CA2405495A1 - 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 - Google Patents

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 tot al weight of polyester filament, polybutylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), preferably PTMT, characterised in tha t a) the spinning draft is set in the range 70 to 500, b) directly after exiti ng 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, befor e 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/m in and 3500 m/min.

Description

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 The present invention relates to processes for spinning and winding POY polyester filaments not Iess than 90$
b y weight, based on the total weight of the polyester filament, polyb utylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), preferably PTMT, and also to the POY polyester filaments obtainable b y the process. The present invention further also relates to processes for draw texturing the spun and wound polyester filaments and also to the b ulky polyester filaments obtainable thereby.
The production of continuous polyester filaments and especially of polyethylene terephthalate (PET) filaments in a two-step process is already known. In this process, the first step comprises spinning and winding flat POY filaments which are fully drawn and heatset or draw-textured to bulky filaments in a second step.
An overview of this field is given b y the b ook Synthetische Fasern b y F. Fourne (1995), pub lished b y Hanser, Munich. However, only the production of PET
fib ers is described and no unified spinning technology is presented, only an overview describ ing the most diverse features.
Fib er production from various spinnab 1e polymers, including polypropylene, polyamides, polyester, etc., forms part of the subject matter of DE-A 38 19 913.
However, only the production of PET fibers is described in the examples, as is discernible from the temperature ,.. _ ~ _ at which the polymer is processed.
The problem with producing continuous polytrimethylene terephthalate (PTMT) or polyb utylene terephthalate (PBT) filaments is that POY filaments, not only directly after spinning and in winding b ut also for several hours after winding, in the course of storage at room temperature, exhibit a considerable tendency to shrink, which leads to yarn shortening. The package is compressed as a result, so that, in the extreme case, the package will shrink solid onto the winding mandrel and can no longer be removed. Furthermore, the package will develop a so-called saddle with hard edges and a waisted center portion. As a result, textile data of the filaments, for example the Uster value, become less uniform and prob lems develop when unwinding the packages. The only remedy is to restrict the package weight to less than 4 kg. Such problems do not arise in the processing of PET fibers.
It is further ob served that, in contradistinction to PET filaments, POY PBT or PTMT filaments age fast in the course of storage. Structure hardening occurs and causes the b oiloff shrinkage to decrease to such a large extent that aftercrystallization can be detected.
Such PBT or PTMT filaments are only partially suitable for further processing in that they lead to defects in draw texturing and to a significant reduction in the breaking strength of the textured yarn. The consequence is a reduction in the texturing speed or in the draw ratio.
These differences between PET on the one hand and PBT
and PTMT on the other are attributable to structural and property differences, as reported for example in Chemical Fib ers Int., p. 53, vol. 50 (2000) and discussed at the 39th International Manmade Fib re ' - 2 _ Congress at Dornb irn from September 13 to 15. It is accordingly b elieved that different chain formations are responsible for the property differences.
The first approaches to solving these prob lams are describ ed in WO 99/27168 and EP 0,731,196 B1. WO
99/27168 discloses a polyester fib er which is at least 90~ b y weight polytrimethylene terephthalate and has a b oiloff shrinkage b etween S~ and 16~ and a b reaking extension of 20~ to 60~. The polyester fib er described in WO 99/27168 is produced by spinning and drawing. The maximum spinning takeoff speed reported is 2 100 m/min.
The process is uneconomical because of the low spinning speed. In addition, the polyester fib ers obtained are, as the reported parameters document, highly crystalline and hence only partially suitab 1e for draw-texturing processes.
EP 0,731,196 B1 describ es a process fox spinning, drawing and winding a synthetic yarn b y subjecting the yarn to a heat treatment after drawing and b efore winding to reduce its tendency to shrink. Synthetic fib ers which can b a used include polytrimethylene terephthalate fib ers. In EP 0,731,196 B1, the heat treatment is effected b y the synthetic yarn b eing guided in close vicinity to b ut essentially contactlessly along an elongate heating surface. The application of a heat treatment adds to the cost of the process and, what is more, provides synthetic yarns of high crystallinity which are only partially suitab 1e for draw-texturing processes.
The article b y Dr. H.S. Brown and H.H. Chuah;
"Texturing of textile filament yarns b ased on polytrimethylene terephthalate" Chemical Fib ers International, Volume 47, Feb r. 1997, p. 72-74 describ es the draw texturing of POY 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 fib ers having better material properties are obtained in this case. The b reaking strength of the polytrimethylene terephthalate fib ers is reported as 26.5 cN/tex (texturing speed 450 m/min) and 29.15 cN/tex (texturing speed 850 m/min) and the breaking extension as 38.0$
(texturing speed 450 m/min) and 33.5 (texturing speed 850 m/min).
WO 01/04393 describes PTMT filaments having a b oiloff shrinkage in the range from 3 to 40$. However, this value is determined immediately after the filaments have been formed. This value decreases to below 20$ in the course of 4 weeks of storage under standard conditions, as documented by the accompanying figure 1.
Figure 1 describes the change in the b oiloff shrinkage far three PTMT POY bobbins as a function of the storage time under standard conditions. The three b ob b ins investigated had different initial values. Bob bins #16 and 17, having a high initial value of > 40~, have a b oiloff shrinkage after 4 weeks of ab ove 30~ and preferab 1y of ab ove 40~. However, when the initial boiloff shrinkage value is less than 40~, it is evident from bob b in 18 that the b oiloff shrinkage value will drop to below the critical value of 30$ after a storage time of 4 weeks.
Figure 2 is a schematic view of force-extension diagrams of PTMT POY. For the same breaking extension, Figure 2a) shows a diagram according to the invention featuring a natural draw ratio (NVV) of not Less than 15g and Figure 2b) shows a diagram featuring NVV = 0$.

The b oiloff shrinkage is a measure of the proces-sib ility and the crystallinity of the fib ers.
The fib ers described in WO 01/04393 comprise plastics having a comparatively high crystallinity, which are significantly more difficult to process and can only be processed at a lower draw ratio and/or at a lower texturing speed.
It is an object of the present invention to provide a process for spinning and winding POY polyester filaments not less than 90~ b y weight, based on the total weight of the filaments, PBT and/or PTMT whereb y POY polyester filaments are simple to produce and wind up. More particularly, the POY polyester filaments shall have breaking extension values in the range of 90$-1658, a high uniformity with regard to filament parameters and also a low crystallinity.
It is a further ob ject of the present invention to provide an economical industrial process for spinning and winding POY polyester filaments. The process of the invention shall permit very high spinning takeoff speeds, preferab 1y ab ove 2 200 m/min, and high yarn weights on the package of more than 4 kg.
It is yet a further object of the present invention to improve the storability of the POY polyester filaments obtainable b y the process of the invention. They shall b a storab 1e for a prolonged period, fox example 4 weeks. Ideally, the package shall not compact in the course of storage, especially shall not shrink solid on the winding mandrel and form a saddle having hard edges and waisted center portion, so that there shall b a no problems unwinding from the package.
According to the invention, the POY polyester filaments shall b a simple to further process in a drawing or draw-texturing operation, especially at high texturing speeds, preferab 1y ab ove 450 m/min. The filaments ob tainab 1e b y draw texturing shall have excellent material properties, for example a high b reaking strength of more than 26 cN/tex and a high b reaking extension of more than 30~ for HE filaments or more than 36~ for SET filaments.
These and other objects not explicitly mentioned but readily derivable or apparent from the related matters discussed herein at the b eginning are achieved b y a process for spinning and winding that comprises all the features of claim 1. Advantageous modifications of the process according to the invention are protected in sub claims appendant to claim 1. The POY polyester filament ob tainab 1e b y the spinning process is describ ed in an independent product claim. The draw texturing of the POY polyester filament is claimed in process claim 6, whereas product claims 7 and 8 relate to the b ulky filaments ob tainab 1e b y the draw texturing.
The present invention accordingly provides a process for producing and winding POY filaments not less than 90~ b y weight, b ased on the total weight of the polyester filament, polyb utylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), preferably PTMT, characterized in that it comprises a) setting the spinline extension ratio in the range from 70 to 500, b) passing the filaments directly upon exit from the spinneret through a quench delay zone 30 mm to 200 mm in length, c) quenching the filaments to b elow the solidification temperature, d) converging the filaments at a distance between 500 mm and 2 500 mm from the underface of the spinneret, e) setting the yarn tension ab ove and b etween the takeoff godets b etween 0.05 cN/dtex to 0.20 cN/dtex, preferably to 0.15 cN/dtex, f) taking the yarn up at a yarn tension between 0.025 cN/dtex to 0.15 cN/dtex, g) setting the takeup speed between 2 200 m/min and 3 500 m/min.
This unforeseeab 1e process provides POY polyester filaments which maintain their excellent material properties even after 4 weeks of storage under standard conditions. No significant worsening in the uniformity values of the yarn due to aging and no shrinkage of the spun fiber on the bobbin are observed.
At the same time, the process of the invention has a number of further advantages. These include:
The process of the invention is simple and economical to practice on a large industrial scale.
More particularly, the process permits spinning and winding at high takeoff speeds of at least 2 200 m/min and the production of packages holding high yarn weights of more than 4 kg.
b The process of the present invention obviates the use of spinning additives. Polyester filaments can be obtained particularly economically as a result.
The POY polyester filaments ob tainab 1e b y the process can thus b a further processed in a drawing or draw-texturing operation simply, economically and on a large industrial scale. In the operation, the texturing can b a carried out at speeds above 450 m/min.
Owing to the high uniformity of the POY polyester filaments obtainable b y the process, it is simple to achieve good package build to ensure uniform and sub stantially defect-free dyeing and further processing of the POY polyester filament.
The filaments obtainable by the draw texturing have a high breaking strength of more than 26 cN/tex and a high breaking extension of more than 30~ for HE
filaments and more than 36$ for SET filaments.
The present invention provides a process for producing and for winding POY polyester filaments not less than 90~ b y weight polyb utylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), b ased on the total weight of the filament. Polyb utylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT) are known to one skilled in the art. Polyb utylene terephthalate (PBT) is obtainable b y polycondensation of terephthalic acid with equimolar amounts of 1,4-b utanediol and polytrimethylene terephthalate is ob tainab 1e b y polycondensation of terephthalic acid with equimolar amounts of 1,3-propanediol. Mixtures of the two polyesters are also conceivable. According to the invention, PTMT is preferred.
The polyesters may b a homopolymers or copolymers.
Useful copolymers include especially copolymers which, as well as PTMT and/or PBT repeat units, contain up to 15 mol$, b ased on all the repeat units of the polyesters, of repeat units of customary comonomers, for example ethylene glycol, diethylene glycol, triethylene glycol, 1,4-cyclohexanedimethanol, polyethylene glycol, isophthalic acid and/or adipic acid. For the purposes of the present invention, however, polyester homopolymers are preferred.

_ g _ The polyesters of the invention may include customary amounts of further additives as admixtures, such as catalysts, stab ilizers, antistats, antioxidants, flame retardants, dyes, dye uptake modifiers, light stab ilizers, organic phosphites, optical b righteners and delusterants. Preferably, the polyesters include 0 to 5$ by weight of additives, based on the total weight of the filament.
The polyesters may further include a small fraction, preferably up to 0.5~ b y weight, based on the total weight of the filament, of b rancher components.
Preferred b rancher components according to the invention include polyfunctional acids, such as trimellitic acid, or pyromellitic acid, or tri- to hexavalent alcohols, such as trimethylolpropane, pentaerythritol, dipentaerythritol, glycerol or corresponding hydroxyacids.
Useful polyesters for the invention are preferab 1y thermoplastically formab 1e and can b a spun into filaments and wound up. In this context, particularly advantageous polyesters have a limiting viscosity number in the range from 0.70 dl/g to 0.95 dl/g.
In the process of the invention, the melt or melt mixture of the polyester is pumped by spinning pumps at constant speed, the speed being calculated b y a known formula so that the desired fib er linear density is ob tamed, into spinneret packs to b a extruded through the holes in the die plate of the pack to form molten filaments.
The melt may be prepared for example from polymer chips in an extruder, in which case it is particularly favorable for the chips first to b a dried to a water content <_30 ppm and especially to a water content __<15 _ g _ ppm.
The temperature of the melt, which is commonly referred to as the spinning temperature and which is measured above the spinning pump, depends on the melting point of the polymer or polymer blend used. It is preferably situated in the range given by formula 1:
Formula 1:
Tm + 15°C 5 Tgp<_ Tm + 45°C
where Tm is the melting point of the polyester [°C]
Tgp is the spinning temperature [°C].
The specified parameters serve to limit the hydrolytic and/or thermal viscosity degradation, which should advantageously b a very low. In the context of the present invention, a viscosity degradation of less than 0.12 dl/g and especially less than 0.08 dl/g is desirable.
Melt homogeneity has a direct influence on the properties of the spun filaments. It is therefore preferable to use a static mixer having at least one element and installed b elow the spinning pump to homogenize the melt.
Die plate temperature, which depends on the spinning temperature, is controlled b y the plate's secondary heating system. Useful secondary heating systems include for example a spinning b eam heated with "Diphyl" or additional convective or radiative heaters.
The temperature of the die plates is customarily equal to the spinning temperature.
A temperature increase at the die plate can be obtained through the pressure gradient in the spinneret pack.

Known derivations, for example K. Riggert "Fortschritte in der Herstellung von Polyester-Reifenkordgarn"
Chemiefasern 21, page 379 (1971), describ a a temperature increase of ab out 4°C per 100 b ar of pressure drop.
It is further possible to control die pressure through the use of loose filter media, especially through the use of steel sand having an average particle size between 0.10 mm and 1.2 mm, preferably between 0.12 mm and 0.75 mm and/or filter disks, which can b a formed from woven or nonwoven metal fabrics having a fineness <_40 um.
In addition, the pressure drop in the die hole contributes to the overall pressure. The die pressure is preferab 1y set b etween 80 b ar and 450 b ar, especially between 100 bar and 250 bar.
The spinline extension ratio isp, i.e. the ratio of the takeoff speed to the extrusion speed, is calculated in accordance with US 5,250,245 via formula 2 from the density of the polymer or polymer mixture, the spinneret hole diameter and the filament linear density:
Formula 2:
igp = 2 . 25~105~ (8~n) ~D2 (cm) /dpf (den) where 8 = density of melt [g/cm3]; for PTMT = 1.12 g/cm3 D = spinneret hole diameter [cm]
dpf = denier per filament [den].
For the purposes of the present invention, the spinline extension ratio is b etween 70 and 500, preferab 1y between 100 and 250.

The length/diameter ratio of the spinneret hole is preferably selected to be between 1.5 and 6, especially between 1.5 and 4.
The extruded filaments pass through a quench delay zone. The quench delay zone is configured directly b elow the spin pack as a recess zone in which the filaments emerging from the spinneret holes are protected from the direct action of the cooling gas and are delayed in spinline extension or cooling. An active part of the recess is constructed as an extension of the spin pack into the spinning b eam, so that the filaments are surrounded b y heated walls. A passive part is formed b y insulating layers and unheated frames. The lengths of the active recess are between 0 to 100 mm and those of the passive part between 20 to 120 mm, subject to an overall length of 30 - 200 mm, preferably 30 - 120 mm.
As an alternative to the active recess, a reheater can be disposed below the spinning beam. In contrast to the active recess, this zone of cylindrical or rectangular cross section then comprises at least one heating system independent of the spinning beam.
In the case of radial porous quenching systems which surround the spinline concentrically, the quench delay can be attained using cylindrical shrouds.
The filaments are sub sequently cooled to temperatures below the solidification temperature. For the purposes of the invention, the solidification temperature is the temperature at which the melt passes into the solid state.
In the context of the present invention, it has been determined to b a particularly advantageous to cool the filaments down to a temperature at which they are essentially no longer tacky. It is particularly advantageous to cool the filaments to temperatures below their crystallization temperature, especially to temperatures below their glass transition temperature.
Means for quenching or cooling filaments are known from the prior art. It is particularly useful according to the invention to use cooling gases, especially cooled air. The temperature of the cooling air is preferably in the range from 12°C to 35°C, and especially in the range from 16°C to 26°C. The velocity of the cooling air is advantageously in the range from 0.20 m/sec to 0.55 m/sec.
The filaments may b a cooled using for example single end systems comprising single cooling tub es having a perforated wall. Cooling of each individual filament is ob tamed through active cooling air supply or b y utilizing the self-suction effect of the filaments. As an alternative to the individual tub es, it is also possible to use the familiar crossflow quench systems.
In a particular embodiment of the cooling and spinline extension region, the filaments emerging from the delay zone are exposed to cooling air in a zone 10 to 175 cm and preferably 10 - 80 cm in length. A zone 10 - 40 cm in length is particularly suitable for filaments having a linear density at windup <_1.5 dtex per filament and a zone length of 20 - 80 cm is particularly suitable for filaments having a linear density between 1.5 and 9.0 dtex per filament. The filaments and the accompanying air are sub sequently conjointly passed through a channel having a reduced cross section at a ratio of the air to the spinline speed at takeoff in the range from 0.2 to 20:1, preferably in the range from 0.4 to 5:1, b y controlling the cross-sectional constriction and the dimensioning in the spinline transportation direction.
After the filaments have b een cooled down to temperatures below the solidification point, they are converged to form a yarn bundle. A suitable distance according to the invention for the point of convergence from the underface of the spinneret can b a determined using conventional methods for online measurement of the yarn speed and/or yarn temperature, for example using a laser doppler anemometer from TSI/Germany or an infrared camera from Goratec/Germany type IRRIS 160. It is in the range from 500 to 2 500 mm, preferably from 500 to 1 800 mm. Filaments having an as-spun linear density <_4.5 dtex are preferab 1y converged into a multifilament bundle at a smaller distance <_1 500 mm, while thicker filaments are preferably converged at a greater distance.
It is advantageous for the purposes of the present invention that preferably all surfaces which come into contact with the spun filament are fab ricated of particularly low-friction materials. This substantially avoids b roken filaments and provides higher quality filament yarns. Particularly suitable for this purpose are low-friction surfaces of the "Trib oFil"
specification from Ceramtec/Germany.
The filaments are converged in an oiler pin which supplies the yarn with the desired amount of spin finish at a uniform rate. A particularly suitable oiler pin is characterized b y an inlet part, the yarn duct with oil inlet orifice and an outlet part. The inlet part is funnellike, so that contact b y the still dry filaments is avoided. The contact point of the filaments occurs within the yarn duct after the supply of spin finish. Yarn duct and oil inlet orifice are conformed in width to the yarn linear density and the numb er of filaments. Orifices and widths in the range from 1.0 mm to 4.0 mm are particularly suitable. The outlet part of the oiler pin is configured as a uniformizing zone, which preferab 1y comprises oil reservoirs. Such oilers are obtainable for example from Ceramtec/Germany or Goulston/USA.
The uniformity of oil application is of immense importance for the invention. The uniformity can b a determined for example using a Rossa meter as per the method described in Chemiefasern/Textilindustrie, 42/94 November 1992 at page 896. Preferably, such a procedure provides standard deviation values for the oil application which are less than 90 digits and especially less than 60 digits. Particular preference for the purposes of the invention is given to oil application standard deviation values of less than 45 digits and especially less than 30 digits. A standard deviation value of 90 or 45 digits corresponds approximately to 6.2~ or 3.1~ of the coefficient of variation, respectively.
It is particularly advantageous for the purposes of the present invention to design spin finish lines and pumps to b a self-degassing to avoid gas b ub b les, since gas b ub b les can lead to an appreciab 1e variation in oil application.
According to the invention, it is particularly preferable for the filaments to be entangled before the yarn is wound up. In the context of the present invention, jets having closed yarn ducts will b a found to be particularly suitable, since such systems prevent snubbing of the yarn in the feed slot even at low yarn tension and high air pressure. The entangling jets are preferably disposed between godets and the yarn exit tension is controlled via the different speeds of the inlet and outlet godets. The yarn exit tension should not exceed 0.20 cN/dtex and should primarily have values b etween 0.05 cN/dtex and 0.15 cN/dtex. The entangling air pressure is between 0.5 and 5.5 bar, or at most 3.0 bar in the case of takeup speeds of up to 3 500 m/min.
The yarns are preferably entangled to node counts of at least 10 n/m. Maximum nodeless gaps of less than 100 cm and node count coefficient variation values below 100$
are of particular interest. Advantageously, the employment of air pressures above 1.0 bar provides node counts >_15 n/m, which are characterized b y high uniformity in that the coefficient of variation is not more than 70~ and the maximum nodeless gap is 50 cm. In actual service, systems of the LD type from Temco/Germany, the double system from Slack & Parr/USA
or Polyjet from Heb erlein have b een found to b a particularly useful.
The circumferential speed of the first godet unit is referred to as takeoff speed. Further godet systems can b a employed before the yarn is wound up in the wind assembly to form packages (bobbins) on formers.
Stab 1e, defect-free packages are a basic prerequisite for defect-free winding of the yarn and for an ideally defect-free further processing. Therefore, in the context of the present invention, the takeup tension employed is in the range of 0.025 cN/dtex - 0.15 cN/dtex and preferably in the range of 0.03 cN/dtex -0.08 cN/dtex.
An important parameter of the process according to the invention is the yarn tension setting above and between the takeoff godets. As will b a known, this tension is made up essentially of Hamana's actual orientation tension, the frictional tension on the yarn guides and the oiler and the yarn-air frictional tension. For the purposes of the present invention, the yarn tension above and between the takeoff godets is in the range from 0.05 cN/dtex to 0.20 cN/dtex anal preferably in the range between 0.08 cN/dtex and 0.15 cN/dtex.
An excessively low tension below 0.05 cN/dtex no longer provides the desired degree of partial orientation.
When the tension exceeds 0.20 cN/dtex, this tension will induce a memory effect in the course of winding and storing the bob bins that leads to a deterioration in yarn parameters.
The tension is controlled according to the invention by the distance of the oiler from the jet spinneret, the frictional surfaces and the length of the gap between oiler and takeoff godet. This length is advantageously not more than 6.0 m and preferably less than 2.0 m, the spinning system and the takeoff machine being disposed in such a way b y parallel construction as to ensure a straight yarn path.
The geometric parameters also describe the conditioning time of the yarn between converging point and takeup.
The fast relaxation during the period has an effect on the quality of package build. The conditioning time so defined is preferably chosen to b a between 50 and 200 ms.
The takeup speed of the POY is between 2 200 m/min and 3 500 m/min according to the invention.
Advantageously, the process according to the invention is carried out by adjusting the environment of the yarn package to b a at a temperature _<45°C, especially between 12 and 35°C, and a relative humidity of 40 -85~. The POY is preferab 1y stored at a temperature <_ 45°C until further processing. It is further advantageous to store the POY packages at 12 to 35°C
and a relative humidity of 40-85~ for at least 4 hours prior to further processing.
After 4 weeks of storage under standard conditions, the filament according to the invention has a) a b reaking extension b etween 90~ and 165$, preferably between 90 and 135$, b) a boiloff shrinkage of at least 30$, preferably >_40~, c) a normal Uster b elow 1.1$, preferab 1y b elow 0.9~, d) a birefringence between 0.030 and 0.058, e) a density of less than 1.35 g/cm3, preferably less than 1.33 g/cm3, f) a breaking load coefficient of variation <4.5~, preferably __<2.5$ and g) a breaking extension coefficient of variation S
4.5~, preferably <_2.5$
The term "standard conditions" is known to one skilled in the art and defined via the DIN 53802 standard.
Under "standard conditions" as per DIN 53802, the temperature is 20~2°C and the relative humidity 65-~2~.
It is additionally particularly advantageous for the purposes of the present invention for the b oiloff shrinkage to b a b etween 50 and 65~ when measured directly after windup and to b a at least 30~ and preferably >_40~ after 4 weeks of storage under standard conditions. It has been determined that, surprisingly, POY bobbins produced in this way have excellent further processing properties.
It must b a b orne in mind here that, in industrial practice, standard conditions cannot always b a adhered - 18 _ to in the manufacture, storage or transportation of the POY. However, low-crystallinity fib er would then frequently give rise to the prob lem that the POY
b ob b ins change in shape, the draw ratio and/or the texturing speed has to b a reduced and there is an increasing occurrence of b roken ends in further processing. Yarns which conform to the aforementioned specifications for the boiloff shrinkage are associated with such problems to a lesser degree than conventional yarns.
It has additionally b een determined that preferred yarns of the present invention do not exhibit a changed depth of shade on DTY even after a storage period of 2 months. After a storage period of 20 months, the color change is within 95 f 3~, provided the amb Tent temperature is not more than 45°C.
Furthermore, preferred filaments have a natural draw ratio of not less than 15$. More preferably the natural draw ratio is in the range from 18 to 65~. The higher the natural draw ratio, the better the drawability. For the same extension, a high natural draw ratio will result in a higher draw ratio.
The natural draw ratio is defined as the plateau section in percent of the force-extension diagram. This parameter is known and determined b y a tensile tester in one operation with the determination of strength and extension.
Figures 2a) and 2b) are schematic representations of the indicated parameter of the natural draw ratio (NVV), although the natural draw ratio in Figure 2b) is zero. The diagrams are each plots of the force against the extension, and the diagrams depicted are schematic in order that the parameter may be illustrated.

It is believed that the natural draw ratio is a measure of fib er orientation and an NVV value < 15~ describes the onset of crystallization of the polyester. Low NVV
values are obtained for example by thermal treatment of the fib er until takeup at temperatures which are at least 8°C ab ove the glass transition temperature of PES.
Methods for determining the indicated material parameters are well known to those skilled in the art.
They are discernib 1e from the technical literature.
Although most of the parameters can b a determined in various ways, the following methods for determining the filament parameters will prove particularly advantageous for the purposes of the present invention:
The intrinsic viscosity is measured at 25°C in an Ub b elohde capillary viscometer and calculated b y the familiar formula. The solvent used is a 3:2 w/w mixture of phenol and 1,2-dichlorobenzene. The concentration of the solution is 0.5 g of polyester per 100 ml of solution.
The melting point, the crystallization temperature and the glass transition temperature are each determined using a DSC calorimeter from Mettler. The sample is initially heated to 280°C to melt it and then quenched.
The DSC measurement is done in the range from 20°C to 280°C at a heating rate of 10 Klmin. The reported temperatures are determined by the processor.
Filament density is determined in a density gradient column at a temperature of 23~0.1°C. The reagent used is n-heptane (C~H16) and tetrachloromethane (CC14). The result of the density measurement can b a used to calculate the crystallinity on the basis of the density of the amorphous polyester Da and the density of the crystalline polyester Dk. The calculation is described in the literature and for PTMT for example the corresponding values are Da = 1.295 g/cm3 and Dk =
1.429 g/cm3.
Linear density is determined in a known manner using a precision reel and weighing means. The pretension used is advantageously 0.05 cN/dtex for POY and 0.2 cN/dtex for DTY.
Breaking strength and breaking extension are determined on a Statimat apparatus under the following conditions:
the clamped length is 200 mm for POY and 500 mm for DTY, the rate of extension is 2 000 mm/min for POY and 1 500 mm/min for DTY and the pretension is 0.05 cN/dtex for POY and 0.2 cN/dtex for DTY. The maximum breaking load values are divided b y the linear density to determine the breaking strength, and breaking extension is determined at maximum load.
Boiloff shrinkage is determined b y treating filament skeins in water at 95~1°C for 10~1 min in a tensionless state. The skeins are prepared b-y reeling at a pretension of 0.05 cN/dtex for POY and 0.2 cN/dtex for DTY; the length measurement of the skeins before and after the thermal treatment is carried out at 0.2 cN/dtex. The difference in length is used to calculate the boiloff shrinkage in a known manner.
Birefringence is determined b y the method described in DE 19,519,898, the disclosure of which is explicitly incorporated herein by reference.
The crimp parameters of the textured filaments are measured in accordance with DIN 53840 Part 1 using a Texturmat apparatus from Stein/Germany at a release temperature of 120°C.

The normal Uster values are determined using a 4-CX
Uster tester and are reported as Uster ~ values. The testing speed is 100 m/min and the testing time 2.5 min.
The POY according to the invention is simple to further process, especially draw texture. In the present invention, draw texturing is preferably carried out at a texturing speed of at least 500 m/min and particularly preferab 1y at a texturing speed of at least 700 m/min. The draw ratio is preferably at least 1.35:1 and especially at least 1.40:1. It will b a particularly advantageous to draw texture on a high temperature heater type machine, for example an AFK
machine from Barmag.
The bulky filaments produced in this way exhibit a low numb er of defects and on dyeing at the b oil at 95°C
with a disperse dye (Terasil Navy) without carrier an excellent depth of shade and uniformity of color.
Bulky SET filaments produced according to the invention preferab 1y have a b reaking strength of more than 26 cN/tex and a breaking extension of more than 36~. In the case of bulky HE filaments, which are obtainable without thermal treatment in a second heater, the breaking strength is preferably more than 26 cN/tex and the breaking extension more than 30$.
The b ulk and elasticity b ehavior of the filaments according to the invention is excellent.
Illustrative embodiments of the invention will now b a more particularly described without the invention being limited to these examples.

Examples 1 and 2 S_pinnina and winding PTMT chips having 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 a glass transition temperature of 45°C were tumble dried at 130°C 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. The melt was then fed to the spinning pump through a product line containing an SMX static mixer from Sulzer having 15 elements and an internal diameter of 15 mm. The transported amount of melt was 63 g/min coupled with a residence time of 6 min, and the amount metered from the spinning pump to the spinneret pack was 30.7 g/min.
Various takeup speed settings were used. One element of an HD-CSE type static mixer from Fluitec having an internal diameter of 10 mm had been installed below the spinning pump, but above the point of entry into the spinneret pack. The secondary heating systems for the product line and the spin b lock, which contained the pump and the spinneret pack, had been set to 255°C. The spinneret pack contained 350-500 pm steel sand 30 mm in height and also a 20 um nonwoven filter and a 40 um woven filter as filter media. The melt was extruded through an 80 mm diameter spinneret plate containing 34 holes 0.25 mm in diameter and 1.0 mm in length. The die pressure was 120 bar.
The quench delay zone was 100 mm in length, made up of 30 mm in heated walling and 70 mm in insulation and unheated frame. The molten filaments were quenched with air flowing horizontally against the spinline over a length of 1500 mm. The quenching air had a flow rate of 0.35 m/sec, a temperature of 18°C and a relative humidity of 80~. The filaments became solid at ab out 800 mm below the spinneret.
A yarn oiler positioned at a distance of 1 050 mm from the spinneret was used to apply spin finish to the ends before converging. The oiler had a TriboFil surface and an inlet opening 1 mm in diameter. The amount of spin finish applied was 0.40, based on fiber weight.
The converged spinline was then fed to the winding machine. The distance between the oiler and the first takeoff godet was 3.2 m. The conditioning time was 144 or 168 ms, depending on the speed. A pair of godets was S-wrapped b y the yarn. Situated between the godets was a Temco entangling jet, which was operated using an air pressure of 1.5 bar. In line with the speed setting, the takeup speed of the Barmag SW6 winder was set in such a way that the takeup yarn tension was 5 cN. The room conditions were adjusted to 24°C and 60$ relative humidity so that a temperature of ab out 34°C ensued in the environment of the yarn package.
In the context of the present tests, the takeoff speed was either 2 940 m/min (Example 1) or 2 506 m/min (Example 2). Table 1 indicates the other experimental parameters and Table 2 the material properties of the POY filaments ob tamed. At either setting, b ob b in weights of 10 kg were producible and readily removable from the winding mandrel.

Table 1: Experimental parameters Experimental parameters Example Example Takeoff speed (m/min] 2 940 2 506 Takeup speed [m/min] 2 926 2 500 Spinline extension 178 152 ratio Yarn tensions above godetsl (cN] 14 10 between godetsl max [cN] 11 7.5 above godets2 [cN/dtex] 0.13 0.08 between godets2 max [cN/dtex] 0.10 0.06 Yarn tension) [cN] 5.0 5.0 Yarn tension2 [cN/dtex] 0.048 0.041 1: absolute 2: based on linear density Table 2: Material properties of PTMT POY filaments) Material properties Example Example Linear density [dtex] 105 123 Breaking strength [cN/dtex] 23.4 20.7 Breaking extension [ g ] 98 127 Normal Uster [$] 0.9 0.76 Boiloff shrinkage [~] 46 33 Birefringence103 4n 52 43 Density [g/cm3] 1.320 1.318 Breaking load CV [~] 2,2 1,g Breaking extension (~] 2.2 1.9 CV

CV: coefficient of variation 1: measured after 9 weeks of storage under normal conditions Draw texturing The PTMT filament bobbins were stored for 4 weeks under standard conditions as defined in DIN 53802 and then presented to a Barmag FK6-S-900 draw texturing machine.
The experimental parameters for draw texturing to produce SET filaments are summarized in table 3 and the material properties of the resulting b ulky SET
filaments in table 4.
Texturing defects were determined using Barmag's UNITENS system at the following limiting value settings: UP/LP = 3.0 cN, UM/LM = 6.0 cN.
Table 3: Experimental parameters of draw texturing Experimental par ameters Example 1 Exempla 2 Speed [m/min] [m/min] 700 700 Draw ratio 1:1.48 1:1.65 D/Y ratio 2.1 2.1 Heater 1 tem . [C] 155 155 Heater 2 tem . [C] 160 160 Texturing defects [n/10 km] 0 0 Yarn tension F1, above assembly [cN] 20 20 F2, below assembly [cN] 19 18 F2-CV [$] 1.2 1.3 F2-CV: coefficient of variation of F2 Table 4: Material properties of draw-textured filaments Material properties Example Exa~apl~

Linear density [dtex] 78 82 Breaking strength (cN/tex] 27.7 29.0 Breaking extension [$] 39.4 39.9 Inspection of uniform uniform dyeability Crimp rigidity [$] 85 87 Crimp contraction [$] 24.5 25 The bulking behavior can be varied by operating the 2nd heater cold, ie b y producing so-called HE filaments.
The crimp contraction then increases to ab out 47$. The breaking extensions then decrease to 33~.

Claims (8)

What is claimed is:

1. A process for producing and winding POY polyester filaments not less than 90% by weight, based on the total weight of the polyester filament, polyb utylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), preferably PTMT, characterized in that it comprises a) setting the spinline extension ratio in the range from 70 to 500, b) passing the filaments directly upon exit from the spinneret through a quench delay zone 30 mm to 200 mm in length, c) quenching the filaments to b elow the solidification temperature, d) converging the filaments at a distance between 500 mm and 2 500 mm from the underface of the spinneret, e) setting the yarn tension above and between the takeoff godets b etween 0.05 cN/dtex to 0.20 cN/dtex, f) taking the yarn up at a yarn tension between 0.025 cN/dtex to 0.15 cN/dtex, g) setting the takeup speed between 2 200 m/min and 3 500 m/min.

2. A process as claimed in claim 1, characterized in that PBT and/or PTMT having a limiting viscosity number in the range from 0.7 dl/g to 0.95 dl/g are used.

3. A process as claimed in claim 1 and/or 2, characterized in that the taking up is effected by setting a temperature <= 45°C in the amb ience of the yarn package.

4. A process as claimed in at least one of the preceding claims, characterized in that the POY
bobbins are stored at 12-35°C and 40-85% relative humidity for at least 4 hours prior to further processing.

5. POY polyester filaments obtainable by a process as claimed in at least one of the preceding claims, characterized in that it has a) a breaking extension between 90% and 165%, b) a boiloff shrinkage of at least 30%, c) a normal Uster below 1.1%, d) a birefringence between 0.030 and 0.058, e) a density of less than 1.35 g/cm3, preferably less than 1.33 g/cm3, f) a breaking load coefficient of variation <=4.5%
and g) a breaking extension coefficient of variation <=
4.5%
after 4 weeks of storage under standard conditions as defined in DIN 53802.

6. A process for producing bulky polyester filaments, characterized in that filaments as claimed in claim 5 are processed in a draw-texturing machine at a speed of at least 500 m/min and a draw ratio of at least 1.35:1 into a bulky yarn.

7. Bulky polyester SET filaments ob tainab le b y a process as claimed in claim 6, characterized in that their b reaking strength is more than 26 cN/tex and the breaking extension more than 36%.

8. Bulky polyester HE filaments ob tainab 1e b y a process as claimed in claim 6, characterized in that their b reaking strength is more than 26 cN/dtex and the breaking extension more than 30%.