Humidity control for long term storage of articles

Abstract

A humidity regulating system and method is disclosed for use in the storage of humidity sensitive items and includes a storage container defining a volume for storing articles of interest and having a selected generally low water vapor transmission rate, a closure arrangement that generally effectively seals fabric items in the storage container thereby creating a storage environment, and one or more humidity regulating units in communication with the interior of the storage container and including humidity regulating material capable of regulating a desired, generally constant relative humidity in the storage environment that will not support mold growth in fabric or other articles of interest during a selected duration.

Description

BACKGROUND OF THE INVENTION[0001]I. Field of the Invention[0002]The present invention relates to controlling humidity in small, relatively closed environments and, more particularly, to a system and method for regulating environmental humidity about stored articles of clothing, other fabric and diverse articles in a manner that precludes mold growth or other humidity-related problems which may occur during long term storage. The system combines storage containers fabricated from materials having generally low water vapor transmission rates and effective closure systems with one or more humidity control devices placed in the containers to produce units which maintain a generally constant relative humidity in the internal environment despite ambient humidity swings.[0003]II. Related Art[0004]Exposure to excess moisture is known to have undesirable and detrimental effects on clothing and other fabrics such as bedding, linens, etc., particularly when they are stored for significant peri...

AI Technical Summary

Benefits of technology

[0015]The system includes storage containers such as bins, drawers, garment bags and the like. The enclosures should be fabricated from materials having generally low water vapor transmission rates (MVTR). Each container should be equipped with a closure arrangement that effectively seals stored items in the storage container keeping leakage to a minimum thereby creating a separate storage environment. To this are added one or more humidity regulating units placed in communication with the interior of the storage container and which are selected to be capable of maintaining a desired, generally constant relative humidity in the storage environment for a selected length of time. In this manner, the relative humidity in the storage environment can be regulated at a value low enough to preclude mold growth in fabric articles contained in the storage container and yet be high enough not to damage the contents because of brittleness caused by being excessively dry.

[0017]Closure of polymer film containers is preferably accomplished by a zipper lock or slider such as is commonly employed in storage bags, a matching strip and groove system, repeatable use tape or other multiple use device that minimizes leakage and the passage of vapor between the ambient storage environment and the interior of the container. Bins or drawers can be provided with sealing sheets which substantially seal about the interior of a drawer or bin over the articles to be stored. This may be of coated paper, cardboard, plastic or wood, for example. In addition, a weather strip, or the like, type of seal between the sheet and the sides of the drawer can also be employed. In the case of hanging clothing enclosures, hanging hooks may be taped in place with washers, or the like, or sealing collars made from soft, closed cell foam, for example.

[0021]While it is feasible to simply seal moisture regulating materials in a pouch made from semi-permeable films, such pouches may develop leaks due to inadequate sealing or small imperfections in the film. In one preferred embodiment, these leaks are mitigated by blending in finely divided brine tolerant hydrocolloids such as Xanthan gum or other thickening agents to inhibit flow of the significantly viscous saturated solution formed by absorption of water vapor from the storage container environment.

[0026]In the humidity regulating units of the invention, the humidity regulating materials may preferably be combined with thickening agents to stabilize the contents of the humidity regulating units against possible leakage and thereby mitigate deliquescent effects of the humidity regulating materials where necessary. These include hydrocolloids such as xanthan gum which may be especially effective if mixed with an amount of powdered (confectioner's) sugar. The sugar helps with the hydration of the hydrocolloid especially when the sugar and gums are milled together. This further enables the material to absorb large amounts of water without achieving a liquid state which would readily leak from a defect in the unit.

[0028]In addition to garment bags customized by modifications strongly inhibiting the entrance of moisture vapor into the bags so that the humidity regulating pouches have a shelf-life of at least several months, bins or dresser drawers can also be employed. Bins made from heavy polyethylene or other plastic materials with tight fitting lids can protect fabrics or other moisture sensitive objects when humidity regulating units are placed on or among the objects. The number of packets or units needed depends on the expected ingress of moisture vapor during the storage test and the size of the container.

[0030]It will be appreciated that the packets of the present invention are also effective in maintaining textural qualities of foods when these commodities are stored in containers made from low permeability materials such as polypropylene, high density polyethylene, polycarbonate, low-density polyethylene, and the like. Ready-to-eat cereals, for example, have been found to remain crisp significantly longer in humid climates such as the Gulf Coast of the United States.

Problems solved by technology

Exposure to excess moisture is known to have undesirable and detrimental effects on clothing and other fabrics such as bedding, linens, etc., particularly when they are stored for significant periods of time up to six months or more.

Not only is “mustiness” unpleasant, but mold growth tends to weaken natural fibers such as cotton, wool, silk and also to produce allergens to trouble those susceptible to airborne particles.

However, these bags are open to rapid to change of ambient air and thus, are ineffective in dealing with high humidity or changes in the humidity to which the clothes are exposed.

Prior and present methods of reducing and regulating moisture content in storage areas to alleviate undesirable conditions for storage of fabrics such as clothing, bedding, etc., include employing air conditioning or dehumidifying systems or storing the items in controlled atmosphere rooms, all of which are quite expensive.

While air conditioning systems are often employed, they suffer from certain shortcomings.

Because the cooling coils operate at higher temperatures, they are correspondingly less effective at reducing moisture content (absolute humidity) of the air contacting the coils.

Likewise, dehumidifiers, which also use refrigeration to cool the air passing over evaporator coils, also have limitations.

Exposed desiccant drying agents, while effective, are inconvenient to use because salt solutions are produced which are messy and which must be the subject of proper disposal procedures.

Furthermore, desiccants have limited capacity to take up water and are generally expensive.

They are of too limited a capacity with respect to the large volumes of air associated with rooms and closets.

Moreover, for example, accidental contact of leather with the most common desiccant salt, calcium chloride, causes irreversible damage to the leather.

Excessive drying of certain fibers is also undesirable.

For example, conditions that are too dry will make fibers such as cotton and wool more brittle and, thus, subject to damage in that manner.

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