Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02J—FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE
  • D02J1/00—Modifying the structure or properties resulting from a particular structure; Modifying, retaining, or restoring the physical form or cross-sectional shape, e.g. by use of dies or squeeze rollers
  • D02J1/22—Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch
• • 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
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/12—Stretch-spinning methods
  • D01D5/16—Stretch-spinning methods using rollers, or like mechanical devices, e.g. snubbing pins

Definitions

• the present invention relates to a method and a device for producing industrial yarns by spinning stretched melt-spun polyester filaments at speeds of 3000 to 6000 m / min, the stretching being carried out by means of a delivery unit and a drawing frame.
• Polyester filaments for use in the industrial sector ie in a total titer range of over 500 dtex and a strength of at least 60 cN / tex, are predominantly produced using the spin-stretching process, which has proven to be very cost-effective. Further cost savings can be achieved by increasing the productivity of the plants by increasing the production speed with final speeds in the range of 6,000 m / min and above. It has also been found that filaments with new properties can also be obtained by increasing the spinning speed.
• a spin draw process of the type is known from US-A-3,790,995. A single-stage spin-stretching process for the production of polyester filaments is described there.
• This process is based on the stretching between two godet duos in such a way that the stretching process on the thread already begins a few loops before leaving the delivery plant due to a lack of adhesion between the thread and the godet surface.
• the stretching process is likewise only ended a few loops after running onto the drafting system. This is made possible by the thread-touching roughened surfaces of the godets, which allows a slip between the filament and the roll surface. This effectively extends the stretching zone to a multiple of the geometric distance between the godet duos. Accordingly, more time is also available for the orientation of the macrol molecules forming the thread mass. In this way a higher degree of orientation is achieved than when using roller surfaces with highly polished surfaces. High-gloss polished surfaces enable maximum adhesion between the thread and the roller surface.
• Extending the stretching time by increasing the distance between the pairs of godets has the decisive disadvantage that the overall height of the production facility would have to be increased to an intolerable level, so that the system could no longer be operated without aids such as lifting platforms and the like.
• the distance between the godet pairs can be reduced by single or multiple deflection of the thread path within the stretching zone, but with some serious disadvantages. Deflections with thread guiding elements within the stretching zone are undesirable and problematic. Deflection pins and the like become very hot due to the high thread tension in the drawing zone and lead to broken filaments after a short operating time. With non-driven deflection rollers, the thread run between the godet pairs can be lengthened, but numerous filament breaks occur, which make the process uneconomical.
• Another object is to provide an improved device with which highly oriented industrial yarns can be manufactured.
• the object is achieved according to the invention in that the thread is deflected between the delivery mechanism and the drafting system and is decelerated by means of at least one thread end braking device.
• the thread deflection is brought about by braked rollers.
• the large vi and v 2 denote the speeds of the Delivery plant or drafting system. The speed must therefore be lower than the thread running speed at the place where they touch the deflection rollers. This can only be carried out by means of rollers which are provided with a structured surface which enables slippage between the thread and the roller surface.
• a further improvement in the stretchability was achieved by additionally heating the deflection rollers to a jacket temperature between 150 and 210 ° C.
• a deflection roller which is wrapped by the thread at almost 180 °, may be sufficient.
• the main advantage of this procedure is that the deflection rollers can be very short, since they only have to offer space for one, at most two, thread running tracks. This is favorable from an investment perspective, since the costs for rolls with a larger working width, as required for multiple wrapping, are much higher.
• Figure 1 shows a diagram of the arrangement according to the invention.
• J_ denotes a delivery system consisting of a heated, driven one
• Drafting system 2 consists of a heatable driven godet 21 and a heatable driven godet 22. Between the delivery unit J_ and the drafting unit 2 . a thread braking device 3_ is arranged. The thread brake device 3_ is equipped with a heatable and brakeable deflection roller 31 and optionally with a heatable and brakeable deflection roller 32, which in turn are located within a thermally insulated housing 33.
• the undrawn filament 4 comes from in a known manner a known spinning device, not shown; the drawn filament 4 'is taken up in a known manner by a winding device, not shown, for example a winder.
• the thread braking device 3 forms the extension of the stretching zone lying in between.
• the filament 4 comes in a manner not shown from a conventional device for melt spinning, cooling and preparation, wraps around the supply mechanism J_ running at a peripheral speed several times, whereby it is heated up in accordance with the set jacket temperature, then reaches the thread braking device .3, whose deflection rollers 31, 32 braked to the circumferential speed v 3 are wrapped around once, and is finally supported by the drafting device 2 running at the circumferential speed v 2 . stretched according to a set speed ratio (v 2 / v,).
• the filament 4 ' is then wound up in a conventional manner, possibly after passing through another godet duo (not shown).
• the deflection rollers 31, 32 must not be smooth. They have a structured surface to allow slippage between the filament 4 and the roll surface.
• the mean roughness of the surface of the deflection rollers 31, 32 is expediently in the range from 2.5 to 3.5 micrometers. To reduce the abrasion, this is expediently a hard metal surface or a coating with a ceramic or other abrasion resistant materials. To avoid fibril damage, the surface structure must be free of sharp bumps. It is appropriately structured as an "orange peel".
• the required braking of the deflection rollers 31 and 32 can be done purely mechanically.
• the peripheral speed of the deflection rollers 31 and 32 is kept constant with the aid of a known control device.
• the use of controlled frequency drives has proven particularly successful.
• such drive units must be equipped with a device for recuperating the braking power or with another type of energy dissipation.
• the required braking power can be up to 1 watt / dtex of the drawn filament.
• the melt throughput per hole was 2.45 g / min.
• the melt jets were cooled in a conventional manner and provided with an anhydrous preparation. They then became two filament bundles summarized and withdrawn from the spinning shaft at a speed v of 3'100 m / min through the delivery unit 1 with godets 11, 12 tempered to 120 ° C.
• the delivery plant J_ was wrapped six times by threads 4. After a single wrap around the deflection rollers 31, 32 of the thread braking device 3_, the threads 4 became the drafting device 2 .
• the stretch godets 21, 22 were wrapped eight times by the threads 4.
• the drafting zone between delivery unit J and drafting unit 2 was created by the deflection device 3_ . extended by 1.5 m.
• the deflection rollers 31, 32 had a diameter of 190 mm and were provided with a ceramic-coated surface with a mean roughness value of 3.5 micrometers. They were heated to a temperature of 180 ° C. and were braked to a speed v 3 of 5,190 m / min with a braking torque of 1 Nm each. The total braking power was 1.82 kW.
• the threads were cooled in a further duo at 120 ° C. and finally wound up at a tension of 250 cN.
• the filaments had a titer of 1100 dtex.
• Polyethylene terephthalate of the same type as in Example 1 was melted, spun and drawn in the same manner, with the difference that the melt throughput was 3.21 g / min. This resulted in a final titer of 1,404 dtex of the drawn yarn.
• the deflection rollers 31, 32 of the thread braking device _3 had to be acted upon with a braking torque of 1.25 Nm each in order to achieve the same peripheral speed as in Example 1.
• the total braking power was 2.28 kW.
• Polyester granulate (polyethylene terephthalate) with a viscosity index of 114 was extruded as in Example 1 and spun into two filament yarns with 256 filaments each.
• the multifilaments were withdrawn from the spinning shaft at 3,100 m / min.
• the optical birefringence (DB) of the filaments thus spun was 0.065.
• the filament yarns were fed to a feed plant J_ at 3,130 m / min and a temperature of 80 ° C., which was looped six times.
• the drafting system 2 had a peripheral speed of 5776 m / min and a temperature of 240 ° C. It was wrapped in threads eight times.
• the thread braking device consisted of the two electrically braked deflection rollers 31, 32, with a temperature of 200 ° C. within a thermally insulated housing, which were once wrapped in the filaments. They were braked to a speed of 5,247 m / min. After stretching, the filament was cooled on another godet duo at 120 ° C, which ran as fast as the drafting system. The filament was then wound up at 5,600 m / min.
• the filament yarn treated in this way had the following properties:
• the yarn is particularly suitable for use in tire cord.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Artificial Filaments (AREA)
• Polyesters Or Polycarbonates (AREA)

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Publications (2)

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• 1997
  • 1997-11-25 TW TW086117644A patent/TW357202B/zh active
  • 1997-12-11 PL PL97334017A patent/PL185801B1/pl not_active IP Right Cessation
  • 1997-12-11 WO PCT/CH1997/000463 patent/WO1998028473A1/fr active IP Right Grant
  • 1997-12-11 US US09/284,110 patent/US6115893A/en not_active Expired - Lifetime
  • 1997-12-11 CN CNB971999511A patent/CN1159477C/zh not_active Expired - Fee Related
  • 1997-12-11 JP JP52818498A patent/JP3516690B2/ja not_active Expired - Fee Related
  • 1997-12-11 PT PT97945717T patent/PT946799E/pt unknown
  • 1997-12-11 EP EP97945717A patent/EP0946799B1/fr not_active Expired - Lifetime
  • 1997-12-11 BR BR9713954A patent/BR9713954A/pt not_active IP Right Cessation
  • 1997-12-11 AT AT97945717T patent/ATE212682T1/de not_active IP Right Cessation
  • 1997-12-11 KR KR10-1999-7005582A patent/KR100463355B1/ko not_active IP Right Cessation
  • 1997-12-11 DE DE59706270T patent/DE59706270D1/de not_active Expired - Fee Related
  • 1997-12-11 ES ES97945717T patent/ES2172010T3/es not_active Expired - Lifetime

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