Patent Application
20240410093
The invention relates to a method and to a device for producing a crimped composite thread, wherein the crimped composite thread comprises a first polymer melt and a second polymer melt.
One example of a crimped thread is a texturised synthetic thread for carpet yarn (BCF yarn—Bulk Continuous Filament Yarn).
A crimp in the thread can be formed mechanically by active compression, by a thermal input which causes shrinkage, or by self-crimping.
EP1184494B1 describes a texturising nozzle for mechanically compressing or crimping a BCF yarn. Using the texturising nozzle, a crimp in the BCF yarn can be mechanically formed by compression in that the BCF yarn is compressed to form a plug in the texturising nozzle, as a result of which the filaments of the yarn are kinked, this leading to crimping.
EP0485871B1 describes a method and a device in which crimping of the multicoloured synthetic threads that are compressed to form a plug is thermally formed by impinging the latter with a flow of a heated fluid, this leading to a thermally initiated shrinkage of the threads, which causes crimping.
WO 2021/118985 A1 describes a carpet having a bi-component thread which comprises one component of polyethylene terephthalate homopolymer, or polyethylene terephthalate copolymer, and a second component of polytrimethylene terephthalate polymer, or a mixture of polytrimethylene terephthalate and polyethylene terephthalate homopolymer or polyethylene terephthalate copolymer, whereby the bi-component thread by virtue of the different shrinkage is self-bulking as soon as the bi-component thread is extruded from the melt-spinning device and shrinking begins.
As already outlined above, crimping or bulking of a BCF thread, or of a multicoloured synthetic thread, can be generated by mechanically or thermally acting means, or the BCF thread is a bi-component thread which comprises polymers that cause self-bulking as a result of the different shrinkage of the respective polymer.
The crimping, or the shrinkage, is initiated in that either the thread is impinged with an external action by mechanically or thermally acting means, or the thread has a combination of polymers which can lead to self-crimping without self-crimping having to be activated by any external action.
Further processing, such as tufting, for example, of the bi-component thread is difficult when the latter is excessively shrunk and/or crimped. Tufting is understood to mean a production method of textile floor coverings in which a bi-component thread is incorporated into a woven backing fabric or into a spun-bonded fabric. If the bi-component thread is excessively crimped, tufting has to be adapted to the crimp present.
Excessive shrinkage and/or crimping substantially compromise/compromises the further processing and renders further processing more complex and expensive.
Excessive shrinkage can occur in mechanical crimping as well as in thermal crimping.
In the case of self-crimping it is disadvantageous that self-crimping can start at a point in time in the production process at which self-crimping should specifically not take place, such as when the synthetic filaments are converged at a so-called convergence point.
Moreover, in the case of bi-component threads a large quantity of the respective polymer melt is required for producing a bi-component thread by the above-mentioned crimping methods in order to achieve the desired crimping quality.
It is thus an object of the invention to provide a method and a device for producing a crimped composite thread, by way of which the abovementioned disadvantages can be avoided or at least mitigated.
It is additionally an object of the invention to provide a system for producing a crimped composite thread from a BCF yarn for carpet yarn, by way of which the abovementioned disadvantages can be avoided or at least mitigated.
In terms of the method, this object is achieved according to the invention by a method having the features according to claim 1.
Provided according to one aspect of the invention is a method for producing a crimped composite thread, wherein the crimped composite thread has a plurality of composite filaments from a first polymer melt and a second polymer melt, wherein the first and the second polymer melt are arranged next to one another, in particular side-by-side, in portions in such a way that a composite thread is formed. The first polymer melt and the second polymer melt each have a different material property so that self-crimping of the composite thread can be initiated open-loop and/or closed-loop controlled by an active crimping initiation at a predetermined point in the method.
A composite filament is understood to mean in particular a synthetic filament of infinite length, which has at least a first and a second polymer melt and is extruded via capillaries of a melt-spinning installation. Each capillary of the melt-spinning installation extrudes one composite filament. The number of capillaries of the melt-spinning installation determines the number of composite filaments.
A composite thread is understood herein to mean a composite thread which has a plurality of combined composite filaments which each have a first polymer melt and a second polymer melt, as well as a multi-composite thread which has a third polymer melt.
It is essential herein that the composite filaments that form the composite thread have at least two different or identical polymers which at least have different material properties such as, for example, a different viscosity. The different viscosities of the polymers require self-crimping of the composite thread by means of an active crimping initiation, such as by an external mechanical and/or thermal activation, for example.
Not only can self-crimping be activated, and the point where self-crimping is to take place be determined, by the variable of the mechanical and/or thermal activation, but also the degree and the extent of self-crimping.
This has the advantage that self-crimping can be initiated at a predetermined point in the method.
Moreover, the degree of self-crimping can be controlled, for example in that the variable of the initiating threshold value of the crimping initiation is open-loop and/or closed-loop controlled. In the case of closed-loop control, sensors that monitor the degree of self-crimping are also provided. The results of the sensors can then be used for closed-loop controlling the variable of the initiating threshold value in such a way that substantially constant self-crimping can be achieved at the desired quality.
The invention comprises a production method for an intensely crimping composite thread, in particular a BCF bi-component thread, from at least a first polymer and a second polymer, or a plurality of polymers.
The polymer combination is chosen in such a way that self-crimping of the composite thread by tension and/or temperature can be initiated by means of a mechanical and/or thermal crimping initiation. This can be achieved, for example, in that the composite thread is drafted to the extent that self-crimping is actively initiated.
Besides the mechanical initiation of self-crimping, the latter can also be thermally initiated by way of temperature.
In both cases, self-crimping is initiated by an additional step which has to be actively carried out. Self-crimping would otherwise not take place without this step.
According to a particular design embodiment of the method, the active crimping initiation of self-crimping is mechanically initiated by applying a predetermined tension variable to the composite thread, wherein a predetermined tensile stress is applied to the composite thread.
In order to initiate self-crimping, which is finer and of better quality in comparison to compression-crimping, a mechanical crimping initiation is preferably applied to the composite thread, for example in that the composite thread emanating from the cooling drum is routed via an additional drafting unit, and a predetermined tensile stress with a predetermined threshold value is applied to the composite thread.
Alternatively or additionally to the mechanical initiation of the bi-component thread crimping, the bi-component thread crimping can also be thermally activated.
In a further, particularly preferred, design embodiment of the method, the active crimping initiation of self-crimping is initiated thermally by heating, whereby a predetermined temperature variable is applied to the composite thread.
In order to initiate self-crimping, which is finer and of better quality in comparison to compression-crimping, a thermal crimping initiation is preferably applied to the composite thread, for example in that the composite thread is heated on the cooling drum by way of a heating installation. The heating then initiates self-crimping of the composite thread so as to form a crimped composite thread.
For this purpose, once the plug has cooled on the cooling drum, said plug can once again be heated at a temperature which is correspondingly lower than a compression-texturising temperature during compression-texturising.
Alternatively, heating by means of the heating installation can also take place between the cooling drum and a drafting unit.
In a particularly preferred design embodiment of the method, the composite thread is configured to be trilobal in shape, and/or each trilobal portion has in each case a first, a second and/or a third polymer melt.
A trilobal cross section of the composite thread is understood to mean a cross section with three lobes, similar to a clover leaf. Cross-sectional shape portions of the trilobal cross section are preferably designed in such a way that at least two of the three cross-sectional shape portions have in each case a first polymer and a second polymer with different self-crimping properties.
In a particularly preferred design embodiment of the method, the first polymer melt has a different viscosity than the second polymer melt.
It is important for activatable self-crimping that the first polymer melt and the second polymer melt each have different viscosities. Owing to the different viscosities, the first and the second polymer melt are supplied to the melt-spinning device at different flow rates, for example by pumps.
In a further, particularly preferred, design embodiment of the method, the tensile stress on the composite thread is initiated by means of a drafting unit, wherein a tensile stress, in particular in the range from 1 to 4.5 cN/dtex, which reaches a predetermined threshold value that initiates self-crimping is applied to the composite thread by means of the drafting unit, wherein the variable of the threshold value determines the degree of self-crimping.
A drafting unit which has a least one godet and/or an idler roller about which the composite thread is able to be wound at least in portions is preferably provided for initiating self-crimping. The godet is operated at a higher rotating speed than the godets disposed upstream thereof in the thread running direction, so that tensile stress is able to be generated in the composite thread. If the tensile stress exceeds a specific threshold value, self-crimping of the composite thread is activated and initiated.
The idler roller is preferably without a drive and serves for guiding the composite thread.
The godet is preferably not heated, but may also be heated. The godet can be heated in such a way that thermal self-crimping is also able to be initiated by the heating effect of the godet.
Alternatively, a thread brake which is positioned behind the cooling drum can also be used.
Alternatively, crimping can also be initiated by an additional godet pair which is positioned in front of compression-texturising. The godet pair has a first godet and a second godet which can both be heatable and may have a dedicated drive which is able to be open-loop and/or closed-loop controlled. The godets preferably have identical diameters.
According to a particular design embodiment of the method, the tensile stress which, for initiating self-crimping, is applied to the composite thread by means of a drafting unit is greater than a tension which is applied to the composite thread for drafting by a drafting unit.
The drafting units for drafting the composite thread are operated at a lower rotating speed than the drafting units for initiating self-crimping. In this way, a different tensile stress also acts on the composite thread.
In a particularly preferred design embodiment of the method, self-crimping of the composite thread is initiated by means of heating by means of a heating installation, wherein self-crimping is initiated at a predetermined temperature variable in the composite thread, in particular at temperature variable in the range from 100 to 150° C., wherein the variable of the temperature determines the degree of self-crimping.
Self-crimping of the composite thread can also be activated by a thermal crimping initiation, in particular once compression-texturising has taken place. Provided for this purpose is an additional heating installation which can be positioned at the cooling drum, for example, or downstream of the cooling drum in the thread running direction.
The preferred temperature for initiating self-crimping is a temperature variable in the range from 100 to 150° C., to which the composite thread is to be heated. The heating installation can be open-loop and/or closed-loop controlled.
Further temperature controlling in the method takes place according to the polymers and can take place at the same temperature level as is normally used in compression-texturising down to room temperature.
In a particularly preferred design embodiment of the method, the first and the second polymer melt are extruded in a melt-spinning device and are spun so as to for a plurality of composite filaments which are cooled so as to form a partially crystalline structure and are converged at a convergence point so as to form a composite thread which is drafted in a first drafting device so as to form a preliminary drafted composite thread, wherein self-crimping in the composite thread is initiated in subsequent steps by applying a predetermined mechanical tension variable and/or a predetermined temperature variable so that a crimped composite thread is formed.
The plurality of composite filaments are combined at a convergence point, so as to form a composite thread.
According to a particular design embodiment of the method, the active crimping initiation of self-crimping of the composite thread is initiated before and/or after compression-crimping, wherein the composite thread during compression-crimping is compressed in the thread during direction in a compression-crimping installation, wherein the compression of the composite thread initiates crimping.
In terms of the device, this object is achieved according to the invention by a device having the features according to claim 11.
Provided according to one aspect of the invention is a device for producing a crimped composite thread, which is specified for carrying out the method according to at least one of the preceding design embodiments, wherein the device has an installation for the active initiation of self-crimping of the composite thread.
According to a particular design embodiment of the device, the installation for the active initiation of self-crimping has a drafting device for generating tensile stress in the composite thread, and/or has a heating installation for generating an increase in temperature in the composite thread.
In terms of the system, this object is achieved by a system having the features according to claim 13.
Provided according to one aspect of the invention is a system for producing a crimped composite thread from a BCF yarn for carpet yarn, which is specified for carrying out the method according to at least one of the preceding design embodiments, and/or has at least one of the devices according to at least one of the preceding design embodiments.
The device according to the invention will be explained in more detail hereunder by means of several exemplary embodiments of the device according to the invention and of the method according to the invention, with reference to the appended figures.
In the figures:
The composite thread KF is usually spun from at least a first polymer melt 80 and a second polymer melt 81 next to one another by means of a melt-spinning device 2, so that the composite thread KF is formed with at least two portions.
Thereafter, drafting takes place in a drafting step D1 in which orienting the previously randomly arranged chain molecules so as to form oriented chain molecules is performed.
Mechanically applied crimping can then be caused by means of a compression-texturising installation 22, in that the composite thread KF is compressed in a compression chamber of the compression-texturising installation 22 in such a way that a loop yarn is created, whereby the filaments of the composite thread KF are kinked, this causing texturising, or crimping, of the composite thread KF.
The composite thread KF can thereafter be deposited onto a cooling drum 12, or cooling roller 12, so that the internal temperature of the composite thread KF is below the glass transition temperature and the texturising previously generated, hereunder also referred to as crimping, is set.
In the device having the compression-texturising installation 22 shown in
The device shown in
The two, or the plurality of, polymers can be of the same polymer type (e.g. two PETs with different proportions of IV and/or TiO2), or be different polymer types (e.g. PET and PTT). The polymer combination of the composite thread KF is chosen in such a way that self-crimping of the composite thread KF can be initiated by introducing tensile stress and/or temperature into the composite thread KF.
The plastics material chips of the first and of the second polymer store 30, 32 are in each case separately processed in a first extruder 1.1 and a second extruder 1.2 so as to form a first and a second polymer melt 80, 81, and are supplied by way of a separate melt line 34 to a melt-spinning device 2 by means of a first and a second melt pump 36, 36.
The first and the second polymer melt are arranged next to one another, in particular side-by-side, in portions above capillaries so as to form a thread in such a way that a composite thread KF is formed. The composite threads can be combined at a convergence point 44 so as to form a thread F.
After the convergence point 44, the composite thread KF is preferably guided over a preparation installation 4 and provided with a preparation agent. The preparation agent minimises friction, ensures static discharging, and facilitates transportation of the composite thread KF.
The thread running direction F runs from the melt-spinning installation 2 towards a take-up winding device 20.
In a first drafting zone D1, or in a first drafting step D1, the composite threads KF are drawn from the melt-spinning installation 2 by means of an inlet unit 6 having an idler roller 60 and a godet 61, and are drafted by a first drafting unit 8 and a second drafting unit 10, each consisting of one godet pair.
After the drafting step D1, in a texturising step T1, the composite thread is compressed in a compression-texturising installation 22, as a result of which the composite thread KF is crimped by compression.
After the texturising step T1, the composite thread KF is guided over a cooling drum 12, whereby the composite thread KF is cooled to a predetermined temperature in a cooling zone C1.
After the cooling step in the cooling zone C1, relaxing takes place in a relaxing zone R1. In the process, the crimped composite thread KKF is also interlaced by means of an interlacing installation 18 in such a way that entanglement knots are formed in the crimped composite thread KKF, so that the crimped composite threads KKF remain permanently combined and held so as to form an overall thread.
The relaxing zone R1 has a first relaxing unit 14 and a second relaxing unit 16. The interlacing installation 18 is preferably positioned between the first relaxing unit 14 and the second relaxing unit 16.
The drafted, texturised and relaxed overall thread is thereafter wound in a take-up winding device 20 so as to form a package for further processing such as, for example, to form a carpet.
Exemplary embodiments of the device according to the invention and of the method according to the invention for producing a crimped composite thread KKF with actively initiated self-crimping SK are described in
The crimped composite thread KKF of the exemplary embodiments described in
The features described in
However, not all features of the exemplary embodiments shown in
Described in
The mechanically actively initiated self-crimping SK is initiated by means of tensile stress with a predetermined variable, which is applied to the composite thread KF by means of additional godets, this being indicated by the reference sign SK which indicates the position of the mechanical active initiation of self-crimping SK in the respective exemplary embodiments of the device, or in the respective exemplary embodiments of the method, in
The thermally actively initiated self-crimping is initiated by an additional heating installation 50 which acts on the composite thread KF, this being indicated by the reference sign SK which indicates the position of the thermal initiation of self-crimping SK in the respective exemplary embodiments of the device, or in the respective exemplary embodiments of the method, in
Self-crimping SK of the composite thread KF can advantageously be initiated at any arbitrary position within the production process, or within the device of
In other words, self-crimping SK can be initiated by mechanical and/or thermal activation at a predetermined position with the device. The initiation of self-crimping SK can take place with mechanical and/or thermal means, also by means of the compression-texturising installation 22 as illustrated in the exemplary embodiments in
The invention comprises a method and a device for producing a very intensely self-crimping composite thread KF from at least two, or a plurality of, polymers 80, 81. The activatable self-crimping SK of the composite thread KF improves the quality of crimping. Moreover, polymer melt 80, 81 can be effectively saved in the process, as a result of which a composite thread KKF with improved crimping quality can be produced with less material.
Particularly effective crimping of the composite thread KF is possible by means of the devices described hereunder, whereby a smaller quantity of the respective polymer melt is simultaneously required in the process.
The components and features with the identical reference signs from
The features and devices of the method according to the invention and of the device according to the invention are described in particular hereunder, said features and devices potentially also being part of the device of
The method shown in
A further embodiment is shown drawn with dashed lines in
The third, and the fourth, drafting unit 40.1, 40.2 are adjusted in such a manner that a predetermined tensile stress acts on the composite thread KF, said tensile stress causing corresponding self-crimping SK of the composite thread KF.
In order for the self-crimping property to be effective, a first polymer melt 80 and a second polymer melt 81 with different viscosities are in each case supplied at different flow rates to the melt-spinning installation 2 by way of the first and the second extruder 1.1 and 1.2 and the associated melt lines 34, said melt-spinning installation 2 by way of its capillaries and spinning nozzles then generating a side-by-side composite thread KF which has the properties of activatable self-crimping SK
The godet pair 42 is able to be assigned to a third drafting unit 42, and has a first and a second godet 71, 72. The third drafting unit 42 is positioned in a second drafting zone D2 for carrying out a second drafting step D2, which causes additional mechanical drafting on the composite thread KF and leads to self-crimping SK being initiated.
The crimped composite thread KKF in the thread running direction F in the relaxing zone R1 is thereafter additionally compression-crimped T1 in the compression-texturising installation 22, and thereafter cooled in a cooling step C1 at the cooling drum 12.
In further steps, the self-crimped and the compression-crimped composite thread KKF is relaxed in a first relaxing unit 14 and a second relaxing unit 16, and is provided with entanglement knots in an interlacing installation 18. The interlacing installation 18 is positioned between the first and the second relaxing unit 14, 16.
The first relaxing unit 14 and the second relaxing unit 16 each have an idler roller 60 and a godet 61.
The godets 71, 72, 61 can be heated and/or not heated. In this way, further temperature-controlling is possible in the method and can be closed-loop controlled so as to correspond to the polymers used and preferably be performed according to the degree of crimping, right down to room temperature.
Initiating self-crimping SK in the composite thread KF at the respective position can optionally also be activated and initiated by way of the heated godets 71, 72 and 61.
The activated self-crimping SK by mechanical drafting can be provided with associated sensors which detect the tensile stress introduced into the composite thread KF and the initiated self-crimping SK in such a way that it is possible to closed-loop control self-crimping and the degree of self-crimping SK.
The godet pair 42.1, illustrated by dashed lines, is optional.
The respective godet pair 42.1, or 42.2, can also be heated so that thermal activation of self-crimping SK of the composite thread KF is also possible besides the mechanical activation of self-crimping SK.
The second drafting zone D2 subdivides the relaxing zone R into a first relaxing zone R1 and into a second relaxing zone R2.
The first relaxing zone R1 has the compression-texturising installation 22 and the cooling drum 12, which are disposed behind one another in the thread running direction F.
The first relaxing zone R2 has the first relaxing unit 14 and the second relaxing unit 16 and the interlacing installation 18. The interlacing installation 18 in the thread running direction F is positioned between the first relaxing unit 14 and the second relaxing unit 18.
The exemplary embodiment shown in
The heating installation 50 incorporates into the composite thread a predetermined temperature in the range from 100 to 150° C., which causes initiation of self-crimping SK. The variable of the incorporated temperature can also determine the degree of self-crimping SK. The heating installation 50 can be provided with associated sensors which detect the temperature incorporated into the composite thread KF and the initiated self-crimping SK in such a way that it is possible to closed-loop control self-crimping and the degree of self-crimping SK.
The heating installation 50 can be provided with associated sensors which detect the temperature incorporated into the composite thread KF and the initiated self-crimping SK in such a way that it is possible to closed-loop control self-crimping and the degree of self-crimping SK.
The exemplary embodiments shown in
The exemplary embodiments proposed here, and the drafting zones D2 and heating zones H1 shown therein for initiating self-crimping SK, can also be combined with one another. In this way, the method and the device may also have a drafting zone D2 and a heating zone H1.
In a particularly preferred exemplary embodiment of the method, the first polymer melt 80 and the second polymer melt 81 are extruded in the melt-spinning device 2 in step S1, and in step S2 spun so as to form a plurality of composite filaments.
The number of capillaries in the melt-spinning device 2 determines the number of composite filaments.
In step S3, the plurality of composite filaments are cooled so as to form a partially crystalline structure. Cooling can be carried out by transverse and/or radial cooling in suitably specified cooling ducts, with air guided transversely to and/or in the thread running direction F.
In step S4, the plurality of composite filaments are combined at the convergence point 44 so as to form a composite thread KF.
In step S5, the combined composite thread KF is provided with a preparation oil in a preparation installation 4, which improves friction and processing of the composite thread KF and prevents, or at least minimises, static charging of the composite thread KF.
In a first drafting step D1, preliminary drafting of the composite thread KF by the first drafting device 6, 8, 10 takes place in step S6.
After drafting, compression-texturising, or compression-crimping T1, by the compression-texturising installation 22 can take place in step S7. In the process, the composite thread KF is crimped by compression T1 and compressed so as to form a plug.
In step S8, the plug is cooled on the cooling drum 12 in a cooling step C1.
In step S9, the plug is drafted and relaxed in a relaxing step R1 so as form a composite thread KF that is able to be entangled, and provided with entanglement knots which combine and hold together the filaments of the crimped composite thread KKF for further processing.
Finally, the relaxed and entangled composite thread KKF is wound so as to form a wound package by means of a take-up winding device 20 in step S10.
The activation of self-crimping SK by applying a predetermined mechanical tensile stress variable in a second drafting step D2, and/or by applying a predetermined temperature variable in a heating step H1, preferably takes place before, during and/or after cooling step C1.
Shown in
Shown in
In the exemplary embodiment shown in
Shown in
Self-crimping SK can also be initiated and activated at other positions of the device in the thread running direction F, and in other method steps in the production method.
In an exemplary embodiment not illustrated, the activation of self-crimping SK is only mechanical or thermal, or mechanical and thermal, and no compression-crimping is necessary.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 002 303.5 | Jun 2023 | DE | national |
