out on separate machines or apparatuses, to be carried out on a single machine or apparatus and which may achieve a high passage or throughput speed ofthethread, and a reduction of the drying time after the dyeing process.

This is so, in as far as the stretching zone is located between the first and second godet rolls in an area or region defined by the heating or heater element.

The apparatus of the present invention makes possible not only simultaneous stretching and thermofixing or thermosetting of the thread or the like but still further enables the drying of the thread after dyeing.

Furthermore, the thread can be supplied in a still warm condition to the finishing or avivage means which are arranged forwardly or downstream of the second godet roll. In this condition the thread absorbs the finishing or avivage medium or agent more rapidly, whereby a higher thread passage speed is enabled. Furthermore, losses of finishing medium or agent due to any propelling away action can be prevented. The finishing means when inserted into the thread travel or running path, also cause more rapid cooling of the thread so that the thread hardly has a temperature above room temperature during the wind-up operation. The apparatus of the invention may achieve thread passage speeds in the range of about 400 to about 500 m/min.

Preferably, the apparatus further includes a common machine frame; mounting means for mounting a thread feed package; and said mounting means, said first godet roll and second godet roll, said heating element, said finishing means, and said winding means being mounted at said common machine frame.

Using such apparatus it is possible to wind-up the thread in a single-passage operation from a still wet or moist dyeing package to the finished delivery package containing a precision-wound package.

Preferably also, the heating or heater element is arranged in a chamber which is connected with suction means.

As a result of this, the environmental air is kept cleaner and the drying of the thread is accelerated.

Also, heating energy is saved by preventing heat radiation from the heating element.

The finishing or avivage means may include a container for the bath containing the finishing or avivage medium or agent. A driven delivery roll may be partially immersed into the finishing bath. The thread to be treated then contacts the delivery roll which is partially immersed into the finishing bath, so that an application of excess finishing medium or agent is avoided which otherwise would be the case if, for example, the thread would be pulled through the bath.

The rotational speed of the delivery roll partially immersed into the finishing bath and/or its depth of immersion intothefinishing bath may be adjustable.

There is thus rendered possible a fine adjustable dosage or application of the finishing medium or agent to the thread.

Afurther mounting device may be provided e.g. at a common frame of the apparatus, for receiving a further, next following thread package.

There is thus permitted, in this way, a continuous thread passage by performing a thread knotting or trying operation between the thread of one package and the next.

The heating or heater element may constitute a stationary heating or heater element and the thread may be multiply wound around the heating element.

Such stationary heating element enables a more precise temperature regulation as compared to the case of a rotating heater roll.

For example, the thread can be wound ten or twenty times around the stationary heating element, whereby the dwell or contact time of the thread with the heating element can be determined by means of the number ofwindings of the thread on the stationary heating element the extent of drying as well as the amount of fixing of the thread can be adapted to predetermined conditions.

As alluded to above, the present invention is not only concerned with the aforementioned apparatus aspects, but also relates to an improved method e.g.

using such apparatus, which comprises a heater element for thermal fixing the thread, a first godet roll arranged rearwardly or upstream of the heater element in the thread travel or running path, a second godet roll arranged forwardly or downstream of the heater element in the thread travel or running path, a stretching zone for stretching the thread and arranged in the travel or running path, the stretching zone being located intermediate the first godet roll and the second godet roll in a region or area defined by the heater element, finishing means arranged forwardly or downstream of the second godet roll in the thread travel or running path, the finishing means being selectively insertable into travel orthethread running path, and winding means forwinding-upthe thread and arranged in the thread travel or running path.

Specifically, a method of the invention using the apparatus described in the immediately preceding paragraph contemplates the steps of: (i) placing a centrifuged or spun dyeing package on mounting means; and (ii) withdrawing the still moist dyed thread from the centrifuged or spun dyeing package and feeding the still moist, dyed thread into the apparatus.

As further already alluded to above, the present invention also provides a method of manufacturing from a raw yarn orthe like made of synthetic fibers, especially polyester fibers, a ready-for-use dyed sewing thread.

Specific embodiments of the present invention in all its aspects as alluded to above will now be described in detail, by way of example and not by way of limitation, with reference to the accompanying drawing which is a simplified, somewhat diagramatic illustration of an apparatus of the present invention.

With reference to the accompany drawing, it is to be understood that only enough of the structure of the exemplary embodiment of the apparatus has been shown as needed for those skilled in the art two readily understand the underlying principles and concepts of the present invention, while simplifying the showing of the drawing. Turning now to this drawing, the apparatus will be seen to contain a machine frame 10 as a common carrier or support for elements or components to be described hereinafter. A supply package 12, preferably a freshly dyed and centrifuged or spun dyeing package, is placed on a mounting device or means 14, so that its thread 16 or the like can be pulled off overhead. The thread 16 which is made of synthetic fibers, then successively passes through a thread brake 18 and a thread monitoring device or, respectively, a thread cutter 20.

A first godet roll 22 is arranged in a predetermined thread travel or running path 70 and serves as an infeed delivery system for withdrawing the thread 16 from the supply package 12. A deflection roller 24 is operatively associated with this first godet roll 22.

Usually, the thread 16 is multiply wound around the godet roll 22 and the deflection roll 24.

A heating or heater element 26 for thermofixing or thermosetting the thread 16 is arranged forwardly or downstream of the deflection roll 24 in the thread travel or running path 70 and the thread 16 is multiply wound around this preferably stationary heating or heater element 26. The heating or heater element 26 possesses a first heating surface 26' and a second heating surface 26". Both the first heating surface 26' and the second heating surface 26" are outwardly domed and are bridged or straddled at both their ends by related freely rotatable rollers 28 and 30. The thread 16 preferably is wound 10 to 20 times around the stationary heating element 26. The thread 16 is pulled over the heating surfaces 26' and 26" in this arrangement.

After leaving the heating element 26, the thread 16 is wound around a second godet roll 32 which is also arranged in the thread travel or running path 70 and constitutes an outfeed delivery system, and such thread 16 is also wound around an associated deflection roll 34. The thread 16 is also wound a number of times around this second godet roll 32 as well as around the deflection roll 34. The second godet roll 32 is driven at a greater circumferential speed than the first godet roll 22, so as to achieve the desired stretching of the thread 16 in a region or area defined by the heating or heater element 26. The region or area between the first godet roll 22 and the second godet roll 32 is designated as the stretching zone 36.

After the second godet roll 32, the stretched thread 16' is guided over a thread monitor 38 and a dancer arm 40 before it arrives at a finishing or avivage device or means 42. The finishing device or means 42 contains a finishing bath container 44. A rotatably driven delivery roll 46 is partially immersed into a finishing or avivage bath 48 contained in said container 44 and containing a finishing or avivage medium or agent. The thread 16' contacts the delivery roll 46 at a fraction of the region of its upwardly directed circumference. The thread 16' is guided over two stationary pins or mandrels 50 without being immersed into a finishing bath 48. The delivery roll 46 is operable at an adjustable rotational speed and can be immersed into the finishing bath 48 at an adjustable immersion depth.

Not specifically illustrated grooves in the stationary pins or mandrels 50 serve for laterally guiding the threads 16'. The grooves are axially offset from each other, so that the thread 16' contacts the delivery roll 46 at an angle which deviates by some degrees from a right angle with respect to the axis of rotation. By means of such arrangement it is ensured that the thread 16' rolls slightly at the surface of the delivery roll 46 so as to be wetted or imbued by the finishing or avivage medium or agent at its complete circumference.

After leaving the finishing device or means 42 the finished thread 16" arrives via a guide 52 at winding means 45 upon which the thread 16" is wound-up in the form of a precision package at a delivery spool 56.

The heating element 26 is placed in a chamber 58 which, by means of a conduit 60, is connected with an exhaust apparatus or suction means 62 possessing a blower 64. The exhaust apparatus or suction means 62 not only serves for drawing-off vapors formed in the region or area of the heating or heater element 26 but also serves to stimulate precipitation.

The vapors which must be drawn-off, constitute moisture residues from the dyeing operation and other vapors formed during the heating of the polyester materials. The chamber 58 is bordered by a housing 66 which can be easily opened and which is partially open at the bottom. The housing 66 fulfills its purpose not only by enclosing the chamber 58 which is necessary for the suction operation, but also within wide limits prevents heat radiation from the heating element 26 so that energy can be saved.

Because of the spatial arrangement of the various components, as illustrated in the drawing, there can be achieved a relatively low structural height of the apparatus, so that a machine or apparatus which is equipped with these components is easy to inspect or monitor and to service. The threading-in of the thread can be carried out immediately by hand without the assistance of, for example, hooks, rods, steps and the like.

A number of units formed by the apparatus illustrated and described hereinbefore, is arranged next to each other and combined to form a single machine or apparatus which may possess a common exhaust or suction means 62 for all the aforementioned units. In this arrangement each unit may possess two mounting devices 14 each for one supply package 12, so that a continuous operation is rendered possible by means of knotting or piecing the threads which originate from the two packages.

The temperature of the heating or heater elements 26 may be centrally adjustable for the entire machine or arrangement, however, each heating or heater element 26 possesses an individual proportional plus floating plus derivative regulator (PID regulator). The rotational speed of the delivery roll 46 can be continuously changed and there is advantageously provided a central adjustment for the entire machine or arrangement. The finishing or avivage medium or agent, for example, a finishing oil, e.g.

silcon oil, can be pumped to each winding location by means of a gear pump. An overflow with a return flow conduit always ensures a constant liquid level in the finishing bath 48. The finishing medium or agent is filtered by a simple filter prior to its return into a storage container.

Should the case arise that for certain threads or yarns the finishing operation is not required, the finishing device or means 42 can be by-passed, for example, by guiding the thread 16' only over one of the pins or mandrels 50.

The apparatus being described with reference to the drawing, is not combined with a twisting arrangement. In such a combination the processing speed generally is limited to approximately 50 mimin. Contrary thereto, the apparatus being described with reference to the drawing permits passage speeds in the range of about 400 to about 500 mimin.

The extent by which the thread 16 is stretched in the stretching zone 36 can be changed by exchanging not particularly illustrated toothed disks, by means of which the godet rolls 22 and 32 are driven via toothed belts.

In the apparatus as described with reference to the drawing four process steps are saved as compared with conventional processes.

Optimal silicon oil application is achieved because the oil is applied to the still warm thread.

There is no loss of silicon oil because a closed oil loop can be used.

Optimum process flexibility is obtained by selectable stress-strain characteristic, selectable boiling shrinkage and selectable silicon application.

Due to stretching of the sewing thread there can be produced per kilogram of sewing thread, a thread length which is increased in correspondence to the stretching ratio (the sewing thread is sold in units of length).

Depending upon the boiling shrinkage values, a thread passage speed up to a maximum of about 600 m/min. is possible.

Because of the fixing operation which follows the dyeing operation it is possible to obtain up to 8% greater length of the sewing thread.

Claims (14)

1. An apparatus for processing a thread made of synthetic fibers along a predetermined thread running path in order to produce a yarn or thread, especially a sewing thread, that is ready for use, comprising: a heating elementforthermofixing said thread; a first godet roll arranged rearwardly of said heating element in said predetermined thread running path; a second godet roll arranged forwardly of said heating element in said predetermined thread running path; a stretching zone for stretching said thread and arranged in said predetermined thread running path; said stretching zone being located intermediate said first godet roll and said second godet roll and in a region defined by said heating element; finishing means arranged forwardly of said second godet roll in said predetermined thread running path; and winding means for winding-up said thread and arranged in said predetermined thread running path.

2. The apparatus as defined in claim 1, said finishing means being selectively insertable into said predetermined thread running path.

3. The apparatus as defined in claim 1 or 2, further including: a common machine frame; mounting means for mounting a thread feed package; and said mounting means, said first godet roll and second godet roll, said heating element, said finishing means, and said winding means being mounted at said common machine frame.

4. The apparatus as defined in claim 3 wherein: said mounting means contain a mounting device receiving said thread feed package; and said mounting means containing a further mounting device for receiving a successive thread feed package following said first-mentioned thread feed package.

5. The apparatus as defined in any preceding claim further including: suction means; a chamber accommodating said heating element; and said suction means communicating with said chamber.

6. The apparatus as defined in any preceding claim wherein: said finishing means contains a finishing bath container and a driven delivery roller; and said driven delivery roller being partially immersed into said finishing bath.

7. The apparatus as defined in claim 6, wherein said driven delivery roller is operable at an adjustable rotational speed.

8. The apparatus as defined in claim 6 or 7, when claim 6 is directly or indirectly dependent on claim 2 wherein said driven delivery roller is partially immersable into said finishing bath to an adjustable immersion depth.

9. The apparatus as defined in any preceding claim wherein: said heating element constitutes a stationary heating element; and said thread running path makes multiple turns around said stationary heating element.

10. An apparatus for processing a thread made of synthentic fibers along a predetermined thread running path in orderto produceayarn or thread, especially a sewing thread, that is ready for use, substantvally as hereinbefore described with reference to the accompanying drawings.

11. A method of manufacturing from a raw yarn made of synthetic fibers, especially polyester fibers, a ready-for-use dyed sewing thread, said method comprising the steps of: winding-up said raw yarn on a dyeing spool in order to form ayarn package; dyeing and thereafter centrifuging said yarn package and thereby obtaining a package of moist yarn; and sequentially subjecting, in a single-passage operation, said package of still moist yarn to the steps of: withdrawing said still moist yarn from said package; stretching said still moist yarn withdrawn from said package; simultaneously with said stretching operation, theremofixing said still moist yarn; and winding-up said stretched and thermofixed yarn in order to thereby obtain a precision-wound package.

12. The method as defined in claim 10, wherein; said step of sequentially subjecting in a singlepassage operation, said package of said still moist yarn includes subjecting said still moist yarn to the further step of finishing said yarn following said simultaneous stretching and thermofixing operation and prior to the step ofwinding-upsaid stretched and thermofixed yarn.

13. The method as defined in claim 11 or 12 employing an apparatus as claimed in any of clairns 1 to 10.

14. A method of manufacturing from a raw yarn made of synthetic fibers, especially polyester fibers, a ready-for-use dyed sewing thread substantially as hereinbefore described with reference to the accompanying drawings.