WO2002050348A1

WO2002050348A1 - Method for spinning and winding pet filaments

Info

Publication number: WO2002050348A1
Application number: PCT/EP2001/014876
Authority: WO
Inventors: Alexander Klein; Dietmar Wandel
Original assignee: Zimmer Ag
Priority date: 2000-12-19
Filing date: 2001-12-17
Publication date: 2002-06-27
Also published as: CN1633528A; AU2002231712A1; EP1356143A1; TW554096B; KR100820098B1; EP1356143B1; US20040026818A1; PL365326A1; DE10063286A1; MY124905A; ATE298376T1; KR20030061826A; CN1298899C; DE50106599D1

Abstract

The invention relates to a method for production and winding of pre-oriented, non-crystalline filaments, comprising at least 90 wt. % PET, based on the total weight of the filaments, with a spinning draw speed of greater than 3800 m/min.

Description

Process for spinning and winding PET filaments

The present invention relates to processes for spinning and winding up pre-oriented, non-crystalline filaments which consist of at least 90% by weight, based on the total weight of the filament, of polyethylene terephthalate (PET).

Usually pre-oriented, non-crystalline PET filaments, which are also referred to as POY, are produced depending on the titer to be produced at take-off speeds of 2500 to 3500 m / min. Such filaments have elongation at break values of 90-165%, which have proven to be advantageous for further processing in a drawing or drawing texturing process. In the speed range mentioned, no crystallization is yet generated in the PET filaments, e.g. Fig. 2 from man-made fibers / textile industry, January 1980, page 27.

However, if one tries to increase the take-off speed further, as in the production of spinning-oriented, crystalline PET filaments, which are also referred to as FOY or HOY, then the lower thermal and mechanical stability of the POY yarns leads to higher fractions, more uneven characteristic data and / or Errors in further processing, especially in stretch texturing, observed.

The first approaches to solving these problems are described in patent applications WO 99/51799, WO 99/07927 and WO 93/19229. WO 99/51799 discloses a method for spinning continuous filaments, in which the freshly spun filaments are cooled in a tube using an accelerated cooling gas. Such a procedure enables the spinning take-off speed to be increased to up to 4530 m / min without reducing the elongation at break of the filaments. Information regarding the fractions cannot be found in the publication.

WO 99/07927 relates to a process for producing pre-oriented filaments from polymer mixtures based on polyester. In the presence of a certain amount of an additi copolymer, PET filaments with high elongation at break values are obtained even at high spinning take-off speeds of up to 6000 m / min. Information regarding the fractions cannot be found in this document either.

In contrast, WO 93/19229 describes a method for spinning and cooling continuous filaments by means of a spinning device with spinnerets containing nozzle plates and cooling shafts with an air-permeable wall, through which an air stream is sucked into the interior of the cooling shafts. With a small number of spinning breaks, uniform PET filaments are produced. However, at high speeds of 4200 to 5700 m / min, significantly lower elongations at break of 85 to 54% are obtained. Such values are characteristic of spin-oriented, crystalline filaments.

Although the above-mentioned processes enable the spinning and winding of pre-oriented, non-crystalline filaments at high spinning take-off speeds, they still need improvement in the manufacture of POY. The following points are disadvantageous:

defective filaments are obtained due to mechanical and / or thermal thread damage; • The efficiency of the processes is significantly reduced by forming loops and thread breaks;

• furthermore saddle formation on the bobbin and thread stopper, d. H. a slipping of single or total filaments from the bobbin edge is observed.

In view of the prior art, it was an object of the present invention to provide a method for spinning and winding up pre-oriented, non-crystalline filaments which consist of at least 90% by weight, based on the total weight of the filament, of PET, which enables the production and winding of pre-oriented, non-crystalline PET filaments at high spinning take-off speeds with a low number of defects. In particular, the pre-oriented, non-crystalline PET filaments should have elongation at break values in the range of 90% - 165% and a high degree of uniformity with regard to the filament characteristics and the preparation order.

Another object of the present invention was to provide a method for spinning and winding up pre-oriented, non-crystalline PET filaments which can be carried out on an industrial scale and at low cost. The method according to the invention should be as high as possible

Allow spinning take-off speeds, preferably greater than 3800 m / min, in particular in the range from 4200 to 8000 m / min, with the lowest possible spinning error rate. Furthermore, a good bobbin build should be adjustable to enable high thread weights on the bobbin of more than 4 kg and good bobbin winding behavior in further processing.

An object of the present invention was also to be seen in the fact that the POYs obtainable by the process according to the invention have a very high degree of good staining and processing level with the lowest possible material error rate stretching or stretch texturing.

These and other tasks not explicitly mentioned, which, however, can easily be derived or inferred from the contexts discussed at the outset, are achieved by a method for spinning and winding with all the features of patent claim 1. Appropriate modifications of the method according to the invention are set out in claims 1 back-related subclaims placed under protection.

The fact that a process for the production and winding of pre-oriented, non-crystalline PET filaments with spinning take-off speeds greater than 3800 m / min is available, which is characterized in that

a) the spinning distortion is set in the range from 50 to 250, b) the filaments pass through a cooling delay zone of 20 mm to 300 mm in length immediately after emerging from the spinneret, c) the filaments are cooled below the solidification temperature, d) the filaments in one Distance between 500 mm and 2500 mm from the underside of the nozzle, e) spinning preparation is metered in with at least one oiler pin per thread with a preparation order variation of the standard deviation of less than 90 digits, f) oiler pins, thread bundling and thread guiding elements with low-friction surfaces are used, g) the thread tension in front of the take-off godets is set between 0.07 cN / dtex and 0.5 cN / dtex, h) the thread with a thread tension between 0.05 cN / dtex and 0.20 cN / dtex and an air pressure between 1.0 swirled bar and 5.5 bar with a knot count of at least 10 n / m at a coefficient of variation of the knot count below 100%, i) the thread is wound with a thread tension between 0.03 cN / dtex and 0.20 cN / dtex, the drive the winding roller of the winder is controlled with a frequency of at least 0.3% higher than the drive of the winding mandrel and the thread laying angle is varied over the bobbin running time between a minimum of 3.5 ° and a maximum of 7.5 °,

It is not easily predictable that it is possible to produce and wind up pre-oriented, non-crystalline PET filaments at a high spinning take-off speed with a low number of fibers. The pre-oriented, non-crystalline PET filaments have elongation at break values in the range of 90% - 165% and a high degree of uniformity with regard to the filament characteristics and the preparation order.

At the same time, the method according to the invention has a number of further advantages. These include:

=> The method according to the invention can be carried out in a simple manner, on an industrial scale and inexpensively. In particular, the method allows spinning and winding at high take-off speeds of greater than 3800 m / min, in particular between 4200 and 8000 m / min, and the production of high thread weights on the bobbin of more than 4 kg.

---- The bobbins of pre-oriented, non-crystalline PET filaments obtainable by the process can thus be processed in a simple manner, with the least possible deficiencies, in a drawing or drawing texturing process. = t> Due to the high uniformity of the pre-oriented, non-crystalline filaments obtainable by the process, a uniform and almost error-free dyeing and further processing of the pre-oriented polyester filament is made possible.

The present invention relates to a process for the production and winding of pre-oriented, non-crystalline filaments, which consist of at least 90% by weight, based on the total weight of the filament, of polyethylene terephthalate (PET), for example by polycondensation in a known manner and Way is available from terephthalic acid and ethylene glycol.

The polyethylene terephthalate can be either a homo- or a copolymer. Suitable copolymers are, in particular, those which, in addition to the above-mentioned repeating units, also contain up to 15 mol%, based on all repeating units of the PET repeating units of conventional comonomers, such as, for. B. 1,3-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,4-cyclohexanedimethanol, polyethylene glycol, isophthalic acid and / or adipic acid. However, PET homopolymers are preferred in the context of the present invention.

Furthermore, the PET can also have a small proportion, preferably up to 0.5% by weight, based on the total weight of the filament, of branching components. The branching components preferred according to the invention include, inter alia, polyfunctional acids, such as trimellitic acid, pyromellitic acid, or tri- to hexavalent alcohols, such as trimethylolpropane, pentaerythritol, dipentaerythritol, glycerol, or corresponding hydroxy acids.

In the context of the present invention, it may also be expedient to add up to 2.5% by weight of the PET to the total weight of the Mix filaments of additive polymers as elongation enhancers. Additive polymers which are particularly suitable according to the invention include the polymers and / or copolymers mentioned below:

1. A copolymer which contains the following monomer units:

A = acrylic acid, methacrylic acid or CH ₂ = CR - COOR ', where R is an H atom or a CH ₃ group and R' is a C ₅ alkyl group or a C _{_5-12} -cycloalkyl radical or a

is

B = styrene or C ₁ . _3- alkyl substituted styrenes,

the copolymer consisting of 60 to 98% by weight of A and 2 to 40% by weight of B, preferably of 83 to 98% by weight of A and 2 to 17% by weight of B, and particularly preferably of 90 to 98% by weight % A and 2 to 10% by weight B (total = 100% by weight).

2. A copolymer which contains the following monomer units:

C = styrene or C-.j-alkyl-substituted styrenes,

D = one or more monomers of the formula I, II or III

where R ¹ , R ² and R ^{3 are} each an H atom or a C ,. ₁₅ -alkyl radical or a C 1-4 aryl radical or a C ₅ _ ₁₂ -cycloalkyl radical, the copolymer being composed of 15 to 95% by weight of C and 2 to 80% by weight of D, preferably of 50 to 90% by weight C and 10 to 50 wt% D and particularly preferably consists of 70 to 85% of C and 15 to 30% by weight of D, the sum of C and D totaling 100% by weight.

A copolymer containing the following monomer units:

E = acrylic acid, methacrylic acid or CH ₂ = CR - COOR ', where R is an H atom or a CH ₃ group and R' is a C ₅ alkyl radical or a C ₅ . ₁₂ cycloalkyl radical or a C ₆ . _{] 4 is an} aryl radical,

F = styrene or C ,. _3- alkyl substituted styrenes,

G = one or more monomers of the formula I, II or III

(I) (III) (II)

where R ¹ , R ² and R ³ each represent an H atom or a C ₅ alkyl radical or a C ₅ . ₁₂ -cycloalkyl radical or a C ₆ . ₁₄ aryl radical,

H = one or more ethylenically unsaturated monomers copolymerizable with E and / or with F and / or G from the group consisting of α-methylstyrene, vinyl acetate, acrylic acid esters, methacrylic acid esters other than E, vinyl chloride, vinylidene chloride, halogen-substituted styrenes, vinyl ethers , Isopropenyl ethers and dienes, the copolymer consisting of 30 to 99% by weight E, 0 to 50% by weight F,> 0 to 50% by weight G and 0 to 50% by weight H, preferably 45 to 97 % By weight E, 0 to 30% by weight F, 3 to 40% by weight G and 0 to 30% by weight H and particularly preferably from 60 to 94% by weight E, 0 to 20% by weight % F, 6 to 30% by weight G and 0 to 20% by weight H, the sum of E, F, G and H together making 100% by weight.

4. A polymer from the following monomer unit:

wherein R 'and R ^{2 are} substituents consisting of the optional atoms C, H, O, S, P and halogen atoms and the sum of the molecular weights of R ¹ and R ^{2 is} at least 40. Exemplary monomer units include acrylic acid, methacrylic acid, and CH ₂ = CR - COOR ', where R is an H atom or a CH ₃ group and R' is a C ,. ₁₅ alkyl radical or a C ₅ . ₁₂ -cycloalkyl radical or a C ₆ . _{14 is} aryl, and styrene and C ,. ₃ alkyl substituted styrenes.

Details on the production of these substances and on the mixing of the additive polymers with the PET are described in the patent specification WO 99/07 927. In addition, with regard to the metering and dispersion of the additive in PET, reference is made to DE 100 22 889.5.

In the context of the present invention, additive polymers and / or copolymers are preferred which are amorphous and insoluble in the polyester matrix. They preferably have a glass transition temperature of 90 to 200 ° C., the glass transition temperature being determined in a known manner, preferably by differential scanning calorimetry. Further details can be found in the prior art, for example in publication WO 99/07927, the disclosure of which is hereby expressly incorporated by reference. According to the invention, the additive polymer and / or copolymer is selected such that the ratio of the melt viscosities of the additive polymer and / or copolymer and the matrix polymer is 0.8: 1 to 10: 1, preferably 1.5: 1 to 8: 1 , The melt viscosity is measured in a known manner using an oscillation rheometer at an oscillation frequency of 2.4 Hz and a temperature which is equal to the melting temperature of the matrix polymer plus 34 ° C. For polyethylene terephthalate, the measuring temperature for the melt viscosity is 290 ° C. Further details can in turn be found in WO 99/07927. The melt viscosity of the additive polymer and / or copolymer is preferably higher than that of the matrix polymer, and it has been found that the choice of a specific viscosity range for the additive polymer and / or copolymer and the choice of the viscosity ratio to optimize the properties of the product Fadens contributes. With an optimized viscosity ratio, it is possible to minimize the amount of additive polymer and / or copolymer added, which among other things also improves the economics of the process. The polymer mixture to be spun preferably contains 0.05 to 2.5% by weight of additive polymer and / or copolymer.

By choosing the favorable viscosity ratio, a narrow distribution of the particle sizes of the additive polymer and / or copolymer in the polymer matrix is achieved with the desired fibril structure of the additive polymer and / or copolymer in the thread. The glass transition temperature of the additive polymer and / or copolymer, which is high in comparison to the matrix polymer, ensures that this fibril structure is rapidly solidified in the filament. The maximum particle sizes of the additive polymer and / or copolymer are about 1000 nm immediately after emerging from the spinneret, while the average particle size is 400 nm or less. After the spinning of the thread, the favorable fibril structure is achieved in which the thread has at least 60% by weight of the additive polymer and / or copolymer in the form of fibrils with lengths in the range from 0.5 to 20 μm and diameters in the range from 0.01 to 0.5 μm.

The polyethylene terephthalate according to the invention can contain customary amounts, preferably 0 to 5% by weight, preferably 0 to 1% by weight, in each case based on the total weight of the filament, of further additives, such as catalysts, stabilizers, antistatic agents, antioxidants, flame retardants, dyes, Dye uptake modifiers, light stabilizers, organic phosphites, optical brighteners and matting agents.

According to the invention, the PET is spun to a pre-oriented, non-crystalline filament at a take-off speed greater than 3800 m / min, advantageously at least 4200 m / min, preferably greater than 4600 m / min, in particular at least 6000 m / min, particularly preferably greater than 6000 m / min wound. A particularly preferred range in the context of the present invention is between 4200 and 8000 m / min, in particular between 4600 and 6000 m / min.

For the purposes of the present invention, preoriented, non-crystalline filaments refer to those filaments which have an elongation at break of between 90 and 165%.

It may be expedient for the method according to the invention to use a spinning cooling device in which the stress-induced crystallization is reduced at high spinning take-off speeds. In a particularly preferred embodiment of the present invention, a spinning cooling device is used, as is described in the publication WO 99/51799. The disclosure of this publication is explicitly referred to in this context. The PET which can be used in the sense of the invention preferably has an intrinsic viscosity (intrinsic viscosity) in the range from 0.55 dl / g to 0.75 dl / g.

In the process according to the invention, a melt of the PET is spun at constant speed, the speed being set according to a known calculation formula so that the desired thread titer is obtained, pressed into nozzle packs and extruded through the nozzle holes of the nozzle plate of the pack to form molten filaments.

The melt can be produced from polymer chips in an extruder, for example, it being necessary to dry the chips beforehand to a water content <100 ppm, in particular to a water content <50 ppm. The direct feed of the PET melt from the end reactor of a polycondensation plant to the spinning mill is preferred.

The temperature of the melt, commonly referred to as the spinning temperature and measured in front of the spinning pump, depends on the melting point of the PET. It is preferably in the range given by Formula 1:

Formula 1 :

T _ra + 19 ° C ≤ T _Sp <T _m + 49 ° C with

T _m : melting point of PET, approx. 260 ° C

T _Sp : spinning temperature [° C].

The homogeneity of the melt has a direct influence on the material properties of the spun filaments. A static mixer with at least two elements, which is installed before and / or after the spinning pump, is therefore preferably used to homogenize the Melt. For example, a Promix spinning pump from Barmag / D with an integrated mixer can be used.

The temperature of the nozzle plate, which is dependent on the spinning temperature, is regulated by its so-called trace heating. As trace heating, for example, a spinning beam heated with "diphyl" or additional convection, induction or radiant heaters are possible. The temperature of the nozzle plates is usually at the level of the spinning temperature.

A temperature increase on the nozzle plate can be achieved through the pressure drop in the nozzle package. Known derivations, such as, for example, K. Riggert "Advances in the Production of Polyester Tire Cord Yarn" Chemical fibers 21, page 379 (1971), describe a temperature increase of approximately 4 ° C. per 100 bar pressure drop.

Furthermore, it is possible to control the nozzle pressure by using loose filter media, in particular steel sand with an average grain size between 0.10 mm and 1.2 mm, preferably between 0.12 mm and 0.75 mm and / or filter discs made of metal mesh or nonwovens with a fineness of <40 μm, preferably 5 to 20 μm, can be produced.

In addition, the pressure drop in the nozzle hole contributes to the total pressure. The nozzle pressure is preferably set between 80 bar and 450 bar, in particular between 100 bar and 250 bar, the latter corresponding to an increase in the melt temperature directly before the extrusion of 4-10 ° C.

Spinning delay i ^, ie the quotient of take-off speed and spraying speed, is calculated according to US Pat. No. 5,250,245 using Formula 2 with the density of the PET, the nozzle hole diameter and the titer of the single filament: Formula 2: i _Sp = 2.25 “10 ^{5 *} ” (δ-π) “D ² (cm) / dpf (den) with δ: density of the melt [g / cm ³ ]; for PET = 1.22 g / cm ³

D: nozzle hole diameter [cm] dpf: titer of the single filament [den]

Within the scope of the present invention, the spinning delay is between 50 and 250, preferably between 70 and 170.

The length / diameter ratio of the nozzle hole is preferably chosen between 1.5 and 6, in particular between 1.5 and 4.

The extruded filaments pass through a cooling delay zone. Directly below the nozzle package, this is designed as a recess zone, in which the filaments emerging from the nozzle holes are protected from the direct action of the cooling gas and are delayed in delay or cooling. An active part of the recess is designed as an offset of the nozzle package into the spinning beam, so that the filaments are surrounded by heated walls. A passive part is formed by insulation layers and unheated frames. The lengths of the active recess are between 0 and 300 mm, those of the passive part between 20 and 150 mm, with a total length of 20 - 300 mm being maintained.

As an alternative to the active return, a reheater can be installed below the spinning beam. In contrast to the active return, this zone with a cylindrical or rectangular cross section then has at least one heating independent of the spinning beam. In the case of radial porous cooling systems concentrically surrounding the thread, the cooling delay can be achieved with the aid of cylindrical covers.

The filaments are then cooled to temperatures below their solidification temperature. According to the invention, the solidification temperature denotes the temperature at which the melt changes to the solid state.

Means for cooling the filaments are known to the person skilled in the art from the prior art. The use of cooling gases, in particular cooled air, has proven particularly useful according to the invention. The cooling air preferably has a temperature of 12 ° C. to 35 ° C., in particular 16 ° C. to 26 ° C. The speed of the cooling air is advantageously in the range from 0.20 m / sec to 0.55 m / sec.

For cooling the filaments, for example, single thread systems can be used which consist of individual cooling tubes with a perforated wall. A cooling of each individual filament is achieved by active cooling air supply or also by utilizing the self-suction effect from the filaments and / or by extracting the cooling air. As an alternative to the individual pipes, the known cross-flow blowing systems can also be used.

A special embodiment of the cooling and warping area is to supply the filaments emerging from the delay zone in a zone of length in the range from 10 to 175 cm, preferably in a zone of length in the range of 10 to 80 cm, of cooling air. A zone length in the range of 10 - 40 cm for filaments with a titer of less than 1.5 dtex per filament and a zone length in the range of 20 - 80 for filaments with a titer between 1.5 and 9.0 dtex per filament cm particularly suitable. Subsequently, the filaments and the air accompanying them are passed together through a reduced-cross-section channel, the ratio of the air to the thread speed during the drawing off being 0.2 to 20: 1, preferably 0.4, by controlling the cross-sectional taper and the dimensioning in the thread running direction up to 5: 1.

After the filaments have cooled to temperatures below the solidification temperature, they are bundled into a thread. The distance of the bundling from the underside of the nozzle which is suitable according to the invention can be determined by methods known to the person skilled in the art for online measurement of the thread speed and / or thread temperature, for example using a laser Doppler anemometer from TSI / D or an infrared camera from Goratec / D Type IRRIS 160. It is 500 to 2500 mm. Individual filaments with a spinning titer <4.5 dtex are preferably bundled at a smaller distance <1500 mm, thicker filaments preferably at a larger distance.

In the context of the present invention, it is advantageous that preferably all surfaces that come into contact with the spun filament are made of particularly low-friction materials. In this way, fluff formation can be largely avoided, higher quality filaments are obtained. Low-friction surfaces of the "TriboFil" specification from Ceramtec / D have proven to be particularly suitable for this purpose.

The filaments are bundled in an oil pen, which feeds the desired amount of spin finish evenly to the thread. A particularly suitable oil pen is characterized by an inlet part, the thread channel with an oil inlet opening and the outlet part. The inlet part is widened in a funnel shape, so that contact through the still dry filaments is avoided becomes. The point of impact of the filaments takes place within the thread channel after the inflow of the preparation. The width of the thread channel and oil inlet opening is adapted to the thread titer and the number of filaments. Openings and widths in the range from 1.0 mm to 4.0 mm have proven particularly successful. The outlet part of the oiler pen is designed as a smoothing section, which preferably has oil reservoirs. Suitable oiling pens can be obtained, for example, from Ceramtec / D, type TriboFil, from Goulston / USA, type LuroJet, from Kyocera / J, type SF, and from Rauschert / D, type PN.

The uniformity of the oil application is of great importance according to the invention. It can be determined, for example, with a Rossa measuring device in accordance with the method described in chemical fibers / textile industry, 42J94, Nov. 1992 on page 896. The amount of oil applied and its fluctuation is given in relative units, so-called digits. In the context of the present invention, values for the standard deviation of the oil application of less than 90 digits, in particular less than 60 digits, are obtained with such a procedure. According to the invention, values for the standard deviation of the oil application of less than 45 digits, in particular of less than 30 digits, are particularly preferred. A value for the standard deviation of 45 digits corresponds to approximately 3.1% of the coefficient of variation.

In the context of the present invention, it has proven to be particularly advantageous to design preparation lines and pumps to be self-degassing to avoid gas bubbles, since these can lead to a considerable fluctuation in oil application. In a very particularly preferred embodiment of the present invention, a preparation pump of the Profin type from Barmag / D is used. According to the invention, the filaments are swirled before winding. Conventional systems have proven to be of little use, because due to the high speed and thus the increased air pressure, considerable formation of loops and fluff can be observed. In addition, they require high winding tensions, which have a negative impact on the bobbin build-up and lead to saddle formation, slipping in and thread chipping on the bobbin.

In the context of the present invention, these disadvantages are advantageously avoided by using nozzles with closed yarn channels, since in such systems the thread is prevented from getting caught in the insertion slot even when the thread tension is low and the air pressure is high. The entangling nozzles are preferably arranged between godets, the exit thread tension being regulated by means of different speeds of the inlet and outlet godets. It should not exceed 0.20 cN / dtex and primarily the thread tension should have values between 0.05 cN / dtex and 0.18 cN / dtex. The air pressure of the entangling air is between 1.0 and 5.5 bar.

Node numbers of at least 10 n / m are set. Maximum opening lengths of less than 100 cm and values for the coefficient of variation of the number of nodes below 100% are of particular interest. When using air pressures> 3.0 bar, node numbers> 15 n / m are advantageously achieved, which are characterized by a high degree of uniformity, the coefficient of variation being less than or equal to 70% and the maximum opening length being 50 cm.

In practice, systems of the type LD from Temco / D, the double system from Slack & Parr / USA, or nozzles of the type Polyjet from Heberlein have proven to be particularly suitable. Particularly positive effects regarding lint reduction are achieved if a migration nozzle is used before the actual entangling. At air pressures of less than 1 bar, a further homogenization of the applied spin finish or mixing of the individual filaments is achieved. These nozzles are used before the first trigger godet, preferably directly after the oil pen.

The peripheral speed of the first godet unit is referred to as the take-off speed. Further godet systems can be used before the thread is wound into bobbins (bobbins) on tubes in the winder unit.

Stable, error-free bobbins are a basic requirement for error-free removal of the thread and for error-free further processing. Therefore, a winding tension in the range of 0.03 cN / dtex - 0.20 cN / dtex, preferably in the range of 0.0 5 cN / dtex - 0.15 cN / dtex, is used in the context of the present method.

The winder is preferably provided with a vane wheel traversing for thread laying and a driven feeler roller for controlling the speed of the winding mandrel, which in turn is driven, and onto which the winding tube is attached. To avoid thread chops, it is advantageous to control the drive of the sensing roller with at least 0.3% higher frequency than the drive of the winding mandrel.

Furthermore, it is extremely expedient, using a mirror interference method, to vary the laying angle in steps by at least 1 ° in order to prevent thread layers from slipping in, especially in mirror areas. A variation of the laying angle over the coil travel between 3.5 ° and 7.5 ° is particularly preferred according to the invention for stabilizing the coil structure. The angle between the is considered perpendicular to the coil tube Thread running direction on the bobbin and the perpendicular to the bobbin tube referred to as the laying angle.

With the help of the entangling and winder conditions according to the invention, stable coils are produced.

An important parameter of the method according to the invention is the setting of the thread tension before the take-off godets. As is known, this tension essentially consists of the actual orientation tension according to Hamana, the friction tension on the thread guides and the oiler pin and the thread-air friction tension. In the context of the present invention, the thread tension in front of the take-off godets is in the range from 0.07 cN / dtex to 0.50 cN / dtex, preferably between 0.07 cN / dtex and 0.20 cN / dtex.

A too low tension below 0.07 cN / dtex no longer results in the desired degree of pre-orientation. If the tension exceeds 0.50 cN / dtex, thread damage due to frictional heat occurs, which leads to a deterioration of the thread characteristics.

According to the invention, the tension is regulated by the spinning take-off speed, the lubricator pin distance from the nozzle, the friction surfaces and the length of the distance between the oil pin and the take-off godet. This line length is advantageously not more than 6.0 m, preferably less than 2.5 m, the spinning mill and the take-off machine being arranged in a parallel manner in such a way that a straight thread run is ensured.

To adjust the winding tension according to the invention, the winding speed of the POY is advantageously 0-2% below the take-off speed. A winding speed that is 0-1% below the spinning take-off speed is preferably selected. Advantageously, a temperature <35 ° C., in particular between 12 and 28 ° C., and a relative humidity between 40-90% is set in the environment of the on dishwasher in the implementation of the method. Furthermore, it is advisable to store the POY coils at least 4 hours at 12 to 28 ° C and a relative humidity between 40 - 90% before further processing.

Methods for determining the specified material parameters are well known to the person skilled in the art. They can be found in the specialist literature, for example the publication WO 99/07927, the disclosure of which is hereby expressly incorporated by reference.

The characteristics of the intermingling are determined with an ITEMAT node counter from Enka-Technica / D at a speed of 100 m / min and a set level No. 1.

A Fraytec device from ENKA-Tecnica / D is used for online fluff detection during spinning. The fluff detection sensor has to trigger a video camera directly downstream, the image of which is saved, thus making possible errors evaluable and classifiable. Incorrect measurements, e.g. Oil droplets or vibrations can be avoided by such a procedure. The evaluation allows in particular to determine texturing-relevant errors. These defects, which look like filament tufts and are caused by postponing breaks, could be reduced to 0 per hour at a spinning take-off speed of 5000 m / min by using the method according to the invention.

The invention is explained in more detail below by means of an example, without the invention being restricted to this example. A melt of polyethylene terephthalate was discharged from a reactor with an intrinsic viscosity of 0.64 dl / g corresponding to a melt viscosity at 290 ° C of 250 Pas and a temperature of 282 ° C and by means of a booster pump with a pressure of 205 bar and an amount of 302.4 kg / h required by the melt line. The melt flowed through a filter with a fineness of 20 μm and a heat exchanger that cooled the melt temperature from 292 ° C to the spinning temperature of 290 ° C.

This filtered partial stream 1 of the amount 302.4 kg / h was in the second partial stream of the amount 13.98 kg / h, corresponding to 4.62 wt .-% of the first stream, and the third partial stream of the amount 288.42 kg / h split and branched.

For dosing and transporting the second partial flow and the additive flow, a 6-speed planetary gear pump from Mahr GmbH, Göttingen / DE, operated in a counterclockwise direction, was used. It is a 6-fold spinning pump which combines the same volume flows from 6 input channels in one output channel by reversing the direction of rotation and thus the direction of flow.

The second partial flow was fed in equal parts to 5 of 6 inputs of a 6-speed planetary gear pump from Mahr GmbH, Göttingen / DE, operated in a left-turning manner.

A copolymeric additive from the 3rd group of substances, containing 9% by weight of styrene, 89% by weight of methyl methacrylate and 2% by weight of N-cyclohexylmaleimide, was selected with a viscosity ratio of 5.8.

The additive dried to a residual moisture content of <0.1% by weight was melted in an extruder and at a melt temperature of 265 ° C. at a rate of 2.33 kg / h, corresponding to 0.77% by weight of the first Partial flow, the remaining input channel of the 6-fold planetary pump.

This additive flow was combined in the outlet channel of the planetary gear pump with the polyester flow from one of the 5 input channels fed with polyester and by means of a static premixer of the type SMXS DN 12 from Sulzer AG, Zurich / CH, with an inner diameter of 12.9 mm and 3 times Length of the inner diameter premixed before the polyester streams of the 4 remaining input channels were fed to this premix in the outlet of the planetary gear pump.

The residence time of the additive melt until it was brought together with the other polymers was approximately 70 seconds.

The subsequent preparation of the first polymer mixture with an additive content of 16.7% by weight was carried out in a first static main mixer of the type SMXS DN 17 from Sulzer AG, Zurich / CH, with an inside diameter of 17.8 mm and 9 times the length of the Inside diameter.

This first mixture was introduced into the third partial flow and, after a flow section L of 4 times the inside diameter of the first main mixer, was fed to a second SMX main mixer from Sulzer AG with an inside diameter of 52.5 mm and a length of 10 times the diameter, there homogenized and dispersed.

The residence time of the additive melt until it came into contact with the third partial stream was approximately 100 seconds.

The polymer mixture was distributed to 12 spinning positions, each containing 6 spinneret packs, using product lines. Each spin pack contained a round nozzle with 34 holes with a diameter of 0.25 mm and the length of the 2- times the diameter. Furthermore, the spin pack above the nozzle plate contained a spin filter pack consisting of a steel sand pack of 30 mm high and a grain size of 0.35 to 0.50 mm as well as a finest mesh fabric of 40 μm and a steel fleece filter of 20 μm pore diameter. The cross-sectional area of the spinning filter packet was 45 cm ² . A nozzle pressure of 150 bar was established during the throughput of the melt mixture. The residence time of the melt in the Filteφaket was about 1.5 minutes. The surface of the spinneret was 30 mm above the lower edge of the heating box (active recess). The total recess was 110 mm. The heating of the spin pack was set to 290 ° C using HTM heat transfer oil.

The molten filaments extruded from the nozzle holes were cooled by means of blown air, which flowed in horizontally to the thread run over a length of 1500 mm at a speed of 0.5 m / sec and had a temperature of 19 ° C., and at a distance of 1400 mm from the nozzle plate was bundled into a thread in a TriboFil-type oil pen from CeramTec, the diameter of the oil channel being 1 mm, and coated with spin finish from Goulston, an order of 0.35% having been set. The standard deviation of the order was 38 digits.

An S-shaped pair of godets wound the thread at a speed of 5000 m min, the spinning delay ratio being set to 141 and the thread tension before the first godet to 28 cN. Between the godets, a swirling nozzle from Temco, type LD, which was closed during normal thread run, was installed, which at an air pressure of 4.0 bar impressed the thread with a swirl knot number of 22 n / m at a CV value of 53.9%. The thread tension at the inlet of the interlacing nozzle was set to 16 cN, that at the outlet to 18 cN. The thread guides were of the "Low Friction" surface type from Barmag / D. Six threads each from a spinning position were spooled into spool packages in a winder, the speed of 4985 m / min being chosen such that the thread tension before winding was 12 cN. The cantilever roll was 0.6% higher than the mandrel. The installation angle was varied between 4.3 ° and 6.5. The lint counter did not register any filament tufts to produce a 19 kg spool.

Preoriented (POY) threads were obtained which were characterized by a titer of 141 dtex, a tensile strength of 25 cN / tex and an elongation at break of 11%. The POY coils were stretch-textured in a Barmag FK6 texturing machine at a speed of 900 m / min. 1.70 was selected as the draw ratio. The first heater had a temperature of 210 ° C, the second of 170 ° C.

The textured yarn had a titer of 88 dtex, a tensile strength of 42 cN / tex and an elongation at break of 22% and was characterized by good dyeing uniformity. The method according to the invention was also distinguished here in particular by a small number of thread breaks both during spinning and during texturing.

98% full 19 kg bobbins were produced in the spinning mill and 92% full 5 kg bobbins in the stretch texturing.

Claims

claims:

1. A process for the production and winding of pre-oriented, non-crystalline filaments, which consist of at least 90 wt .-% based on the total weight of the filament made of PET, with spinning take-off speeds greater than 3800 m / min, characterized in that a) the spin delay in Range from 50 to 250 is set, b) the filaments pass through a cooling delay zone of 20 mm to 300 mm in length immediately after emerging from the spinneret, c) the filaments are cooled below the solidification temperature, d) the filaments are spaced between 500 mm and 2500 mm are bundled from the underside of the nozzle, e) spinning preparation is metered in using at least one oiler pin per thread with a preparation order fluctuation of the standard deviation of less than 90 digits, f) oiler pins, thread bundling and thread guiding elements with low-friction surfaces are used, g) the thread tension is pre-set the withdrawal godets between 0.07 cN / d tex and 0.5 cN / dtex is set, h) the thread is swirled with a thread tension between 0.05 cN / dtex and 0.20 cN / dtex and an air pressure between 1.0 bar and 5.5 bar, whereby a Number of knots of at least 10 n / m is set with a coefficient of variation of the number of knots below 100%, i) the thread is wound with a thread tension between 0.03 cN / dtex and 0.20 cN / dtex, the drive of the winding roller of the winder is driven with a frequency that is at least 0.3% higher than the drive of the mandrel and the Thread laying angle is varied over the bobbin running time between a minimum of 3.5 ° and a maximum of 7.5 °.

2. The method according to Anspmch 1, characterized in that the spinning take-off speed is set in the range from 4200 to 8000 m / min, in particular in the range from 4600 to 6000 m / min.

3. The method according to claim 1 and / or 2, characterized in that a PET is used, which up to 2.5% by weight, based on the total weight of the filament, of additive polymer is added as an elongation-increasing agent.

4. The method according to at least one of the preceding claims, characterized in that the filaments are cooled by means of a cooling device which reduces the stress-induced crystallization at high spinning speeds.

5. The method according to at least one of the preceding claims, characterized in that a PET is used, which up to 2.5% by weight, based on the total weight of the filament, of additive polymer is added as a stretching agent, and the filaments by means of a cooling device cools, which reduces the stress-induced crystallization at high spinning speeds.