Patent Application
20240200235
This disclosure is generally related to fabrics for apparels, beddings, and automobile and household applications, and more specifically to cooling yarns and fabrics made of the cooling yarns.
Problems associated with the energy crises and climate change are becoming more critical and needs to be addressed. According to recent research, 15% of all electricity consumed globally is used to cool homes and offices, which in turn causes an increase of greenhouse gas emissions worldwide. Therefore, development of new technologies to reduce the energy demand is needed. For example, increasing the cooling set-point temperature by 2° C. can save over 20% of HVAC energy demand globally.
Personal cooling management would be an effective method to reduce the energy cost. In a typical indoor environment, the bodies' radiative heat lost in the mid-infrared thermal radiation (wavelength range of 7 to 14 μm) with a skin temperature of 33.5° C. in human body accounts for more than 50% of the total heat lost. Most of the conventional textile fabrics like cotton and polyester fail as they are infrared radiation (IR) opaque materials. Additionally, fabrics made of high thermal conductive material will further increase the body heat loss through conduction. Most of the conventional textile fabrics like cotton and polyester have low thermal conductivity.
Described herein are cooling yarns and fabrics for use in apparels, footwears, tents, sleeping bags, and bedding that are comfortable to human use and durable to wash cycles.
In one aspect, a yarn includes a plurality of filaments. At least one of the filaments include polyethylene (PE). A size of each one of the filaments is less than 8 denier. A size of the yarn is less than or equal to 300 denier.
In some embodiments, the filaments include a linear low-density polyethylene fiber, low-density polyethylene fiber or a high-density polyethylene fiber.
In some embodiments, one of the filaments includes a fiber having a core and a coating comprising polyethylene coated on the core.
In some embodiments, the filaments include a plurality of fibers having at least one core fiber and at least one shell fiber wrapping around the at least one core fiber, where the at least one shell fiber includes polyethylene.
In some embodiments, the filaments include an additive. For example, the additive include one or more of dyestuff, an ultraviolet block agent, ceramic fillers and hydrophilicity modifier.
In some embodiments, the ultraviolet block agent includes one or more of ZnO or TiO2 and/or other organic compounds (e.g., heterocyclic compounds).
In another aspect, fabric includes a first yarn and a second yarn blended with the first yarn, where the second yarn is different from the first yarn. The first yarn includes a plurality of filaments. At least one of the filaments include polyethylene. A size of each of the filaments is less than 8 denier. A size of the first yarn is less than or equal to 300 denier.
In some embodiments, the second yarn includes one of polypropylene, nylon, polyethylene terephthalate, cotton, wool, rayon, bamboo, polylactic acid, polyolefin, or polyurethane.
In some embodiments, at least 20% of a surface of the fabric is covered by polyethylene of the first yarn.
In some embodiments, at least 20% of the surface of the fabric is occupied by the first yarn.
In some embodiments, the fabric has an IR transmittance at a wavelength of 9.5 μm of at least 37%.
In another aspect, an apparatus includes one of the above fabrics. The apparatus may be one of an apparel, a footwear, a tent, a sleeping bag or bedding.
Certain features of various embodiments of the present technology are set forth with particularity in the appended claims. A better understanding of the features and advantages of the technology will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings of which:
In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the disclosure. However, one skilled in the art will understand that the disclosure may be practiced without these details. Moreover, while various embodiments of the disclosure are disclosed herein, many adaptations and modifications may be made within the scope of the disclosure in accordance with the common general knowledge of those skilled in this art. Such modifications include the substitution of known equivalents for any aspect of the disclosure in order to achieve the same result in substantially the same way.
Unless the context requires otherwise, throughout the present specification and claims, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to.” Recitation of numeric ranges of values throughout the specification is intended to serve as a shorthand notation of referring individually to each separate value falling within the range inclusive of the values defining the range, and each separate value is incorporated in the specification as it were individually recited herein. Additionally, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may be in some instances. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Various embodiments described herein are directed to cooling yarns and fabrics, and their uses in apparels and footwears. In some embodiments, the cooling effect of the disclosed yarns and fabrics are drawn from particular material combinations and structures. The cooling effect of the disclosed yarns and fabrics may be achieved utilizing human factors including both instant cool touch and continuous cooling feel that the disclosed technologies provide based on the material combinations and structures. Further, the fabrics made of the cooling yarns are designed to be thermally conductive and infrared (IR) transparent to maximize the cooling effect.
In some embodiments, a cooling yarn includes a plurality of filaments. At least one of the filaments include polyethylene. Based on extensive testing of materials, polyethylene is found to be have superior property for satisfy the requirements for both continuous cooling and instant cool touch. The techniques disclosed herein use polyethylene in one or more filaments to make the yarn. Polyethylene can be in a form of linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE) or a high-density polyethylene (HDPE). For example, at least one of the filaments for the yarn may be a LLDPE, LDPE fiber or a HDPE fiber.
In some implementations, at least one of the filaments of the cooling yarn includes PE polymer. For example, at least one of the filaments of the cooling yarn includes pure PE polymer.
In some embodiments, a cooling yarn may be composed of a plurality of fibers/filaments that include at least one core fiber and a shell fiber wrapping around the core fiber. The core fiber may or may not include PE polymer. For example, the core fiber may be a pure PE fiber, a bi-component having PE polymer on its surface, or a fiber contains no PE polymer. A core fiber that contains no PE polymer may include one or more of PP, nylon. PET, PU, polyolefin and PLA. A bi-component core fiber may include a core made of one or more PP, nylon, PET, PU, polyolefin and PLA, and a shell made of PE polymer.
In some embodiments, the filaments for the cooling yarn may include one or more additives that can provide more desired properties for the cooling yarn. For example, the additives to the filaments may enhance thermal conductivity, anti-microbial ability, ultraviolet protection factors, wicking, opacity, and/or fire retardant property, or provide colors to the yarn. For example, the additives may include dyestuff. Additional or alternatively, the additives may an ultraviolet block agent that includes one or more of ZnO or TiO2 and/or other organic compounds (e.g., heterocyclic compounds). In some instances, the additives may include ceramic fillers.
To provide desired cooling effects, a size of each of the filaments for the cooling yarn is less than 8 denier. As commonly known, one denier is one gram per 9000 meters of a filament. To provide even more effective cooling properties, a size of each of the filaments for the cooling yarn may be less than 7.5 denier, 7 denier, 6 denier, 5 denier, 4 denier, 3 denier, 2 denier, or 1 denier.
In some embodiments, not only the size of the filaments of a cooling yarn is designed as explained above, but also a size of the yarn is particularly configured. For example, to provide desired cooling effects, a size of the yarn is designed to be less than or equal to 300 denier. These designs can maximize thermal conductivity and IR transparency of the fabrics made from the cooling yarn. In some embodiments, a size of the cooling yarn may be even thinner, such as less than 280 denier, 260 denier, 250 denier, 240 denier, 220 denier, 200 denier, 180 denier, 160 denier, 150 denier, 140 denier, 120 denier, 100 denier, 80 denier, 60 denier, 50 denier, 40 denier, 30 denier, 25 denier, or 20 denier, or between any two of these values. In one embodiment, a cooling yarn may have a size of 75 denier to 150 denier, inclusive. The yarn can be fully drawn or textured.
A fabric made of the disclosed cooling yarn may have an IR transmittance at a wavelength of 9.5 μm of at least 37%, for example. In some embodiments, with thinner cooling yarn, the IR transmittance at a wavelength of 9.5 μm can be increased to, for example, at least 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% or even at least 90%, or between any two of these values.
In addition to cooling yarns, a fabric may further include other materials to provide desirable texture, feel, tough, and/or strength. For example, a cooling fabric may include yarns made of PP, nylon, PET, cotton, wool, rayon, bamboo, PLA, polyolefin, or PU as long as at least 20% of a surface of the fabric is covered by PE polymer. To provide a better cooling effect, the PE surface coverage on the surface of the fabric may be adjusted to at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, and up to 100%, or between any two of these values.
In some embodiments, when a fabric made of a cooling yarn as disclosed herein and one or more other yarns, at least 20% of the surface of the fabric is occupied by the cooling yarn. To provide an even better cooling effect, the surface of the fabric may be covered by the cooling yarn by at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, and up to 100%, or between any two of these values.
A cooling fabric may be formed by woven, knit, or nonwoven techniques with the cooling yarns disclosed herein. In some implementations, a cooling fabric may be laminated with another cooling fabric or other types fabrics for making apparels, beddings, or automobile and home products. Cooling fabrics for woven or knit techniques (e.g., plain weave or single jersey knit, or double weave or double knits) can be constructed with PE polymer on the side with skin contact.
Thermal conductivity of various yarn materials show that PE polymer has a thermal conductivity of 0.33 W/(mK); PET polymer has a thermal conductivity of 0.05 W/(mK); nylon has a thermal conductivity of 0.25 W/(mK); cotton has a thermal conductivity of 0.04 W/(mK). The results indicate PE polymer has a better thermal conductivity than other tested materials and is suitable for cooling purpose.
The instant cool touch is tested by measures of thermal transport (Qmax). The tests were conducted under FTTS-FA-019 standard. The test results are shown in Table I below. An acceptable Qmax value for the cool feeling textiles is considered at least 0.130 for knit fabrics and at least 0.170 for woven fabrics per FTTS-FA-019 standard. The test results indicate that samples of Plain Woven 100% PE, Plain Woven Nylon/PE blend (PE >20%), and Single jersey knit 100% PE (157 gsm) satisfy the requirement for instant cool touch. Also, the PE-rich (back) side of the Double knit (asymmetric fabric) satisfy the requirement. In practice, the PE-rich side of the fabric made of the Double knit would be designed to place in contact with human skin to achieve the instant cool touch.
Continuous cooling test was conducted with ASTM F1868 standard using a hot plate. The test results are shown in Table II below. Lower thermal resistance is considered a better property for a cooling fabric. As shown in Table 2, 100% PE fabrics are cooler than the PET fabrics both in woven and knit forms.
Softness is an important factor to consider for yarns and fabrics when they are used to make apparels. The softness/stiffness test was conducted under ASTM D1388 standard. The test results are shown in Table III below. The results indicate that fabrics made of ultra-high-molecular-weight polyethylene (UHMWPE) are much stiffer than those made of LLDPE/LDPE/HDPE. The test demonstrates that UHMWPE is not suitable for apparels while fabrics made of LLDPE/LDPE/HDPE have the softness desired for apparels.
6.1 (L)
0.6 (L)
In one aspect, the techniques disclosed herein provide a cooling yarn and a fabric made with the cooling yarn, which offers solutions for cost-effective apparel applications. The cooling performance of the cooling yarns and fabrics is demonstrated by various tests.
In some embodiments, a cooling fabric includes fine yarns and filaments (e.g., 100 denier/48 filament) to increase contact area for regulating heat from the skin. Finer yarns can give better smoother next-to-skin handfeel.
The foregoing description of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments. Many modifications and variations will be apparent to the practitioner skilled in the art. The modifications and variations include any relevant combination of the disclosed features. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical application, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalence.
This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 63/185,550, filed May 7, 2021, the content of which is hereby incorporated in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63185550 | May 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2022/028104 | May 2022 | WO |
| Child | 18503738 | US |
