Double knit fabric

Abstract

A double knit fabric includes a first knit layer, a second knit layer, and a plurality of fill yarns. The fill yarns are located between the first knit layer and the second knit layer. The double knit fabric includes a plurality of secure regions and a plurality of separate regions. In the secure regions, the first knit layer and the second knit layer are knit together, while in the separate regions, the first knit layer and the second knit layer are unconnected. The average peak distance between the first and second knit layers in the separate regions is at least about 3 mm, and the double knit fabric has about 10 to 30 separate regions per square inch. The secure regions include at least two knit stitches in at least one direction, and the secure regions have a width of at least about 1 mm.

Description

Technical Field

[0001] This invention relates to double-knitted fabrics, and more particularly to double-knitted fabrics for clothing. Background Technology

[0002] Performance fabrics manufactured for clothing insulation typically include pile fabrics, which are fabrics with a raised or brushed fiber surface to enhance insulation performance. The surface of such fabrics is usually formed by brushing, making it raised through mechanical brushing, resulting in a relatively high loft. However, it has been recognized that the brushing process often leads to fiber breakage, and these broken fibers may loosen over time, potentially causing microfiber contamination. Fiber loss (e.g., during washing) also contributes to a deterioration in insulation performance. Furthermore, it is recognized that broken fibers released during washing can enter wastewater, causing contamination. Therefore, a fabric with low fiber loss, low weight, and high insulation performance for outerwear and other garment applications is desired. Summary of the Invention

[0003] This invention relates to a double-knitted fabric having an upper surface and a lower surface, and having warp and weft directions, wherein the weft direction is perpendicular to the warp direction. The double-knitted fabric includes a first knitted layer containing multiple first yarns, a second knitted layer containing multiple second yarns, and multiple filling yarns. The first knitted layer forms the upper surface of the double-knitted fabric, while the second knitted layer forms the lower surface. The filling yarns are located between the first and second knitted layers.

[0004] The double-knitted fabric includes multiple fixed areas and multiple separate areas, wherein the multiple separate areas are scattered among the fixed areas. In the fixed areas, the first and second knitted layers are knitted together, while in the separate areas, the first and second knitted layers are not connected.

[0005] The first knitted layer and the second knitted layer are joined together in a fixed area by at least one method selected from the following: interlacing the first yarn of the first knitted layer with the second yarn of the second knitted layer, interlacing the second yarn of the second knitted layer with the first yarn of the first knitted layer, and interlacing multiple third yarns with the first yarn of the first knitted layer and the second yarn of the second knitted layer.

[0006] The average peak distance between the first and second knitted layers in the separation area is at least about 3 mm, and the double-knitted fabric has about 10 to 30 separation areas per square inch. The fixing area includes at least two knitted stitches in both the warp and weft directions, and the fixing area has a width of at least about 1 mm in both the warp and weft directions. Attached Figure Description

[0007] Figure 1 This is a cross-sectional view of a double-knitted fabric according to one embodiment of the present invention.

[0008] Figure 2A This is a photograph of the upper surface of a double-knitted fabric according to one embodiment of the present invention. Figure 2B yes Figure 2A The illustration is a photo.

[0009] Figure 3A This is a photograph of a double-knitted fabric placed at a certain angle according to one embodiment of the present invention. Figure 3B yes Figure 3A The illustration is a photo. Detailed Implementation

[0010] Now for reference Figure 1 The double-knitted fabric 10 of the present invention has an upper surface 10a and a lower surface 10b, a warp direction and a weft direction (wherein the weft direction is perpendicular to the warp direction), and includes a first knitted layer 20, a second knitted layer 30 and a plurality of filling yarns 40. The first knitted layer 20 forms the upper surface 10a of the double-knitted fabric 10, the second knitted layer 30 forms the lower surface 10b of the double-knitted fabric 10, and the filling yarns 40 are located between the first knitted layer 20 and the second knitted layer 30.

[0011] Separation zones 420 are scattered between fixed zones 410. In fixed zones 410, the first knit layer 20 and the second knit layer 30 are knitted together (forming a single integral knit layer), while in separation zones 420, the first knit layer 20 and the second knit layer 30 are unconnected (and are separate knit layers). This knitting of the first and second knit layers is performed simultaneously on the same knitting machine as the knitting of the first and second knit layers. This contrasts with quilted fabrics, in which the two layers are formed independently and then sewn together. Filler yarn 40 is a bulky yarn (shown as entering the illustrated plane) that fills the separation zones 420 and gives them a raised appearance. The separation zones can have any suitable shape, including but not limited to squares, rectangles, ovals, octagons, hexagons, irregular amoeba-like shapes, jelly-like shapes, rhombuses, and elongated lines. Preferably, the separation zones are regular grids (including horizontal / vertical grids, offset grids, brick-pattern grids, etc.).

[0012] Depending on the end use, the separating region 420 and the connecting region 410 can form different amounts of surface area on the upper surface 10a of the double-knitted fabric 10. Since the separating region 420 tends to be more insulating, its surface area is preferably increased relative to the amount of surface area of ​​the upper surface 10a of the double-knitted fabric 10. In a preferred embodiment, the separating region 420 forms about 60% to 99% of the surface area of ​​the upper surface of the double-knitted fabric, more preferably about 75% to 98%, and even more preferably about 85% to 96%.

[0013] exist Figure 2A The image shows a photograph of the upper surface 10a of the double-knitted fabric 10, which shows the surface of the first knitted layer 20. In this figure, "bumps" on the fabric can be seen, which are the separating regions 420, while the lines defining the grid of bumps are the connecting regions 410. Figure 2B yes Figure 2A The illustration. In Figure 3A The photograph shown in the image depicts a cross-section of the double-knitted fabric 10, making the separation region 420 and the connecting region 410 more clearly visible. Figure 3B yes Figure 3A The illustration.

[0014] Preferably, the double-knitted fabric has about 10 to 30 separation zones per square inch, more preferably about 15 to 25 separation zones per square inch. It has been found that this range of zones per square inch produces an insulating fabric with good weight, thickness, and aesthetics. In one embodiment, the separation zone 420 preferably has a size of at least about 1 mm, more preferably at least about 2 mm, and even more preferably at least about 3 mm in the plane of the double-knitted fabric 10. Each separation zone 420 includes a plurality of knitted stitches.

[0015] Each fixed area 410 includes at least two knitting stitches in at least one of the warp and weft directions, unlike other double-knitted fabrics. In a preferred embodiment, the fixed area 410 includes at least two knitting stitches in both the warp and weft directions. In another embodiment, each fixed area 410 includes at least three knitting stitches in at least one of the warp and weft directions, more preferably in both directions. In yet another embodiment, the fixed area 410 has a width of at least about 1 mm in both the warp and weft directions, more preferably at least about 1.8 mm in both directions.

[0016] The height of the separation zone 420 also contributes to the insulation value and fabric appearance. In one embodiment, the average peak distance between the first and second knitted layers in the separation zone is at least about 3 mm. The average peak distance is calculated by measuring the distance between the inner surfaces (faces facing each other) of the first and second knitted layers. This distance is measured at at least 10 different separation zones, and the results are then averaged. In another embodiment, the average peak distance between the first and second knitted layers in the separation zone is at least about 3.5 mm, more preferably at least about 4.0 mm.

[0017] Besides the average peak distance, the entrainment air coefficient can also be an important characteristic of a fabric. Entrainment air is the air located between the upper surface 10a of the double-knitted fabric 10 and the wearer's skin. This extra air also serves to insulate the wearer. The amount of entrainment air is calculated using the following procedure.

[0018] The Keyence VHX-6000 is used to obtain a 3D image of the double-knitted fabric. This image should represent an area of ​​at least 2.9 cm × 3.5 cm on the surface of the double-knitted fabric. The contour tool provided by the Keyence VHX-6000 is used to generate the top surface 10a of the double-knitted fabric 10 (aligned with the main symmetry direction of the material). The generated contour is an average contour, with a range of 5 lines and an interval of 300 μm. This is equivalent to averaging the contour over 11 lines (5 on each side of the center line), all of which are 300 mm or 0.03 cm apart. This has the effect of averaging height fluctuations due to variations in individual yarns. The center line of this contour is oriented along the target direction and centered on the high point / center of the separated area in the contour direction. For each image of the fabric sample, there are typically multiple rows and columns (approximately perpendicular to each other) of repeating structures of the separated areas. Contours are formed for each distinct row and column as described above.

[0019] The target metric of the analysis relates to the air space that would be formed if the fabric were placed against a surface and the high points of the profile were in contact with that surface. The air space above the top surface of the fabric is calculated, along with an imaginary line connecting the high points of the profile for each repeating unit. For this purpose, the profile is depicted as multiple sections reflecting repeating units along the direction represented by the profile. The high points of the profile for each of these sections are determined using mathematical tools such as Excel. Within the spreadsheet, a straight line is calculated between the high points of adjacent repeating units of the profile; if the high points are placed against the surface, this line represents the boundary layer. At the edges of the profile, one of two cases occurs. If a maximum point exists at the edge of the profile, the line reaches the high point. If there is no high point at the edge, the line extends from the nearest maximum point in the profile to a height that is the average height of the maximum points on the profile at both extremes. Once the boundary line is calculated, the difference at each point in the profile between the boundary line and the top of the profile is calculated. The numerical integral of the area between the top of the profile and the boundary line is calculated. This area is then divided by the image length along the profile direction. This provides the entrained air height for the rows or columns of the image. The entrained air height is then calculated for each distinct row and column of the image and averaged together to provide the average entrained air height of the sample. Preferably, the average entrained air height is from about 0.3 mm to 25 mm. In another embodiment, the calculated entrained air is from about 0.4 mm to 25 mm. In yet another embodiment, the calculated entrained air is from about 0.5 mm to 25 mm.

[0020] The first knitted layer 20 comprises a plurality of first yarns, and the second knitted layer 30 comprises a plurality of second yarns. The yarns constituting these layers can be any suitable yarn. In this application, the term "yarn" includes monofilament elongated strands, multifilament elongated strands, ribbons, strips, yarns, tapes, fibers, etc. Knitted layers 20 and 30 may comprise one or more of the aforementioned yarns or combinations thereof. The yarn can be in any suitable form, such as staple fiber yarn, monofilament or multifilament, single-component, bicomponent, or multicomponent, and have any suitable cross-sectional shape, such as circular, multi-lobed, square or rectangular (ribbon-like), and elliptical.

[0021] The yarns of knitted layers 20 and 30 may be formed from (but are not limited to) the following: cellulose yarns (e.g., cotton, rayon, flax, jute, hemp, cellulose acetate, and combinations thereof, mixtures, or blends), polyester yarns (e.g., polyethylene terephthalate yarn, polypropylene terephthalate (PET) yarn, polymethyl terephthalate yarn), polybutylene terephthalate yarn, and blends thereof), polyamide yarns (e.g., nylon 6 yarn, nylon 6,6 yarn, nylon 4,6 yarn, and nylon 12 yarn), polyvinyl alcohol yarn, elastic polyester-polyurethane copolymer (SPANDEX®), polypropylene yarn, polyethylene yarn, polyvinyl acetate yarn, polylactic acid yarn, flame-retardant meta-aramid (NOMEX®) or para-aramid, and combinations thereof, mixtures, or blends thereof. In a preferred embodiment, knitted layers 20 and 30 comprise multifilament polyester yarns, as these have shown good performance at low cost. In one embodiment, the first and second knitted layers 20, 30 comprise substantially all (defined as at least about 98 wt%) multifilament polyester yarn. In one embodiment, the yarns constituting the knitted layers 20, 30 all have substantially the same thickness or denier. In other embodiments, there are differences in denier. In another embodiment, more than one type of yarn (different in material, construction, and / or denier) may be present within a knitted layer, or the yarns used may comprise more than one type of fiber. In one embodiment, at least one of the first and second knitted layers 20, 30 comprises nylon fibers or yarn.

[0022] See again Figure 1 The fabric also includes a plurality of filler yarns 40 located between the first knitted layer 20 and the second knitted layer 30. These filler yarns can be any suitable yarn and are preferably bulky so that they fill the area between the first and second knitted layers and provide insulation. Preferably, the filler yarns are multifilament polyester yarns. It has been shown that polyester yarns can easily swell and retain their volume over time. In a preferred embodiment, the filler yarns are false-twist textured yarns. Preferably, the filler yarns extend substantially parallel to each other in the weft direction of the double-knitted fabric.

[0023] In a preferred embodiment, the entire fabric is primarily polyester yarn, more preferably continuous multifilament polyester yarn. In another embodiment, the entire fabric (including the first knitted layer, the second knitted layer, the filling yarn, and any other yarns) is substantially (defined as at least 98 wt%) polyester yarn, more preferably continuous multifilament polyester yarn.

[0024] The thicknesses of the two layers 20 and 30 can be any suitable thickness and can be approximately equal in distribution, or one of these layers can be thicker than the other. The typical thickness of the fabric is about 0.1-6 mm, more preferably about 1-4 mm.

[0025] The two knitted layers 20 and 30 can be combined, knitted, and joined together in any suitable way (during the knitting process). One method is to interweave the first yarn of the first knitted layer 20 into the second yarn of the second knitted layer 30, which means that a portion of the yarn of the first knitted layer leaves the first knitted layer, travels down into the second knitted layer, where it interweaves with the yarn in the second knitted layer, and then travels up back into the first knitted layer.

[0026] The second method is to interweave the second yarn of the second knit layer 30 into the yarn of the first knit layer 20. This means that a portion of the yarn of the second knit layer 30 leaves the second knit layer, travels upward into the first knit layer, where it interweaves with the yarn in the first knit layer, and then travels downward back to the second knit layer.

[0027] The third method involves interlacing multiple additional yarns between the yarns of the first knitted layer 20 and the yarns of the second knitted layer 30. This means that the additional yarns (which may be the same as or different from the yarns in the first or second knitted layer) travel between the layers, interlacing with the yarns from both layers and essentially binding them together. These additional yarns can be selected from any yarns described for the yarns in the first knitted layer.

[0028] In a preferred embodiment, the second method is used to interweave and knit the first knitted layer 20 and the second knitted layer 30 together. This method is preferred because it involves lower complexity during the knitting process using circular knitting.

[0029] Preferably, the double-knitted fabric has a clo value of at least about 0.2, which is measured by testing ASTM F1868. Clo is a measure of the thermal insulation value of a fabric. In another embodiment, the double-knitted fabric has a clo value of at least about 0.3, more preferably at least about 0.4, which is measured by testing ASTM F1868. In another embodiment, the double-knitted fabric has a breathability of at least about 150 CFM, more preferably about 175 CFM, more preferably about 200 CFM, and more preferably about 225 CFM.

[0030] When fabric 10 is made into a garment article (also called clothing), in one embodiment, the lower surface 10b will face away from the wearer, while the upper surface 10a will face the wearer. In another embodiment, the lower surface 10b will face the wearer, while the upper surface 10a will face away from the wearer. Double-knitted fabric 10 is a single piece of material formed together by these two layers in a knitting machine; these two layers are sometimes separate and sometimes knitted together. Layers 20 and 30 are not formed as separate knitted layers and then joined together in subsequent operations. Fabric 10 can be manufactured by any suitable knitting method, including warp knitting and weft (or circular) knitting. In some embodiments, circular knitting is preferred because it is more cost-effective. Garment articles can be any suitable articles, including but not limited to shirts, jackets, trousers, tights, leggings, hats, underwear, and socks.

[0031] In another embodiment, the garment may use the fabric described above, among other fabrics. For example, a shirt may use the fabric of the present invention on the torso and another fabric on the sleeves. Additionally, the fabric of the present invention may also be used as an insert. Furthermore, the fabric can be used for any other suitable purpose, including but not limited to tents, car covers, upholstery, mattress covers, and pet beds.

[0032] All references cited in this article, including publications, patent applications and patents, are incorporated herein by reference to the extent that each reference is individually and specifically indicated to be incorporated herein by reference and set forth in its entirety herein.

[0033] The terms “a,” “an,” and “the,” and similar indicators used in the context of describing the subject matter of this application (particularly in the context of the appended claims) shall be construed as encompassing both singular and plural forms, unless otherwise stated herein or clearly contradicted by the context. Unless otherwise specified, the terms “comprising,” “having,” “including,” and “containing” shall be construed as open-ended terms (i.e., meaning “including but not limited to”). Unless otherwise stated herein, the description of numerical ranges herein is intended only as a shorthand method for individually referring to each individual value falling within the range, and each individual value is incorporated into the specification as if it were individually described herein. All methods described herein may be performed in any suitable order, unless otherwise stated herein or clearly contradicted by the context. The use of any and all instances or exemplary language (e.g., “for example”) provided herein is intended only to better illustrate the subject matter of this application and does not limit the scope of the subject matter, unless otherwise stated. No language in the specification should be construed as indicating that any unclaimed element is essential to the practice of the subject matter described herein.

[0034] This document describes preferred embodiments of the subject matter of this application, including the best modes known to the inventors for implementing the claimed subject matter. Variations of those preferred embodiments will be apparent to those skilled in the art after reading the foregoing description. The inventors expect those skilled in the art to appropriately employ such variations, and the inventors intend to practice the subject matter described herein in ways different from those specifically described herein. Therefore, this disclosure includes all modifications and equivalents of the subject matter described in the appended claims as permitted by applicable law. Furthermore, unless otherwise stated herein or clearly contradicted by the context, this disclosure covers any combination of the foregoing elements in all possible variations.

Claims

1. A double-knitted fabric having an upper surface and a lower surface and having a warp direction and a weft direction, wherein the weft direction is perpendicular to the warp direction, wherein the double-knitted fabric comprises: A first knitted layer comprising a plurality of first yarns, wherein the first knitted layer forms the upper surface of the double-knitted fabric; A second knitted layer comprising a plurality of second yarns, wherein the second knitted layer forms the lower surface of the double-knitted fabric; as well as Multiple filler yarns, wherein the filler yarns are located between the first knitted layer and the second knitted layer; The double-knitted fabric includes multiple fixed areas and multiple separate areas, wherein the multiple separate areas are distributed among the fixed areas, wherein in the fixed areas, a first yarn from the first knitted layer and a second yarn from the second knitted layer are woven together, and wherein in the separate areas, the first knitted layer and the second knitted layer are not connected; The first knitted layer and the second knitted layer are joined together in the fixed area by at least one method selected from the following: interlacing the first yarn of the first knitted layer with the second yarn of the second knitted layer, interlacing the second yarn of the second knitted layer with the first yarn of the first knitted layer, and interlacing multiple third yarns with the first yarn of the first knitted layer and the second yarn of the second knitted layer; The average peak distance between the first knitted layer and the second knitted layer in the separation region is at least 3 mm, wherein the double-knitted fabric has 10 to 30 separation regions per square inch, wherein the fixing region includes at least two knitting stitches in at least one of the warp and weft directions, and wherein the fixing region has a width of at least 1 mm in both the warp and weft directions.

2. The double-knitted fabric according to claim 1, wherein the average peak distance between the first knitted layer and the second knitted layer in the separated region is at least 3.5 mm.

3. The double-knitted fabric of claim 1, wherein the double-knitted fabric has 15 to 25 separation zones per square inch.

4. The double-knitted fabric according to claim 1, wherein the fixed region comprises at least three knitting stitches in at least one of the warp and weft directions.

5. The double-knitted fabric according to claim 1, wherein the fixing region has a width of at least 1.8 mm in both the warp and weft directions.

6. The double-knitted fabric of claim 1, wherein the double-knitted fabric has a clo value of at least 0.2 as determined by ASTM F1868 testing.

7. The double-knitted fabric of claim 1, wherein the double-knitted fabric has a clo value of at least 0.3 as determined by ASTM F1868 testing.

8. The double-knitted fabric of claim 1, wherein the double-knitted fabric has a clo value of at least 0.4 as determined by ASTM F1868 testing.

9. The double-knitted fabric according to claim 1, wherein the double-knitted fabric has a breathability of at least 150 CFM.

10. The double-knitted fabric of claim 1, wherein the double-knitted fabric has a breathability of at least 200 CFM.

11. The double-knitted fabric according to claim 1, wherein the separation region has a dimension of at least 3 mm in the plane of the double-knitted fabric.

12. The double-knitted fabric of claim 1, wherein the filling yarns extend parallel to each other.

13. The double-knitted fabric of claim 1, wherein the first knitted layer and the second knitted layer are joined together by means of a combined portion formed by interlacing the first yarn of the first knitted layer with the second yarn of the second knitted layer.

14. The double-knitted fabric according to claim 1, wherein the first yarn is a polyester yarn.

15. The double-knitted fabric of claim 1, wherein the double-knitted fabric is composed of at least 98 wt% polyester.

16. The double-knitted fabric of claim 1, wherein the separation region has an irregular ellipse on a repeating grid pattern.

17. The double-knitted fabric of claim 1, wherein the upper surface of the double-knitted fabric comprises a morphology formed by the fixed region and the separated region, wherein the morphology has an average entrained air height of 0.3 mm to 25 mm.

18. A garment comprising the double-knitted fabric according to claim 1.

19. The garment of claim 18, wherein the garment is selected from jackets, trousers, hats, and shirts.

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