Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D7/00—Collecting the newly-spun products
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
  • D01D10/04—Supporting filaments or the like during their treatment
  • D01D10/0436—Supporting filaments or the like during their treatment while in continuous movement
  • D01D10/0454—Supporting filaments or the like during their treatment while in continuous movement using reels
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D13/00—Complete machines for producing artificial threads
  • D01D13/02—Elements of machines in combination
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof

Definitions

• the present invention relates to the surface adaptation of a roller to be employed in the production of cellulose filament yarns.
• Continuous filament yarns are widely used in the textile industry to produce fabrics with a distinct character compared to fabrics produced from yarns made using staple fibers.
• a continuous filament yarn is one in which all of the fibers are continuous throughout any length of the yarn.
• a continuous filament yarn will commonly consist of 10 to 300 or more individual filaments which are all parallel to each other and the axis of the yarn when produced.
• the yarn is produced by extruding a solution or melt of a polymer or a polymer derivative and then winding the yarn produced onto a bobbin or reel or by forming a cake by centrifugal winding.
• Synthetic polymer continuous filament yarns are common.
• nylon, polyester and polypropylene continuous filament yarns are used in a wide variety of fabrics. They are produced by melt spinning a molten polymer through a spinneret with a number of holes corresponding to the number of filaments required in the yarn produced. After the molten polymer has started to solidify, the yarn may be drawn to orient the polymer molecules and improve the properties of the yarn.
• Continuous filament yarns can also be spun from cellulose derivatives such as cellulose diacetate and cellulose triacetate by dry spinning. The polymer is dissolved in a suitable solvent and then extruded through a spinneret. The solvent evaporates quickly after extrusion causing the polymer to precipitate in the form of filaments forming a yarn. The newly produced yarn may be drawn to orient the polymer molecules.
• Lyocell technology is a technology based on the direct dissolution of cellulose wood pulp or other cellulose-based feedstock in a polar solvent (for example n-methyl morpholine n-oxide, hereinafter referred to as ‘amine oxide’) to produce a viscous highly shear-thinning solution which can be formed into a range of useful cellulose-based materials.
• a polar solvent for example n-methyl morpholine n-oxide, hereinafter referred to as ‘amine oxide’
• the technology is used to produce a family of cellulose staple fibers (commercially available from Lenzing AG, Lenzing, Austria under the trademark TENCEL®) which are widely used in the textile and nonwovens industries.
• EP 823945 B1 discloses a process for the manufacture of cellulose fibers, which comprises the extrusion and coagulation of a cellulose spinning solution in accordance with the lyocell process, mandatorily comprising a step of drawing the filaments and cutting the filaments into cellulose fibers, which may be used in various fields of application. Process step of drawing the coagulated cellulose filaments is essential according to the teaching of this prior art technology in order to obtain in particular staple fibers with a desired balance of properties.
• EP 0 853 146 A2 discloses a process for the preparation of cellulosed based fibers. According to the teaching of this document two different raw materials having widely differing molecular weights are mixed in order to obtain fibers.
• WO 98/06754 discloses a similar method, which require that the two different raw materials are first dissolved separately, before admixing the prepared solution to obtain a spinning solution.
• DE 199 54 152 A1 discloses a method of preparing fibers, wherein spinning solutions having a relatively low temperature are employed.
• WO 97/23667 discloses a process for manufacturing lyocell fibers.
• DE 102005 040 001 A1 discloses a device which may be used to produce lyocell fibers. O. Santos et al. disclose in Journal of Food Engineering 64 (2004), 63-79 information about modified stainless steel surfaces targeted to reduce fouling.
• the filaments and/or filament bundles After the initial filament coagulation in a coagulation bath, are transported by means of various rollers to the further stages of the process, such as washing etc.. Initially the filaments or filament bundles are still susceptible to damage and/or may undesirably adhere to each other when they come into contact, so that care has to be taken that the passage of the filaments or filament bundles around the rollers does not lead to undesired impact on the filaments produced.
• Example of such negative impacts are slippage due to unsatisfactory adhesion to the roller surface, axial movement of the filaments or filament bundles on the roller surface (i.e.
• the present invention provides the roller as defined in claim 1 as well as the method according to claim 2.
• Preferred embodiments are given in claims 3 to 11 and the specification, as well as in use claims 12 to 15.
• the lyocell process comprises, after preparation of the spinning solution, the extrusion of filaments through nozzles, followed in most cases by an initial cooling in an air gap, followed by coagulation in a bath. Thereafter the filaments or filament bundles are taken up, usually by a guidance roller to guide the product to the further process steps, such as liquid removal and washing steps. Also during these stages the filaments or filament bundles are moved to the next process steps by means of rollers. Additional stages of filament production may be stages to apply further substances to the filament or the filament yarn, such as application of finishing agents etc.
• these requirements for the roller surface are not easily fulfilled, as the different requirements due to the fiber nature are conflicting.
• these requirements may be different at the different production stages identified above.
• the adhesion to the surface should be as high as possible.
• the filaments or filament bundles have to detach themselves from the roller surface (i.e. release of the filaments and/or filament bundles from the roller surface without exerting undesired high mechanical forces on the filaments or filament bundles), which requires that adhesion is as low as possible. Accordingly, it is required to find a solution in order to comply with these conflicting demands.
• the surface of the roller to be in contact with the lyocell filament or filament bundle is selected so that the roller surface comprises first sections displaying a surface tension so that, depending on the liquid adhering to the filament or yarn, one of the following conditions is fulfilled: a) surface tension of the first sections is in the range of from 0.25 to 3.5 times, preferably 0.35 to 2.5 times, more preferably 0.4 to 0.8 times the surface tension of the liquid, provided that the surface tension of the liquid is 45 mN/m or more; or b) surface tension of the first sections is in the range of from 0.5 to 10 times, preferably 0.8 to 2.5, more preferably 1 to 2 times the surface tension of the liquid, provided that the surface tension of the liquid is less than 45 mN/m.
• the principle as outlined above means that (taking water as the washing liquid, having a surface tension of about 72.8 mN/m) the first sections may have a surface tension of from 254.8 mN/m to 18.2 mN/m.
• a low surface tension liquid such as an avivage composition, which may for example have a surface tension of about 29 mN/m
• the range of surface tension for the first sections may range from 14,5 mN/m to 290 mN/m.
• the roller surface may also comprise second sections having a surface tension lower that the surface tension of the first sections. This may in particular aid with the proper detachment of the filament or filament bundles from the roller surface, which further avoids undesired effects with regard to the filament or filament bundle, such as breaking of filaments etc..
• the roller in accordance with the present invention may comprise second surface sections, which allow an even better removal or detachment of the filament or filament bundle from the roller surface without detrimental effect on the filament or filament bundle. In accordance with the present invention, this is ensured by providing appropriate detachment sections over the surface of the roller, preferably in regular intervals, wherein these sections are characterized in that these display a surface tension of less than the surface tension of the first sections.
• these second sections display a surface tension, which is at least 5%, more preferable at least 10%, even more preferably at least 25% lower than the surface tension of the first sections.
• the difference is at least 10 mN/m, preferably at least 25 mN/m.
• the surface tension of the second sections may be in a range in principle covered by the ranges defined for the first sections. However, as long as the surface tension of the second sections is lower than the surface tension of the first sections, both types of sections can be clearly defined and it is possible to distinguish between the two types of surface sections.
• the second sections having another structure (surface structure, such as roughness or a different three dimensional structure, such as recesses or creases) or being made from a different material this is more readily apparent.
• the second sections are able to serve the desired purpose (aiding with the detachment of the filament/yarn from the roller), as during use these differences are sufficient (even if the absolute values would still be within the surface tension range defined for the first sections).
• creases or grooves preferably extending parallel to the axis of the roller, on the roller surface.
• the (theoretical) surface of the roller changes from the principle high surface tension material employed for the roller (fulfilling the requirements identified above required for good adhesion) by means of simply providing an absent surface (i.e. air).
• an “absent” surface is considered in the context of the present invention as a material having a low surface tension.
• these creases or grooves are filled with water, which likewise provides a surface tension within the required range.
• a further option is the reduction of the surface roughness, as also this will lead to surface tension values for the detachment sections in the range as identified above.
• creases or grooves preferably these are provided with a breadth (i.e. the dimension perpendicular to the axis of the roller) in the range of from 0.5 to 5 mm, preferably 1.5 to 2.5 mm.
• the distance between two such grooves or creases may be in the range of from 2 to 25 mm, preferably 2.5 to 10 mm, more preferably 3 to 4.5 mm.
• This dimension may also be employed with respect to the coating of the roller surface in order to create detachment points, for example by using synthetic polymers.
• first sections typically are made from the principle material used for roller surface manufacture, it often is commercially beneficial if these surface sections make up the majority of the roller surface.
• Typical first section proportions in relation with the overall roller surface are from 40 to 95%, preferably from 50 to 80%, including from 60 to 70%. In embodiments, the roller surface consists of the first sections only.
• the creases and grooves as well as the micro-cracks or micro-fissures to be provided on the roller surface may be prepared in accordance with methods known to the skilled person, by appropriate surface treatment methods, such as etching processes.
• the skilled person is in a position to coat the roller surface, for example, with synthetic polymers in order to create coatings providing the detachments sections.
• the provision of sections with reduced surface roughness is likewise well within the usual practice of the skilled person.
• Suitable materials for the high surface tension section of the roller surface are in particular metals, in particular iron based materials, stainless steel, chromium, aluminum etc.. However, it has been found that as long as the surface tension requirement is fulfilled, that also other materials may be employed, such as ceramics.
• the materials suitable for providing the detachment sections typically, in case that not simply creases or grooves are provided, are synthetic polymers, such as PVC, PA, polyolefins, PTFE, PET, PMMA, etc. In order to facilitate production of a roller surface as provided by the present invention, the use of thermoplastic polymers is preferred.
• the present invention proposes to use a roller as defined and described herein during lyocell filament production, in particular as the guidance roller taking up the filaments or filament bundles after coagulation, but also for any subsequent roller employed for example during liquid removal, washing or drying operations.
• a roller as defined and described herein during lyocell filament production, in particular as the guidance roller taking up the filaments or filament bundles after coagulation, but also for any subsequent roller employed for example during liquid removal, washing or drying operations.
• the surface tension of the roller was determined according to the methodology described below. Using rollers having surfaces with surface tensions of about 37 mN/m (surface tension of roller about 0.5 times the surface tension of the washing liquid) high quality lyocell filament yarns could be produced without any problems concerning filament breakage etc. even during high speed filament production. Similar results were obtained using roller surfaces with surface tensions of about 44, 56, 93 and 185 mN/m, i.e. with factors 0.6, 0.75, 1.3 and 2.4.
• Ethylene glycol for analysis (purity > 99.5%, available for example from Merck: K42538921
• Diiodomethane (purity > 99%, stabilized, available for example from Acros organics:

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Rolls And Other Rotary Bodies (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2019
  • 2019-10-23 EP EP19204806.4A patent/EP3812489A1/de not_active Withdrawn
• 2020
  • 2020-10-21 BR BR112022005966A patent/BR112022005966A2/pt not_active Application Discontinuation
  • 2020-10-21 PT PT207929886T patent/PT4048831T/pt unknown
  • 2020-10-21 FI FIEP20792988.6T patent/FI4048831T3/fi active
  • 2020-10-21 US US17/771,283 patent/US20220396899A1/en not_active Abandoned
  • 2020-10-21 JP JP2022524060A patent/JP2022553731A/ja active Pending
  • 2020-10-21 ES ES20792988T patent/ES3061387T3/es active Active
  • 2020-10-21 WO PCT/EP2020/079560 patent/WO2021078768A1/en not_active Ceased
  • 2020-10-21 EP EP20792988.6A patent/EP4048831B1/de active Active
  • 2020-10-21 KR KR1020227017333A patent/KR20220082084A/ko active Pending
  • 2020-10-21 CN CN202080074059.9A patent/CN114585778A/zh active Pending
  • 2020-10-22 TW TW109136748A patent/TWI828947B/zh active
• 2024
  • 2024-12-30 US US19/005,076 patent/US20250129519A1/en active Pending

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