Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
  • D02G1/20—Combinations of two or more of the above-mentioned operations or devices; After-treatments for fixing crimp or curl
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
  • D02G1/02—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist
  • D02G1/04—Devices for imparting false twist
  • D02G1/08—Rollers or other friction causing elements
  • D02G1/087—Rollers or other friction causing elements between the flanks of rotating discs

Definitions

• the present invention relates to false twist textured yarns and a method for producing the same by melt spinning polymers and subsequent false twist texturing.
• False-twist textured yarns are usually produced from melt-spinnable polymers using template materials.
• the chemical and physical properties of such polymers are reflected in the so-called glass transition temperature.
• the latter is to be understood (cf.Römpp, Chemielexikon, Georg Thieme Verlag (1995), 9th edition, Vol. 2, p. 1587) the temperature at which amorphous or partially crystalline polymers change from the liquid or rubber-elastic state to the hard-elastic or glassy state Change state or vice versa.
• the cause of the phenomenon of the glass transition temperature which is also referred to as the glass transition temperature or glass transition temperature, is the freezing or thawing of the Brownian molecular movements of longer chain segments of the polymers.
• the glass transition temperature is therefore often referred to as the glass transition temperature, softening temperature or point or, since the transitions usually take place in a temperature range, as the glass transition interval or softening range.
• the glass transition temperature gives important clues about the dimensional stability of the polymers during heating and thus statements about the temperature range in which the polymers can be used.
• the glass transition temperature can be determined, among other things, using dilatometric, dielectric, dynamic-mechanical or refractory measurements or with the aid of NMR spectroscopy.
• the glass transition temperature depends on Among other things, the chemical structure of the polymers, their molecular weight, the flexibility of the polymer chains and the pressure to which the polymer system is exposed.
• stable operating conditions are particularly important when producing false twists in the false twist unit Texturing machines essential.
• the false twist units used are, for example, vertical three-axis friction disc units or horizontal-axis double disc units, such as BARMAG Ringtex units, but also strappy units, for example from MURATA. Magnetic spindle units are also often used in older texturing machines.
• the false twist assembly provides the yarn with a so-called false twist on the feed side, which dissolves after passing through the false twist assembly, so that the resulting yarn has no real twists.
• the false twist on the feed side is fixed in a heating unit, so that the resulting textured yarn is crimped due to the thermally fixed twist bends.
• a reduction in the so-called tilt tendency can be achieved by fixing the yarn in a second heating zone after the false twist unit.
• SET yarn In contrast to the HE yarn (highly elastic yarn) which is not thermally post-fixed, such a yarn is referred to as SET yarn, although it is also possible to reduce the tendency to crane using special anti-crane air nozzles without thermal post-fixing.
• the yarn is drawn with a suitable drawing ratio either in a separate process step in front of the texturing area, but mostly simultaneously within the texturing area.
• the textured yarn is loaded with a winding oil before the winding, which enables problem-free further processing, for example in the knitting mill, in the weaving mill or in the warp knitting mill.
• the spun original materials have to be provided with a spinning preparation specially developed for the texturing in order to enable safe and stable further processing on the texturing machines.
• the spin preparation here has the function, among other things, of a To ensure the integration of the individual filaments in the thread composite, which is primarily achieved by the adhesive effect of the spin preparation.
• the spin finish has an antistatic effect, so that the risk of the filaments being spread apart by electrostatic charging is reduced.
• the spin behavior can optimize the friction behavior of both the filaments with one another and the thread on the different thread guide elements.
• Spinning preparations are generally applied at one per mille to one percent and winding oils at five per mille to four percent, each based on the weight of the yarn.
• Both the spin finishes and the winding oils contain organic substances, for example mineral oils, white oils, ester oils, high molecular weight hydrocarbons, antistatic agents or ionic or nonionic surfactants. Such organic substances are often ecologically questionable and can lead to health problems such as eye or skin irritation and contact allergies.
• Both the spin finishes and the winding oils must therefore be removed from preliminary products, for example when dyeing texturing bobbins, or from end products, for example when finishing textiles of all kinds. The washing out of the spin finishes and the winding oils is polluting both in the aqueous medium and by chemical cleaning with a solvent and the more complicated and expensive the higher the required degree of cleaning.
• the preparation layer in the textured yarn can be further reduced to about half to two parts per thousand, but it is not possible to completely evaporate the preparation medium, because especially higher-boiling preparation layers prove to be the case with false twist Texturing prevailing temperatures as extremely stable and thus remain as an undesirable residue.
• textured yarns for sausage skin nets or for circular knitted hoses are produced in accordance with the procedure described above, the latter serving as filters around drainage pipes for soil drainage.
• European patent EP 0 305 808 B1 discloses a process for producing preparation-free chemical fibers by melt spinning high polymers with a glass transition temperature of over 100 ° C. and subsequent stretching of the filaments by means of preheating godets and at a predetermined stretching ratio, the filaments being subjected to a liquid before stretching be that can evaporate residue-free during the stretching process, and the temperature of the preheating godet is chosen to be at least 40 ° C higher than in the usual procedure of the preparation.
• the present invention is based on the object of providing a process for producing false-twist textured yarns by melt spinning polymers, in which not only special polymers which are complicated to produce but also standard polymers can be used, so that a broad spectrum of possible fields of application is ensured.
• the present invention furthermore aims at a method in which the false twist-textured yarns are produced in a preparation-free manner without impairing the properties of the finished products.
• This object is achieved in that the filaments melted from polymers and solidified after subsequent cooling are subjected to a liquid during the melt spinning process which evaporates without residue during the false twist texturing.
• polyester in particular polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), or alternatively polyamides, in particular PA6 or PA6.6, preferably being used.
• PET polyethylene terephthalate
• PBT polybutylene terephthalate
• PA6 or PA6.6 polyamides
• demineralized water as a liquid or, alternatively, alcohols, in particular, according to particularly advantageous developments of the method according to the invention
• Methanol, ethanol, glycol and / or glycerin, or their mixtures with water can be used. It is crucial that the selected liquid or liquid mixture evaporates at the temperature of the false twist texturing process. A further adjustment is to be made in such a way that the selected liquid or the selected liquid mixture does not dissolve the filaments obtained by melt spinning in the course of the process.
• the liquid can be applied in a metered manner by pumps using a preparation thread guide.
• application of the liquid is also conceivable by at least partially immersing the rolls so that the filaments running over the wetted surface of the rolls absorb a predetermined amount of liquid.
• the polymers are spun as multifilaments with a single filament fineness of approximately 1 to 10 dtex, in particular approximately 3 to 7 dtex, based on the textured yarn. If the value falls below the lower value of approximately 1 dtex, the filament breakage can be extremely disadvantageous, whereas exceeding the upper value of approximately 10 dtex in the spinning mill can cause problems as a result of undesirable core-shell structures during cooling can set different behavior of core and shell.
• the above-mentioned preferred fineness range of about 1 to 10 dtex further ensures that the properties of the finished products do not have an undesirable, because the handle is too hard.
• the filaments are expediently drawn before or during the false twist texturing in a ratio which corresponds to approximately 80 to 100% of the drawing ratio of prepared filaments produced analogously and is preferably approximately 1.3 to 3.0.
• the optimal stretching ratio at which the desired properties of the finished products are achieved is determined by the respective starting materials.
• false twist units with soft twist generators are used, for example vertically triaxial friction disk units can be used. It is also conceivable to use horizontal-axis double disc units, such as BARMAG Ringtex units, or strappy units, for example from MURATA. Magnetic spindle units can also be used in the method according to the invention. In this context, it should be noted the great importance of soft swirlers. For example, vertical triaxial units with PU disks of the disk combination 1-4-1 result in considerably less thread damage, i.e. significantly higher strength and elongation than units with ceramic disks of the disk combination 1-9-0.
• the yarn closure is increased by intermingling with air entangling agents, expediently with Airfix nozzles at one pressure from about 0.5 to 5.0 bar, in particular from about 1.0 to 3.0 bar.
• air entangling agents expediently with Airfix nozzles at one pressure from about 0.5 to 5.0 bar, in particular from about 1.0 to 3.0 bar.
• a sufficient intermingling effect is not achieved at a pressure below about 0.5 bar, whereas when the intermingling effect is exceeded about 5.0 bar the intermingling effect is so strong that the quality of the yarns is generally impaired.
• the polymers are expediently spun as filaments at temperatures from approximately 230 ° C. to 330 ° C., in particular from approximately 250 ° C. to 310 ° C. If the value falls below the lower value of approximately 230 ° C., the viscosity may be too high, so that optimal spinning is no longer possible. Exceeding the upper value of about 330 ° C, however, can cause undesirable decomposition phenomena.
• the optimal spinning temperature generally depends on the type and molecular weight of the polymer used.
• the filaments are advantageously false-twist textured at temperatures from approximately 170 ° C. to 230 ° C., in particular from approximately 180 ° C. to 210 ° C. If the temperature falls below the lower value of approximately 170 ° C., the thermal embossing effect or the desired crimp is generally too weak. Exceeding the upper value of around 230 ° C, on the other hand, can lead to undesired melting when texturing false twists.
• the false twist textured yarns can expediently be additionally fixed in at least one heating stage downstream of the false twist texturing.
• the tendency to fight can be with special anti-crane air nozzles be reduced if this should prove necessary.
• the present invention also relates to false twist textured yarns made according to the method set forth above, and to the use of liquid-spun melt-spun yarns for false twist texturing using yarns as defined above, and is hereinafter used described by examples.
• Examples 1 and 2 relate to the process according to the invention; for comparison, examples 3 and 4 are given according to the prior art. The corresponding results for the most important parameters of this comparison are finally shown in Table 1.
• a thirty-filament master yarn made of polyethylene terephthalate (PET) was spun at a temperature of 285 ° C on a classic godet spinning machine with a spinning titer of 405 dtex at a speed of 2,000 m / min. After the filaments had cooled in the blow shaft, about 2.5 percent demineralized water was applied to the thread instead of a spin finish by application by a preparation thread guide. Before passing the two S-shaped godets, the yarn was swirled in an Airfix device with an air pressure of 1.4 bar.
• PTT polyethylene terephthalate
• the original yarn was textured on a BARMAG-FK6 texturing machine at a draw ratio of 2.2, a heating temperature of 190 ° C. and a D / Y ratio of 2.15 at a speed of 400 m / min.
• Three-axis units with the disc combination 1-4-1 with PU working discs (hardness 85 shore A) were used.
• the yarn was additionally interlaced with BARMAG Type 76 Airfix nozzles at an air pressure of 2.0 bar, with the application of winding oil being dispensed with.
• the original material was spun out as in Example 1, but with a spinning titer of 260 dtex with roller oiling without spinning air fixation.
• the texturing was also carried out analogously to Example 1, but textured with an aspect ratio of 2.25 and at a speed of 500 m / min.
• Example 2 A template material analogous to Example 2 was used, but an 11% aqueous emulsion of the B ⁇ HME Filapan 7537 spinning preparation was applied instead of demineralized water. The preparation requirement was three per thousand.
• the original material was textured using an HE standard process without air fixation, with B ⁇ HME Isafil PE / R spooling oil being applied.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=7794799

Family Applications (1)

Country Status (2)

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• 1996
  • 1996-05-20 DE DE1996120274 patent/DE19620274C2/de not_active Expired - Fee Related
• 1997
  • 1997-05-16 EP EP97108025A patent/EP0808924A3/fr not_active Withdrawn

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