Patent Application
20200359716
The present disclosure further relates to portable cooling units comprising phase change material contained in flexible encapsulating textile for cooling humans, animals, food and beverages.
Temperature controlled phase change material (PCM) is a material that stores or releases a large amount of energy during a change in state or phase, e.g. crystallization (solidifying) or melting (liquefying), at a specific temperature. During such phase changes, the temperature of the material remains relatively constant. Thus, when crystallized PCM is exposed to heat from a human body for example, it continuously absorbs heat and changes from solid to liquid. While the PCM melts, temperature of the PCM remains constant at the melting point until all the material has changed into a liquid.
Thus, an attractive feature of PCM is that when it is set at a specific temperature, it maintains that temperature while absorbing heat until the material has changed from a solid to a liquid. For example, if PCM is initially set at 15° C. and exposed to a human body, it will maintain a constant temperature of 15° C. while absorbing body heat until the material has changed from a solid to a liquid (approximately 3 to 6 hours with some PCM materials).
An advantage of PCM is that it is extremely portable, easy to apply, and can work for an extended period with minimal thermal discomfort or obstruction. For this reason, PCM is known for use in cooling pack applications in environments in which such use would be beneficial, including individuals working in industries that are exposed to long periods of heat, such as construction workers, mascots, surgeons in operating rooms, and coal miners; individuals suffering from health ailments that are aggravated by heat such as Multiple Sclerosis and Dystonia; and athletes for reducing the risk of heat stroke.
PCM cooling packs can also be used in cooling applications such as athletics to reduce post workout soreness and injury. Charged PCM packs can be placed over specific muscle groups through direct application of PCM packs to the skin, or through insertion of PCM packs under commercially available compression shorts or shirts. Charged PCM packs can also be used to keep food and beverages cool and for controlled shipping of temperature-sensitive cargo such as vaccines or chocolate.
One disadvantage to the prior art cooling packs is that standard PCM is generally a solid or rigid block when it is charged. Charged PCM packs are rigid and bulky, and of limited comfort during physical activity. When used in athletics, charged PCM packs have an additional disadvantage in that the packs cannot be contoured around a target muscle group or body part, such as the shoulder. Likewise, when used to cool food or beverages, charged PCM packs cannot be easily reconfigured to the shape of the item on which the packs are applied.
Another disadvantage to the prior art PCM packs is that containers made of polyethylene or polyurethane are stiff and can be loud when handled due to the firmness of the material required to contain the PCM. In addition, phase change of PCM causes condensation of water from the air on the polyethylene and polyurethane outer surface, so the outside of the polyethylene or polyurethane container becomes wet as the PCM melts.
Therefore, there is a need for a cooling product comprising a PCM contained in a flexible encapsulating material, including those that address one or more of the above-identified problems.
The present disclosure relates to products comprising PCM cooling units including encapsulating textiles. In various embodiments the cooling units may be used for cooling humans, animals, and objects. The cooling units may include a first weldable textile layer having a peripheral edge, a second weldable textile layer having a peripheral edge, the peripheral edge of the first layer weldable textile layer adjoined to the peripheral edge of the second weldable textile layer around a circumference of the cooling unit, and a phase change material composition contained between the first weldable textile layer and the second weldable textile layer. The phase change material composition may include a shape stable phase change material and may further include an aqueous gel. The shape stable phase change material may be pelletized. In some embodiments, the pelletized shape stable material may include a plurality of pellets of a uniform size while in other embodiments, the plurality of pellets may be of more than one size.
In some embodiments, the phase change material composition may be a suspension of approximately 40-60% shape stable phase change material and approximately 40-60% aqueous gel. In some embodiments, the phase change material composition may be a suspension of approximately 50% shape stable phase change material and approximately 50% aqueous gel.
The weldable textile of the first and/or second weldable textile may be a nylon with a polyvinyl chloride (PVC) coating or laminate, for example. The cooling units may further include a plurality of spot welds fusing the first and second weldable layers together. The first and/or second weldable textile layers may have a thickness of about 0.33 mm.
The cooling units may further include a first polymer layer having a peripheral edge and a second polymer layer having a peripheral edge. The peripheral edge of the first polymer layer may be adjoined to the peripheral edge of the second polymer layer around the circumference of the cooling unit with the first and second polymer layers located between the phase change material composition and the first and second weldable textile layers.
In some embodiments, the cooling units may include a top weldable textile layer having a peripheral edge, a bottom weldable textile layer having a peripheral edge, the peripheral edge of the top layer weldable textile layer adjoined to the peripheral edge of the bottom weldable textile layer around a circumference of the cooling unit, and a phase change material composition contained between the top layer and the bottom layer, the phase change material composition comprising a suspension of pelletized shaped stable phase change material in a gel. The top and bottom weldable textile layers may include a natural or synthetic fabric having a polymer coating or polymer laminate. The top and bottom weldable textile layers may include a nylon fabric having a polyvinyl chloride coating or laminate. The phase change material composition may include approximately 50% pelletized shaped stable phase change material and approximately 50% aqueous gel. The cooling unit may further include a plurality of spot welds distributed throughout a central portion of the cooling unit, wherein the spot welds fuse the first weldable textile layer to the second weldable textile layer.
Still other embodiments include methods of using a portable cooling unit to cool a human, animal, or object. The methods may include the steps of applying a cooling unit to a surface of a human, animal or object and shaping the cooling unit to conform to the surface of the human, animal or object. The method may further include inserting the cooling unit into a fabric carrier such as an article of clothing, the fabric carrier having a pocket, the pocket sized and shaped to match the cooling unit. The cooling unit may include a first weldable textile layer having a peripheral edge, a second weldable textile layer having a peripheral edge, the peripheral edge of the top layer weldable textile layer adjoined to the peripheral edge of the bottom weldable textile layer around a circumference of the cooling unit, and a phase change material composition contained between the top layer and the bottom layer. The phase change material composition may include a pelletized shape stable phase change material.
While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the various embodiments of the present disclosure are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the various embodiments of the present disclosure, it is believed that the disclosure will be better understood from the following description taken in conjunction with the accompanying Figures, in which:
The present disclosure relates to portable and rechargeable PCM cooling units comprising shape stable PCM contained in a flexible encapsulating material for cooling humans, animals, furniture, and food and beverages, for example. The encapsulating material(s) housing the PCM may include one or more layers, some or all of which may be a textile. For example, in some embodiments, the PCM is contained in a single layer of textile. In other embodiments, the textile comprises an outer layer in the form of a fabric covering.
Various PCMs may be used in the PCM cooling units, and the textile encapsulating the PCM may be modified to assist with the shape and containment of the PCM. For example, in some embodiments, the PCM may include small discrete units of PCM, such as granules, pellets, or beads of shape stable PCM, which may be used alone or suspended in a fluid or gel. In these and other embodiments in which the charged PCM may be mobile within the PCM cooling unit, the textile material and/or other encapsulating materials may be modified to assist in maintaining more even distribution of the PCM throughout the PCM cooling unit, such as through the use of spot welds and/or thermoforming. The resulting PCM cooling units may be used for cooling things such as humans, animals, furniture, food and beverages. The cooling products may be used alone and/or may be configured for use as athletic apparel, weighted blankets, horse blankets, beach mats, scarves, upholstery, chair pads, pillow wraps, car seats, and more. Athletic apparel may include cooling capes or therapeutic apparel, such as vests, shirts, shorts, or hats.
Encapsulating materials may be sheets of material for containing PCM. The encapsulating material may be in the form of a top sheet and a bottom sheet which are adjoined around the edges and which contain the PCM between them. When the encapsulating material is a textile or includes a textile, it may be referred to herein as an encapsulating textile. The encapsulating textile may be the only layer of encapsulating material containing the PCM as a single layer, or it may be one of two or more layers of encapsulating material.
The encapsulating textile may be a weldable fabric that may be sealed along the perimeter and/or in one or more locations in the center to hold the PCM in place and prevent clustering of PCM due to gravity. The fabric may alternatively or additionally capable of being thermoformed into a desired shape. The encapsulating textile may substantially limit or substantially minimizes leaching of PCM from the container and may substantially limit or substantially minimize water vapor loss and may have a low water vapor transmission rate. It may further reduce the perception of condensation on the outer surface of the PCM cooling unit. The encapsulating textile may also be easy to wipe down, easy to maintain, and durable. The specific composition of the encapsulating textile and the thickness of the encapsulating textile may be customized based on these or other factors. For example, in some applications—such as for horse blankets —durability may be a more important factor, and the thickness of the fabric may be increased.
An advantage of the encapsulating textile of the present invention is that it may be used alone without a polyethylene or polyurethane layer, and as such may be more flexible and quieter than the polyethylene and polyurethane containers of the prior art. The flexibility of the encapsulating textile may be varied based on various considerations. For example, in general, the use of a stiffer fabric may result in a lower the water vapor transmission rate. In some embodiments, the water transmission rate may be of more importance that the flexibility or vice versa.
In some embodiments, the PCM cooling units may include only a single layer of encapsulating material, such as a single layer of an encapsulating textile. In other embodiments, the PCM cooling units may be formed as a two-layer container including one or more encapsulating textile material layers. In some such embodiments, both layers may be encapsulating textiles. In other such embodiments, the two-layer PCM cooling unit may comprise an inner polymer layer such as a polyethylene layer and an outer encapsulating textile material layer such as a nylon layer. This “double bagging” may help minimize leaching of the PCM from the container. The outer encapsulating textile layer may provide additional protection against water vapor loss and the feel of condensation against the skin and/or leaching for applications in which water vapor transmission rate and/or leaching are strong considerations. In embodiments having multiple encapsulation material layers, the innermost layer may be a weldable material while one or more of the outer layers may or may not be weldable.
The textile of the present invention may consist of any natural or synthetic material, including but not limited to cotton, linen, microfiber, etc. When the encapsulating textile is welded, a weldable material may be used. In some embodiments, the encapsulating textile may be a nylon material.
In some embodiments, the encapsulating textile may be a coated and/or laminated textile, such as a polymer coated and/or laminated textile. For example, the coated and/or laminated textile may be a vinyl, polyvinyl chloride (PVC) or a polyurethane (PU) coated and/or laminated textile. In coated textiles, the coating material may be applied to the textile in a liquid form such that the coating material penetrates the textile, fills air pockets, and encapsulates the textile fibers. In contrast, in laminated textiles, the laminate material may be pre-set and applied to the textile in a solid form as an outer layer. Either may be used in various embodiments.
In some embodiments, the polymer portion of the coated and/or laminated textile may comprise between about 50-95% of the textile, or between about 60-90%, or between about 70-80% of the textile. The textile material may comprise some or all of the remaining material of the coated or laminated textile, such as between about 5-50%, or between about 10-40%, or between about 20-30% of the coated textile. In one embodiment, the coated textile is about 75% polymer and about 25% textile.
In one embodiment, the encapsulating textile comprises a coated textile, Staftex 71 Healthcare Fabric. Testing information relating to the Staftex 71 Healthcare Fabric is shown in Table 1.
Staphylococcus Aureus
Aspergillus Niger
In some embodiments, the textile comprises a nylon textile such as a nylon taffeta with a PVC coating. For example, the textile may comprise a 70 denier/210 thread count nylon fabric with a PVC coating. The PVC may comprise between about 50-95% of the fabric, or between about 60-90%, or between about 70-80% of the textile. The nylon may comprise some or all of the remaining material, such as between about 5-50%, or between about 10-40%, or between about 20-30%. In one embodiment, the fabric is 75% PVC and 25% nylon.
As previously noted, the thickness of the textile may be customized to balance between water transmission rate, flexibility, and durability. In some embodiments, the thickness of the textile including polymer coating such as PVC coating is between about 0.1-0.4 mm. In some embodiments, the thickness of the textile including polymer coating such as PVC coating is between about 0.10 and about 0.25 mm, or between 0.15 mm and about 0.20 mm, such as about 0.18 mm. In other embodiments, the thickness of the textile including polymer coating such as PVC coating is between about 0.25 and about 0.40, or between 0.30 and about 0.35 mm, such as about 0.33 mm. Thinner, lighter fabrics might be used in embodiments in which user comfort or performance are paramount considerations; thicker, heavier fabrics may be used in embodiments in which product durability is paramount.
Spot welding may be applied to the encapsulating material in various locations throughout central portions of the PCM cooling unit to fuse the top and bottom encapsulating layers together. Thermoforming may be used as an alternative to or in combination with spot welds for maintaining the overall structure of the container and the appropriate distribution of PCM for a particular application. As with spot welds, uniquely shaped cavities may be thermoformed to provide ideal amount and placement of PCM for a particular application.
The number and configuration of spot welds may be varied based on certain considerations. For example, the relative ease of filling the PCM cooling unit with PCM depends on the configuration of spot welds. If the spot welds are configured in straight rows, as shown in
The amount and configuration of spot welds may also be impacted by the overall or per-unit amount of PCM used for a particular application. In some applications, it may be desirable to provide a higher concentration of spot welds in the encapsulating material such as the encapsulating textile to reduce the amount of PCM and thus the weight of the resulting product. For example, in a weighted blanket application, there are limits to the weight of the product based on comfort and safety. Another consideration is amount of time the product is desired to hold its charge, and thus, the amount of PCM necessary to maintain the desired thermal conductivity. In general, the more spot welds in the encapsulated textile container, the less PCM that may be inserted. Thus, the number of spot welds may be modified based on the amount of PCM needed for a desired thermal conductivity.
The PCM cooling units including encapsulating textiles may be sized and shaped for use as an insert into fabric carrier for various cooling applications. For example, the PCM cooling unit can be shaped as an insert for a human cooling vest. One example of a PCM cooling unit insert 300 which may be used as an insert for a human cooling vest is shown in
The PCM cooling unit 300 may be used as an insert into the back of various vests having a compartment of matching size and shape for containing the PCM cooling unit 300. One example of such a vest is shown in
The PCM cooling units with encapsulating textiles may also be used in a variety of athletic applications. For example, the PCM cooling units can be shaped as inserts for athletic vest such as athletic cooling vest 700, as shown in
Any of the PCM cooling units may alternatively be inserted directly under clothing or other material, such as under commercially available compression shorts or shirts or compression wraps for athletic therapies.
In alternative embodiments, the PCM cooling units including encapsulating textiles may be used independently for direct wear or application and no additional shell or fabric carrier is needed. Such direct wear applications include weighted blankets, horse blankets, therapy packs, athletic cooling blankets or capes, and food and beverage cooling applications.
The PCM cooling units with encapsulating textiles may be used in various other configurations and various uses. For example,
Various materials may be used as the PCM in the PCM cooling units. In various embodiments, the PCM of the present invention may be a shape stable PCM such as the shape stable PCM disclosed in Provisional Patent Application No. 62/530,816 and PCT Application No. US2018/041431. In some embodiments, the shape stable PCM may comprise pellets which may be spherical in shape and may remain as spherical pellets despite phase changes. For example, the pellets may be a hard solid when charged and may change phase to a softer gel while keeping their shape as separate pellets. The shape stable PCM such as pellets may be used alone or may be suspended in a gel such as an aqueous gel to yield a high heat transfer while maintaining the ability to absorb/release a relatively large amount of heat with the particle. The particle size and percentage of pellets versus aqueous gel may be customized based on application and/or personal preference. This can be applicable to a product that needs to immediately absorb heat (e.g. to comfort the wearer or the product); however, for longevity of comfort, in alternative embodiments a larger particle (i.e. lower surface area to volume) may be preferred and may be used (alone or in combination with smaller, e.g., pelletized particles). While not as capable of quickly absorbing heat as the smaller particle, the larger particles may be preferred for sustained temperature control and can also be formed into a shape that would form well to the contours of the wearer.
One advantage of a composition including shape stable PCM pellets which may be suspended in a gel such as an aqueous gel is that it is generally more malleable and flexible when charged than standard PCM. In general, the lower the percentage of pellets, the lower the thermal conductivity and the more similar the shape stable PCM is to standard PCM. Depending on the application, suitable ratios of pellets to gel such as aqueous gel include, for example, 50:50, 40:60, 60:40, 30:70:70:30. For example, the pellets may form between about 30-70%, or between about 40-60% of the composition, while the gel such as the aqueous gel may form the remainder of the composition. In one embodiment, the shape stable PCM composition may comprise between about 55-65%, such as about 60% aqueous gel (such as a 1% sodium polyacrylate gel), and between about 35-45% shape stable PCM pellets, such as about 40% shape stable PCM pellets. The shape stable PCM composition may be flexible and malleable even when fully charged.
In other embodiments, other ratios of pellets to aqueous gel may be used based on desired comfort and heat conductivity. For example, as the percentage of pellets increases, a cooling pack comprising the shape stable PCM composition will feel increasingly granular and may be perceived as less comfortable. Additionally, the percentage of pellets may impact the ease with which a cooling pack comprising the shape stable PCM can be contoured to the body. However, the more pellets included, the longer the cooling pack will stay cold.
In order to charge the PCM, the PCM cooling unit including with an encapsulating textile may be subjected to a temperature lower than its solidification temperature until complete solidification of the PCM occurs. Shape stable PCM may be charged, for example, by placement in a refrigerator, cold stream, cooler, or other cold environment. In some embodiments, it may or may not be necessary or recommended that the shape stable PCM be charged by placement in a freezer.
While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the various embodiments of the present disclosure are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
In the foregoing description various embodiments of the invention have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principals of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.
This application claims priority to provisional application 62/849,335, the disclosure of which is herein incorporated by reference in its entirety. This application references U.S. Provisional Patent Application No. 62/530,816 and PCT Application No. US2018/041431, the disclosure of both of which are also herein incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62849335 | May 2019 | US |
