Patent Description:
Reported in the art are fabrics with middle layers comprising yarns of various materials. <CIT> reports a fabric with a middle layer of monofilament or multifilament texturized yarns, for example impact absorbing elastic texturized polyester (PES), polyamide (PA) yarns or PES or PA yarns with elastane or Spandex. <CIT> reports a method to increase the moisture management property of 3D-knitted fabrics by using both a thermo-fuse yarn and a hydrophobic supportive yarn for the transverse threads of the middle layer with inlays of hydrophilic yarn connected only to the middle layer transverse threads. <CIT> reports a fabric with a middle layer of a hydrophilic fusible yarn for moisture management. <CIT> reports a fabric with a middle layer of a hydrophilic fiber and heat-fusible fiber or a middle layer of hydrophilic fiber and heat-fusible fiber and a hydrophobic fiber. <CIT> reports a fabric with a middle layer of a hydrophilic thermoplastic fiber or a hydrophobic thermoplastic fiber subjected to a hydrophilic treatment. There is a need in the art for 3D-knitted spacer fabrics with improved moisture management properties.

<CIT> discloses a three-dimensional (3D) multifunctional knitted fabric structure comprising two independent layers connected by cross-threads being able to be applied as absorbency structure in medium incontinence men's reusable underwear. The structure is produced in a single step using weft-knitting technology and designed to perform several functions in a single fabric. The inner layer, to be in contact with human body, is responsible to transport liquid, urine and perspiration from the human body to the outer layer, through the cross-threads, keeping dry the human skin. Cross-threads are responsible to keep apart both independent layers and to transport liquid from the inner layer to the outer layer. The outer layer is responsible to absorb the liquid and, at same time, to control the odor and microorganisms proliferation generated by the urine. The outer layer is coated or laminated with a moisture control polyurethane in order to prevent liquid passage to the user paints and at same time to provide vapor transmission.

<CIT> discloses a double-knitted fabric comprising a face cloth and a back cloth which are joined together by a tie yarn, wherein the tie yarn contains not less than <NUM> % by weight of a heat-bonding yarn and the back cloth contains not less than <NUM> % by weight of a heat-bonding yarn, a molded article made thereof and a mouse pad made thereof.

<CIT> discloses a heat resistant spacer fabric comprising a first and second fabric layers that are formed of a flame resistant material arranged in opposing face-to-face relation and are spaced apart from each other. The first and second fabric layers are interconnected to each other with one or more spacer fibers that interconnect the first and second fabric layers and define a space therebetween. The spacer fibers comprise at least one core fiber having one or more wrap fibers of a flame resistant material wrapped thereabout. The spacer fabric can be used in protective garments such as coats, gloves, pants, cover-alls, suits, etc..

The term "warp knitted" refers to a fabric produced by machine with the yarns running in a lengthwise direction. Warp knitting is the sequential formation and interlinking of loops in an axial direction on a lateral array of needles with at least one separate thread being supplied to each needle. The loops are joined together in a width-wise direction by moving the threads back and forth between adjacent needles. The needles produce parallel rows of loops simultaneously that are interlocked in a zigzag pattern.

The term "weft-knitted" refers to a knit fabric produced in machine or hand knitting with the yarns running crosswise across the width of the fabric or in a circle.

A "hydrophilic yarn" refers to a yarn that absorbs liquids and moisture.

A "hydrophobic yarn" refers to a yarn that resists liquids and moisture penetration.

"Heat-fusible" or "thermo-fuse" fibers or yarns refer to fibers and yarns that under the effects of heat (e.g., steam, hot air, infrared rays) will melt and then, after/during cooling, recrystallize, becoming solid. The term "blended thermo-fuse wicking yarn" refers to a yarn comprising hydrophilic fiber and thermo-fuse fiber.

The term "functional yarn" refers to a type of yarn that combines mechanical and functional properties, for example a yarn that has the functional property of wicking fluids. The term "functional wicking yarn" refers to a yarn that has the functional property of wicking fluids.

The term "moisture-manageable yarn" refers to a yarn that has the property of absorbing and/or wicking fluids and/or the property of drying. The term "property of drying" refers to the drying rate (g/h) for a fabric to evaporate <NUM> liquid water, for example using standard AATCC TM201 or AATCC TM201 to test. Depending on the purpose of moisture management, the requirement for drying speed may vary. A moisture-manageable yarn as used herein has a fast-drying property, of ≥<NUM>/h according to GB21655.

The term "supportive yarn" refers to a yarn having a certain elasticity of compression and a certain resilience along the length direction of the yarn. A supportive yarn is rigid enough to withstand a certain force or compressive pressure. A supportive yarn withstands load and recover to the original shape automatically when the force is removed. In a 3D-knittted spacer fabric, the supportive yarn in the middle layer can maintain the distance between top and bottom surfaces when there is no load on it and recover to the original shape when the force is removed. Exemplary supportive yarns are polyethylene terephthalate (PET) monofilament, polyethylene (PE) monofilament, or thermoplastic polyester elastomer (TPEE) monofilament. Some supportive yarns can withstand load. Ability to withstand load, depends, for example, on material type of the yarn, fineness of the yarn, and/or knitting structure of the middle layer. For example, the thicker the yarn and the more serried the middle layer, the stronger the support. The larger the amount of yarn knitted in a unit area of the middle layer, the stronger the support.

The term "non-supportive yarn" refers to a yarn without elasticity of compression and without resilience along the length direction of the yarn. A non-supportive yarn is too soft to withstand load and cannot recover to the original shape automatically when the force is removed. Exemplary non-supportive yarns are cotton yarn, silk yarn, polyester multifilament yarn.

The term "wicking" refers to the action of absorbing or drawing off liquid by capillary action. The term "wicking yarn" refers to a yarn that absorbs or draws off liquid by capillary action.

The term "synthetic fiber" refers to a fiber commonly created through the indirect synthesis of petroleum derivatives. Exemplary synthetic fibers are nylon and polyester.

The term "artificial fiber" (also known as "semi-synthetic fiber") refers to a fiber such as rayon that is generally derived from natural material, through chemical processes. Exemplary artificial fibers are viscose, Tencel, and Modal.

The term "modified polyester" refers to a polyester modified to be hydrophilic. Polyester is originally hydrophobic. For example, polyester may be modified to be made hydrophilic by the following two methods:.

Compositions or methods "comprising" or "including" one or more recited elements may include other elements not specifically recited. When the disclosure refers to a feature comprising specified elements, the disclosure should alternatively be understood as referring to the feature consisting essentially of or consisting of the specified elements.

Designation of a range of values includes all integers within or defining the range, and all subranges defined by integers within the range.

Unless otherwise apparent from the context, the term "about" encompasses insubstantial variations, such as values within a standard margin of error of measurement (e.g., SEM) of a stated value.

The singular forms of the articles "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

The invention provides 3D-knitted spacer fabric compositions with properties of moisture management, compression, and rebound resistance and methods of making the compositions. The 3D-knitted spacer fabric compositions comprise three layers, a first (top) layer, a second (middle or intermediate) layer, and a third (bottom) layer. The first (top) layer comprises a hydrophilic yarn and is closest to the skin of the wearer. All material(s) used in the middle layer is (are) hydrophilic and are non-supportive functional wicking yarn. No hydrophobic yarn is used. The second layer comprises a first yarn and a second yarn, each of which is hydrophilic. The first yarn of the second layer is a hydrophilic yarn, and the second yarn of the second layer is a blended heat-fusible yarn, comprising hydrophilic fiber and heat-fusible fiber. The third (bottom) layer comprises a hydrophobic yarn and is farthest from the skin of the wearer. The hydrophilic middle layer provides improved liquid transfer from the top layer to the bottom layer of the compositions. The 3D-knitted fabrics may be warp-knitted or weft-knitted. Heat treatment of the 3D-knitted spacer fabric compositions solidifies the heat-fusible yarn of the middle layer, allowing the fabric to be set to a desired shape and providing compression and rebound resistance, and maintaining the moisture management and wicking properties after heat treatment.

This invention provides a knitting structure for the middle layer of the spacer fabric, connected to top and bottom surfaces. The structure of the middle layer has wicking properties. In an exemplary warp-knitting process, one bar of yarn (on middle bar <NUM> in <FIG>) is blended thermo-fuse wicking yarn (<NUM> on <FIG>), made of hydrophilic fiber and thermo-fuse fiber; The other bar of yarn (on middle bar <NUM> in <FIG>) is non-supportive hydrophilic functional wicking yarn (<NUM> on <FIG>). In exemplary weft-knitting process, a middle guide bar (<NUM> in <FIG>) is threaded with two yarns, a first yarn that is a blended thermo-fuse wicking yarn (<NUM> on <FIG>), made of hydrophilic fiber and thermo-fuse fiber; and a second yarn that is a non-supportive hydrophilic functional wicking yarn (<NUM> on <FIG>). The top layer of the fabric is knit from a hydrophilic yarn and the bottom layer is knit from a hydrophobic yarn in order to increase one-direction moisture transfer property of the 3D-knitted spacer fabric. A top layer of the fabric is put next to a wet subject when in use, and liquid will be absorbed and transfer to the bottom surface layer through the yarn of the middle layer. The bottom hydrophobic yarn promotes fast drying. An exemplary warp-knitted fabric of the invention is depicted in <FIG>. An exemplary weft-knitted fabric of the invention is depicted in <FIG>. <FIG> depicts a close-up view of the second and third layers of an exemplary weft-knitted 3D-knitted spacer fabric, looking down from the first (top) layer onto the second and third layers.

Three-dimensional (3D)-knitted spacer fabrics are knit on a double-bed knitting machine and may be warp-knitted or weft-knitted. Both warp-knitted and weft knitted 3D spacer fabrics consist of two face layers (a top layer and a bottom layer) and a middle filler layer (intermediate layer, second layer). The top layer and the bottom layer are joined together by cross-yarns constituting the intermediate layer.

To form a 3D shape, the filler material is required to be supportive. Therefore, filler materials for traditional 3D-knitted spacer fabrics are usually resilient hydrophobic monofilament such as polyethylene terephthalate (PET), thermoplastic polyether ester elastomer (TPEE), polyamine(PA), thermoplastic polyurethane (TPU), or polypropylene (PP), knitted with designed angles between the two face layers, which are knitted from hydrophobic or even water-repellent material. The thickness of an exemplary traditional 3D-knitted spacer fabric is thicker than that of three normal-knitted single fabric layers piled together, in the case of using same yarns for each layer. An exemplary traditional 3D-knitted spacer fabric has thickness larger than <NUM>. Functional yarns, such as hydrophilic or moisture manageable yarns, are not used in the filler layer of traditional 3D-knitted spacer fabrics because functional yarns are usually non-supportive and cannot form a 3D shape with the thickness of a traditional 3D-knitted spacer fabric. Therefore, there is little liquid transfer from one face surface to the other face surface through the middle layer perpendicularly, resulting in poor liquid absorbing, transferring, and drying properties of a traditional 3D-knitted spacer fabric.

In a traditional 3D-knitted spacer fabric, both face layers are knitted with same material as each other. For a traditional 3D-knitted spacer fabric, the two surface layers could be both hydrophobic materials, for example, bouncy hydrophobic monofilament such as PA,TPU, PET, TPEE, or PP; or could both be hydrophilic materials, for example, natural yarn, synthetic yarn, artificial yarn, such as cotton, wool, viscous, multifilament nylon, or polyester.

3D-knitted spacer fabrics may be knitted with a range of hole patterns, for example a small-hole pattern, a medium-hole pattern, or a large-hole pattern. In a small-hole pattern, the diameter of the hole is not larger than about twice the width of a knitted loop, or less than about <NUM>. In a medium-hole pattern, the diameter of the hole is about <NUM> to <NUM>. In a large-hole pattern, the diameter of the hole is larger than about <NUM>. A traditional 3D-knitted spacer fabric is knitted with a small-hole pattern on the two surface layers.

<FIG> depicts a schematic showing moisture management properties of a traditional 3D knitted spacer fabric which has a middle layer (<NUM>) of hydrophobic yarn (<NUM>), and which has a first layer (<NUM>) and a third layer (<NUM>) both knitted of same material as each other. Although the traditional 3D-knitted spacer fabric has good breathability, liquid water (sweat) (<NUM>) stays between the skin (<NUM>) and the first layer (<NUM>, layer closest to skin), depicted in <FIG> as a solid-line horizontal double-headed arrow. Evaporation of water through the hydrophobic middle layer (<NUM>, ) and the third (<NUM>) layer is shown as short-long dashed-line vertical arrows in <FIG>, with water vapor depicted as (<NUM>), however evaporation through the fabric is relatively slow. Liquid water is not transferrable through the middle layer of supportive hydrophobic yarn.

A traditional 3D-knitted spacer fabric has poor liquid moisture management property. Methods of increasing liquid moisture management properties in 3D-knitted spacer fabric have been reported, but have disadvantages.

Moisture management properties of 3D-knitted spacer fabrics may be increased by treating the fabric with hydrophilic agent auxiliaries (for example, "SOFTENER SR" from TAKAMATSU OIL & FAT CO. This method helps with moisture absorbing of the face layers made of multifilament yarns. However, the method requires high craft quantity, the yarn modulus will decrease after treatment, and it doesn't add any liquid transfer property between two face layers through middle layer perpendicularly.

<CIT> reports a method to increase the moisture management property of 3D-knitted spacer fabrics by using covered or twisted yarn to replace the filler monofilament. The covered or twisted yarn has a core-shell structure. The core is a supportive monofilament, and the shell is a moisture manageable yarn. Although this method increases liquid transfer property between two face layers through middle layer perpendicularly, it requires a complicated, time-consuming, and cost-consuming yarn preparation process. Also, the covered yarn is hard to knit on a production machine.

<CIT> reports a method to increase the moisture management property of 3D-knitted spacer fabrics by using both a hydrophilic yarn and a hydrophobic supportive yarn in a middle layer. The amount of yarn in fabric has a limit, and in this fabric, parts of the supportive yarns are replaced with non-supportive hydrophilic yarns. Therefore, this fabric loses support compared to a traditional 3D-knitted spacer fabric.

<CIT> reports a method to increase the moisture management property of 3D-knitted spacer fabrics by using both a thermo-fuse yarn and a hydrophobic supportive yarn in middle layer for the transverse threads of the middle layer with inlays of hydrophilic yarn connected only to the middle layer transverse threads. This structure is complicated with three different yarn systems in the middle layer and costs more to produce than a traditional 3D-knitted spacer fabric.

The invention modifies a 3D-knitted spacer fabric for improved moisture management, compression, and rebound resistance properties by providing a middle layer comprising all hydrophilic fiber. No hydrophobic yarn is used in the middle layer. Liquid can transfer from top surface to the bottom surface of the fabric through all the yarns in the middle layer.

The fabric comprises a top surface layer (in contact with skin, for example skin of a human), a middle layer and a bottom layer. Liquid sweat is absorbed by the yarn in the top face layer (next to skin) and be wicked through the moisture management yarn in the middle layer to the bottom face layer, which increases the liquid spreading area and accelerates sweat evaporation.

The top layer comprises hydrophilic yarn/moisture manageable yarn. The middle layer comprises at least two hydrophilic yarns. An exemplary middle layer comprises two hydrophilic yarns. The first yarn in the middle layer is a hydrophilic yarn, and the second yarn in the middle layer is a blended heat-fusible yarn, comprising hydrophilic fiber and heat-fusible fiber. The hydrophilic yarn and the hydrophilic fiber in the blended heat-fusible yarn provide moisture management property to the fabric and the thermo-fuse fiber in the blended heat-fusible yarn provides support to a 3D shape of the fabric. The bottom surface layer comprises hydrophobic yarn.

Both surface layers are designed as medium hole patterns. Compared to traditional 3D spacer which are knitted as small-hole patterns, medium holes increase breathability and air permeability, and maintain sufficient support. Breathability of a medium-hole fabric may be better than that of a small-hole fabric because more area is empty in the medium-hole fabric, and more vapor moisture can spread out through the holes. Wicking property of a medium-hole fabric may be better than that of a large-hole fabric because more middle-layer yarns are available, and more liquid moisture can transfer to the outside through middle-layer wicking yarns. A medium-hole pattern provides improved balance between breathability and wicking property and provides both vapor and liquid moisture management, compared to small-hole patterns and large-hole patterns.

Both the blended thermo-fuse wicking yarn and the hydrophilic yarn in the middle layer are originally non-supportive and do not form a 3D shape in the knitting process. Heat treatment of the fabric after knitting melts and re-crystallizes the thermo-fuse fiber in the blended thermo-fuse yarn of the middle layer, allowing the fabric to be set to a desired 3D shape. The 3D-knitted spacer fabric of the invention provides support without comprising hydrophobic yarn.

3D knitted spacer fabrics of the invention provide improved moisture management properties over traditional 3D knitted spacer fabrics.

Evaporating sweat away from skin, for example skin of a human, through fabric may proceed by two processes:.

The 3D-knitted spacer fabrics of the invention have a hydrophilic middle layer, and provide improved moisture transfer through the middle layer wicking yarn. The improved moisture transfer increases the effect of the second process of evaporation.

3D knitted spacer fabrics of the invention provide improved thermal comfort, good breathability, and fast absorbing of liquid water, making a wearer's skin dry fast. <FIG> depicts a schematic showing moisture management properties of 3D knitted spacer fabrics of the invention. Liquid (<NUM>) can transfer along both the blended thermo-fuse wicking yarn (<NUM>) and the non-supportive hydrophilic functional wicking yarn (<NUM>) from the first (closest to skin) layer (<NUM>) to the third layer (<NUM>), water transfer shown in <FIG> as vertical solid-line arrows on the yarns of the middle layer marked with left-leaning narrow line hatching (<NUM>) and yarns of the middle layer marked with left -leaning wide line hatching (<NUM>),, which is then evaporated (water vapor shown as <NUM>) as the liquid goes through the third layer (<NUM>). Therefore, the fabric has extremely fast spreading of liquid water, increases the area for evaporation, and better cools down a person wearing the fabric.

This invention provides perpendicular liquid moisture management properties, including fast absorbing and fast drying. Compared to a traditional 3D-knitted spacer fabric and alternative methods of as in Section <NUM>, the 3D-knitted spacer fabric of the invention provides improved perpendicular moisture management property. This property will make the wearer feel dry and cool much faster than existing techniques as in Section <NUM>, increasing human thermal comfort.

3D knitted spacer fabrics of the invention may be warp-knitted or weft-knitted. Warp knitted fabrics may be knitted for example on a double-bed warp knitting machine, e.g., a Karl Mayer (China) Ltd. , Model No. HD6 /<NUM>-<NUM>. <FIG> depicts an exemplary process for manufacturing a warp-knitted 3D knitted spacer fabric. For example, in a double-bed warp knitting machine with two middle layer bars (<NUM>), the left-most middle bar (<NUM>) is threaded with non-supportive hydrophilic functional wicking yarn and the right-most middle bar (<NUM>) is threaded with blended thermo-fuse wicking yarn, made of hydrophilic fiber and thermo-fuse fiber. In <FIG>, for purposes of illustration, the front needle bed (<NUM>) is depicted as making the top (first) layer (<NUM>) of the warp-knitted 3D-knitted spacer fabric of the invention, and the back needle bed (<NUM>) is depicted as making the bottom (third) layer (<NUM>) of the warp-knitted 3D-knitted spacer fabric of the invention. The invention also includes processes where the back needle bed (<NUM>) makes the top (first) layer of the warp-knitted 3D-knitted spacer fabric of the invention, and the front needle bed (<NUM>) makes the bottom (third) layer of the warp-knitted 3D-knitted spacer fabric of the invention.

Weft knitted fabrics may be knitted flat or circular. Weft knitted fabrics may be knitted for example on a double-bed weft knitting machine e.g., a Stoll Machine (China) Co. , CMS <NUM>. Weft knitted fabrics may be knitted for example on a double-bed flat weft knitting machine or on a double-bed circular weft knitting machine. <FIG> depicts an exemplary process for manufacturing a weft-knitted 3D knitted spacer fabric. Middle layer guide bar (<NUM>) is threaded with a blended thermo-fuse wicking yarn (<NUM>), made of hydrophilic fiber and thermo-fuse fiber; and a non-supportive hydrophilic functional wicking yarn (<NUM>). In <FIG>, the top and bottom layers are each marked as (<NUM>). The invention includes a process where the first needle bed makes the top (first) layer of the weft-knitted 3D-knitted spacer fabric of the invention and the second needle bed makes the bottom (third) layer of the weft-knitted 3D-knitted spacer fabric of the invention. The invention includes a process where the second needle bed makes the top (first) layer of the weft-knitted 3D-knitted spacer fabric of the invention and the first needle bed makes the bottom (third) layer of the weft-knitted 3D-knitted spacer fabric of the invention.

The processing to manufacture a 3D-knitted spacer fabric of the invention is similar to traditional 3D-knitted spacer fabric. Therefore, the overall cost is similarly low. The methods disclosed herein to manufacture the 3D-knitted spacer fabric of the invention do not require extra post chemical treatment or yarn covering process, which makes it much cheaper than the alternative methods described in Section <NUM> above.

3D knitted spacer fabrics of the invention may be heat treated and set to impart a 3D shape to the fabric. Thermo-fuse fiber in the blended thermo-fuse yarn in the middle layer melts and recrystallizes during the heat treatment process. A 3D shape may be imparted to the fabric using a pin plate to hold the fabric during the heat treatment process. After this process, the thermo-fuse blended yarn becomes solid, supporting the fabric to have the designed thickness and giving the 3D spacer strong compression and rebound resilience. The heat-treated fabric retains the one-way moisture management function because of the hydrophilic fiber in the blended thermo-fuse yarn. The heat-treated fabric provides both one-way moisture management and a 3D shape.

During the setting process after knitting, the thermo-fuse fiber will melt and recrystallize, reshape the blended yarn in filler layer from non-supportive to supportive, give the 3D spacer compression and rebound resilience, and retain the one-way moisture management function. <FIG> depicts an exemplary heat treatment process of 3D-knitted fabrics of the invention, showing the fabric before (<FIG>) and after (<FIG>) heat treatment and setting. Before heat treatment (<FIG>), the yarns of the middle layer are non-supportive and do not hold a 3D shape. After heat treatment (<FIG>), the yarns of the middle layer are supportive and hold a 3D shape. The change in thickness of the fabric in <FIG> after heat treatment is for illustration and is not limiting. The thickness of the fabric after heat treatment depends on the distance between the two needle beds during knitting process. That distance determines how long the middle layer yarn is between two surface layers because the middle layer yarn travels from one bed to the other to connect the two layers. The pin plate is used to hold the fabric and allows the middle layer to elongate to its longest extent by gravity.

Fabric may be heat set using a heat setting machine (e.g., Model LK 828II-2300HO, LK&LH Co. , Ltd), with a pin plate. (e.g., Model LK 828II-<NUM> pin plate, LK&LH Co. , Ltd) to control the thickness of the shape. An exemplary heat-setting process is described in Example <NUM>.

Blended thermo-fuse yarns are made of hydrophilic fiber and thermo-fuse fiber. Some blended thermo-fuse yarns have a core-shell structure made by a composite spinning method, where the core layer is made of hydrophilic polyester, and the shell layer is made of thermo-fuse polyester. In an example, the thermo-fuse polyester fiber in the blended thermo-fuse yarn has a melting point of about <NUM>. In an example, the melting point for a hydrophilic polyester fiber in the blended thermo-fuse yarn is <NUM>-<NUM>. Heat-setting of the fabrics of the invention may be performed at <NUM>. Only the thermo-fuse fiber in the blended thermo-fuse yarn will melt and recrystallize to solidify the yarn in the fabric.

A hydrophilic yarn used as a first yarn in a middle layer can comprise natural fiber, a synthetic fiber, or an artificial fiber (also known as a semi-synthetic fiber). Exemplary natural fibers are cotton and wool. Exemplary synthetic fibers are nylon and modified polyester. An exemplary artificial fiber is viscose. The hydrophilic yarn used as a first yarn in the middle layer is a functional wicking yarn. The hydrophilic yarn used as a first yarn in the middle layer is non-supportive.

A blended thermo-fuse (heat-fusible) yarn used as a second yarn in a middle layer comprises hydrophilic fiber and thermo-fuse fiber. A hydrophilic fiber in a blended thermo-fuse (heat-fusible) yarn can be a natural fiber, a synthetic fiber, or an artificial fiber (also known as a semi-synthetic fiber). Exemplary natural fibers are cotton and wool. Exemplary synthetic fibers are nylon and modified polyester. An exemplary artificial fiber is viscose. A thermo-fuse (heat-fusible) fiber in a blended thermo-fuse (heat-fusible) yarn is a material with a low melting point, for example, a low-melting-point viscose, nylon, or polyester. An exemplary commercial blended thermo-fuse yarn has a core-shell structure made by a composite spinning method (XiangLu Chemical Fibers Co. , Ltd, 450D Cat. No. <NUM>), where the core layer is made of hydrophilic polyester, and the shell layer is made of thermo-fuse polyester. The melting point for the thermo-fuse polyester fiber in the exemplary commercial blended thermo-fuse yarn is about <NUM>. The melting point for the exemplary hydrophilic polyester fiber in the commercial blended thermo-fuse yarn is <NUM>-<NUM>. The blended thermo-fuse wicking yarn is a functional wicking yarn (moisture-manageable). The blended thermo-fuse wicking yarn is non-supportive before heat treatment. After heat treatment, the blended thermo-fuse wicking yarn is supportive.

Hydrophilic yarn (also known as a moisture manageable yarn or a functional wicking yarn) used in a top layer can comprise a natural fiber, synthetic fiber, or an artificial fiber. Exemplary natural fibers are cotton and wool. Exemplary synthetic fibers are nylon and modified polyester. An exemplary artificial fiber is viscose.

Hydrophobic yarn used in a bottom layer can be a monofilament yarn, e.g., polyethylene terephthalate (PET), thermoplastic polyether ester elastomer (TPEE), polyamide (PA), thermoplastic polyurethane (TPU), polypropylene (PP), or polyethylene (PE), or a multifilament yarn, e.g., polyester, polyethylene, or polypropylene. Hydrophobic yarn used in a bottom layer is water-repellant.

3D-knitted spacer fabrics with hydrophilic second layer may be tested for breathability by standard tests, for example by an ISO <NUM> test (Example <NUM>) and for moisture management by standard tests, for example by an AATCC TM195 test (Example <NUM>) and by using an infrared camera to film how fast liquid water was transferred from one surface to the other side on the cross section(Example <NUM>).

The 3D-knitted spacer fabric of the present invention are designed to absorb and wick body fluids such as sweat, urine, blood, and mucus. An article of manufacture, including an article of clothing comprising the 3D-knitted fabric is permeable to body fluids and comfortable for the user.

The 3D-knitted spacer fabric of the invention can be used in industrial, medical, and consumer products for moisture management, compression, and rebound resilience. The 3D-knitted spacer fabric of the invention is useful in products for individuals who work for extended periods in hot sun, under conditions of high solar radiation and/or high temperature. The 3D-knitted spacer fabric of the invention with its ability to form a desired 3D shape and moisture management properties provides moisture management and padding in products for individuals in high solar radiation and/or high temperature environment.

When the 3D-knitted spacer fabric of the invention is used as wearable equipment worn by workers, the liquid sweat will be absorbed by the yarn in the top face layer (first layer, next to human skin, for example skin of a human) and be wicked through all the yarn in the middle layer to the bottom face layer (third layer) immediately, which increases the liquid spreading area and accelerate sweat evaporation. Water vapor can also pass freely thought the 3D-knitted spacer fabric to the outside.

Compositions of the invention useful in providing moisture management, compression and rebound resistance to individuals in high solar radiation and/or high temperature environments. In an example, the individual is a utility worker, construction worker, or general industrial worker. The 3D-knitted spacer fabric of the invention may be used in personal protective equipment for industry. The 3D-knitted spacer fabric of the invention may be used in protective article of clothing, for example a safety harness, a fall protection harness, a safety helmet or hat, or a safety shoe.

An exemplary use is in a utility harness, for example a Honeywell Miller H700 Utility Harness (Honeywell Industrial Safety, Fort Mill, SC, USA). Some safety harnesses comprise a 3D-knitted spacer fabric of the invention in a padding. A safety helmet or hat may comprise the 3D-knitted spacer fabric with hydrophilic second layer in a helmet or hat cushion. A safety shoe may comprise the 3D-knitted spacer fabric of the invention in a safety shoe insole. Other exemplary uses are in consumer products (e.g., clothing, hats, vests, shoes) to provide cooling to individuals in high solar radiation environments and/or high temperature environments. Exemplary uses are in consumer products such as an elbow pad, kneepad, beekeeper suit, or sole of a shoe, or a hat. Exemplary uses are in sporting equipment, for example, in a kneepad, an elbow pad, a sports shoe, or a sole of sports shoe. Other exemplary uses are in furniture products, for example, a seat cushion, a back cushion, a mattress, a pillow, a table mat, or as a decorative layer in furniture. Other exemplary uses are in medical products for example a base fabric in a surgical dressing.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims.

Exemplary materials used in preparation of an exemplary 3D-knitted spacer fabric according to the invention are described in Table <NUM>.

A warp knitted 3D-Knitted Spacer Fabric is fabricated on a double needle bed warp knitting machine, for example a Karl Mayer (China) Ltd. , Model No. HD6 /<NUM>-<NUM>, with no less than two middle bars, which can work on the middle layer. One or more of the middle bars is threaded with a non-supportive hydrophilic functional wicking yarn, and the left middle bar(s) is threaded with a blended thermo-fuse wicking yarn. The knitting process is basically the same as normal warp knitting, with extra load adjustment on each yarn to make it knit smoothly, for example, using a MULTITENS motorical yarn tensioner system with individual-yarn control, by Karl Mayer Co.

A weft-knitted 3D-Knitted Spacer Fabric is fabricated on a double needle bed weft knitting machine (including circular knitting machine and flat knitting machine). An exemplary weft-knitting machine is a Stoll Machine (China) Co. , CMS <NUM>. A traditional middle layer is knitted by one single supportive yarn at a time. The knitting process is basically the same as normal weft knitting, however with multiple yarns for the middle layer and fed together at the same time and with extra load adjustment equipment on each yarn of the second layer to make it knit smoothly, for example, using a MULTITENS motorical yarn tensioner system with individual-yarn control, by Karl Mayer Co.

The heat setting process is similar to a traditional setting process, and uses a pin plate to control the thickness of the shape.

ISO <NUM>: Textiles - Physiological effects - Measurement of thermal and water-vapor resistance under steady-state conditions (sweating guarded-hotplate test) Breathability is tested by this standard method. The lower Ret(water-vapor resistance) is, the more water is evaporated through the fabric and more heat is taken away, the better thermal comfort the fabric will provide.

AATCC TM195: Liquid Moisture Management Properties of Textile Fabrics Moisture management is tested by this standard method. Exemplary equipment for the test is an SDLATLAS M290 Moisture Management Tester.

Claim 1:
A three-dimensional, 3D,-knitted spacer fabric, the 3D-knitted spacer fabric comprising a top layer (<NUM>), a bottom layer (<NUM>), and an intermediate layer (<NUM>), wherein the top layer (<NUM>) and the bottom layer (<NUM>) are joined together by cross-yarns constituting the intermediate layer (<NUM>) configured for providing a resilient connection between the top layer (<NUM>) and the bottom layer (<NUM>),
wherein the intermediate layer (<NUM>) comprises a first yarn (<NUM>) and a second yarn (<NUM>),
wherein the first yarn (<NUM>) is a first hydrophilic yarn and the second yarn (<NUM>) is a heat-fusible yarn,
wherein the top layer (<NUM>) comprises a second hydrophilic yarn, and
wherein the bottom layer (<NUM>) comprises a hydrophobic yarn, characterised in that the second yarn (<NUM>) is a blended heat-fusible yarn, comprising a hydrophilic fiber and a heat-fusible fiber.