Method for preparing thermal-moisture comfortable polyester FDY

Abstract

A thermal-moisture comfortable polyester FDY for summer use and a preparation method thereof are provided. The FDY is made of matting agents dispersed polyester via the steps of spinning melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding. The woven fabrics manufactured with the FDY possess a wicking height and an evaporation rate of larger than or equal to 135 mm and 0.22 g/h, respectively. The compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K ranges from 0.97 to 1.03, and the oiling involves the oiling agent containing 67.30-85.58 wt % of crown ether.

Claims

1. A method for preparing a thermal-moisture comfortable polyester FDY, comprising: performing metering, extruding via a spinneret, cooling, oiling, drawing, heat setting and winding on a spinning melt to obtain the thermal-moisture comfortable polyester FDY for summer; wherein the spinning melt comprises the polyester and a matting agent; wherein the spinneret is simultaneously provided with a plurality of cruciform orifices and a plurality of circular orifices; a ratio of a length of each cruciform orifice of the plurality of cruciform orifices to a length of each circular orifice of the plurality of circular orifices is equal to a product of a ratio of an equivalent diameter of the each cruciform orifice to an equivalent diameter of the each circular orifice and a coefficient K, the equivalent diameter of the each cruciform orifice is a ratio of a cross-sectional area to a cross-sectional circumference of the each cruciform orifice, the equivalent diameter of the each circular orifice is a ratio of a cross-sectional area to a cross-sectional circumference of the each circular orifice, and the coefficient K ranges from 0.97 to 1.03; an oiling agent in the oiling contains 67.30 wt %-85.58 wt % of crown ether.

2. The method for preparing the thermal-moisture comfortable polyester FDY of claim 1, wherein the length of the each cruciform orifice or the length of the each circular orifice is 0.20 mm-0.92 mm, the equivalent diameter of the each cruciform orifice or the equivalent diameter of the each circular orifice is 0.10 mm-0.23 mm; wherein the plurality of circular orifices and the plurality of cruciform orifices are arranged on the spinneret; centers of the plurality of circular orifices or circumferential centers of the plurality of cruciform orifices are arranged in regular intervals on a plurality of equally spaced concentric circles; a plurality of orifices of the plurality of cruciform orifices and the plurality of circular orifices are arranged on a same circle; the plurality of orifices on the same circle comprises cruciform orifices and circular orifices, and a quantity ratio of the circular orifices to the cruciform orifices is 2-5:1.

3. The method for preparing the thermal-moisture comfortable polyester FDY of claim 1, wherein a weight loss of the oiling agent is less than 15 wt % after a heat treatment at 200° C. for 2 hours; wherein the oiling agent has a kinetic viscosity of 27.5 mm.sup.2/s−30.1 mm .sup.2/s at 50±0.01° C. and the kinetic viscosity becomes 0.93 mm.sup.2/s−0.95 mm.sup.2/s when the oiling agent is dispersed with a content of 10 wt % in water to form an emulsion; wherein the oiling agent has an oil film strength of 121 N−127 N; wherein the oiling agent has a surface tension of 23.2 cN/cm-26.8 cN/cm and a specific resistance of 1.0×10.sup.8Ω.Math.cm-1.8×10.sup.8Ω.Math.cm; after the oiling, a static friction coefficient between the thermal-moisture comfortable polyester FDYs is 0.250-0.263, and a dynamic friction coefficient between the thermal-moisture comfortable polyester FDYs is 0.262-0.273; and after the oiling, a static friction coefficient between the thermal-moisture comfortable polyester FDY and a metal is 0.202-0.210, and a dynamic friction coefficient between the thermal-moisture comfortable polyester FDY and the metal is 0.320-0.332.

4. The method for preparing the thermal-moisture comfortable polyester FDY of claim 3, wherein the crown ether is 2-hydroxymethyl-12-crown-4, 15-crown ether-5 or 2-hydroxymethyl-15-crown-5; the oiling agent further contains a mineral oil, a potassium phosphate, trimethylolpropane laurate and sodium alkyl sulfonate; the mineral oil is one selected from the group consisting of 9 #-17 #mineral oil; the phosphate potassium salt is a potassium salt of dodecyl phosphate, iso-tridecanol polyoxyethylene ether phosphate or dodeca-tetradecanol phosphate; the sodium alkyl sulfonate is a sodium salt of dodecyl sulfonate, pentadecyl sulfonate or hexadecyl sulfonate; the oiling agent before used is dispersed with a content of 10 wt %-20 wt % in water to form the emulsion; and a method for preparing the oiling agent comprises: mixing the crown ether, the potassium phosphate, the trimethylolpropane laurate and the sodium alkyl sulfonate to obtain a first mixture, and then adding the first mixture into the mineral oil to obtain the oiling agent; an amount of each of the mineral oil, the phosphate potassium salt, the trimethylolpropane laurate, the crown ether, and the sodium alkyl sulfonate by weight is as follows: mineral oil 0 phr-10 phr, trimethylolpropane laurate 0 phr-20 phr, crown ether 70 phr-100 phr, potassium phosphate 8 phr-15 phr, sodium alkyl sulfonate 2 phr-7 phr, the mixing is carried out by performing a stirring at 40° C.−55° C. for 1 hour-3 hours.

5. The method for preparing the thermal-moisture comfortable polyester FDY of claim 1, wherein a plurality of spinning process parameters of the thermal-moisture comfortable polyester FDY for summer are as follows: spinning temperature 280° C.−290° C.; cooling temperature 20° C.−25° C.; interlacing pressure 0.20 MPa−0.30 MPa; speed of a first godet roller 2200 m/min−2600 m/min; temperature of the first godet roller 75° C.−85° C.; speed of a second godet roller 3600 m/min−3900 m/min; temperature of the second godet roller 135° C.−165° C.; winding speed 3580 m/min−3840 m/min; and an initial pressure of a spinning pack is 120 bar and a pressure rising ΔP is equal to or less than 0.6 bar/day.

6. The method for preparing the thermal-moisture comfortable polyester FDY of claim 1, wherein a cruciform monofilament has a fineness of 0.5 dtex-0.7 dtex and a circular monofilament has a fineness of 0.20 dtex-0.30 dtex.

7. The method for preparing the thermal-moisture comfortable polyester FDY of claim 1, wherein the thermal-moisture comfortable polyester FDY for summer use has a fineness of 70 dtex-100 dtex, a breaking strength of greater than or equal to 3.8 cn/dtex, a breaking elongation of 33.0:±:3.0%, a linear density deviation rate of less than or equal to 0.5%, a breaking strength CV of less than or equal to 5.0%, a breaking elongation CV of less than or equal to 10.0%, a yarn evenness CV of less than or equal to 2.00%, a boiling water shrinkage of 7.5±0.5%, and an oil content of 0.90±0.20%.

8. The method for preparing the thermal-moisture comfortable polyester FDY of claim 7, wherein the thermal-moisture comfortable polyester FDY for summer use has a lousiness rate of less than or equal to 2 per package and a capillary parameter of larger than or equal to 0.17.

9. The method for preparing the thermal-moisture comfortable polyester FDY of claim 1, wherein an additive content of the matting agent in the polyester is 1 wt %-1.5 wt %, and a content of the amorphous silicon dioxide in matte mixture is 15 wt %-30 wt %.

10. The method for preparing the thermal-moisture comfortable polyester FDY of claim 2, wherein a plurality of spinning process parameters of the thermal-moisture comfortable polyester FDY for summer are as follows: spinning temperature 280° C.−290° C.; cooling temperature 20° C.−25° C.; interlacing pressure 0.20 MPa−0.30 MPa; speed of a first godet roller 2200 m/min−2600 m/min; temperature of the first godet roller 75° C.−85° C.; speed of a second godet roller 3600 m/min−3900 m/min; temperature of the second godet roller 135° C.−165° C.; winding speed 3580 m/min−3840 m/min; and an initial pressure of a spinning pack is 120 bar and a pressure rising ΔP is equal to or less than 0.6 bar/day.

11. The method for preparing the thermal-moisture comfortable polyester FDY of claim 3, wherein a plurality of spinning process parameters of the thermal-moisture comfortable polyester FDY for summer are as follows: spinning temperature 280° C.−290° C.; cooling temperature 20° C.−25° C.; interlacing pressure 0.20 MPa−0.30 MPa; speed of a first godet roller 2200 m/min−2600 m/min; temperature of the first godet roller 75° C.−85° C.; speed of a second godet roller 3600 m/min−3900 m/min; temperature of the second godet roller 135° C.−165° C.; winding speed 3580 m/min−3840 m/min; and an initial pressure of a spinning pack is 120 bar and a pressure ruing ΔP is equal to or less than 0.6 bar/day.

12. The method for preparing the thermal-moisture comfortable polyester FDY of claim 4, wherein a plurality of spinning process parameters of the thermal-moisture comfortable polyester FDY for summer are as follows: spinning temperature 280° C.−290° C.; cooling temperature 20° C.−25° C.; interlacing pressure 0.20 MPa−0.30 MPa; speed of a first godet roller 2200 m/min−2600 m/min; temperature of the first godet roller 75° C.−85° C.; speed of a second godet roller 3600 m/min−3900 m/min; temperature of the second godet roller 135° C.−165° C.; winding speed 3580 m/min−3840 m/min; and an initial pressure of a spinning pack is 120 bar and a pressure rising ΔP is equal to or less than 0.6 bar/day.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIGURE is the map of arrangement of orifices in the compositional spinneret used in Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(2) Based on above mentioned method, the following embodiments are carried out for further demonstration in the present invention. It is to be understood that these embodiments are only intended to illustrate the invention and are not intended to limit the scope of the invention. In addition, it should be understood that after reading the contents described in the present invention, those technical personnel in this field can make various changes or modifications to the invention, and these equivalent forms also fall within the scope of the claims attached to the application.

Example 1

(3) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(4) (1) Concoction of Oiling Agent

(5) 2-hydroxymethyl-12-crown-4, potassium dodecyl phosphate, trimethylolpropane laurate and sodium hexadecyl sulfonate are fully blended under room temperature and then added into the mineral oil 12 #, and stirred furtherly under a temperature of 40° C. for 2.5 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 5 phr of mineral oil 12 #, 95 phr of 2-hydroxymethyl-12-crown-4, 9 phr of potassium dodecyl phosphate and 2 phr of sodium hexadecyl sulfonate. The obtained oiling agent has a crown ether content of 85.58 wt %, a high temperature resistance (9 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (29.5 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.93 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 121N, a surface tension of 24.3 cN/m and a specific resistance of 1.0×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.260 and 0.263, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.202 and 0.330, respectively. The really applied oiling agent is a water based emulsion with a concentration of 19 wt %.

(6) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.0 wt %, and in the extinction mixture the content of amorphous silica is 22 wt %.

(7) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(8) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices (arrangement being showed in FIGURE, in which A stands for cruciform orifices while B for circular ones), and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.01. The length of cruciform and circular spinneret orifices are 0.38 mm and 0.38 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.20 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 2:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 280° C., a cooling temperature of 21° C., an interlacing pressure of 0.25 MPa, a godet roller1 speed of 2400 m/min, a godet roller1 temperature of 78° C., a godet roller2 speed of 4050 m/min, a godet roller2 of 145° C., a winding speed of 3950 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.6 bar/day.

(9) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.19, and the cruciform monofilaments have a fineness of 0.70 dtex whereas that of the circular monofilaments is 0.22 dtex. The woven fabrics (surface density of 100 g/m.sup.2) made of the FDY mentioned above have a wicking height of 140 mm and an evaporation rate of 0.28 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 100 dtex, a breaking strength of 4.2 cN/dtex, a breaking elongation of 33.0%, a linear density deviation rate of 0.33%, a breaking strength CV of 4.5%, a breaking elongation CV of 8.5%, a yarn evenness CV of 1.5%, a boiling water shrinkage of 7.5% and an oil content of 0.90%.

Example 2

(10) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(11) (1) Concoction of Oiling Agent

(12) 15-crown ether-5, potassium iso-tridecanol polyoxyethylene ether phosphate, trimethylolpropane laurate and sodium dodecyl sulfonate are fully blended under room temperature and then added into the mineral oil 13 #, and stirred furtherly under a temperature of 52° C. for 2 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 10 phr of mineral oil 13 #, 5 phr of trimethylolpropane laurate, 70 phr of 15-crown ether-5, 8 phr of potassium iso-tridecanol polyoxyethylene ether phosphate and 6 phr of sodium dodecyl sulfonate. The obtained oiling agent has a crown ether content of 70.70 wt %, a high temperature resistance (13.5 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (28.6 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.95 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 126N, a surface tension of 24.9 cN/m and a specific resistance of 1.2×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.251 and 0.262, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.202 and 0.332, respectively. The really applied oiling agent is a water based emulsion with a concentration of 11 wt %.

(13) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.1 wt %, and in the extinction mixture the content of amorphous silica is 28 wt %.

(14) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(15) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 0.99. The length of cruciform and circular spinneret orifices are 0.16 mm and 0.16 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.16 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 1.2:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 282° C., a cooling temperature of 23° C., an interlacing pressure of 0.29 MPa, a godet roller1 speed of 2600 m/min, a godet roller1 temperature of 79° C., a godet roller2 speed of 4000 m/min, a godet roller2 of 150° C., a winding speed of 4050 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.55 bar/day.

(16) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use is composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.19, and the cruciform monofilaments have a fineness of 0.58 dtex whereas that of the circular monofilaments is 0.22 dtex. The woven fabrics (surface density of 300 g/m.sup.2) made of the FDY mentioned above have a wicking height of 142 mm and an evaporation rate of 0.27 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 75 dtex, a breaking strength of 4.0 cN/dtex, a breaking elongation of 33.0%, a linear density deviation rate of 0.45%, a breaking strength CV of 5.0%, a breaking elongation CV of 9.9%, a yarn evenness CV of 1.9%, a boiling water shrinkage of 7.0% and an oil content of 0.70%.

Example 3

(17) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(18) (1) Concoction of Oiling Agent

(19) 2-hydroxymethyl-15-crown-5, potassium dodeca-tetradecanol phosphate, trimethylolpropane laurate and sodium pentadecyl sulfonate are fully blended under room temperature and then added into the mineral oil 11 #, and stirred furtherly under a temperature of 48° C. for 3 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 8 phr of mineral oil 11 #, 10 phr of trimethylolpropane laurate, 85 phr of 2-hydroxymethyl-15-crown-5, 11 phr of potassium dodeca-tetradecanol phosphate and 5 phr of sodium pentadecyl sulfonate. The obtained oiling agent has a crown ether content of 70.83 wt %, a high temperature resistance (11 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (30.1 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.94 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 125N, a surface tension of 23.2 cN/m and a specific resistance of 1.8×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.250 and 0.272, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.209 and 0.329, respectively. The really applied oiling agent is a water based emulsion with a concentration of 10 wt %.

(20) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.3 wt %, and in the extinction mixture the content of amorphous silica is 20 wt %.

(21) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(22) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.02. The length of cruciform and circular spinneret orifices are 0.20 mm and 0.201 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.20 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 2:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 288° C., a cooling temperature of 20° C., an interlacing pressure of 0.20 MPa, a godet roller1 speed of 2300 m/min, a godet roller1 temperature of 83° C., a godet roller2 speed of 4130 m/min, a godet roller2 of 165° C., a winding speed of 3980 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.54 bar/day.

(23) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.17, and the cruciform monofilaments have a fineness of 0.50 dtex whereas that of the circular monofilaments is 0.20 dtex. The woven fabrics (surface density of 240 g/m.sup.2) made of the FDY mentioned above have a wicking height of 139 mm and an evaporation rate of 0.28 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 95 dtex, a breaking strength of 4.5 cN/dtex, a breaking elongation of 36.0%, a linear density deviation rate of 0.48%, a breaking strength CV of 4.8%, a breaking elongation CV of 9.5%, a yarn evenness CV of 1.4%, a boiling water shrinkage of 7.0% and an oil content of 0.70%.

Example 4

(24) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(25) (1) Concoction of Oiling Agent

(26) 2-hydroxymethyl-12-crown-4, potassium dodecyl phosphate, trimethylolpropane laurate and sodium hexadecyl sulfonate are fully blended under room temperature and then added into the mineral oil 12 #, and stirred furtherly under a temperature of 40° C. for 2.5 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 5 phr of mineral oil 12 #, 95 phr of 2-hydroxymethyl-12-crown-4, 9 phr of potassium dodecyl phosphate and 2 phr of sodium hexadecyl sulfonate. The obtained oiling agent has a crown ether content of 85.58 wt %, a high temperature resistance (9 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (29.5 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.93 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 121N, a surface tension of 24.3 cN/m and a specific resistance of 1.0×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.260 and 0.263, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.202 and 0.330, respectively. The really applied oiling agent is a water based emulsion with a concentration of 19 wt %.

(27) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.0 wt %, and in the extinction mixture the content of amorphous silica is 15 wt %.

(28) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(29) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.03. The length of cruciform and circular spinneret orifices are 0.32 mm and 0.32 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.10 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 3:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 281° C., a cooling temperature of 21° C., an interlacing pressure of 0.22 MPa, a godet roller1 speed of 2500 m/min, a godet roller1 temperature of 75° C., a godet roller2 speed of 4200 m/min, a godet roller2 of 155° C., a winding speed of 4000 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.58 bar/day.

(30) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.22 and the cruciform monofilaments have a fineness of 0.68 tex whereas that of the circular monofilaments is 0.25 dtex. The woven fabrics (surface density of 140 g/m.sup.2) made of the FDY mentioned above have a wicking height of 135 mm and an evaporation rate of 0.28 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 85 dtex, a breaking strength of 3.8 cN/dtex, a breaking elongation of 30.0%, a linear density deviation rate of 0.35%, a breaking strength CV of 5.0%, a breaking elongation CV of 8.0%, a yarn evenness CV of 1.3%, a boiling water shrinkage of 8.0% and an oil content of 1.10%.

Example 5

(31) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(32) (1) Concoction of Oiling Agent

(33) 15-crown ether-5, potassium iso-tridecanol polyoxyethylene ether phosphate, trimethylolpropane laurate and sodium dodecyl sulfonate are fully blended under room temperature and then added into the mineral oil 13 #, and stirred furtherly under a temperature of 52° C. for 2 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 10 phr of mineral oil 13 #, 5 phr of trimethylolpropane laurate, 70 phr of 15-crown ether-5, 8 phr of potassium iso-tridecanol polyoxyethylene ether phosphate and 6 phr of sodium dodecyl sulfonate. The obtained oiling agent has a crown ether content of 70.70 wt %, a high temperature resistance (13.5 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (28.6 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.95 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 126N, a surface tension of 24.9 cN/m and a specific resistance of 1.2×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.251 and 0.262, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.202 and 0.332, respectively. The really applied oiling agent is a water based emulsion with a concentration of 11 wt %.

(34) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.5 wt %, and in the extinction mixture the content of amorphous silica is 15 wt %.

(35) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(36) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 0.98. The length of cruciform and circular spinneret orifices are 0.54 mm and 0.54 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.16 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 4:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 290° C., a cooling temperature of 25° C., an interlacing pressure of 0.26 MPa, a godet roller1 speed of 2200 m/min, a godet roller1 temperature of 75° C., a godet roller2 speed of 4150 m/min, a godet roller2 of 135° C., a winding speed of 4050 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.5 bar/day.

(37) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.19, and the cruciform monofilaments have a fineness of 0.59 dtex whereas that of the circular monofilaments is 0.27 dtex. The woven fabrics (surface density of 260 g/m.sup.2) made of the FDY mentioned above have a wicking height of 140 mm and an evaporation rate of 0.22 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 100 dtex, a breaking strength of 4.4 cN/dtex, a breaking elongation of 33.0%, a linear density deviation rate of 0.46%, a breaking strength CV of 4.8%, a breaking elongation CV of 9.6%, a yarn evenness CV of 1.8%, a boiling water shrinkage of 7.5% and an oil content of 1.10%.

Example 6

(38) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(39) (1) Concoction of Oiling Agent

(40) 2-hydroxymethyl-15-crown-5, potassium dodeca-tetradecanol phosphate, trimethylolpropane laurate and sodium pentadecyl sulfonate are fully blended under room temperature and then added into the mineral oil 14 #, and stirred furtherly under a temperature of 55° C. for 1 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 3 phr of mineral oil 14 #, 10 phr of trimethylolpropane laurate, 75 phr of 2-hydroxymethyl-15-crown-5, 14 phr of potassium dodeca-tetradecanol phosphate and 10 phr of sodium pentadecyl sulfonate. The obtained oiling agent has a crown ether content of 68.80 wt %, a high temperature resistance (12 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (27.5 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.95 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 126N, a surface tension of 25.4 cN/m and a specific resistance of 1.6×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.255 and 0.267, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.203 and 0.330, respectively. The really applied oiling agent is a water based emulsion with a concentration of 20 wt %.

(41) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.5 wt %, and in the extinction mixture the content of amorphous silica is 24 wt %.

(42) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(43) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.00. The length of cruciform and circular spinneret orifices are 0.59 mm and 0.59 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.19 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 2:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 285° C., a cooling temperature of 24° C., an interlacing pressure of 0.30 MPa, a godet roller1 speed of 2500 m/min, a godet roller1 temperature of 85° C., a godet roller2 speed of 4090 m/min, a godet roller2 of 140° C., a winding speed of 3950 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.6 bar/day.

(44) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.18, and the cruciform monofilaments have a fineness of 0.70 dtex whereas that of the circular monofilaments is 0.30 dtex. The woven fabrics (surface density of 210 g/m.sup.2) made of the FDY mentioned above have a wicking height of 138 mm and an evaporation rate of 0.30 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 75 dtex, a breaking strength of 4.0 cN/dtex, a breaking elongation of 36.0%, a linear density deviation rate of 0.5%, a breaking strength CV of 4.2%, a breaking elongation CV of 9.1%, a yarn evenness CV of 2.0%, a boiling water shrinkage of 8.0% and an oil content of 0.90%.

Example 7

(45) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(46) (1) Concoction of Oiling Agent

(47) 15-crown ether-5, potassium dodecyl phosphate, trimethylolpropane laurate and sodium hexadecyl sulfonate are fully blended under room temperature and then added into the mineral oil 15 #, and stirred furtherly under a temperature of 41° C. for 2 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 8 phr of mineral oil 15 #, 20 phr of trimethylolpropane laurate, 100 phr of 15-crown ether-5, 15 phr of potassium dodecyl phosphate and 2 phr of sodium hexadecyl sulfonate. The obtained oiling agent has a crown ether content of 68.97 wt %, a high temperature resistance (8.5 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (28.4 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.94 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 122N, a surface tension of 26.8 cN/m and a specific resistance of 1.8×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.263 and 0.268, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.210 and 0.320, respectively. The really applied oiling agent is a water based emulsion with a concentration of 13 wt %.

(48) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.1 wt %, and in the extinction mixture the content of amorphous silica is 28 wt %.

(49) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(50) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 0.97. The length of cruciform and circular spinneret orifices are 0.92 mm and 0.92 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.18 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 5:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 289° C., a cooling temperature of 20° C., an interlacing pressure of 0.29 MPa, a godet roller1 speed of 2600 m/min, a godet roller1 temperature of 78° C., a godet roller2 speed of 4140 m/min, a godet roller2 of 160° C., a winding speed of 4130 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.46 bar/day.

(51) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.16, and the cruciform monofilaments have a fineness of 0.58 dtex whereas that of the circular monofilaments is 0.24 dtex. The woven fabrics (surface density of 180 g/m.sup.2) made of the FDY mentioned above have a wicking height of 137 mm and an evaporation rate of 0.33 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 95 dtex, a breaking strength of 4.6 cN/dtex, a breaking elongation of 30.0%, a linear density deviation rate of 0.44%, a breaking strength CV of 4.3%, a breaking elongation CV of 9.2%, a yarn evenness CV of 1.5%, a boiling water shrinkage of 7.5% and an oil content of 0.90%.

Example 8

(52) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(53) (1) Concoction of Oiling Agent

(54) 2-hydroxymethyl-12-crown-4, potassium dodeca-tetradecanol phosphate, trimethylolpropane laurate and sodium pentadecyl sulfonate are fully blended under room temperature and then added into the mineral oil 16 #, and stirred furtherly under a temperature of 45° C. for 3 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 9 phr of mineral oil 16 #, 80 phr of 2-hydroxymethyl-12-crown-4, 12 phr of potassium dodeca-tetradecanol phosphate and 5 phr of sodium pentadecyl sulfonate. The obtained oiling agent has a crown ether content of 83.33 wt %, a high temperature resistance (14 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (30.0 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.93 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 127N, a surface tension of 23.5 cN/m and a specific resistance of 1.5×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.262 and 0.273, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.208 and 0.328, respectively. The really applied oiling agent is a water based emulsion with a concentration of 18 wt %.

(55) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.4 wt %, and in the extinction mixture the content of amorphous silica is 30 wt %.

(56) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(57) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.01 The length of cruciform and circular spinneret orifices are 0.32 mm and 0.32 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.16 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 4:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 280° C., a cooling temperature of 20° C., an interlacing pressure of 0.25 MPa, a godet roller1 speed of 2300 m/min, a godet roller1 temperature of 80° C., a godet roller2 speed of 4000 m/min, a godet roller2 of 155° C., a winding speed of 3970 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.4 bar/day.

(58) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.21, and the cruciform monofilaments have a fineness of 0.55 dtex whereas that of the circular monofilaments is 0.25 dtex. The woven fabrics (surface density of 190 g/m.sup.2) made of the FDY mentioned above have a wicking height of 145 mm and an evaporation rate of 0.24 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 75 dtex, a breaking strength of 3.8 cN/dtex, a breaking elongation of 36.0%, a linear density deviation rate of 0.5%, a breaking strength CV of 5.0%, a breaking elongation CV of 10.0%, a yarn evenness CV of 1.9%, a boiling water shrinkage of 7.0% and an oil content of 0.70%.

Example 9

(59) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(60) (1) Concoction of Oiling Agent

(61) 2-hydroxymethyl-15-crown-5, potassium dodecyl phosphate, trimethylolpropane laurate and sodium dodecyl sulfonate are fully blended under room temperature and then stirred furtherly under a temperature of 55° C. for 3 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 15 phr of trimethylolpropane laurate, 90 phr of 2-hydroxymethyl-15-crown-5, 8 phr of potassium dodecyl phosphate and 7 phr of sodium dodecyl sulfonate. The obtained oiling agent has a crown ether content of 81.81 wt %, a high temperature resistance (10 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (29.7 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.94 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 126N, a surface tension of 24.8 cN/m and a specific resistance of 1.8×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.250 and 0.264, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.210 and 0.321, respectively. The really applied oiling agent is a water based emulsion with a concentration of 10 wt %.

(62) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.5 wt %, and in the extinction mixture the content of amorphous silica is 30 wt %.

(63) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(64) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.03 The length of cruciform and circular spinneret orifices are 0.60 mm and 0.60 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.23 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 2:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 283° C., a cooling temperature of 23° C., an interlacing pressure of 0.30 MPa, a godet roller1 speed of 2500 m/min, a godet roller1 temperature of 79° C., a godet roller2 speed of 4130 m/min, a godet roller2 of 135° C., a winding speed of 4010 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.38 bar/day.

(65) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.27, and the cruciform monofilaments have a fineness of 0.69 dtex whereas that of the circular monofilaments is 0.30 dtex. The woven fabrics (surface density of 140 g/m.sup.2) made of the FDY mentioned above have a wicking height of 144 mm and an evaporation rate of 0.26 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 85 dtex, a breaking strength of 4.5 cN/dtex, a breaking elongation of 33.0%, a linear density deviation rate of 0.39%, a breaking strength CV of 3.5%, a breaking elongation CV of 9.4%, a yarn evenness CV of 1.4%, a boiling water shrinkage of 7.0% and an oil content of 0.90%.

Example 10

(66) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(67) (1) Concoction of Oiling Agent

(68) 2-hydroxymethyl-15-crown-5, potassium dodecyl phosphate, trimethylolpropane laurate and sodium dodecyl sulfonate are fully blended under room temperature and then stirred furtherly under a temperature of 55° C. for 3 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 15 phr of trimethylolpropane laurate, 90 phr of 2-hydroxymethyl-15-crown-5, 8 phr of potassium dodecyl phosphate and 7 phr of sodium dodecyl sulfonate. The obtained oiling agent has a crown ether content of 81.81 wt %, a high temperature resistance (10 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (29.7 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.94 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 126N, a surface tension of 24.8 cN/m and a specific resistance of 1.8×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.250 and 0.264, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.210 and 0.321, respectively. The really applied oiling agent is a water based emulsion with a concentration of 10 wt %.

(69) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.3 wt %, and in the extinction mixture the content of amorphous silica is 18 wt %.

(70) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(71) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.02 The length of cruciform and circular spinneret orifices are 0.32 mm and 0.326 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.19 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 3:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 286° C., a cooling temperature of 24° C., an interlacing pressure of 0.27 MPa, a godet roller1 speed of 2400 m/min, a godet roller1 temperature of 75° C., a godet roller2 speed of 4200 m/min, a godet roller2 of 165° C., a winding speed of 3980 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.55 bar/day.

(72) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.17, and the cruciform monofilaments have a fineness of 0.65 dtex whereas that of the circular monofilaments is 0.29 dtex. The woven fabrics (surface density of 170 g/m.sup.2) made of the FDY mentioned above have a wicking height of 141 mm and an evaporation rate of 0.31 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 80 dtex, a breaking strength of 4.1 cN/dtex, a breaking elongation of 36.0%, a linear density deviation rate of 0.37%, a breaking strength CV of 3.9%, a breaking elongation CV of 8.9%, a yarn evenness CV of 1.5%, a boiling water shrinkage of 7.5% and an oil content of 1.10%.

Example 11

(73) A method for preparing the thermal-moisture comfortable polyester FDY for summer use, comprising the steps:

(74) (1) Concoction of Oiling Agent

(75) 2-hydroxymethyl-12-crown-4, potassium dodecyl phosphate, trimethylolpropane laurate and sodium dodecyl sulfonate are fully blended under room temperature and then added into the mineral oil 9 #, and stirred furtherly under a temperature of 40° C. for 1 h to produce the oiling agent. Counted by weight parts, the oiling agent consists of 2 phr of mineral oil 9 #, 10 phr of trimethylolpropane laurate, 90 phr of 2-hydroxymethyl-12-crown-4, 8 phr of potassium dodecyl phosphate and 3 phr of sodium dodecyl sulfonate. The obtained oiling agent has a crown ether content of 79.6 wt %, a high temperature resistance (14.5 wt % of weight loss, after 2 hr of heating at 200° C.), a low viscosity (29.6 mm.sup.2/s of kinetic viscosity at 50±0.01° C., or 0.93 mm.sup.2/s when dispersed with a content of 10 wt % in water to form an emulsion), a high oil strength of 125N, a surface tension of 24.8 cN/m and a specific resistance of 1.83×10.sup.8Ω.Math.cm. After oiling the static friction coefficient (μ.sub.s) and dynamic friction coefficient (μ.sub.d) between fibers are 0.255 and 0.266, while the static friction coefficient and dynamic friction coefficient between fibers and metals are 0.203 and 0.320, respectively. The really applied oiling agent is a water based emulsion with a concentration of 15 wt %.

(76) (2) The polyester is dispersed by the matting agent, i.e., the mixture of amorphous titanium dioxide and amorphous silica. The additive content of the matting agent in polyester is 1.2 wt %, and in the extinction mixture the content of amorphous silica is 15 wt %.

(77) (3) The thermal-moisture comfortable polyester FDY for summer use is prepared from the polyester melt mentioned above through the steps of melt metering, extruding via the compositional spinneret, cooling, oiling, drawing, heat setting and winding.

(78) Herein said compositional spinneret is simultaneously provided with cruciform orifices and circular orifices, and the length ratio of cruciform orifice to circular orifice is equal to the product of their equivalent diameter ratio and a coefficient K, here equivalent diameter is the ratio of orifice cross-section area to its circumference and K value is 1.03 The length of cruciform and circular spinneret orifices are 0.80 mm and 0.80 mm respectively, while the equivalent diameter of cruciform spinneret orifices is 0.12 mm. All the spinneret orifices, specifically, all the center of circular orifices or all the circumferential center of cruciform orifices are arranged in regular intervals along the equally spaced concentric circles on the spinneret, and in the same ring both circular orifices and cruciform orifices are set up with a number ratio of 2:1. The spinning parameters in those technology steps are respectively set up as: a spinning temperature of 287° C., a cooling temperature of 25° C., an interlacing pressure of 0.24 MPa, a godet roller1 speed of 2300 m/min, a godet roller1 temperature of 85° C., a godet roller2 speed of 4100 m/min, a godet roller2 of 150° C., a winding speed of 4140 m/min, an initial spinning pack pressure of 120 bar and a spinning pack pressure rising of less than or equal to 0.57 bar/day.

(79) The final obtained fiber is one kind of thermal-moisture polyester FDY for summer use composed of both cruciform monofilaments and circular monofilaments extruded from the same spinneret, possessing a lousiness rate of less than or equal to 2/package and a capillary parameter of 0.18, and the cruciform monofilaments have a fineness of 0.50 dtex whereas that of the circular monofilaments is 0.21 dtex. The woven fabrics (surface density of 280 g/m.sup.2) made of the FDY mentioned above have a wicking height of 138 mm and an evaporation rate of 0.29 g/h. Moreover, the basic physicochemical indices of the polyester FDY are given as follows: a fineness of 100 dtex, a breaking strength of 4.3 cN/dtex, a breaking elongation of 30.0%, a linear density deviation rate of 0.44%, a breaking strength CV of 4.8%, a breaking elongation CV of 8.5%, a yarn evenness CV of 2.0%, a boiling water shrinkage of 8.0% and an oil content of 0.90%.