Patent Application
20250051970
The invention relates to a method and an installation for producing a twisted or cabled synthetic yarn according to the preamble of the independent patent claims.
When producing a synthetic yarn, twisting of a multifilament yarn is almost obligatory. The twisting operation is a separate process which is completely disconnected from the process of spin-drawing the multifilament yarn.
According to the prior art, a large number of continuous filaments are produced by means of a spinneret, are combined to form one or more yarns and, depending on the process sequence, are dyed and/or textured before, after further treatment steps for consolidation, being wound by a winder. The filaments and the yarns produced therefrom are here conveyed in the installation at different speeds before being wound at a speed of from 2000 m/min to 4000 m/min. For the subsequent twisting operation, the bobbins with the wound yarns must be temporarily stored, which may even have to take place in an air-conditioned area depending on the material and the application. This storage time with handling of the bobbins is very cost-intensive and is only performed because the subsequent twisting operation is carried out at a speed of usually from 40 m/min to 80 m/min. The difference in speed between the spin-drawing process and the twisting operation has already been reduced in initial unsuccessful approaches by increasing the speed of the twisting process, but this finds its current technical limit at about 12,000 revolutions per minute.
U.S. Pat. No. 6,164,054 discloses a spin-drawing installation in which a yarn is guided from the spin-drawing installation without interruption to a twisting installation. An interruption or disruption in the process puts both installation component out of operation.
U.S. Pat. No. 6,119,320 describes an installation for producing a synthetic multicoloured yarn from different coloured textile threads which, after texturing, are tangled and then wound up.
Subsequent twisting or cabling in a continuous process is not disclosed here.
Starting from this known prior art, an object of the invention is to provide a method and an installation with which the spin-drawing process and the twisting operation are possible in a continuous process. A continuous process is understood as being a production method in which the yarn is no longer wound onto a bobbin and temporarily stored separately before the twisting operation.
The invention relates to a method and an installation for producing a twisted synthetic yarn, in which continuous filaments are produced from a liquid plastics material by means of at least one spinneret and then at least one yarn is produced from at least two continuous filaments, which yarn is delivered from a treatment apparatus and is transferred by means of a collection and transport apparatus to a twisting apparatus. The invention includes the technical teaching that the collection and transport apparatus can be in the form of a buffer. The collection and transport apparatus here serves as a buffer with which it is possible to compensate for different working speeds of the spin-drawing installation and of the twisting apparatus. For example, in the event of a change of the bobbins of the twisting apparatus or in the event of a broken continuous filament or yarn in the spin-drawing installation, the collection and transport apparatus is for a short time able to compensate for a possible loss of production.
Alternatively, or in addition, the collection and transport apparatus can also be in the form of a spatial connection between the spin-drawing installation and the twisting apparatus.
Alternatively, or in addition, the collection and transport apparatus can also be configured to treat the yarn further downstream of the treatment apparatus of the spin-drawing installation or to relax or freeze the current orientation of the molecular chains relative to one another, for example by means of temperature-controlled drums, cylinders or rollers, and/or to be transported in an atmosphere of gas or hot steam.
The invention has the advantage that, by means of the collection and transport apparatus, a continuous process is possible without interruption from production of the continuous filaments to the twisted yarn. The installation can be operated without interruption in a line from the liquid plastics material or granular material to the twisted yarn, which saves space and reduces storage capacity and handling costs. Although the spin-drawing installation is operated with a lower capacity compared to the prior art, this is more cost-effective overall because the spin-drawing installation is operated without interruption and is equipped with simple components. Because of the lower speed of the spin-drawing installation, the risk of yarn breakage is reduced, while at the same time the yarn can be produced with a higher quality because the molecules have more time to orient themselves and to assume the specific temperature of the individual components. Owing to the slower speed of the spin-drawing installation, the components can be made larger, so that up to 20 yarns or more can simultaneously be guided and drawn on one godet.
A predetermined length of the at least one yarn is here accommodated by the collection and transport apparatus in order to compensate for a production difference between the spin-drawing installation and the twisting apparatus. This length can be from several hundred to several thousand metres, in which the yarn is deposited, wound or guided in windings or loops.
Preferably, at least two yarns can be transferred by means of a collection and transport apparatus from the spin-drawing installation to the twisting apparatus. If the existing spin-drawing installation has one or more treatment apparatuses for a plurality of yarns, it is possible, for example, for a spin-drawing installation having a plurality of collection and transport apparatuses to be connected to a plurality of separate twisting apparatuses, as a result of which the productivity increases.
In one embodiment, the at least one yarn is treated in an atmosphere of hot steam or gas while it is being transferred from the spin-drawing installation to the twisting apparatus. The collection and transport apparatus can be held in an atmosphere of hot steam or a conditioned gas, which accordingly makes a housing or an enclosure necessary.
In one embodiment, the at least one yarn is guided out of the spin-drawing installation at a speed of from 100 m/min to 300 m/min, preferably at a speed of from 100 m/min to 150 m/min. A speed range of from 200 m/min to 300 m/min is possible if the twisting apparatus can be operated at a correspondingly high rotational speed of over 12,000 rpm. As things stand today, this requires the use of magnetic bearings for the spindles.
In another embodiment, the at least one yarn (G) is introduced into the twisting apparatus at a speed of from 10 m/min to 300 m/min, preferably at a speed of from 10 m/min to 150 m/min.
The spin-drawing installation must be reduced to the production speed of the twisting apparatus, slight differences in the production speed being possible and necessary in order to allow the buffer of the collection and transport apparatus to be used, specifically for emptying and for filling.
In yet another embodiment, the at least one yarn is guided inside the collection and transport apparatus by means of temperature-controlled drums, cylinders or rows of deflection rollers and can thereby be treated further.
In one embodiment, at least undrawn and/or drawn and/or relaxed and/or textured yarn, which consists of at least two individual filaments, is delivered from the delivery apparatus and transferred in the form of a yarn or a plurality of yarns on the collection and transport apparatus to the twisting apparatus.
In a further embodiment, the at least one yarn, which consists of at least two individual filaments, is conditioned or relaxed by means of a delivery apparatus, which can be in the form of at least one transport roller, this process preferably being assisted by means of steam or conditioned gas. The delivery apparatus can thus serve as an extension of the treatment apparatus, for example as a substitute for the function of the winder, with which drawing or relaxing likewise takes place at the last roll pair.
By means of a controller, the spin-drawing installation and the twisting apparatus are adapted in terms of their production speed to the current buffer capacity of the collection and transport apparatus. The starting point here is a mean production speed which both components can exceed or fall below according to whether the collection and transport apparatus is to be emptied or filled in terms of buffer capacity. By means of the same controller, the speed of the collection and transport apparatus can also be adapted to the current speed of the spin-drawing installation and of the twisting apparatus.
The installation according to the invention for producing a twisted synthetic yarn comprises at least one spin-drawing installation which is configured to produce continuous filaments from a liquid plastics material or granular material by means of at least one spinneret and then to produce at least one yarn from at least two continuous filaments, having a downstream treatment apparatus for treating the at least one yarn. It further comprises a collection and transport apparatus and a downstream twisting apparatus. The installation is configured to transfer the at least one yarn without interruption from the spin-drawing installation to the twisting apparatus or to transfer at least two yarns to the cabling apparatus.
According to the invention, a continuous process is thus possible without interruption from production of the continuous filaments to the twisted yarn. The installation can be operated without interruption in a line from the liquid plastics material or granular material to the twisted yarn, which saves space and reduces storage capacity and handling costs. Although the spin-drawing installation is operated with a lower capacity compared to the prior art, this is more cost-effective overall because the spin-drawing installation is operated without interruption and is equipped with simple components. Because of the lower speed of the spin-drawing installation, the risk of yarn breakage is reduced, while at the same time the yarn can be produced with a higher quality because the molecules have more time to orient themselves and to assume the specific temperature of the individual components.
The collection and transport apparatus is here configured to compensate for a difference in the production speed between the spin-drawing installation and the twisting apparatus. It is thus possible to change bobbins in the twisting apparatus and also to eliminate a breakage of the yarn or continuous filament without the installation having to be stopped completely.
In one embodiment, the at least one yarn is delivered from the treatment apparatus by means of a delivery apparatus. The delivery apparatus can consist of at least one transport roller, and can perform further functions for treatment of the yarn. The yarn can thus be relaxed or drawn in the delivery apparatus and at the same time or separately can be treated with hot steam or a conditioned gas.
The collection and transport apparatus can be based on multiple principles for buffering the at least one yarn. It can be in the form of a revolving belt, in the form of a drum having a thread guide, in the form of cylinders that are adjustable in terms of their distance from one another, or in the form of a buffer having two rows of deflection rollers that are adjustable in terms of their distance from one another. Each form has different advantages and disadvantages in terms of the buffer capacity and the possibility for treatment of the yarn.
The collection and transport apparatus can especially be arranged inside a housing which is configured to be filled with hot steam or conditioned gas. The yarn can thus be treated again upstream of the twisting apparatus, in order, for example, to stabilise the molecular chains or, for example, to impregnate the yarn.
In a further embodiment, the installation has a controller which is configured to adapt the production speed of the spin-drawing installation and of the twisting apparatus to the current buffer capacity of the collection and transport apparatus, and vice versa. This is understood as meaning that the installation components are sped up and slowed down in order to slowly empty or refill the buffer.
The controller is, however, also configured to reconcile the difference between the production speed of the spin-drawing installation and of the twisting apparatus. The buffer capacity of the collection and transport apparatus is here monitored in order to slow down the twisting apparatus, in the event of a prolonged stoppage of the spin-drawing installation, for example, such that it is slowly brought to a standstill if the buffer capacity is exceeded.
In another embodiment, the controller is part of the spin-drawing installation, because that is where most technical difficulties can occur and the twisting apparatus must be adapted to such operating states.
Further measures enhancing the invention are described in detail below together with the description of a preferred exemplary embodiment of the invention, with reference to the figures, in which:
The installation according to the invention and the method are explained below with reference to
In a first embodiment, a mixer 1 is configured to thoroughly mix a melt container 2 filled with solid plastics particles. The plastics particles are usually supplied in the form of chips and are introduced on their own or together with chips of a different type of plastics material into the melt container 2, where they are melted by means of energy input to form liquid plastics material. The mixer 1 ensures continuous thorough mixing of the plastics material, which in this method step varies in terms of its state of aggregation between solid and liquid (granules and solution). From the melt container 2, the liquid plastics material is guided via a pipeline to a spinning beam 5.
Alternatively, the plastics particles can be guided from silos via a supply device 3 to an extruder 4, which by means of energy input and pressure converts the solid plastics particles into a liquid plastics material and guides the liquid plastics material by means of a pipeline to the spinning beam 5 of a spin-drawing installation. Polypropylene, PA6, PA6.6, PET, PTT or other materials can be used as the plastics material. The materials can be improved in terms of their desired properties with a heat stabiliser, dyes, titanium dioxide, a UV stabiliser or other additives. The additives can be added continuously or can be mixed in with the raw materials.
The two methods can be used as alternatives. They have different advantages and disadvantages, but these are not relevant to the invention.
Inside the spinning beam 5 there is arranged at least one spinning pump 6 by means of which the liquid plastics material is pressed into and through the spinneret 7, which has a large number of small openings. Depending on the form of the spinneret 7, it can have a small number of openings, preferably at least two or also, for example, from 50 to 60, or a large number of up to more than 1000 openings. The spinneret 7 is connected to a heater 8 so as to avoid freezing of the plastics material. A continuous filament E flows through each opening of the spinneret 7, all of the continuous filaments passing through the shaft-like blow shaft 9 beneath the spinneret 7 having the heater 8, whereby the pasty molecular structure of the plastics material is consolidated for the first time. Beneath the blow shaft 9, additional cooling air is introduced into the blow shaft 9 via a drop pipe 10. In the blow shaft 9, the cooling molecular structure of the continuous filaments E is influenced via the amount of cooling air, the temperature and the relative humidity.
Subsequently, at least one yarn G is produced from at least two continuous filaments E, but preferably from a greater plurality of continuous filaments, and is guided via a first godet 11 to a treatment apparatus 12. Each yarn G preferably consists of at least two continuous filaments E.
The treatment apparatus 12 can have a plurality of heated or cooled godets, by means of which the yarn G is drawn. The godets can be in the form of mono- or duo-rollers, which draw or compress or relax the yarn G in stages at different speeds. Further apparatuses for treating the yarn G can be arranged therebetween, by means of which apparatuses the yarn G is, for example, tangled and/or textured and/or provided with an application and/or subjected to further treatment. According to the prior art, the yarn G is finally wound by a winder downstream of the treatment apparatus 12. According to the invention, the yarn G is transferred downstream of the treatment apparatus 12 directly to a collection and transport apparatus 14, which temporarily buffers the yarn G and then transfers it to a twisting apparatus 15. This is a continuous process in which the yarn G is not wound and temporarily stored separately but is transferred in a single step from the spin-drawing installation S to the twisting apparatus 15.
The yarn G is preferably delivered via a transport roller 13 and transferred to a collection and transport apparatus 14. The transport roller 13 can be associated with the spin-drawing installation S or it can be arranged as a separate component between the spin-drawing installation S and the collection and transport apparatus 14. The yarn G can be further drawn or relaxed by the transport roller 13. The transport roller 13 can thereby be either cooled or heated and/or can be arranged in a suitable housing which is filled with steam or conditioned gas.
The above-described installation components from the mixer 1 or the supply device 3 to the treatment apparatus 12 are referred to as a whole as the spin-drawing installation S.
According to
According to the invention it is provided to adapt the spin-drawing installation S to the twisting apparatus 15 in terms of production speed. Preferably, the yarn G is delivered downstream of the treatment apparatus 12 and supplied to the collection and transport apparatus 14 at a speed of from 100 m/min to 150 m/min. The downstream twisting installation 15 is operated at a speed of from 10 m/min to 150 m/min. The principle of operation of the spin-drawing installation S remains the same. It is merely operated at a speed that is lower by a factor of 30, as a result of which the components to be used are much simpler and less expensive to produce. During normal operation, the spin-drawing installation S and the twisting apparatus 15 are preferably operated at the same speed, which can be, for example, from 100 m/min to 120 m/min. The collection and transport apparatus 14 is configured, for example, to accommodate a buffer capacity for a production period of the yarn G of one hour, that is to say to accommodate 6000 m of yarn at a production speed of 100 m/min. Such a buffer is sufficient, for example, to eliminate the breakage of a yarn G or of a continuous filament E without the twisting apparatus 15 having to be stopped. Such a buffer is likewise sufficient to allow the bobbins of the twisting apparatus 15 to be changed without stopping production of the spin-drawing installation S. If the buffer with produced yarn G is slowed down, for example as a result of breakage of a continuous filament and subsequent stoppage of the spin-drawing installation S, the production speed of the twisting apparatus 15 can be reduced at the same time, for example to 50 m/min. This can take place until the buffer for yarn G in the collection and transport apparatus 14 has had its speed returned to a defined desired value. To that end, the spin-drawing installation S is operated at an increased speed of up to 150 m/min. A controller of the installation as a whole is configured to adapt the production speed of the spin-drawing installation S and of the twisting apparatus 15 such that there is always a sufficient supply of yarn G at the transport and collection apparatus 14 to compensate for disruptions in production or irregularities in production.
In an alternative embodiment, the speed of the spin-drawing installation S and the speed of the twisting apparatus 15 can be brought more closely together. However, this requires a particularly complex, for example magnetic, bearing for the spindles of the twisting apparatus 15, so that the twisting apparatus 15 is able to operate at a rotational speed far greater than 12,000 rpm and is operated in continuous operation at a speed of from 10 m/min to 300 m/min. Here too, it is provided according to the invention to adapt the spin-drawing installation S to the twisting apparatus 15 in terms of production speed. In this embodiment, the yarn G is delivered downstream of the treatment apparatus 12 at a speed of from 200 m/min to 300 m/min and supplied to the collection and transport apparatus 14. The downstream twisting apparatus 15 is operated at a speed of from 10 m/min to 300 m/min. The principle of operation of the spin-drawing installation S remains the same. It is merely operated with a speed that is lower by a factor of 15, for example, than according to the prior art, as a result of which the components to be used are much simpler and less expensive to produce. During normal operation, the spin-drawing installation S and the twisting apparatus 15 are preferably operated at the same speed, which can be, for example, from 200 m/min to 240 m/min. The collection and transport apparatus 14 is configured, for example, to accommodate a buffer capacity for a production period of the yarn G of half an hour, that is to say to accommodate 6000 m of yarn at a production speed of 200 m/min. Such a buffer is in any case sufficient to allow the bobbins of the twisting apparatus 15 to be changed without stopping production of the spin-drawing installation S. Depending on the extent of the disruption in the spin-drawing installation S, such a buffer may be sufficient, for example, to eliminate the breakage of a yarn G or of a continuous filament E without the twisting apparatus 15 having to be stopped. If the buffer with produced yarn G is slowed down, for example as a result of breakage of a continuous filament and subsequent stoppage of the spin-drawing installation S, the production speed of the twisting apparatus 15 can be reduced at the same time, for example to 50 m/min. This can take place until the buffer for yarn G in the collection and transport apparatus 14 has had its speed returned to a defined desired value. To that end, the spin-drawing installation S is operated at an increased speed of up to 300 m/min. A controller of the installation as a whole is configured to adapt the production speed of the spin-drawing installation S and of the twisting apparatus 15 such that there is always a sufficient supply of yarn G at the transport and collection apparatus 14 to compensate for disruptions in production or irregularities in production. Depending on the mode of operation of the spin-drawing installation and the available space for the collection and transport apparatus 14, a buffer for a loss of production of from 10 to 15 minutes may also be sufficient, in order to compensate for smaller disruptions or the change of the bobbins in the twisting apparatus 15.
By way of example for all the other embodiments too, it is shown in this figure that two yarns G can leave the treatment apparatus 12 and be relaxed by means of a delivery apparatus, which may be in the form of at least one transport roller 13. This operation can be assisted in the delivery apparatus by means of hot steam or conditioned gas.
According to the invention, the spin-drawing installation S is operated at a lower delivery speed than according to the prior art. The production speed of the spin-drawing installation is equal to or slightly higher than that of the twisting apparatus 15. The production of the spin-drawing installation S is slowed down by a factor of from 15 to 30, which has prevented experts from considering this in respect of the investment of a spin-drawing installation, because the price per tonne of yarn would rise by almost the same factor. However, because of the lower productivity or production speed, the spin-drawing installation can be of a more simple design, as a result of which the investment costs fall. What is important, however, is that all handling and temporary storage between the spin-drawing installation S and the twisting apparatus 15 is omitted, as a result of which the method according to the invention is worthwhile again in terms of operating costs.
The invention has the advantage that, by means of the collection and transport apparatus 14, a continuous process is possible without interruption from production of the continuous filaments E to the twisted yarn. The collection and transport apparatus 14 can be configured to compensate for a production difference between the spin-drawing installation S and the twisting apparatus 15. In addition, the collection and transport apparatus 14 can be configured to further treat the yarn by means of gas or hot steam or by means of temperature-controlled drums, cylinders or deflection rollers. The installation can be operated without interruption in a line from the liquid plastics material to the twisted yarn, which saves space and reduces storage capacity and handling costs. Although the spin-drawing installation is operated with a lower capacity compared to the prior art, this is more cost-effective overall because the spin-drawing installation is operated without interruption.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 133 037.8 | Dec 2021 | DE | national |
This application is a U.S. National Stage of International application No. PCT/EP2022/081471, filed Nov. 10, 2022, which claims priority to German application 10 2021 133 037.8 filed Dec. 14, 2021.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/081471 | 11/10/2022 | WO |
