Abstract:
Poly(trimethylene terephthalate) is formed into a bulk continuous filament yarn by a process comprising:  
     (a) melt-spinning poly(trimethylene terephthalate) at a temperature within the range of about 240 to about 280° C. to produce a plurality of spun filaments;  
     (b) cooling the spun filaments;  
     (c) converging the spun filaments into a yarn;  
     (d) drawing the yarn at a first draw ratio within the range of about 1.01 to about 2 in a first drawing stage defined by at least one feed roller and at least one first draw roller, each of said at least one feed roller operated at a temperature less than about 100° C. and each of said at least one draw roller heated to a temperature greater than the temperature of said at least one feed roller and within the range of about 50 to about 150° C.;  
     (e) subsequently drawing the yarn at a second draw ratio of at least about 2.2 times that of the first draw ratio in a second drawing stage defined by said at least one first draw roller and at least one second draw roller, each of said at least one second draw roller heated to a temperature greater than said at least one first draw roller and within the range of about 100 to about 200° C.; and  
     (e) winding the drawn yarns, after optionally texturing the drawn yarns.  
     The invention process enables the production of poly(trimethylene terephthalate)-based carpet having the bulk and resiliency of nylon as well as the stain resistance and low static generation of polyester.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This is a continuation-in-part of Ser. No. 435,065, filed May 8, 1995. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to the spinning of synthetic polymeric yarns. In a specific embodiment, the invention relates to spinning poly(trimethylene terephthalate) into yarn suitable for carpets.  
           [0003]    Polyesters prepared by condensation polymerization of the reaction product of a diol with a dicarboxylic acid can be spun into yarn suitable for carpet fabric. U.S. Pat. No. 3,998,042 describes a process for preparing poly(ethylene terephthalate) yarn in which the extruded fiber is drawn at high temperature (160° C.) with a steam jet assist, or at a lower temperature (95° C.) with a hot water assist. Poly(ethylene terephthalate) can be spun into bulk continuous filament (BCF) yarn in a two-stage drawing process in which the first stage draw is at a significantly higher draw ratio than the second stage draw. U.S. Pat. No. 4,877,572 describes a process for preparing poly(butylene terephthalate) BCF yarn in which the extruded fiber is drawn in one stage, the feed roller being heated to a temperature 30° C. above or below the Tg of the polymer and the draw roller being at least 100° C. higher than the feed roll. The application of conventional polyester spinning processes to prepare poly(trimethylene terephthalate) BCF results in yarn which is of low quality and poor consistency. It would be desirable to have a process for preparing high-quality BCF carpet yarn from poly(trimethylene terephthalate).  
           [0004]    It is therefore an object of the invention to provide a process for preparing high-quality bulk continuous filament yarn from poly(trimethylene terephthalate).  
         SUMMARY OF THE INVENTION  
         [0005]    According to the invention, poly(trimethylene terephthalate) is formed into a bulk continuous filament yarn by a process comprising:  
           [0006]    (a) melt-spinning poly(trimethylene terephthalate) at a temperature within the range of about 240° C. to about 280° C. to produce a plurality of spun filaments;  
           [0007]    (b) cooling the spun filaments;  
           [0008]    (c) converging the spun filaments into a yarn;  
           [0009]    (d) drawing the yarn at a first draw ratio within the range of about 1.01 to about 2 in a first drawing stage defined by at least one feed roller and at least one first draw roller, each of said at least one feed roller operated at a temperature less than about 100° C. and each of said at least one draw roller heated to a temperature greater than the temperature of said at least one feed roller and within the range of about 50 to about 150° C.;  
           [0010]    (e) subsequently drawing the yarn at a second draw ratio of at least about 2.2 times that of the first draw ratio in a second drawing stage defined by said at least one first draw roller and at least one second draw roller, each of said at least one second draw roller heated to a temperature greater than said at least one first draw roller and within the range of about 100 to about 200° C.; and  
           [0011]    (f) winding the drawn yarn.  
           [0012]    The process may optionally include texturing the drawn yarn prior to or after winding step (f).  
           [0013]    The process of the invention permits the production of poly(trimethylene terephthalate) bulk continuous filament yarn suitable for high-quality carpet. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0014]    [0014]FIG. 1 is a schematic diagram of one embodiment of the invention yarn preparation process.  
         [0015]    [0015]FIG. 2 is a schematic diagram of a second embodiment of the invention process.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    The fiber-spinning process is designed specifically for poly(trimethylene terephthalate), the product of the condensation polymerization of the reaction product of trimethylene diol (also called “1,3-propane diol”) and a terephthalic acid or an ester thereof, such as terephthalic acid and dimethyl terephthalate. The poly(trimethylene terephthalate) may be derived from minor amounts of other monomers such as ethane diol and butane diol as well as minor amounts of other diacids or diesters such as isophthalic acid. Poly(trimethylene terephthalate) having an intrinsic viscosity (i.v.) within the range of about 0.8 to about 1.0 dl/g, preferably about 0.86 to about 0.96 dl/g (as measured in a 50/50 mixture of methylene chloride and trifluoroacetic acid at 30° C.) and a melting point within the range of about 215 to about 230° C. is particularly suitable. The moisture content of the poly(trimethylene terephthalate) should be less than about 0.005% prior to extrusion. Such a moisture level can be achieved by, for example, drying polymer pellets in a dryer at 150-180° C. until the desired dryness has been achieved.  
         [0017]    One embodiment of the invention process can be described by reference to FIG. 1. Molten poly(trimethylene terephthalate) which has been extruded through a spinneret into a plurality of continuous filaments  1  at a temperature within the range of about 240 to about 280° C., preferably about 250 to about 270° C., and then cooled rapidly, preferably by contact with cold air, is converged into a multifilament yarn and the yarn is passed in contact with a spin finish applicator, shown here as kiss roll  2 . Yarn  3  is passed around denier control rolls  4  and  5  and then to a first drawing stage defined by feed roll  7  and draw roll  9 . Between rolls  7  and  9 , yarn  8  is drawn at a relatively low draw ratio, within the range of about 1.01 to about 2, preferably about 1.01 to about 1.35. Roller  7  is maintained at a temperature less than about 100° C., preferably within the range of about 40 to about 85° C. Roller  7  can be an unheated roll, in which case its temperature of operation will be somewhat elevated (30-45° C.) due to friction and the temperature of the spun fiber. Roller  9  is maintained at a temperature within the range of about 50 to about 150° C., preferably about 90 to about 140° C.  
         [0018]    Drawing speeds of greater than 1000 m/min. are possible with the invention process, with drawing speeds greater than 1800 m/min. desirable because of the high tenacity of the resulting yarn.  
         [0019]    Drawn yarn  10  is passed to a second drawing stage, defined by draw rolls  9  and  11 . The second-stage draw is carried out at a relatively high draw ratio with respect to the first-stage draw ratio, generally at least about 2.2 times that of the first stage draw ratio, preferably at a draw ratio within the range of about 2.2 to about 3.4 times that of the first stage. Roller  11  is maintained at a temperature within the range of about 100 to about 200° C. In general, the three rollers will be sequentially higher in temperature. The selected temperature will depend upon other process variables, such as whether the BCF is made with separate drawing and texturing steps or in a continuous draw/texturing process, the effective heat transfer of the rolls used, residence time on the roll, and whether there is a second heated roll upstream of the texturing jet. Drawn fiber  12  is passed in contact with optional relax roller  13  for stabilization of the drawn yarn. Stabilized yarn  14  is passed to optional winder  15  or is sent directly to the texturing process.  
         [0020]    The drawn yarn is bulked by suitable means such as a hot air texturing jet. The preferred feed roll temperature for texturing is within the range of about 150 to about 220° C. The texturing air jet temperature is generally within the range of about 150 to about 210° C., and the texturing jet pressure is generally within the range of about 50 to about 120 psi to provide a high-bulk BCF yarn. Wet or superheated steam can be substituted for hot air as the bulking medium.  
         [0021]    [0021]FIG. 2 shows a second embodiment of the two-stage drawing process showing texturing steps downstream of the drawing zone. Molten poly(trimethylene terephthalate) is extruded through spinneret  21  into a plurality of continuous filaments  22  and is then quenched by, for example, contact with cold air. The filaments are converged into yarn  24  to which spin finish is applied at  23 . Yarn  27  is advanced to the two-stage draw zone via rolls  25  and  26 , which may be heated or non-heated.  
         [0022]    In the first draw stage, yarn  31  is drawn between feed roll  28  and draw roll  29  at a draw ratio within the range of about 1.01 and about 2. Drawn yarn  32  is then subjected to a second draw at a draw ratio at least about 2.2 times the first draw ratio, preferably a draw ratio within the range of about 2.2 to about 3.4 times that of the first draw. The temperature of roll  28  is less than about 100° C. The temperature of draw roll  29  is within the range of about 50 to about 150° C. The temperature of draw roll  30  is within the range of about 100 to about 200° C. Drawn yarn  33  is advanced to heated rolls  34  and  35  to preheat the yarn for texturing. Yarn  36  is passed through texturing air jet  37  for bulk enhancement and then to jet screen cooling drum  38 . Textured yarn  39  is passed through tension control  40 ,  41  and  42  and then via idler  43  to optional entangler  44  for yarn entanglement if desired for better processing downstream. Entangled yarn  45  is then advanced via idler  46  to an optional spin finish applicator  47  and is then wound onto winder  48 . The yarn can then be processed by twisting, texturing and heat-setting as desired and tufted into carpet as is known in the art of synthetic carpet manufacture.  
         [0023]    Poly(trimethylene terephthalate) yarn prepared by the invention process has high bulk (generally within the range of about 20 to about 45%, preferably within the range of about 26 to about 35%), resilience and elastic recovery, and is useful in the manufacture of carpet, including cut-pile, loop-pile and combination-type carpets, mats and rugs. Poly(trimethylene terephthalate) carpet has been found to exhibit good resiliency, stain resistance and dyability with disperse dyes at atmospheric boil with optional carrier.  
       EXAMPLE 1  
     Effect of Intrinsic Viscosity on Poly(trimethylene terephthalate) Fiber Drawing  
       [0024]    Four poly(trimethylene terephthalate) polymers having intrinsic viscosities of 0.69, 0.76, 0.84 and 0.88 dl/g, respectively, were each spun into 70 filaments with trilobal cross-sections using a spinning machine having a take-up and drawing configuration as shown in FIG. 1. Roll  1  (see detail below) was a double denier control roll; roll  2  ran at a slightly higher speed to maintain a tension and act as a feed roll for drawing. First stage drawing took place between rolls  2  and  3 , and second-stage drawing took place between rolls  3  and  4 . The drawn yarn contacted relax roll  5  prior to wind-up. The spin finish was a 15% Lurol PF 4358-15 solution from G. A. Goulston Company applied with a kiss roll.  
         [0025]    Fiber extrusion and drawing conditions for each polymer were as follows:  
                                                                                 Extrusion Conditions            Polymer IV (dl/g):   Units   0.84, 0.88   0.69, 0.76       Extruder Temp. Profile:       Zone 1   ° C.   230   225       Zone 2   ° C.   250   235       Zone 3   ° C.   250   235       Zone 4   ° C.   250   235       Melt Temp.   ° C.   255   240       Extrusion Pack Pressure   psi   1820-2820   500-1300       Denier Control Roll Speed   m/min.   225   220                    Fiber Drawing Conditions            Polymer IV (dl/g)   0.88   0.84   0.76   0.69       Roll Temp.: ° C.       Roll 2   80   80   80   80       Roll 3   95   95   95   95       Roll 4   155   155   155   155       Roll 5   RT   RT   RT   RT       Roll Speeds: m/min.       Roll 2   230   230   230   230       Roll 3   310   310   404   404       Roll 4   1020   1165   1089   1089       Roll 5   1035   1102   1075   1075       First Stage Draw Ratio   1.35   1.35   1.76   1.76       Second Stage Draw Ratio   3.29   3.29   2.70   2.70                  
 
         [0026]    [0026]                                     TABLE 1                           Fiber tensile properties are shown in Table 1.                I.V.   Yarn Count   Tenacity           Run   (dl/g)   (den.)   (g/den.)   % Elongation               1   0.69   1182   1.51   70.7       2   0.76   1146   1.59   79.7       3   0.84   1167   2.03   89.0       4   0.88   1198   2.24   67.5                    
         [0027]    Poly(trimethylene terephthalate) of intrinsic viscosities 0.69 and 0.76 (Runs 1 and 2) gave yarn of inferior tensile properties compared with the yarn of Runs 3 and 4. These polymers were re-spun at a lower extruder temperature profile. Although they could be spun and drawn, the fibers had high die swell. When the fiber cross-sections were examined with an optical microscope, the 0.69 i.v. fibers swelled to a point that they were no longer trilobal in shape and resembled delta cross-sections. They also had relatively low tenacity.  
       EXAMPLE 2  
     Two-Stage Drawing of PTT Fibers  
       [0028]    0.88 i.v. poly(trimethylene terephthalate) was extruded into 72 filaments having trilobal cross-section using a fiber-spinning machine having take-up and drawing configurations as in Example 1. Spin finish was applied as in Example 1. Extrusion and drawing conditions were as follows.  
                                                               Extrusion Conditions                Extruder Temperature Profile:   Units                            Zone 1   ° C.   230           Zone 2   ° C.   260           Zone 3   ° C.   260           Zone 4   ° C.   260           Melt Temp.   ° C.   265           Denier Control Roll Speed   m/min.   230                      
 
         [0029]    [0029]                                                                     Fiber Drawing Conditions            Runs   Units   5   6   7   8   9   10   11               Roll 2 Temp./Speed   ° C./m/min   80/235    80/235   100/235   100/235   100/235   100/235   100/235       Roll 3 Temp./Speed   ° C./m/min   90/317   100/286   100/817   100/817   100/817   100/993   100/945       Roll 4 Temp./Speed   ° C./m/min   155/1123    100/1021    155/1047    140/1103    140/1145   130/1044   140/996       Roll 5 Temp./Speed   ° C./m/min    RT/1096    RT/1011    RT/1029    RT/1082    RT/1134    RT/1019   RT/981       1st Stage Draw Ratio       1.35   1.22   3.48   3.48   3.48   4.23   4.02       2nd Stage Draw Ratio       3.55   3.87   1.28   1.35   1.40   1.05   1.05       Total Draw Ratio       4.79   4.36   4.48   4.70   4.87   4.44   4.22       Yarn Count, den.   den.   1225   1281   1278   1185       1210   1288       Tenacity, g/den.   g/den.   1.95   1.95   1.61   1.32       1.85   1.11       Elongation   %   55   75   70   76       78   86                    
         [0030]    It was observed during spinning and drawing that, when the first-stage draw ratio (between rolls  2  and  3 ) was less than about 1.5, as in Runs 5 and 6, there were fewer broken filaments and the tenacities of the filaments were generally higher than when first-stage draw was higher than about 1.5. When the first-stage draw was increased to greater than 3 (Runs 7, 8, 9, 10, and 11), it was observed that the fibers had a white streaky appearance, the threadlines were loopy, and there were frequent filament wraps on the draw rolls. The process was frequently interrupted with fiber breaks.  
       EXAMPLE 3  
     Spinning, Drawing and Texturing Poly(trimethylene terephthalate) BCF to High Bulk  
       [0031]    The extrusion conditions in this experiment were the same as in Example 2. The fibers were spun, drawn and wound as in Example 1. They were then textured by heating the fibers on a feed roll and exposing the fibers to a hot air jet. The textured fibers were collected as a continuous plug on a jet-screen cooling drum. Partial vacuum was applied to the drum to pull the ambient air to cool the yarns and keep them on the drum until they were wound. The yarns were air entangled between the drum and the winder. The feed roll and texturizer air jet temperatures were kept constant, and the air jet pressure was varied from 50 to 100 psi to prepare poly(trimethylene terephthalate) BCF of various bulk levels.  
         [0032]    Drawing and texturing conditions were as follows.  
                                                                     Drawing Conditions            Rolls   Temperature, ° C.   Speed, m/min.               Roll 1   RT   225       Roll 2   80   230       Roll 3   95   264       Roll 4   90   1058        Roll 5   110    1042                     Texturing Conditions                Feed Roll Temperature, ° C.   180           Feed Roll Speed, m/min.   980           Air Jet Temperature, ° C.   180           Interlacing Pressure, psi    10                      
 
         [0033]    Yarn bulk and shrinkage were measured by taking 18 wraps of the textured yarn in a denier creel and tying it into a skein. The initial length L 0  of the skein was 22.1 inches in English unit creel. A 1 g weight was attached to the skein and it was hung in a hot-air oven at 130° C. for 5 minutes. The skein was removed and allowed to cool for 3 minutes. A 50 g weight was then attached and the length L 1  was measured after 30 seconds. The 50 g weight was removed, a 10 Lb weight was attached, and the length L 2  was measured after 30 seconds. Percent bulk was calculated as (L 0 −L 1 )/L 0 ×100% and shrinkage was calculated as (L 0 −L 2 )/L 0 ×100%. Results are shown in Table 2.  
                                   TABLE 2                                   Package No.   Yarn Count, den.   % Bulk   % Shrinkage                           T50   1437   32.6   3.6           T60   1406   35.7   2.7           T70   1455   39.4   3.2           T80   1500   38.0   3.6           T90   1525   37.6   4.1           T100   1507   38.0   3.6                      
 
         [0034]    The experiment showed that poly(trimethylene terephthalate) BCF can be textured to high bulk with a hot air texturizer.  
       EXAMPLE 4  
     Carpet Resiliency Comparison  
       [0035]    Poly(trimethylene terephthalate) BCF yarns were made in two separate steps: (1) spinning and drawing set-up as in Example 1 and (2) texturing. Extrusion, drawing and texturing conditions for the poly(trimethylene terephthalate) yarns were as follows.  
                                                               Extrusion Conditions                Extruder Temperature   Units                            Zone 1   ° C.   240           Zone 2   ° C.   255           Zone 3   ° C.   255           Zone 4   ° C.   255           Melt Temperature   ° C.   260           Pack Pressure   psi   1830                       
 
         [0036]    [0036]                                                               Drawing Conditions                Units                            Roll 1 Temp.   ° C./m/min.   RT/223           Roll 2 Temp.   ° C./m/min.   80/230           Roll 3 Temp.   ° C./m/min.   95/288           Roll 4 Temp.   ° C./m/min.   150/1088           Roll 5 Temp.   ° C./m/min.   RT/1000                        
         [0037]    [0037]                                                           Texturing Conditions                Units                            Feed Roll Temp.   ° C.   180           Feed Roll Speed   m/min.   980           Air Jet Temp.   ° C.   180           Air Jet Pressure   psi    90           Interlacing Pressure   psi    10                        
         [0038]    The yarn produced was 1150 denier with 2.55 g/den tenacity and 63% elongation. The textured yarn was twisted, heat set as indicated, and tufted into carpets. Performances of the poly(trimethylene terephthalate) carpets were compared with a commercial 1100 denier nylon 66 yarn. Results are shown in Table 3.  
                               TABLE 3                                   Accelerated                       Floor   % Loss               Heat Setting   Traffic   in Pile       Run   Twist/Inch   Conditions   Rating   Thickness                   12 (Poly(trimethylene   4.5 × 4.5   270° F.    3.75   2.4       terephthalate)       Autoclave       13 (Poly(trimethylene   4.5 × 4.5   180° C. Seussen   3.5   7.1       terephthalate)       14 (Poly(trimethylene   5.0 × 5.0   270° F.    3.75   1.7       terephthalate)       Autoclave       15 nylon 66   4.0 × 4.0   270° F.   3.0   6.4               Autoclave       16 nylon 66   4.0 × 4.0   190° C. Seussen   3.5   4.5                  
 
         [0039]    The heat-set yarns were tufted into 24 oz. cut-pile Saxony carpets in ⅛″ gauge, {fraction (9/16)}″ pile height, and dyed with disperse blue 56 (without a carrier) at atmospheric boil into medium blue color carpets. Visual inspection of the finished carpets disclosed that the poly(trimethylene terephthalate) carpets (Runs 12, 13 and 14) had high bulk and excellent coverage which were equal to or better than the nylon controls (Runs 15 and 16). Carpet resiliency was tested in accelerated floor trafficking with 20,000 footsteps. The appearance retention was rated 1 (severe change in appearance), 2 (significant change), 3 (moderate change), 4 (slight change) and 5 (no change). As can be seen in Table 3, the poly(trimethylene terephthalate) carpets were equal to or better than the nylon 66 controls in the accelerated walk tests and in percent thickness loss.  
       EXAMPLE 5  
     One-Step Processing of Poly(trimethylene terephthalate) BCF Yarn from Spinning to Texturing  
       [0040]    Poly(trimethylene terephthalate) (i.v. 0.90) was extruded into 72 trilobal cross-section filaments. The filaments were processed on a line as shown in FIG. 2 having two cold rolls, three draw rolls and double yarn feed rolls prior to texturing. The yarns were textured with hot air, cooled in a rotating jet screen drum and wound up with a winder. Lurol NF 3278 CS (G. A. Goulston Co.) was used as the spin finish. Texturing conditions were varied to make poly(trimethylene terephthalate) BCF yarns having different bulk levels. Extrusion, drawing, texturing and winding conditions were as follows.  
                                                               Extrusion Conditions                Extruder Temperature Profiles   Units                            Zone 1   ° C.   240           Zone 2   ° C.   260           Zone 3   ° C.   260           Zone 4   ° C.   265           Melt Temperature   ° C.   265           Pump Pressure   psi   3650                       
 
         [0041]    [0041]                                                                           Drawing Conditions                Temperature ° C.   Speed, m/min.                        Cold Roll 1   RT   211       Cold Roll 2   RT   264       Draw Roll 1   50   290       Draw Roll 2   90   330       Draw Roll 3   110    1100                     
         [0042]    The yarns were twisted, heat set and tufted into carpets for performance evaluation. Results are shown in Table 4.  
                                                                             TABLE 4                       Sample   Feed Roll   Texturing   Texturizing Jet   Yarn Count,           Accelerated Walk       Number   Temp, ° C.   Jet temp., ° C.   Press., psi   den.   % Bulk   % Shrinkage   Test Rating                                1   150   180   70   1490   19.2   1.58   3.25       2   150   180   110   1420   26   1.59   3.5       3   150   200   110   1546   30.5   1.59   3.0       4   180   180   70   1429   24.6   2.04   3.0       5   180   180   110   1496   29.8   1.81   3.5       6   180   200   70   1475   26.5   1.36   2.75       7   180   200   110   1554   32.8   0.86   3.0       8   150   190   90   1482   26   2.31   3.25       9   180   190   90   1430   29   1.58   3.5       10    165   190   90   1553   29   2.26   3.75       Nylon 6                           3.5       Nylon 66                           3.5                  
 
       EXAMPLE 6  
     Effects of Draw Ratio and Roll Temperature on Yarn Properties  
       [0043]    Poly(trimethylene terephthalate) (0.90 i.v.) was spun into 72 filaments with trilobal cross-sections using a machine as described in Example 5. Extrusion conditions were as follows.  
                                                 Extrusion Conditions                Extruder Temperature Profiles   Units                       Zone 1   ° C.   240           Zone 2   ° C.   260           Zone 3   ° C.   260           Zone 4   ° C.   260           Melt Temperature   ° C.   260                      
 
         [0044]    The poly(trimethylene terephthalate) BCF yarns and commercial nylon 6 and 66 yarns were tufted into 32 oz. {fraction (5/32)} gauge cut-pile Saxony carpets having {fraction (20/32)}″ pile height. They were walk-tested with 20,000 footsteps accelerated floor trafficking for resiliency and appearance retention comparisons. Roll conditions and results are shown in Table 5.  
       EXAMPLE 7  
     Use of Low First-Stage Draw Ratio  
       [0045]    Poly(trimethylene terephthalate) (0.9 i.v.) was spun into 69 filaments with trilobal cross-sections using a drawing and texturing configuration similar to that shown in FIG. 1, with the yarn passing via unheated haul-off Roll  1 , first-stage draw between Roll  1  and draw Roll  2 , and second-stage draw between Roll  2  and dual Roll  3 . The drawn yarns were then textured, relaxed and wound up. Extrusion conditions were as follows.  
                                                                                 TABLE 5                       Sample:   1   2   3   4   5   nylon 6   nylon 66                                Roll 1 Temp   ° C.   50   50   50   50   50               Roll 2 Temp   ° C.   90   90   90   90   90       Roll 3 Temp.   ° C.   110   110   110   150   150       Roll 1 speed   m/min.   290   290   290   290   290       Roll 2 Speed   m/min.   330   330   330   330   330       Roll 3 Speed   m/min.   1000   1100   1150   1100   1000       Draw Ratio       3.45   3.79   3.97   3.97   3.45       Feed Roll Temp.   ° C.   165   165   165   165   165       Feed Roll Speed   m/min.   1000   1100   1150   1100   1000       Texturing Jet Temp.   ° C.   190   190   190   190   190       Texturing Jet Pressure   psi   90   90   90   90   90       Interlacing Pressure   psi   30   30   30   30   30       Bulk   %   26.1   31.6   31.9   35.8   33       Shrinkage   %   1.75   2.04   2.13   2.26   192       Walk test Rating       4.0   3.5   3.5   3.5   3.5   3.5   3.5                  
 
         [0046]    [0046]                                                 Extrusion Conditions                Extruder Temp. Profiles   Trial 1   Trial 2                       Zone 1          230° C.   230           Zone 2   260   245           Zone 3   260   255           Zone 4   260   255                        
         [0047]    The speed and temperature of the rolls, texturing conditions and yarn tensile properties are shown in Table 6. In Trial 1, the relax roll was a single roll with a follower, and in Trial 2, the relax roll was a dual roll. The spin finish was Goulston Lurol 3919 applied as a 25-30% emulsion. The first stage draw was about 1.13 (Trial 1) and 1.015 (trial 2) and second-stage draws were about 2.5 and 3.2. Although heat was not added to Roll  1  in these trials, the heat of operation would be expected to be above room temperature. As can be seen from Table 6, the yarn had excellent tenacity and elongation at speeds greater than 2000 m/min.  
                                             TABLE 6                                   Trial 1   Trial 2                                        Roll Speeds (m/min.):                   Roll 1   430   754           Roll 2   486   765           Dual Roll 3   1226    2500            Relax Roll   1176                Relax Dual Roll 4       2010            Winder   1156    1995            Roll Temperatures (° C.):           Roll 1   Unheated   Unheated           Roll 2    49    65           Roll 3   135   165           Relax Dual Roll 4   Unheated   Unheated           Texturizing Conditions:           Air Jet Temperature (° C.)   163   190           Air Jet Pressure (psi)    80    95           Interlacer Pressure (psi)    20    30           Yarn Properties:           Yarn Count (denier)   1450    1328            Tenacity (g/den)      1.3      1.98           Elongation (%)    44     50.4