The present invention relates to a light weight thermal insulating sheets comprised of a core formed of down material mixed with a heat activatable binder and plant based material fibers, in predetermined proportions, and wherein the plant based fibers provide resistant to core compression during heat setting of the binder and act as wicking conductors to improve the extraction of moisture from the down material in the core.
Down material is a superior insulation that synthetic insulation for the fact that it traps warmth in thousands of tiny air pockets formed by the down clusters. At the same time is extremely breathable. Its ability to trap heat is measured by its fill power which measures how many cubic inches one ounce of down can fill. Down is well known to have a fill power of between 450 and 900. This means that one ounce of high quality down can fill 900 cubic inches. Down has a much higher warmth to weight ratio than synthetic insulation. In other words, although it provides more warmth, it remains very lightweight. This also makes it easier to compress down to take up far less pace in insulation products or for other reasons such as for transporting the product. Also, synthetic insulation does not come close when comparing to the resiliency of down. Down material can last for decades and still retain its loft and shape. However, while down posses all of these excellent characteristics, it has a few disadvantages
One disadvantage of down is that down material has its affinity to water and moisture and therefore has difficulty at repelling moisture and when it gets wet its insulating properties diminish. When used in articles of apparel, a lot of sweat is given off by a wearer person during exertion and this sweat is absorbed by the down material. This problem is addressed by the present invention which provides a means which constantly wick moisture out of the down material when present. It also provides for a quicker drying time after washing.
Attempts have been made in the past to fabricate synthetic insulation to replace down and such has been commonly referred to as “synthetic down”. The use of microfibers mixed with crimped bulking fibers for use as an insulation in the fabrication of articles of apparel is known and described in U.S. Pat. No. 4,118,531 issued on Oct. 3, 1978 to the Minnesota Mining and Manufacturing Company. As described microfibers are heavier than alternative types of fibrous insulation. Since the surface area of microfibers is greater than polyester staple fibers, more air is held in place by the microfibers, which results in a deduced transfer of heat within a web containing microfibers. Although the percentage of microfibers in a web of this type of insulation is less than that of an all-microfiber web, sufficient microfibers are apparently retained to make the thermal resistance per unit of thickness of the web comparable to that of an all-microfiber web. Loft and resiliency of such a web is provided by a blend with crimped bulking fibers. The advantage of such insulation using microfibers is that the insulation is of less weight and bulk as compared with insulation using polyester staple fibers and is just as warm. Such synthetic down material did not prove to have the same fill power of down and its disadvantages are numerous, such has the thickness of the insulation as compared to down to provide an equivalent CLO count and consequently its weight increase. Therefore, its application as an insulator as its limitations.
In my U.S. Pat. No. 6,025,041, there is discussed the problems of using down as an insulation, particularly in the fabrication of articles of apparel. Down insulation from goose or duck is known to have excellent insulation properties due to their ability to retain heat. Because down is a natural product it is more expensive than synthetic fibers, such as polyester. It would therefore be desirable to use the qualities of both down and synthetic fibers to fabricate a thermally insulating material having excellent insulating properties and other features including reduce cost, faster drying time and more resistant to shrinkage and provide improved lofting as compared to down insulation. The present invention provides a down/polymer thermally insulation sheet which provides this reduction in cost while at the same time providing other benefits in overcoming manufacturing problems such as maintaining loft during the process of fusing the down and polymer fibers together.
It is therefore a feature of the present invention to provide a light weight down/polymer insulating sheet having an improved core structure which provides high thermal efficiency, resiliency and lofting while at the same time overcoming known problems of down material.
Another feature of the present invention is to provide a down/polymer thermally insulating sheet comprised of down mixed binding fibers and plant-based material fibers to provide improved lofting, resiliency and drying time.
Another feature of the present invention is to provided a down/polymer thermally insulating sheet comprised of a core having a down core mixture which provides added benefit to the finished product at a reduced cost.
A still further feature of the present invention is to provide a down/polymer thermally insulating sheet and wherein the core and polymer fibers are mixed with plant-based material fibers wherein a core structure is formed during heating of the core in its fabrication whereby to resist to compression of the core material caused by the fusing of the fibers.
A further feature of the present invention is to provide a light weight down/polymer thermally insulating sheet comprised of a central core zone and outer trapping barrier zones capable of preventing the escapement of down clusters while also providing breathability and permeability to wick humidity from the central core zone.
Another feature of the present invention is to provide a central core zone comprised of down material, binding fibers and other materials providing mass and volume to the core and orientation support of plant-based material fibers to form a support fiber structure resisting to compression during heat treatment of the core to bind the material mixture.
Another feature of the present invention is to provide a light weight down/polymer thermally insulating sheet and wherein the down/polymer core material and/or the outer scrim sheet comprise an odor absorbing substance or fibers containing carbon for absorbing odors emanating from a person's body having at least a portion of its body covered by the thermally insulating sheet incorporated in article of warmth, such as an article of apparel, a sleeping bag, a duvet cover or other articles of warmth.
According to the above features, from a broad aspect, the present invention provides a light weight composite down/polymer thermally insulating sheet comprised of a core formed of down material mixed with a heat activatable binder material and plant-plant-based material fibers in predetermined proportions. The plant-based material fibers are dispersed and supported in a three-dimensional fiber structure by the down material. The plant based material fibers when subjected to heat treatment temperature to activate said binder material, maintaining their original state due to their melting temperature being higher than the heat treatment temperature causing the binder material to bind thereto and thereby creating an inner bonded support fiber structure made of the plant based material fibers in their original state and with at least some of the binder material attached thereto. The inner bonded support fiber structure maintains the loft in the core by resisting to heat deformation during the heat treatment of the binder material to reduce compression of the core by heat deformation of the binder material. The plant-based material fibers also act as wicking conductors to conduct moisture out of the down material and providing a faster drying of the thermally insulating sheet.
According to another broad aspect of the present invention there is provided . a light weight composite down/polymer thermally insulating sheet comprised of a central core zone formed of down material and opposed thermally insulating outer trapping barrier zones integrally bonded to a top and a bottom outer surface portions of the central core zone. The central core zone contains a binder material to trap the down material. The outer trapping barrier zones are comprised of a mixture of the binder material mixed with plant-based material fibers in predetermined proportions to form a higher density trapping zone to prevent loose down clusters from the central core zone to propagate to an outer top and bottom surface of the down/polymer thermally insulating sheet. The plant-based material fibers impart to the outer trapping barrier zones breathability and permeability to wick humidity from the central core zone to provide faster drying time while maintaining resiliency and stretchability of the thermally insulating sheet permitting it to drape well for use in the manufacture of thermally insulating articles.
According to a still further broad aspect of the present invention there is provided a light weight composite down/polymer thermally insulating sheet comprised of a core formed of down material mixed with a predetermined quantity of a heat activated binder material. The insulating sheet further contains an odor absorbing substance. The odor absorbing substance is constituted by one of carbon fibers mixed with the down and the heat activated binder and a scrim sheet formed of charcoal yarn bonded to at least one of opposed top and bottom surfaces of the core, to absorb odors emanating from a wearer person's body when the thermally insulating sheet is incorporated in an article of warmth.
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
Referring now to the drawings and more particularly to
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The light weight thermally insulating sheet as described above in its example of mixture and fabrication has a multitude of uses and not limited to articles of apparel, and as examples only, it may be used in the manufacture of duvet covers, liners for winter boots, and any other article of commercial use where light weight insulating material in sheet form is desirable. It is also pointed out that the light weight insulating sheet thus produced has improved resiliency and lofting due to the use of polymer fibers as above described. The polymer fibers also provide for a faster drying time of the mixture with down as compared to a full-down insulting sheet and provides minimal shrinking.
As mentioned herein above there is a need to increase the efficiency of the use of down material in a thermally insulating fabric structure including the need to overcome a certain problem during the fabrication of the down sheet to maintain the loft of the down sheet.
During fabrication when the down and binder polyester fibers are subjected to heat, in the range of about 150 degrees F. to 170 degrees F., during heat setting of the composition wherein the fibers soften and interconnect at their crossings and also attach to down cluster, the fibers in the mixture soften and do not maintain their stiffness and tend to collapse in the mixture although held partly by the down material. Such collapsing causes the mixture to compress or loose some of its loft. In order to substantially reduce this compression or collapsing of the soften binding fibers I have discovered that by adding plant based material fibers to the mixture and which fibers can maintain their form during the heat treatment that such plant based fibers would offer resistance to the deforming binding fibers and that the melting material at the outer surfaces of the binding fibers would attach to the plant based fibers creating a fibers structure, much like the framework of a building, supporting the mixture and resisting to compression of the core material. In addition to resolving this compression problem, the plant base material fibers, I have found, also act as wicking conductors for moisture absorbed by the down in the core material and therefore resolve another problem associated with down material thermal insulation. Such plant based material fibers also further provide added features and benefits when used with down material, namely that when the down is wet it dries very quickly to maintain its shape, it provide softness, it stretches and recover quickly, it is resilient and offer breathability, it is light weight and wrinkle resistant as well as being UV and chlorine resistant and biodegradable, all of which features compliment its use with down material. Such additive material also does not affect the draping of the insulation sheet when used in articles of warmth
I have found that the use of plant-based material fibers identified by the registered trademark SORONA of the DuPont company which is a polyester microfiber made partially of corn glucose provides the results sought to provide the improvement of my new composition mixture. When added to the mixture, it produced the benefits sought after, namely the support fiber structure to resist to heat compression of the mixture and its wicking feature to extract moisture from the down material. Another plant-based material providing similar features is a cellulosic yarn fiber made from esters of wood pulp, such as that identified by the registered trademark NAIA of the Eastman company. These fibers have a melting temperature above 200 degrees F., namely in the range of 200 degrees F. to 240 degrees F. wherein during heat setting of the binder material in the range of 150 degrees F. to 170 degrees F., the plant based material fibers maintain their original shape and with the binder material clinging thereto thereby creating a three dimensional framework or fiber structure resisting to compression of the down by the melting binder material deformation causing a compression force on the fluffy and soft down clusters.
Because of the sought after features that plant-based material fibers can provide, a further embodiment of the down/polymer insulating sheet, as shown in
As shown in
In order to provide a central core with improved loft and breathability and faster drying time, the central core zone a predetermined quantity of plant-based material fibers 55 are added to the mixture and they constitute internal wicking fibers distributed throughout the core zone. They provide the benefits as described above with respect to
The thickness ratios between said central core zone 51 and the outer trapping barrier zones 53 are one of approximately 70% to 90% central core zone 51 and 5% to 15% for each said outer trapping barrier zones 53. The outer trapping barrier zones 53 have a thickness ratio in the range of 5% to 10% of the total thickness of said thermally insulating sheet 50.
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Heat activated binding fibers, as referred to herein, are fibers that form an adhesion or bond with other fibers at predetermined temperatures. These can include fibers having a polyester core and sheath fiber with a predetermined melt temperature. Bulking fibers are fibers that provide volume such as high denier per filament, high crimp fibers, hollow-fill fibers and other such type. Examples include polyester, polypropylene and cotton as well as other low cost fibers
Referring to
The improvement herein illustrated is the incorporation into the core material of a predetermined quantity of odor absorbing substance in the form of carbon fibers 76 which absorbs odors. The predetermined quantity of carbon fibers would depend on the intended use of the insulating sheet 70. For example, more carbon fibers would be incorporated into the core 71 if the use of the insulating sheet is to be incorporated into articles of warmth used for sports activities where the wearer person would generate more sweat and consequently more body odors. For leisure articles of apparel less amount of carbon fibers would be necessary.
If scrim sheets 75 are bonded to one or the upper or lower surfaces of the core 71, the scrim sheet may be formed as woven fabric sheets woven with charcoal yarn or other absorbing material yarns to absorb odors emanating from a wearer person's body. The scrim sheets may also be formed of non-woven material impregnated with carbon fibers. It is pointed out that such odor absorbing feature of the down/polymer thermally insulating sheet can be used in other sorts of articles of warmth, such as sleeping bags, duvet covers, pants or other articles intended to be incorporated into articles of warmth to be positioned against a user person.
The down material clusters also have some fat trapped in their clusters having been attached to the skin of the bird and that fat can generate a smelly odor. However, it is important to keep this oily fat in the down clusters to maintain their integrity and a longer effective lasting time. It is also pointed out that the odor absorbing substance may optionally include an odor eliminating compound such as activated silica essential oils, vinegar, bamboo charcoal-doped cotton, or charcoal-doped cotton, polyester, silk or other carbonaceous absorbent materials combination thereof.
It is therefore within the ambit of the present invention to Cover any obvious modification of the examples of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.
This application is a continuation-in-part of application Ser. No. 14/545,714, filed on Jun. 10, 2015 and entitled Down and Polymer Mixture Thermal Insulating Sheet.
Number | Date | Country | |
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Parent | 14545714 | Jun 2015 | US |
Child | 16501204 | US |