RECLOSEABLE ANTI-ALLERGEN SLEEVES
BACKGROUND OF THE INVENTION Technical Field
The present invention relates to a selectively redoseable anti-allergen sleeve and, more particularly, to anti-allergen pillow covers. The invention further relates to a process for manufacturing the selectively redoseable anti-allergen sleeve of the present invention. Description of Related Art
Currently, pillow covers are generally manufactured from a woven cloth material including metallic or plastic zippers having teeth or simply flaps to close the end of the cover. Metallic or plastic zippers are less than desirable for many reasons including, for example, inefficiencies in applying the zippers to the cloth cover and the potential for mechanical failure. Cloth flaps, on the other hand, are prone to tearing and opening through the course of normal use of the pillow. Cloth pillow covers also generally include side seams which must be sewn which is labor intensive.
Perhaps the greatest drawback to utilizing mechanical zippers, cloth flaps and sewn side seams to close known pillow cover embodiments is the failure to effectively preclude allergens such as dust and dust mites, by way of non-limiting example, from penetrating the zipper or sewn side seams. Interestingly, as noted in the British Medical Journal, Vol. 314, June 14, 1997, synthetic pillows are known to be as susceptible or even more susceptible to dust mite proliferation than are feather pillows. Recent studies have suggested that exposure to allergens can give rise to asthmatic conditions and a whole host of other breathing related problems. Upon recognizing the need for anti-allergen barriers and the perceived limitations of cloth, the art turned to laminates formed from materials such as cotton, polyester and blends thereof and a second layer of urethane. However, because these laminates were not "breathable", the use of mating male and female fasteners such as ZIPLOC® and SLIDELOC® closures was not possible. Air entrapped within such laminated (non-breathable) anti-allergen covers which is forced toward the mating male and female mechanical closures as above described would generally cause the redoseable fastener to rupture.
Thus, with the advent of breathable non-woven fabrics which are useful as barriers to allergens, the use of mating male and female closures in association with such materials is now possible.
SUMMARY OF THE INVENTION The present invention therefore relates to a selectively redoseable anti- allergen sleeve comprising: a body formed from a breathable non-woven barrier material including an opening through which objects are inserted and removed from said body; and a redoseable fastener which is resistant to allergen leakage. The present invention also relates to a process for making an anti-allergen sleeve including the steps of: forwarding a first breathable non-woven barrier material web including spaced apart lateral edges; applying a redoseable fastener including male and female elements to said web; cutting the web to the desired length; folding the web in the transverse direction; and sealing the lateral edges to form a selectively redoseable breathable anti- allergen sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view illustrating a selectively redoseable anti-allergen sleeve in accordance with the teachings of the present invention;
Fig. 2a is an isometric view of one process for preparing selectively redoseable anti-allergen sleeves in accordance with the teachings of the present invention;
Fig. 2b is a perspective view illustrating the side seam welding of a selectively redoseable anti-allergen sleeve;
Fig. 3 is a perspective view illustrating a pillow being inserted into a selectively redoseable anti-allergen sleeve in accordance with the teachings of the present invention;
Fig. 4 is a flow diagram for a process for making a selectively redoseable anti-allergen sleeve in accordance with the teachings of the present invention;
Fig. 5 is an enlarged cross-sectional view of a redoseable fastening element useful in association with the present invention;
Fig. 6 is a perspective view demonstrating the redoseable fastening element of Fig. 5 being closed by hand; Fig. 7 is an enlarged fractional perspective view of a selectively redoseable fastening element useful in association with the present invention; and
Fig. 8 is an enlarged, fractional perspective view of another selectively redoseable fastening element useful in association with the present invention.
By "non-woven", it is meant that the material is formed from a planar assembly of fibers or filaments held together by mechanical interlocking in a random sheet, web or bat by fusing or bonding the fibers or filaments. For further information on non-woven materials, reference can be made to Principles of Non- wovens, Fiber Classifications and Definitions, written by Wayne Lochmaier of the Eastman Chemical Company. DETAILED DESCRIPTION OF THE INVENTION
Referring to Fig. 1 , there is shown a perspective view of a selectively redoseable anti-allergen sleeve 10 in accordance with the teachings of the present invention. The anti-allergen sleeve generally comprises a body 12 and a selectively redoseable fastener 14 integrally attached to the body for enclosing objects such as a pillow, by way of non-limiting example.
The body 12 is generally formed from a porous breathable non-woven barrier material preferably having an average pore size of between about 2.0 to about 20.0 microns and, more preferably, between about 6.0 to about 12.0 microns The non-woven material utilized may be selected from a number of non- wovens including, by way of non-limiting example, spunbound and meltblown materials. Among the useful spunbound materials are thermoplastic polymers such as polypropylene, polyethylene and polyesters. Among the useful meltblown materials are various thermoplastic polymers including, for example, polypropylene, polyesters (PBT and PRT), LLDPE, LDPE, HDPE, EVA, EMA, EVOH, polyurethanes, polyester estomers and nylons.
A preferred non-woven material is polypropylene. Highly preferred are spunbound, meltblown-spunbound polypropylenes such as those available- from BBA Non-Wovens, Inc. and PGI Non-Wovens, Inc.
It is preferred that the non-woven material employed exhibits a breathability factor of at least about 5.0 cfm/ft2 as determined by Frasier Air Permeability test methods reported under ASTM Test Procedure D737-96. The body 12 generally includes first and second sidewalls 20 and 20' (as shown in Figs. 2b and 3), side seams 22 and 22' adjoining the sidewalls, a closed bottom 24 and an opening 26 (as shown in Fig. 3) through which objects may be inserted into the sleeve. Preferably, the anti-allergen sleeve will be about 20 inches in width and between about 20 to 40 inches in length such that the sleeve is capable of receiving pillows of various dimensions, i.e., standard, queen or king size.
The selectively redoseable fastener 14 is generally formed from mating thermoplastic male and female elements 16 and 18, respectively. The fastener may include specially designed fastening elements such as the ones illustrated in
Fig. 8. According to this embodiment, the male fastening element is substantially free of interdigitation with the female fastening element and is discontinuous along a given length. This design allows for an audible clicking sound and/or a vibratory or bumpy feel as the male and female fastening elements are brought into closed contact.
Another specialized fastening is illustrated with reference to Fig. 7 which makes use of a slide lock closure system. Here, in addition to male and female fastening elements, a selectively movable mechanism is employed. By adjusting the position of the sliding mechanism along the fastener, the male and female fastening elements are forced into relative contact or released depending on the location of the sliding mechanism 30.
While virtually any thermoplastic redoseable fastening element which is weldable to the non-woven materials described herein may be utilized, those disclosed in U.S. Patent Nos. 4,736,496 to Fisher et al.; 5,009,828 to McCree; 5,070,584 to Dais et al.; 5,140,727 to Dais et al.; 5,647,100 to Porchia et al.; 5,664,299 to Porchia et al.; and 5,836,056 to Porchia et al., each of which are hereby incorporated by reference, are considered to be preferred. The redoseable fastening element utilized again will be effective at limiting allergen seepage along the closure. To manufacture the selectively redoseable anti-allergen sleeves described herein, a process involving the steps set forth in the diagrammatic flow diagram of Fig. 4 is employed. As shown in box 50, a web of breathable non-woven material 110 is advanced via an unwinding machine 100 through a plurality of rollers 102 positioned to maintain the web in a taught condition as illustrated in Fig. 2a. As the web is advanced, the male and female fastening elements 16 and 18 are applied to the web via known extrusion techniques or melt bonding as indicated by box 60.
Once the male and female fastening elements have been applied, the web is then cut to the desired length and folded as denoted by box 70 such that the fastening elements are in proper alignment to form redoseable a fastener 14. Thereafter, the side seams are joined via sonic welding, hot wire or hot knife techniques known in the thermoplastic bag industry. For purposes of illustration, a welding machine is denoted by box 80 similar to the one shown in Fig. 2b to form the selectively redoseable sleeve.
To verify that non-woven materials were breathable anti-allergen barriers, non-woven polypropylene materials as used for the above described closable sleeves were analyzed for barrier efficiency. More particularly, samples of the material were analyzed to determine whether the material was an acceptable barrier to dust mites.
To carry out the analysis, sheets of barrier material were prepared for testing by laundering the sheets with Tide® powdered detergent in a household top loading washing machine. The wash and rinse temperatures were set at 130-135°F with the wash cycle lasting 12 minutes and a rinse cycle of 3 minutes. Thereafter, the sheets were dried on the low setting for 60 minutes in a household clothes dryer.
Samples were taken from the washed sheets at 0, 5, 10 and 25 cycles in an area where stress was noted during the laundering process, i.e., when the sheets wound around the agitator.
The samples were tested by sequentially placing the samples in a dual chambered cylinder with a transfer surface area between the vials of 1.13 cm2 along with two steel bearings so that the sample served as a barrier between an empty and dust containing chamber. The chamber was rotated at 25 rotations per minute for 18 hours. The two 1/8" steel bearings in the allergen vial weighed 132 milligrams each. The dust containing chamber was provided with a reference dust sample containing 0.0250 grams of fine dust containing 6250 nanograms of dust mite allergen. At the conclusion of the tumbling period, the empty side chamber was removed to determine how much allergen had penetrated the material. Material in this side was extracted with 0.5 ml buffer and mixed for one hour. This extract was used for analysis.
A sensitive immunoassay that measures multiple antigenic determinants from both D. farinae and D. pteronyssinus dust mites was used. The polyclonal antibody assay was selected to insure that any allergen transfer (not just group 1 antigens) would be detected. Each of the samples tested resulted in less than 3.9 nanograms of dust mite allergen, which is below the level of detection.
When used as an anti-allergen pillow cover, the sleeves completely encase the pillow disposed therein, thus providing a protective barrier against dust mites and their allergens while allowing air to pass through the fabric. Industrial Applicability
The present invention provides a selectively redoseable anti-allergen sleeve and a method of making said sleeve, utilizing breathable non-woven fabrics which are useful as barriers to allergens. The non-woven material may be selected from a number of non-wovens including spunbound and meltblown materials. Further, virtually any thermoplastic redoseable fastening element which is weldable to the non-woven materials described herein may be utilized. While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the spirit thereof.