PRODUCTION PROCESSES OF POLYESTER FILAMENTS FOR MOISTURE WICKING

Abstract

The process of the present invention may be used to produce polyester filaments that exhibit superior moisture and perspiration absorption. In various embodiments, this process involves: (1) pre-crystallizing polyester chips in a crystallizer; (2) drying and ventilating the polyester chips after crystallization to produce dried polyester chips; (3) melting the dried polyester chips in a screw extruder; (4) filter the melted polyester chips to form a filtered melt; (5) introducing the filtered melt into a spinning box via a metering pump, wherein the filtered melt enters the spinning assembly; (6) extruding the filaments from the spinning assembly; (7) cooling the extruded filaments from the spinning assembly to room temperature in order to solidify the filaments and form a fiber tow; and (8) winding the fiber tow via a winding machine to form a wound tow. The process described herein can produce polyester filaments that comprise a longitudinal groove along the surface of fiber, which can provide a capillary effect that enhances the moisture wicking capabilities of the filaments. Consequently, the polyester filaments of the present invention can be used to produce woven articles, such as reinforcement fabrics, that comprise fiber micro-grooves along the surface of the article, thereby enhancing the article's sweat wicking capabilities, water diffusion capabilities, and water transfer capabilities. Furthermore, the use of these grooved polyester filaments of the present invention can facilitate the migration of water and moisture to the surface of the fabric, thereby allowing the moisture to spread out on the surface and enabling it to quickly evaporate. Consequently, this can keep the skin of the wearer dry.

Description

RELATED APPLICATIONS

This application claims the foreign priority benefit of Chinese Application No. 201710086287.8 filed on Feb. 17, 2017.

BACKGROUND

1. Field of the Invention

The present invention generally relates to a textile fabric production process. More particularly, the present application generally relates to the production of a polyester filament with enhanced wicking functionality.

2. Description of the Related Art

Polyester filament is an important species of synthetic fibers. In particular, polyester filament can exhibit a variety of desirable characteristics and may be used in a wide array of applications. For instance, polyester filament is extensively used to manufacture clothing and various industrial products. Generally, polyester filaments can exhibit strengths that are nearly twice that of cotton and about three times higher than wool, thereby resulting in a more durable fabric.

Furthermore, polyester is heat resistant and can be exposed to temperatures ranging from 70 to 170° C. Thus, synthetic polyester filaments can provide desirable heat resistance and thermal stability. In addition, polyester filaments can exhibit desirable elasticity that is close to the elasticity of wool. Moreover, polyester filaments can exhibit more crease resistance than other fibers. Consequently, fabrics produced from polyester filaments can resist wrinkling and maintain desirable shape retention. At the same time, polyester filaments also exhibit desirable wear resistance and water absorption and can be easily dyed.

Presently, China's total fiber production has become the world's largest, but this production mostly focuses on the manufacture of general conventional fiber. In other words, production of specialized fiber varieties is much lower in China compared to other developed countries. Consequently, many high-tech, high value-added products are monopolized by other countries. Therefore, there has been an increased commitment in China to develop and produce new varieties of high-tech, high value-added fibers that can compete with those that already exist in the international market.

For example, wicking function is now required in many fabrics and/or fibers. Thus, there is a need for specialized fabrics that exhibit desirable moisture absorption and sweat dissipation through the fabric structure. For instance, such fabrics can offer desirable water absorption and drying properties.

Generally, there are three mechanisms that can influence and control the wicking capabilities of a woven fabric: water absorption, water retention, and evaporation. In particular, when manufacturing such fabrics, one must consider: (1) the gap between the fabric and the skin of the wearer, which produces sweat; (2) the evaporation rate of water vapor on the fabric surface and the rate that the vapor condenses into liquid water; and (3) the capillary functionality of the fabric and its ability to transport moisture to the outer surface of the fabric.

Although advances have been made in this field, there is a still need for a filament that can be used to produce a woven fabric that exhibits desirable water absorption, water retention, and water evaporation.

SUMMARY

One or more embodiments of the present invention are directed to a process for producing a moisture-wicking polyester filament. Generally, the process comprises: (a) forming polyester chips in a crystallizer at a temperature of at least 120° C. and for not more than 30 minutes; (b) drying the polyester chips to a water content of 20 to 50 ppm to form dried polyester chips; (c) melting the dried polyester chips in an extruder at a temperature of at least 270° C. to form a polyester melt; (d) filtering the polyester melt with a filter to form a filtered polyester melt; (e) spinning the filtered polyester melt with a spinning pack to form extruded filaments, wherein the spinning pack comprises a head temperature of at least 280° C. and operates at a pressure in the range 100 to 170 kgf/cm²; and (f) cooling the extruded filaments with a gas stream to form a fiber tow.

One or more embodiments of the present invention are directed to a process for producing a wicking polyester filament. Generally, the process comprises: (a) forming polyester chips in a crystallizer at a temperature of at least 100° C.; (b) drying the polyester chips to a water content of less than 200 ppm to form dried polyester chips; (c) melting the dried polyester chips in an extruder at a temperature of at least 225° C. to form a polyester melt; (d) filtering the polyester melt with a filter to form a filtered polyester melt; (e) spinning the filtered polyester melt with spinning pack comprising a non-round shaped spinneret to form extruded filaments, wherein the spinning pack comprises a head temperature of at least 250° C. and operates at a pressure of at least 80 kgf/cm²; and (f) cooling the extruded filaments with a gas stream to form a fiber tow comprising a plurality of polyester filaments, wherein the polyester filaments comprise a lobed-shape cross section comprising a plurality of lobes.

One or more embodiments of the present invention are directed to a woven fabric comprising a polyester filament. Generally, the polyester filament comprises a lobed-shape cross-section containing a plurality of lobes. Furthermore, the woven fabric exhibits a vertical wicking height of at least 100 mm/10 minutes and a diffusion area of at least 1,700 mm²/30 seconds.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the present invention are described herein with reference to the following drawing figures, wherein:

FIG. 1 depicts a cross-sectional view of the moisture-wicking polyester filaments;

FIG. 2 depicts a cross-sectional view of a single moisture-wicking polyester filament;

FIG. 3 is a bar graph depicting the vertical wicking heights of various tested fabrics produced from nylon fibers, conventional polyethylene terephthalate (PET) fibers, cotton fibers, and the inventive polyester filaments; and

FIG. 4 is a bar graph depicting the water droplet diffusion areas of various tested fabrics produced from nylon fibers, conventional polyethylene terephthalate (PET) fibers, cotton fibers, and the inventive polyester filaments.

DETAILED DESCRIPTION

The object of the present invention is to provide a simple production process that provides a moisture-wicking polyester filament that can be used to produce various fabrics, which exhibit desirable moisture absorption, rapid drying capabilities, superior breathability, and advanced water wicking. In particular, the process of the present invention produces a polyester filament that contains a different type of fiber interface, which comprises one or more longitudinal grooves along the filament. As described below, these longitudinal grooves in the polyester filaments can function as capillaries and facilitate the movement of liquids. Consequently, these longitudinal grooves in the polyester filaments of the present invention allow the filaments to enhance the capillary effects of the fabrics produced therefrom. In other words, these filament longitudinal grooves can facilitate sweat wicking, diffusion, and liquid transfer to the surface of the fabric, where it can quickly diverge and evaporate, thereby leaving the wearer with a sense of dry skin. Furthermore, fabrics made from the inventive polyester filaments allow the wearer to maintain a comfortable micro-climate, even when the fabric is in a wet state.

As described herein, the process of the present invention may be used to produce polyester filaments that exhibit superior moisture and perspiration absorption. In various embodiments, this process involves: (1) pre-crystallizing polyester chips in a crystallizer; (2) drying and ventilating the polyester chips after crystallization to produce dried polyester chips; (3) melting the dried polyester chips in a screw extruder; (4) filter the melted polyester chips to form a filtered melt; (5) introducing the filtered melt into a spinning box via a metering pump, wherein the filtered melt enters the spinning assembly; (6) extruding the filaments from the spinning assembly; (7) cooling the extruded filaments from the spinning assembly to room temperature in order to solidify the filaments and form a fiber tow; and (8) winding the fiber tow via a winding machine to form a wound tow.

The process described herein can produce polyester filaments that comprise a longitudinal groove along the surface of fiber, which can provide a capillary effect that enhances the moisture wicking capabilities of the filaments. Consequently, the polyester filaments of the present invention can be used to produce woven articles, such as reinforcement fabrics, that comprise fiber micro-grooves along the surface of the article, thereby enhancing the article's sweat wicking capabilities, water diffusion capabilities, and water transfer capabilities. Furthermore, the use of these grooved polyester filaments of the present invention can facilitate the migration of water and moisture to the surface of the fabric, thereby allowing the moisture to spread out on the surface and enabling it to quickly evaporate. Consequently, this can keep the skin of the wearer dry.

In order to solve the technical needs discussed above, the present invention adopts a production process for producing the moisture-wicking polyester filament that involves a high temperature melt spinning process. In various embodiments, the general process for producing the moisture-wicking polyester filaments comprises: (1) a crystallization step, (2) a melt spinning step, and (3) a winding step.

The crystallization step occurs in a crystallizer, which can be any crystallizer commonly utilized in the art. During the crystallization step, the polyester chips are heated with hot air in the crystallizer to form crystallized polyester chips. In certain embodiments, the polyester chips are formed from polyethylene terephthalate or derivatives thereof.

In various embodiments, the crystallization step can occur at a temperature of at least 100, 110, or 120° C. and/or less than 220, 200, or 170° C. Additionally or alternatively, the crystallization step can occur for at least 5, 10, or 20 minutes and/or less than 60, 40, or 30 minutes. In certain embodiments, the crystallization step occurs at temperature in the range of 120 to 170° C. for a period of 20 to 30 minutes.

Next, the crystallizer may be ventilated and the polyester chips may be dried to form dried polyester chips having a water content of less than 200, 100, 75, or 50 ppm and/or more than 5, 10, or 20 ppm. In various embodiments, the drying step can occur at temperatures of at least 100, 125, or 150° C. and/or less than 250, 200, or 170° C. for a time period of at least 1, 2, or 4 hours and/or less than 12, 10 or 8 hours. Additionally or alternatively, the ventilation during the drying step can occur at a rate of 250 to 320 Nm³/h. Furthermore, in various embodiments, the dew point of the drying air inlet for the drying step is maintained at a range of −40 to 0° C., preferably at −20° C. In certain embodiments, the drying step occurs at a temperature in the range of 150 to 170° C. and over a period of 4 to 8 hours.

After the drying step, the dried polyester chips can be fed into a screw extruder, wherein the chips can be melted and filtered. In one or more embodiments, the screw extruder can comprise any conventional screw extruder commonly utilized in the field of melt spinning. In various embodiments, the melting step in the extruder occurs at a temperature of at least 225, 250, or 270° C. and/or less than 350, 325, or 295° C. In certain embodiments, the melting step can occur at a temperature in the range of 270 to 295° C. Additionally or alternatively, the filter used to filter the polyester melt can comprise a pore size of 0.3 to 0.6 mm, preferably about 0.5 mm.

After the melting step, the polyester melt can be metered into a spinning pack comprising a spinneret head via a metering pump. The metering pump can control the flow of the polyester melt into the spinning box. In various embodiments, the temperature inside the metering pump is at least 225, 250, or 280° C. and/or less than 350, 320, or 290° C. In certain embodiments, the temperature inside the metering pump is in the range of 280 to 290° C. and the pressure is in the range of 100 to 170 kgf/cm².

While in the spinning box, the polyester melt can be pumped through a spinneret (e.g., a die) with one or more holes to form an extruded filament. The spinneret can have a non-round shape in order to produce filaments with a non-round shape. For example, the spinneret can have a lobed-shaped cross section, a clover leaf-shaped cross section, a triangular-shaped cross section, an X-shaped cross-section, or a flat-shaped cross section.

In various embodiments, the temperature inside the spinning box is at least 225, 250, or 280° C. and/or less than 350, 320, or 300° C. In certain embodiments, the temperature inside the spinning box is in the range of 280 to 300° C.

Furthermore, in various embodiments, the temperature of the spinneret head can be at least 225, 250, or 280° C. and/or less than 350, 320, or 300° C. In certain embodiments, the temperature of the spinneret head can be in the range of 280 to 300° C.

After being extruded from the spinneret, the extruded filaments can be cooled and solidified with a side-blowing gas stream in order to form a fiber tow comprising one or more polyester filaments. In certain embodiments, the gas stream can comprise air. In various embodiments, the gas stream can be positioned so as to contact the extruded filaments at an angle ranging from 60 to 120 degrees, preferably at about 90 degrees. Generally, in various embodiments, the gas stream can comprise a temperature in the range from 20 to 30° C., a humidity of 65 to 75 percent, and maintain a flow rate of 0.3 to 0.6 m/s.

After cooling, the solidified fiber tow may be wound by a winding machine at an angle of at least 3, 4, or 5 degrees and/or less than 12, 10, or 7 degrees. In certain embodiments, the fiber tow is wound at an angle ranging from 5 to 7 degrees. Additionally or alternatively, in various embodiments, the overfeeding rate during the winding step can range from 0 to 2 percent, the tension during winding is maintained at 0.2 times the winding speed, and the winding speed of the winding machine is maintained at about 4,800 m/minute.

Although not required, additives, such as a wax, may be added onto the filaments during the winding step. Such additives can include, for example, waxes such as paraffin wax, silicone oil, white oil, and/or rapeseed oil.

As noted above, the resulting polyester filaments in the fiber tow can comprise longitudinal grooves that can function as capillaries. In various embodiments, these longitudinal grooves can be introduced into the filaments during the melt spinning process. For example, during the melt spinning process, a spinneret with a non-round shape can be used to extrude and spin the resulting filaments. Consequently, the resulting filaments will generally comprise a cross-sectional shape that is similar to the shape of the spinneret.

In various embodiments, the polyester filaments comprise a non-round cross-sectional shape, such as, for example, a lobed shape. In one or more embodiments, the filaments can be non-round filaments having a lobed-shaped cross section, a clover leaf-shaped cross section, a triangular-shaped cross section, an X-shaped cross-section, or a flat-shaped cross section.

In one or more embodiments, the filaments have a lobed-shape cross section. In various embodiments, the filaments have a cross-sectional lobed-shape comprising at least 1, 2, 3, 4, 5, 6, 7, or 8 lobes. In certain embodiments, the filaments have a lobed-shape cross section with 4 lobes. As shown in FIG. 1, the process described herein can produce a fiber tow comprising a plurality of polyester filaments having a lobed-shape cross section.

In various embodiments, the polyester filaments can have an average cross-sectional surface area of at least 50, 100, 200, 300, 400, or 500 μm² and/or not more than 10,000, 5,000, or 2,000 μm².

In various embodiments, the filament may have a minimum transverse width of less than about 1,000, 750, 500, 400, 300, 200, 100, or 50 μm. Additionally or alternatively, the filament can have a maximum transverse width of less than about 10,000, 5,000, 2,000 μm, but greater than about 1,000, 750, 500, 400, 300, 200, 100, or 50 μm. As used herein, the “minimum transverse width” denotes the minimum cross-sectional width of a filament as measured perpendicular to the length of the filament. In addition, as used herein, the “maximum transverse width” denotes the maximum cross-sectional width of a filament as measured perpendicular to the length of the filament. FIG. 2 demonstrates how the minimum transverse width and maximum transverse width of the filaments may be measured. In particular, as shown in FIG. 2, the cross-section of the filament 10 comprises a minimum transverse width 12 and a maximum transverse width 14.

Typically, the minimum transverse width and the maximum transverse width should be nearly identical for filaments having a round-shaped cross-section. However, these dimensions may greatly vary if filaments containing different cross-sectional shapes are used (e.g., lobed-shape). In one or more embodiments, the filaments can have a transverse aspect ratio of at least 1:1, 1.25:1, 1.5:1, 1.75:1, 2:1, 3:1, 4:1, 5:1, 10:1, 50:1, or 100:1. Additionally or alternatively, the filaments can have a transverse aspect ratio of less than 10,000:1, 5,000:1, 1,000:1, 500:1, 100:1, 50:1, 20:1, 10:1, 5:1, 4:1, 3:1, 2.5:1, 2:1, 1.75:1, or 1.5:1. As used herein, “transverse aspect ratio” denotes the ratio of a filament's maximum transverse width to the filament's minimum transverse width.

Additionally or alternatively, the polyester filaments can comprise an average denier of at least 0.3, 0.5, 0.75, 1, 1.25, or 1.5 and/or less than 5, 4, 3, 2, or 1.75 denier.

The resulting polyester filaments produced by the process described herein can improve the capillary effects of the fabrics produced from the filaments. In particular, the inventive polyester filaments can comprise grooves along its longitudinal surface that facilitate this capillary function. In other words, by enhancing the capillary functionality of the inventive polyester filaments, one can produce fabrics therefrom that exhibit superior water absorption and moisture wicking. More specifically, the longitudinal grooves facilitate the movement of moisture within the fabric, thereby allowing the moisture to be moved from the wearer's skin to the surface of the fabric, where the moisture can begin to evaporate. Consequently, this results in a fabric that can be more comfortable for the wearer.

In various embodiments, the inventive polyester filaments can be twisted to form a yarn. In such embodiments, the resulting yarn can comprise at least 2, 3, 4, 5, 20, 40, 60, 70 or 80 and/or not more than 250, 200, 150, 125, or 100 filaments. Additionally or alternatively, the yarns produced with the polyester filaments can have an average denier of at least 5, 25, or 50 and/or not more than 125, 100, or 75 denier.

Additionally, in various embodiments, the polyester filaments or yarns produced from the polyester filaments can be used to produce various end products, such as woven fabrics. These fabrics can be used to produce a myriad of articles, including various clothing articles.

In various embodiments, the woven fabrics produced from the inventive polyester filaments may exhibit a vertical wicking height according to AATCC-79 of at least 75, 80, 85, 90, 95, 100, 105, or 110 mm/10 minutes. Additionally or alternatively, the woven fabrics produced from the inventive polyester filaments may exhibit a water diffusion area of at least 1,500, 1,600, 1,700, or 1,800 mm²/30 seconds.

This invention can be further illustrated by the following examples of embodiments thereof, although it will be understood that these examples are included merely for the purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated.

EXAMPLES

Example 1

For this example, a moisture-wicking polyester filament having a lobed-shape cross-sectional shape with four lobes was produced using the melt spinning process described herein. In particular, polyester chips were pre-crystallized in a crystallizer and heated by hot air at 120° C. for 20 minutes to complete the pre-crystallization step. Next, the crystallized polyester chips were subjected to ventilation drying in order to bring the polyester chip moisture content down to 20 ppm. The drying temperature was 150° C. and was carried out for 4 hours, while the ventilation was maintained at 250 Nm³/h and the dry air dew point was maintained at −20° C. After drying, the dried polyester chips were fed into a screw extruder, where they were melted at 270° C. and the resulting polyester melt was filtered with a filter having a pore size of about 0.5 mm. The filtered polyester melt was then metered into the spinning box, wherein the spinning head temperature was maintained at about 280° C., the metering pump temperature was maintained at about 280° C., and the extrusion pressure was about 100 kgf/cm². The filaments extruded from the spinning assembly were cooled with a side air stream blowing at a 90 degree angle relative to the extruded filaments. The air stream had a temperature of about 20° C., a humidity of about 65 percent, and a flow rate of about 0.3 m/s. The resulting solidified fiber tow was then wound by a coiling machine at an angle of about 5 degrees, at an overfeed rate of 0 percent, a tension that was 0.2 times the production type, and at a winding machine speed of 4,800 m/min.

Example 2

For this example, a moisture-wicking polyester filament having a lobed-shape cross-sectional shape with four lobes was produced using the melt spinning process described herein. In particular, polyester chips were pre-crystallized in a crystallizer and heated by hot air at 170° C. for 30 minutes to complete the pre-crystallization step. Next, the crystallized polyester chips were subjected to ventilation drying in order to bring the polyester chip moisture content down to about 50 ppm. The drying temperature was 170° C. and was carried out for 8 hours, while the ventilation was maintained at 320 Nm³/h and the dry air dew point was maintained at −20° C. After drying, the dried polyester chips were fed into a screw extruder, where they were melted at 295° C. and the resulting polyester melt was filtered with a filter having a pore size of about 0.5 mm. The filtered polyester melt was then metered into the spinning box, wherein the spinning head temperature was maintained at about 300° C., the metering pump temperature was maintained at about 290° C., and the extrusion pressure was about 170 kgf/cm². The filaments extruded from the spinning assembly were cooled with a side air stream blowing at a 90 degree angle relative to the extruded filaments. The air stream had a temperature of about 30° C., a humidity of about 75 percent, and a flow rate of about 0.6 m/s. The resulting solidified fiber tow was then wound by a coiling machine at an angle of about 7 degrees, at an overfeed rate of 2 percent, a tension that was 0.2 times the production type, and at a winding machine speed of 4,800 m/min.

Example 3

For this example, a moisture-wicking polyester filament having a lobed-shape cross-sectional shape with four lobes was produced using the melt spinning process described herein. In particular, polyester chips were pre-crystallized in a crystallizer and heated by hot air at 145° C. for 25 minutes to complete the pre-crystallization step. Next, the crystallized polyester chips were subjected to ventilation drying in order to bring the polyester chip moisture content down to about 35 ppm. The drying temperature was 160° C. and was carried out between 4 to 8 hours, while the ventilation was maintained at 285 Nm³/h and the dry air dew point was maintained at −20° C. After drying, the dried polyester chips were fed into a screw extruder, where they were melted at 277° C. and the resulting polyester melt was filtered with a filter having a pore size of about 0.5 mm. The filtered polyester melt was then metered into the spinning box, wherein the spinning head temperature was maintained at about 290° C., the metering pump temperature was maintained at about 285° C., and the extrusion pressure was about 135 kgf/cm². The filaments extruded from the spinning assembly were cooled with a side air stream blowing at a 90 degree angle relative to the extruded filaments. The air stream had a temperature of about 25° C., a humidity of about 70 percent, and a flow rate of about 0.45 m/s. The resulting solidified fiber tow was then wound by a coiling machine at an angle of about 6 degrees, at an overfeed rate of 1 percent, a tension that was 0.2 times the production type, and at a winding machine speed of 4,800 m/min.

Example 4

Woven fabrics were produced from conventional nylon filaments, conventional round PET filaments, conventional cotton filaments, and the inventive polyester filaments. The moisture absorption and wicking properties of the fabrics were tested and compared.

The vertical wicking height (mm/10 minutes) was measured according to AATCC-79 for each of the produced fabrics. The test method for measuring the vertical wicking height comprised cutting the test fabrics into sample pieces having a size of 20 cm by 2.5 cm and submerging a designated portion of the sample fabric in a tank holding water. The tank was installed on a horizontal bar and the temperature of the water in the tank was maintained at 18 to 22° C. The samples were removed from the tank after 10 and 30 minutes in order to measure the rise of water in the portions of the fabric that were not submerged in the water. Consequently, this allowed one to observe the capillary effects of the filaments making up the fabrics. The rise of the water was measured from the designated submerge line to the top vertical height that the water reached in the fabric. These measurements were taken after 10 and 30 minutes. A measurement was repeated five times and the average value was calculated. As shown in FIG. 3, the fabric produced from the inventive polyester filament exhibited a significant higher wicking height after 10 minutes (113 mm/10 minutes) compared to fabrics produced from conventional nylon, PET, and cotton filaments.

In addition, the water droplet diffusion area of the fabrics was also tested in order to further analyze the moisture wicking capabilities of the inventive polyester filaments. For this test, the fabric samples were flattened and suspended in the air. Next, 0.2 mL of water was dropped onto the sample and the diffusion area of the water on the fabric was measured with a ruler after 30 seconds. As shown in FIG. 4, the fabric produced from the inventive polyester filament outperformed fabrics produced from conventional nylon, PET, and cotton filaments.

As can be seen in FIGS. 3 and 4, fabrics produced from the inventive polyester filaments exhibited better moisture absorption and wetting effects compared to fabrics produced from conventional nylon, PET, and cotton filaments. Consequently, this would result in a fabric that would be more comfortable to the wearer.

Definitions

It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, when accompanying the use of a defined term in context.

As used herein, the terms “a,” “an,” and “the” mean one or more.

As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

As used herein, the terms “including,” “include,” and “included” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

Numerical Ranges

The present description uses numerical ranges to quantify certain parameters relating to the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for a claim reciting “greater than 10” (with no upper bounds) and a claim reciting “less than 100” (with no lower bounds).

Claims Not Limited to Disclosed Embodiments

The preferred forms of the invention described above are to be used as illustration only, and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.

The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

Claims

1. A process for producing a wicking polyester filament, wherein the process comprises:

(a) forming polyester chips in a crystallizer at a temperature of at least 120° C., wherein the forming occurs for not more than 30 minutes;

(b) drying the polyester chips to a water content of 20 to 50 ppm to form dried polyester chips;

(c) melting the dried polyester chips in an extruder at a temperature of at least 270° C. to form a polyester melt;

(d) filtering the polyester melt with a filter to form a filtered polyester melt;

(e) spinning the filtered polyester melt with a spinning pack to form extruded filaments, wherein the spinning pack comprises a head temperature of at least 280° C. and operates at a pressure in the range 100 to 170 kgf/cm2; and

(f) cooling the extruded filaments with a gas stream to form a fiber tow.

2. The process of claim 1, wherein the forming of step (a) occurs at a temperature in the range of 120 to 170° C.

3. The process of claim 2, wherein the forming of step (a) occurs over a period of 20 to 30 minutes.

4. The process of claim 1, wherein the melting of step (c) occurs at a temperature in the range of 270 to 295° C.

5. The process of claim 4, wherein the filter in step (d) comprises a pore size in the range of 0.3 to 0.6 mm.

6. The process of claim 1, wherein the spinning pack comprises a head temperature in the range of 280 to 300° C.

7. The process of claim 1, wherein the gas stream is positioned to contact the extruded filaments at an angle ranging from 60 to 120 degrees during the cooling of step (f).

8. The process of claim 7, wherein the gas stream is positioned to contact the extruded filaments at an angle of about 90 degrees during the cooling of step (f).

9. The process of claim 7, wherein the gas stream is at a temperature in the range of 20 to 30° C. and flows at a rate in the range of 0.3 to 0.6 m/s.

10. The process of claim 1, further comprising winding the fiber tow at a winding angle of 5 to 7 degrees with a winding machine to form a wound fiber.

11. The process of claim 1, wherein the drying of step (b) occurs at a temperature in the range of 150 to 170° C. over a period of 4 to 8 hours.

12. A process for producing a wicking polyester filament, wherein the process comprises:

(a) forming polyester chips in a crystallizer at a temperature of at least 100° C.;

(b) drying the polyester chips to a water content of less than 200 ppm to form dried polyester chips;

(c) melting the dried polyester chips in an extruder at a temperature of at least 225° C. to form a polyester melt;

(d) filtering the polyester melt with a filter to form a filtered polyester melt;

(e) spinning the filtered polyester melt with spinning pack comprising a non-round shaped spinneret to form extruded filaments, wherein the spinning pack comprises a head temperature of at least 250° C. and operates at a pressure of at least 100 kgf/cm2; and

(f) cooling the extruded filaments with a gas stream to form a fiber tow comprising a plurality of polyester filaments, wherein the polyester filaments comprise a lobed-shape cross section comprising a plurality of lobes.

13. The process of claim 12, wherein the filaments comprise a transverse aspect ratio of at least 1.5.

14. The process of claim 12, wherein the forming of step (a) occurs at a temperature in the range of 120 to 170° C. and over a period of 20 to 30 minutes.

15. The process of claim 12, wherein the gas stream is positioned to contact the extruded filaments at an angle ranging from 60 to 120 degrees during the cooling of step (f).

16. The process of claim 15, wherein the gas stream is at a temperature in the range of 20 to 30° C. and flows at a rate in the range of 0.3 to 0.6 m/s.

17. The process of claim 12, further comprising winding the fiber tow at a winding angle of 5 to 7 degrees with a winding machine to form a wound fiber.

18. A woven fabric comprising a polyester filament,

wherein the polyester filament comprises a lobed-shape cross-section containing a plurality of lobes, and

wherein the woven fabric exhibits a vertical wicking height of at least 100 mm/10 minutes and a diffusion area of at least 1,700 mm2/30 seconds.

19. The fabric of claim 18, wherein the polyester filament comprises 4 lobes.

20. The fabric of claim 18, wherein the woven fabric exhibits a vertical wicking height of at least 75 mm/10 min and a diffusion area of at least 1,500 mm2/30 seconds.