WO2002036862A1

WO2002036862A1 - Method for the spinning and winding of polyester filaments, polyester filaments obtained by the spinning method, draw texturing of the polyester filaments and bulked polyester filaments obtained by draw texturing

Info

Publication number: WO2002036862A1
Application number: PCT/EP2001/012683
Authority: WO
Inventors: Dietmar Wandel; Achim Dulling; Ulrich Mirwaldt; Alexander Klein
Original assignee: Zimmer Ag
Priority date: 2000-11-03
Filing date: 2001-11-02
Publication date: 2002-05-10
Also published as: CA2405495A1; DE10151875A1; KR20030061305A; TW587108B; EP1330564A1; AU2002224824A1; KR20030043790A; ATE291651T1; ES2237616T3; JP2004513249A; TW589420B; CN1210448C; EA200201196A1; MXPA03001318A; HK1054577A1; EP1330563A1; EP1330564B1; MY136398A; EG23364A; WO2002036864A1

Abstract

The invention relates to a method for the production and winding of pre-oriented polyester filaments, comprising at least 90 wt. %, based on the total weight of polyester filament, polybutylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), preferably PTMT, characterised in that a) the spinning draft is set in the range 70 to 500, b) directly after exiting the spinning nozzle, the filaments run through a cooling delay zone of 30 mm to 200 mm in length, c) the filaments are cooled to below the solidification temperature, d) the filaments are bundled at a separation of between 500 mm and 2500 mm from the bottom face of the nozzle, e) the thread tension, before and between the drawing galettes is set to between 0.05 cN/dtex and 0.20 cN/dtex, f) the threads are wound with a thread tension of between 0.025 cN/dtex and 0.15 cN/dtex and g) the winding speed is set to between 2200 m/min and 3500 m/min.

Description

Process for spinning and winding polyester filaments, by the

Spinnerets available polyester filaments, stretch texturing of the polyester filaments as well as bulky available through the stretch texturing

Polyester filaments

The present invention relates to ner drives for spinning and winding up pre-oriented polyester filaments which consist of at least 90% by weight, based on the total weight of the polyester filament, of polybutylene terephthalate (PBT) and / or polytrimethylene terephthalate (PTMT), preferably of PTMT. and the pre-oriented polyester filaments obtainable by the process. Furthermore, the present invention also relates to processes for stretch texturing of the spun and wound polyester filaments and the bulky polyester filaments obtainable by stretch texturing.

The production of continuous polyester filaments, in particular of polyethylene terephthalate (PET) filaments, in a two-stage process is already known. In the first stage, smooth, pre-oriented filaments are spun and wound up, which in the second stage are stretched and heat-set or stretch-textured into bulky filaments.

The book Synthetic Fibers by F. Fourne (1995), published by Hanser-Verlag Munich, provides an overview of this. However, only the production of PET fibers is described, whereby no closed spinning technology but rather an overview is presented in which the most varied of characteristics are described. The fiber production of various spinnable polymers, including polypropylene, polyamides, polyester etc. is the subject of application DE-OS 38 19 913. However, the examples only describe the production of PET fibers, as can be seen from the temperature at which the polymer is processed.

The problem with the production of continuous polytrimethylene terephthalate (PTMT) or polybutylene terephthalate (PBT) filaments is that preoriented filaments have a considerable tendency to shrink both immediately after spinning and during winding and also several hours after winding up when stored at ambient temperature, which leads to a shortening of the thread. The bobbin is thereby pressed together, so that in extreme cases the bobbin shrinks tightly on the winding mandrel and the bobbin can no longer be removed. Furthermore, a so-called saddle with hard edges and a run-in middle part forms in the winding body. As a result, the textile characteristics of the filaments, such as the Uster, become more uneven and there are run-off problems when processing the packages. The only remedy is to limit the winding weight to less than 4 kg. Such problems do not arise when processing PET fibers.

It is also observed that, unlike PET filaments, pre-oriented PBT or PTMT filaments age more when stored. Structural hardening occurs, which leads to such a sharp decrease in the shrinkage that recrystallization can be demonstrated. Such PBT or PTMT filaments are only of limited suitability for further processing, they lead to errors in the stretch texturing and to a significant reduction in the tensile strength of the textured yarn. The result is a reduction in the texturing speed or the stretching ratio. These differences between PET and PBT or PTMT can be attributed to structure and property differences, such as those described in Chemical Fibers Int., P. 53, vol. 50 (2000) and topic on the 39th Int. Manmade Fiber Congress in Dornbirn from September 13th to 15th. It is assumed that different chain formations are responsible for the property differences.

The first approaches to solving these problems are described in patent application WO 99/27168 and European patent EP 0.731.196 B1. WO 99/27168 discloses a polyester fiber which consists of at least 90% by weight of polytrimethylene terephthalate and has a boiling shrinkage of between 5% and 16% and an elongation at break of 20% to 60%. The polyester fiber described in WO 99/27168 is produced by spinning and drawing. Spinning take-off speeds of up to 2100 m / min are specified. The process is uneconomical due to the low spinning speed. In addition, the polyester fibers obtained are, as the key figures indicated, highly crystalline and therefore only of limited suitability for stretch texturing processes.

European patent EP 0.731.196 B1 claims a process for spinning, drawing and winding a synthetic thread, in which the thread is subjected to a heat treatment after stretching and before winding to reduce the tendency to shrink. Usable synthetic fibers also include polytrimethylene terephthalate fibers. According to EP 0.731.196 B1, the heat treatment takes place in that the synthetic thread is guided in close proximity but essentially without contact along an elongated heating surface. The use of heat treatment makes the process more expensive and also provides synthetic threads with high crystallinity, which are only of limited suitability for stretch texturing processes. In the article by Dr. HS Brown and HH Chuah; "Texturing of textile filament yarns based on polytrimethylene terephthalate" Chemical Fibers International, Volume 47, Feb. 1997, pp. 72 - 74 describes the stretch texturing of pre-oriented polytrimethylene terephthalate filaments at texturing speeds of 450 m / min and 850 m / min. According to this disclosure, the lower texturing speed of 450 m / min is more suitable for polytrimethylene terephthalate filaments, since fibers with better material properties are obtained in this case. The tensile strength of the polytrimethylene terephthalate fibers is 26.5 cN / tex (texturing speed of 450 m / min) or 29.15 cN / tex (texturing speed of 850 m / min) and the elongation at break is 38.0% (texturing speed of 450 m / min) or 33.5% (texturing speed of 850 m / min).

The publication WO 01/04393 describes PTMT filaments which have a boiling shrinkage in the range from 3 to 40%. However, this value is determined directly after the filaments have been produced. After a storage period of 4 weeks under normal conditions, this value decreases below 20%, as shown in the attached FIG. 1.

FIG. 1 describes the change in the cooking shrinkage for three PTMT-POY coils as a function of the storage time under normal climate conditions. The change in POY cooking shrinkage for three coils with different initial values over the storage period under normal climatic conditions was examined. Coils no. 16 and 17 with a high initial value> 40% show a boiling shrinkage above 30%, preferably above 40% after 4 weeks. If, however, the initial value of the cooking shrinkage is less than 40%, the coil 18 shows that, after 4 weeks of storage, it falls below the critical value of 30%. FIG. 2 schematically shows force-strain diagrams of PTMT-POY. With the same elongation at break, FIG. 2a) shows a diagram according to the invention with a natural draw ratio (NW) greater than or equal to 15%, and FIG. 2b) shows a diagram with NW = 0%.

Cook shrinkage is a measure of the processability and degree of crystallization of the fibers. The fibers described in WO 01/04393 have plastics with a higher degree of crystallization, which are much worse to process and can only be processed at a lower stretching ratio and / or lower texturing speed.

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 polyester filaments which consist of at least 90% by weight> based on the total weight of the filaments of PBT and / or PTMT To provide, which enables the production and winding of pre-oriented polyester filaments in a simple manner. In particular, the pre-oriented polyester filaments should have elongation at break values in the range from 90% to 165%, high uniformity with regard to the filament characteristics and a low degree of crystallization.

Another object of the present invention was to provide a method for spinning and winding up pre-oriented polyester filaments which can be carried out on an industrial scale and at low cost. The method according to the invention should allow the highest possible take-off speeds, preferably greater than 2200 m / min and high thread weights on the bobbin of more than 4 kg.

It was also an object of the present invention to improve the shelf life of the pre-oriented polyester filaments obtainable by the process according to the invention. These should also last for a longer period of time, for example 4 weeks. A pressing together of the bobbin during storage, in particular a shrinking of the winding body on the winding mandrel and the formation of a saddle with hard edges and a run-in middle part should be prevented as far as possible, so that no run-off problems occur when processing the bobbins.

According to the invention, the preoriented polyester filaments should be able to be processed in a simple manner in a drawing or drawing texturing process, in particular at high texturing speeds, preferably greater than 450 m / min. The filaments obtainable by stretch texturing should have excellent material properties, e.g. B. a high tensile strength of more than 26 cN / tex and a high elongation at break of more than 30% for HE filaments or more than 36% for SET filaments.

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 pre-oriented polyester filament available through the spinning process is described in the independent product claim. The stretch texturing of the pre-oriented polyester filament is claimed in process claim 6, while the product claims 7 and 8 relate to the bulky filaments obtainable by the stretch texturing.

Characterized in that in a method for the production and winding of pre-oriented polyester filaments, which are at least 90 wt .-%> based on the total weight of the polyester filament from polybutylene terephthalate (PBT) and / or polytrimethylene terephthalate (PTMT), preferably from PTMT exist, a) the spinning delay is set in the range 70 to 500, b) the filaments pass through a cooling delay zone of 30 mm to 200 mm in length immediately after emerging from the spinneret, c) the filaments are cooled below the solidification temperature, d) the filaments are bundled at a distance between 500 mm and 2500 mm from the underside of the nozzle, e) the thread tension before and between the take-off godets is set between 0.05 cN / dtex to 0.20 cN / dtex, preferably up to 0.15 cN / dtex, f) the thread with a thread tension between 0.025 cN / dtex to 0, 15 cN / dtex is wound up, g) and the winding speed is set between 2200 m / min and 3500 m / min, it is possible to provide pre-oriented polyester filaments in a manner which is not readily predictable and which can also be used after storage under normal conditions Preserve their excellent material properties for 4 weeks. A significant deterioration in the uniformity values of the thread due to aging or a winding shrinkage of the spun fiber on the bobbin cannot be observed.

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 at least 2200 m / min and the production of high thread weights on the bobbin of more than 4 kg.

= The process of the present invention makes it possible to dispense with the use of spinning additives. As a result, polyester filaments can be obtained particularly inexpensively. = ^* > The pre-oriented polyester filaments obtainable by the process can thus be processed in a simple manner, on an industrial scale and inexpensively in a drawing or drawing texturing process. The texturing can take place at speeds greater than 450 m / min.

= Because of the high degree of uniformity of the pre-oriented polyester filaments obtainable by the process, it is possible in a simple manner to set a good spool structure which allows the pre-oriented polyester filament to be dyed and processed evenly and with virtually no defects.

= -> The filaments obtainable by stretch texturing have a high tear strength of more than 26 cN / tex and a high elongation at break of more than 30% for HE filaments and more than 36% for SET filaments.

The present invention relates to a method for producing and winding up pre-oriented polyester filaments which consist of at least 90% by weight, based on the total weight of the filament, of polybutylene terephthalate (PBT) and / or polytrimethylene terephthalate (PTMT). Polybutylene terephthalate (PBT) and / or polytrimethylene terephthalate (PTMT) are known to the person skilled in the art. Polybutylene terephthalate (PBT) can be obtained by polycondensation of terephthalic acid with equimolar amounts of 1,4-butanediol, polytrimethylene terephthalate by polycondensation of terephthalic acid with equimolar amounts of 1,3-propanediol. Mixtures of the two polyesters are also conceivable. PTMT is preferred according to the invention.

The polyesters can be both homopolymers and copolymers. Particularly suitable copolymers are those which, in addition to recurring PTMT and / or PBT units up to 15 mol% based on all repeating units of the polyester repeating units of conventional comonomers, such as. B. ethylene glycol, diethylene glycol, triethylene glycol, 1,4-cyclohexanedimethanol, polyethylene glycol, isophthalic acid and / or adipic acid. However, polyester homopolymers are preferred in the context of the present invention.

The polyesters according to the invention can contain customary amounts of other additives, such as catalysts, stabilizers, antistatic agents, antioxidants, flame retardants, dyes, dye absorption modifiers, light stabilizers, organic phosphites, optical brighteners and matting agents. The polyesters preferably contain 0 to 5% by weight, based on the total weight of the filament, of additives.

Furthermore, the polyesters can also contain 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.

The polyesters which can be used in the context of the invention are preferably thermoplastic and can be spun into filaments and wound up. Those polyesters which have an intrinsic viscosity in the range from 0.70 dl / g to 0.95 dl / g are particularly advantageous.

In the process according to the invention, a melt or melt mixture of the polyester is produced by means of spinning pumps at a constant speed, the speed being set according to the known formula so that the desired thread titer is obtained, pressed into die packs and extruded through the die holes of the die plate of the pack to form molten filaments.

The melt can be produced, for example, from polymer chips in an extruder, it being particularly advantageous to dry the chips beforehand to a water content <30 ppm, in particular to a water content <15 ppm.

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

Formula 1:

T _m + 15 ° C <T _Sp <T _m + 45 ° C with

T _m : melting point of the polyester [° C]

T _Sp : spinning temperature [° C].

The specified parameters serve to limit the hydrolytic and / or thermal viscosity reduction, which should expediently be as low as possible. In the context of the present invention, a viscosity reduction by less than 0.12 dl / g, in particular by less than 0.08 dl / g, is desirable.

The homogeneity of the melt has a direct influence on the material properties of the spun filaments. A static mixer with at least one element, which is installed after the spinning pump, is therefore preferably used to homogenize the melt.

The temperature of the nozzle plate, which is dependent on the spinning temperature, is regulated by its so-called trace heating. As trace heating come, for example, a spinning beam heated with "Diphyl" or additional ones Convection or radiant heater in question. 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.

It is also 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 μ 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 spinning draft i _Sp , ie the quotient of the take-off speed and the spraying speed, is calculated according to US Pat. No. 5,250,245 using Formula 2 with the density of the polymer or the polymer mixture, 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 PTMT = 1.12 g / cm ³

D: nozzle hole diameter [cm] dpf: titer of the single filament [den] In the context of the present invention, the spinning delay is between 70 and 500, preferably between 100 and 250.

The length-to-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 100 mm, those of the passive part between 20 and 120 mm, with a total length of 30-200 mm, preferably 30-120 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. In the context of the present invention, it has proven particularly expedient to cool the filaments to a temperature at which they are essentially no longer sticky. It is particularly advantageous to cool the filaments to temperatures below their crystallization temperature, in particular to temperatures below their glass transition temperature.

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 using the self-suction effect of the filaments. 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, with control of the cross-sectional taper and the dimensioning in the thread running direction Ratio of the air to the thread speed when pulling from 0.2 to 20: 1, preferably 0.4 to 5: 1, is set.

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, preferably 500 to 1800 mm. Filaments with a titer <3.5 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 oiling stone, which feeds the desired amount of spin finish evenly to the thread. A particularly suitable oil stone 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. 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 The outlet part of the oiler is designed as an equalization section, which preferably has oil reservoirs. Such oilers can be obtained, for example, from Cermatec / D or Goulston / USA.

The uniformity of the oil application can be of great importance according to the invention. It can be determined, for example, with a Rossa measuring device according to the method described in chemical fibers / textile industry, 42794, Nov. 1992 on page 896. With such a procedure, values for the standard deviation of the oil application of less than 90 digits, in particular less than 60 digits, are preferably obtained. 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 90 digits or 45 digits corresponds to approximately 6.2% or 3.1% of the coefficient of variation.

In the context of the present invention, it has proven to be particularly advantageous to design lines and pumps to be self-degassing to avoid gas bubbles, since these can lead to a considerable fluctuation in oil application.

An entangling before winding the thread is particularly preferred according to the invention. In this case, nozzles with closed yarn channels have proven to be particularly suitable, since in such systems the thread is prevented from getting caught in the insertion slot even with low thread tension and high air pressure. 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 should primarily have values between 0.05 cN / dtex and 0.15 cN / dtex. The air pressure of the entangling air is between 0.5 and 5.5 bar, with winding speeds up to 3500 m / min at a maximum of 3.0 bar. Node numbers of at least 10 nm are preferably 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 above 1.0 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.

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

Stable, error-free thread packages are a basic prerequisite for error-free thread withdrawal and for error-free further processing. Therefore, a winding tension in the range of 0.025 cN / dtex - 0.15 cN / dtex, preferably in the range of 0.03 cN / dtex - 0.08 cN / dtex, is used in the context of the present method.

An important parameter of the method according to the invention is the setting of the thread tension before and between 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 and the thread-air friction tension. In the context of the present invention, the thread tension before and between the take-off godets is in the range from 0.05 cN / dtex to 0.20 cN / dtex, preferably between 0.08 cN / dtex and 0.15 cN / dtex. A too low tension below 0.05 cN / dtex no longer results in the desired degree of pre-orientation. If the tension exceeds 0.20 cN / dtex, this tension triggers a memory effect when winding and storing the bobbins, which leads to a deterioration of the thread characteristics.

According to the invention, the tension is regulated by the oiler distance from the nozzle, the friction surfaces and the length of the distance between the oiler and the discharge godet. This line length is advantageously not more than 6.0 m, preferably less than 2.0 m, the spinning mill and the take-off machine being arranged by means of a parallel construction in such a way that straight thread running is ensured.

The conditioning parameters of the thread between the bundling point and the winding are also described by the geometric parameters. The rapid relaxation during this time influences the quality of the coil structure. The conditioning time defined in this way is preferably chosen between 50 and 200 ms.

According to the invention, the winding speed of the POY is between 2200 m / min and 3500 m / min.

Advantageously, a temperature ≤ 45 ° C., in particular between 12 and 35 ° C., and a relative humidity of 40-85% is set in the vicinity of the thread winding during the implementation of the method according to the invention. The POY is preferably stored until further processing at a temperature <45 ° C. Furthermore, it is advisable to store the POY coils at least 4 hours at 12 to 35 ° C and a relative humidity of 40-85% before further processing. After 4 weeks of storage under normal conditions, the filament according to the invention has a) an elongation at break between 90 and 165%>, preferably between 90 and 135% b) a boiling shrinkage of at least 30%, preferably> 40%, c) a normal uster below 1 , 1%>, preferably less than 0.9%, d) a birefringence between 0.030 and 0.058, e) a density less than 1.35 g / cm ³ , preferably less than 1.33 g / cm ³ , f) a variation coefficient of the breaking load <4.5%, preferably <2.5% and g) a coefficient of variation of the elongation at break <4.5%, preferably <2.5%.

The term "normal conditions" is known to the person skilled in the art and is defined by the DIN 53802 standard. Under "normal conditions" according to DIN 53802, the temperature is 20 + 2 ° C and the relative humidity is 65 ± 2%.

In the context of the present invention, it is also particularly advantageous that the cooking shrinkage, measured directly after winding, is between 50 and 65% and after 4 weeks of storage under normal conditions is at least 30%, preferably> 40%. Surprisingly, it has been shown that POY coils produced in this way can be easily processed further.

It must be taken into account here that in practice normal climatic conditions during the manufacture, storage or transportation of the POY cannot always be maintained. With low crystalline thread, however, the problem often arises that the POY coils change in shape, the draw ratio and / or the texturing speed have to be reduced, and breaks occur more frequently in further processing. Yarns that the Complying with the aforementioned specifications of the cooking shrink have such problems to a lesser extent than conventional yarns.

In addition, it is found that preferred yarns of the present invention do not have any changed dyeing depth of the DTY even after a storage time of 2 months. After a storage period of 20 months, the color change is within 95 ± 3% as long as the ambient temperature is not greater than 45 ° C.

Furthermore, preferred filaments have a natural draw ratio greater than or equal to 15%. This size is particularly preferably in the range from 18 to 65%. The higher the natural stretch ratio, the better the stretchability. With the same elongation, a higher draw ratio is achieved with a high natural draw ratio.

The natural stretch ratio is defined as the plateau section in percent of the force-strain diagram. This size is known and is determined on the ripper in one operation when determining strength and elongation.

FIGS. 2 a) and 2 b) schematically show the specified parameter of the natural draw ratio (NW), the natural draw ratio in FIG. 2 b) being zero. The force against the elongation is plotted in each of the diagrams, schematic diagrams being shown in order to explain the parameter in more detail.

It is assumed that the natural draw ratio is a measure of the thread orientation and a value NW <15% describes the beginning crystallization of the polyester. Low NW values are obtained, for example, by thermal treatment of the thread up to winding with temperatures that are at least 8 ° C above the glass transition temperature of the PES. 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. Although most of the parameters can be determined in different ways, the following methods for determining the filament parameters have proven to be particularly useful in the context of the present invention:

The intrinsic viscosity is measured in a capillary viscometer from Ubbelohde at 25 ° C and calculated using a known formula. A mixture of phenol / 1,2-dichlorobenzene in a weight ratio of 3: 2 is used as the solvent. The concentration of the solution is 0.5 g polyester per 100 ml solution.

A calorimeter DSC device from Mettler is used to determine the melting point, the crystallization temperature and the glass transition temperature. The sample is first heated to 280 ° C and melted and then quenched. The DSC measurement takes place in the range from 20 ° C to 280 ° C with a heating rate of 10 K / min. The temperature values are determined by the processor.

The density of filaments is determined in a density gradient column at a temperature of 23 + 0.1 ° C. N-Heptane (C ₇ H ₁₆ ) and tetrachloraiethan (CC1 ₄ ) are used as reagents. The result of the density measurement can be used to calculate the degree of crystallinity by using the density of the amorphous polyester D _a and the density of the crystalline polyester D _k . The corresponding calculation is known from the literature, for example, for PTMT, D _a = 1.295 g / cm ³ and D _k = 1.429 g / cm ³ .

The titer is determined in a known manner using a precision weight and a weighing device. The pre-tension is expediently 0.05 cN / dtex for pre-oriented filaments (POYs) and 0.2 cN / dtex for textured yarn (DTY). The tensile strength and the elongation at break are determined in a Statimat measuring device under the following conditions; the clamping length is 200 mm for POY or 500 mm for DTY, the measuring speed is 2000 mm / min for POY or 1500 mm min for DTY, the preload is 0.05 cN / dtex for POY or 0.2 cN / dtex for DTY. The tensile strength is determined by dividing the values for the maximum tear load by the titer, and the elongation at break is evaluated at maximum load.

To determine the cooking clump, strands of filaments are treated without tension in water at 95 ± 1 ° C for 10 ± 1 min. The strands are produced using a willow with a pretension of 0.05 cN / dtex for POY or 0.2 cN / dtex for DTY; The length measurement of the strands before and after the temperature treatment takes place at 0.2 cN / dtex. The cooking shrinkage is calculated in a known manner from the difference in length.

The birefringence is determined in accordance with the procedure described in DE 19,519,898. Therefore, in this context, reference is made explicitly to the disclosure of DE 19,519,898.

The crimped kemi values of the textured filaments are measured in accordance with DIN 53840, Part 1 using the Stein / D texture data at a development temperature of 120 ° C.

The normal Uster values are determined with the Uster tester 4-CX and specified as Uster% values. The test time is 2.5 min at a test speed of 100 m / min.

The POY according to the invention can be further processed in a simple manner, in particular stretch-textured. In the context of the present invention, the stretch texturing is preferably carried out at a texturing speed of at least 500 m / min, particularly preferably at a texturing speed of at least 700 m / min. The draw ratio is preferably at least 1: 1.35, in particular at least 1: 1.40. Stretch texturing on a machine of the high-temperature heater type, such as the AFK from Barmag, has proven to be particularly useful.

The bulky filaments produced in this way have a small number of fluff and, after dyeing under cooking conditions at 95 ° C. with a disperse dye (Terasil navy blue) without a carrier, have excellent color depth and color uniformity.

Bulky SET filaments produced according to the invention preferably have a tensile strength of more than 26 cN / tex and an elongation at break of more than 36%. In the case of bulky HE filaments which can be obtained in a second heater without the use of temperature, the tensile strength is preferably more than 26 cN / tex and the elongation at break is more than 30%.

The bulk and elasticity behavior of the filaments according to the invention is excellent.

The invention is explained in more detail below by examples, without the invention being restricted to these examples.

Examples 1 and 2

Spinning and winding

PTMT chips with an intrinsic viscosity of 0.93 dl / g, a melt viscosity of 325 Pa s (measured at 2.4 Hz and 255 ° C), a melting point of 227 ° C, a crystallization temperature of 72 ° C and one Glass transition temperature of 45 ° C were dried at a temperature of 130 ° C in a tumble dryer to a water content of 11 ppm. The chips were melted in a 3E4 extruder from Barmag, so that the temperature of the melt was 255 ° C. It was then fed to the spinning pump through a product line which contained a static mixer from Sulzer, type SMX with 15 elements and an inner diameter of 15 mm. The amount of melt transported was 63 g / min with a residence time of 6 min, the amount metered into the nozzle pack by the spinning pump was 30.7 g / min. An element of a static mixer, type HD-CSE with 10 mm inside diameter from Fluitec was installed after the spinning pump before entering the nozzle package. The trace heating of the product line and spinning block, which contained the pump and the nozzle package, were set to 255 ° C. The nozzle package contained steel sand with a grain size of 350-500 μm with a height of 30 mm as well as a 20 μm fleece and a 40 μm fabric filter. The melt was extruded through a die plate 80 mm in diameter and 34 holes 0.25 mm in diameter and 1.0 mm in length. The nozzle pressure was 120 bar.

The cooling delay zone was 100 mm long, with 30 mm heated wall and 70 mm insulation and unheated frame. The melt threads were then cooled in a blow shaft with cross-flow blowing with a blow length of 1500 mm. The cooling air had a speed of 0.35 m / sec, a temperature of 18 ° C and a relative humidity of 80%. The solidification point of the filaments was 800 mm below the spinneret.

With the help of a thread oiler at a distance of 1050 mm from the nozzle, the threads were provided with spinning preparation and bundled. The oiler was designed with a TriboFil surface and had an inlet opening of 1 mm in diameter. The amount of preparation applied was 0.40% based on the thread weight. The bundled thread was then fed to the winding machine. The distance between the oiler and the first discharge godet was 3.2 m. The conditioning time is 144 or 168 ms, depending on the speed. A pair of godets was wrapped in an S-shaped thread. A Temco entangling nozzle was installed between the godets and operated at an air pressure of 1.5 bar. In accordance with the speed setting, the winding speed of the type SW6 winder from Barmag was set in such a way that the winding thread tension was 5 cN. The indoor climate was set to 24 ° C at 60% relative humidity, so that a temperature of about 34 ° C was established in the area surrounding the thread winding.

In the context of the present experiments, the take-off speed was either 2940 m / min (example 1) or 2506 m / min (example 2). Table 1 shows the further test parameters, Table 2 the material properties of the pre-oriented filaments (POYs) obtained. With both settings, bobbin weights of 10 kg could be produced and easily removed from the winder dome.

Table 1: Test parameters

': absolutely

² : based on the titer

Table 2: Material properties of the pre-oriented PTMT filaments ¹

CN: Coordination coefficient

¹ : measured after 4 weeks of storage under normal conditions drawtexturizing

The PTMT filament spools were stored for four weeks in normal climate in accordance with DIN 53802 and then presented to a stretch texturing machine from Barmag, type FK6-S-900. The search parameters of the stretch texturing for the production of so-called SET filaments are shown in Table 3, the material properties of the resulting bulky SET filaments are summarized in Table 4.

The texturing errors were recorded using Fima Barmag's UΝITEΝS with the following limit settings: UP / LP = 3.0 cΝ, UM LM = 6.0 cΝ.

Table 3: Search parameters of stretch texturing

F -CN: variation coefficient of F Table 4: Material properties of the stretch-textured filaments

By a cold mode of operation of the 2nd heater, i.e. H. The manufacturing behavior can be varied by producing so-called HE filaments. The crimp then increases to about 47%. The teardowns then drop to 33% o.

Claims

claims:

1. Nerfahren for the production and winding of pre-oriented polyester filaments, which consist of at least 90 wt .-% based on the total weight of the polyester filament from polybutylene terephthalate (PBT) and / or polytrimethylene terephthalate (PTMT), preferably from PTMT that a) the spinning distortion is set in the range 70 to 500, b) the filaments pass through a cooling delay zone of 30 mm to 200 mm in length immediately after emerging from the spinneret, c) the filaments are cooled below the solidification temperature, d) the filaments in a distance between 500 mm and 2500 mm from the underside of the nozzle, e) the thread tension before and between the take-off godets is set between 0.05 cΝ / dtex to 0.20 cΝ / dtex, f) the thread with a thread tension between 0.025 cΝ / dtex up to 0.15 cΝ / dtex, g) and the winding speed is set between 2200 m / min and 3500 m / min.

2. Ner driving according spoke 1, characterized in that PBT and / or PTMT are used with an intrinsic viscosity in the range from 0.7 dl / g to 0.95 dl / g.

3. The method according to claim 1 and / or 2, characterized in that a temperature <45 ° C is set during winding in the vicinity of the thread winding

4. The method according to at least one of the preceding claims, characterized in that the POY coils at least 4 hours stored at 12-35 ° C and 40-85% relative humidity before further processing.

5. Preoriented polyester filaments obtainable by a process according to at least one of the preceding claims, characterized in that after 4 weeks of storage under normal conditions according to DIN 53802 a) an elongation at break between 90% and 165%>, b) a boiling shrinkage of at least 30 %, c) a normal uster below 1.1%, d) a birefringence between 0.030 and 0.058, e) a density less than 1.35 g / cm3, preferably less than 1.33 g / cm ³ f) a coefficient of variation of Tear load <4.5%> and g) has a variation coefficient of elongation at break <4.5%.

6. A process for the production of bulky polyester filaments, characterized in that filaments according to claim 5 are processed into a bulky thread in a draw texturing machine at a speed of at least 500 m / min and a draw ratio of at least 1: 1.35.

7. Bulky polyester SET filaments obtainable by a method according spoke 6, characterized in that their tensile strength is more than 26 cN / tex and the elongation at break is more than 36%.

8. Bulky polyester HE filaments obtainable by a method according to spoke 6, characterized in that their tensile strength is more than 26 cN / tex and the elongation at break is more than 30% ».