Abstract:
A method for containerlessly packaging non-woven safety garments to minimize particulate shedding, including at least partially filling a pressing cavity of a orthorhombic parallelepiped shape with compressible, non-woven safety garments, applying isostatic pressure to the cavity to compact the garments into a compressed mass, wrapping the compressed mass and removing the compressed mass from the cavity. The wrapped compressed mass retains a substantially rectangularly parallelepiped-shape.

Description:
TECHNICAL FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to the field of packaging, and more specifically to a method and apparatus for providing boxless and regularly shaped stackable packages of safety garments.  
       BACKGROUND OF THE INVENTION  
       [0002]     Safety garments, such as disposable smocks, jumpsuits, gloves, shoe coverings, and hair coverings, are required apparel for the performance of many jobs. Some of the jobs requiring safety garments are performed in clean room environments, wherein the introduction of foreign matter must be minimalized. For example, technicians in certain sensitive medical fields dealing with infectious matter, aerospace researchers assembling interplanetary probes, and material scientists developing and manufacturing ultrapure materials all wear safety garments in clean room environments. The safety garments perform the dual function of protecting the wearer from the potentially hazardous materials he is working with as well as preventing unwanted matter from the wearer&#39;s person from contaminating his work product.  
         [0003]     Safety garments are typically provided in lots containing a plurality of identical safety garments. These lots are typically provided in boxes made of a structural material such as cardboard, and are shaped as regularly sized rectangular blocks for ease of storage and handling. The safety garments are typically packed into these boxes, either by hand or by machine. One drawback of providing boxed safety garments is that particulate organic material may from the packaging process and/or from the box itself may adhere to the safety garment, thus partially defeating the purpose of the clean room environment. Further, the boxes themselves tend to attract vermin such as rodents and insects that enjoy consuming organic comestibles such as cardboard packaging. In addition to producing excess packaging particles when consuming the packaging material, such vermin also contribute even more particulate contamination in the form of carried dirt, shed hair, fecal waste matter, and the like. Thus, cardboard boxes are problematic for the transport and storage of safety garments intended for clean room use.  
         [0004]     One partial solution has been to bag the safety garments in polymer bags or the like that do not contribute particulate contaminants and do not attract vermin. The problem with this approach is that the bags are inherently irregularly shaped and are thus not easily or conveniently stacked for storage and transport. Another partial solution has been to package the safety garments in boxes made of inorganic materials, such as plastics or metal that do not shed particulate contaminants and do not attract vermin. However, such packaging materials are inherently more expensive than traditional boxes and cannot be easily broken down for disposal, contributing even more expense to the enclosed products.  
         [0005]     There thus remains a need for a need for an inexpensive packaging system that does not contribute particulate contamination, does not attract vermin and may be easily stacked for storage and readily disposed of after it has served its purpose. The present invention addresses this need.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention relates to a method and apparatus for compressively packaging safety garments to form stackable wrapped blocks. Compressible safety garments are placed into a rectangular parallelepiped compression chamber and an isostatic ram operationally connected to the compression chamber is inserted thereinto to apply a compression force to the garments. A vacuum pump fluidically connected to the compression chamber is actuated to reduce the air pressure in the compression chamber during the compression process, and the resulting compressed rectangular parallelepiped blocks are wrapped in flexible plastic wrapping material to yield wrapped rectangular parallelepiped blocks that may be stacked and stored for future use.  
         [0007]     One object of the present invention is to provide an improved method and apparatus for packaging safety garments. Related objects and advantages of the present invention will be apparent from the following description.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a schematic illustration of a first embodiment apparatus for producing wrapped compressed blocks of safety garments of the present invention.  
         [0009]      FIG. 2  is an enlarged partial view of the embodiment of  FIG. 1 .  
         [0010]      FIG. 3  is a schematic view of safety garments being loaded into the compression chamber of  FIG. 1 .  
         [0011]      FIG. 4  is a schematic view of safety garments being compressed in the apparatus of  FIG. 1 .  
         [0012]      FIG. 5  is a schematic view of a compressed block of safety garments in the apparatus of  FIG. 1 .  
         [0013]      FIG. 6  is a schematic view of the compressed block of safety garments of  FIG. 5  being wrapped.  
         [0014]      FIG. 7  is a perspective view of the wrapped block of safety garments as wrapped in  FIG. 6 .  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     For the purposes of promoting an understanding of the principles of the invention and presenting its currently understood best mode of operation, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, with such alterations and further modifications in the illustrated device and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0016]      FIGS. 1-7  schematically illustrate a first embodiment of the present invention, a packaging apparatus  10  and method for the containerless or boxless packaging of non-woven garments  12 , such as smocks or coveralls made from spunbond/melt blown/melt blown/spunbond (SMMS) material and the like. The nonwoven garments are characterized by an associated loose density. The packaging apparatus  10  includes a cavity or chamber  14  for compressing a plurality of safety garments  12  placed thereinto. The chamber  14  preferably includes a rectangular base  16  with four generally planar walls  18  extending perpendicularly therefrom to define an orthorhombic parallelepiped enclosure  14 . In some preferred embodiments, the base  16  is a square. The chamber  14  more preferably defines a volume from about 4500 cubic inches to about 8100 cubic inches. In some preferred embodiments, the chamber  14  is a cube.  
         [0017]     The chamber  14  is sized to receive an isostatic ram member  20 , shown in detail in  FIG. 2 . The isostatic ram member  20  is operationally connected to the chamber  14  and is able to move into the chamber  14  to provide a compressive force to the interior of the chamber  14  sufficient to compress nonwoven safety garments  12  loaded into the chamber  14  and remove substantially all of the entrapped air therefrom. Preferably, a ram  20  pressure of about 80 PSI is sufficient to compress the garments  12  and facilitate removal of most or all of the entrapped air from the chamber  14 . Also preferably, there is sufficient gap between the ram member  20  and the chamber walls  18  to allow air to escape as the ram member  20  is introduced into the chamber  14 .  
         [0018]     The apparatus  10  preferably further includes a vacuum system  26  for pulling a partial vacuum on the chamber  14  during the compression operation. The vacuum system  26  includes a vacuum pump  28  fluidically connected to the chamber  14  such that actuation of the vacuum pump  28  reduces the air pressure in the chamber  14 . The vacuum system  26  further includes an air conduit  30  pneumatically or fluidically connected to the chamber  14  for at least partially removing the air therefrom, and also an enclosure defining a vacuum chamber  32  within which the chamber  14  is disposed. The vacuum chamber  32  is shown herein schematically, and may be of any convenient configuration sufficient to allow the generation of a partial vacuum within the compression chamber  14 .  
         [0019]     The apparatus  10  further includes means for wrapping a compressed block  36  with a flexible nonshedding wrapping material  38  to yield an substantially orthorhombic parallelepiped-shaped block of compressed safety garments  40 , such as a polymer sheet, plastic film, or the like. Such means is illustrated schematically herein, and may comprise any convenient automated wrapping technology in the art. The polymer wrapping material  38  is preferably a polymer material capable of sustaining a pressure differential (i.e., vacuum wrapping a bundle of compressed garments  12 ) and is more preferably polyethylene, polypropylene, polyester (such as MYLAR®) or the like. The polymer wrapping material  38  is preferably of sufficient thickness to retard gas leakage thereacross. In the case of a polyethylene wrapping material  38 , the preferred sheet thickness is about 4 mils. However, any convenient flexible wrapping material  38  of sufficient thickness to wrap a compressed block  36  sufficiently to retain its substantially orthorhombic parallelepiped shape may be selected. Moreover, by wrapping the block  36  in additional layers, thinner and more deformable wrapping material  38  may be suitable.  
         [0020]     In operation, a number of compressible safety garments  12  are preferably folded and stacked, and then placed into the chamber  14 . Preferably, between about 10 and about 15 pounds of safety garments  12  are placed into the chamber  14  at once. The chamber is preferably sized to accept the stack of safety garments  12  with a minimum amount of excess volume. The interior of the chamber  14  is preferably lined with a polymer or plastic wrapping material  38 , such that the safety garments  12  are placed into the wrapping material  38  in the chamber  14 . Alternately, the wrapping material  38  may be applied to the compressed mass  36  after the removal of the compressed mass  36  from the chamber  14 .  
         [0021]     Preferably, a partial vacuum is then produced within the chamber  14  and the safety garments  14  are then isostatically pressed to compact their volume and remove entrapped air. However, the compaction process does not necessarily require the presence of a partial vacuum and may be performed at standard air pressure. Preferably, the safety garments are compacted to a density of between about 2 and about 5 times their associated loose density, and more preferably to about 3 times their loose density. Preferably, a force of between about 50 and about 120 PSI is sufficient to achieve such compression. Typically, the density of a compressed mass  36  is about 0.004 pounds per cubic inch.  
         [0022]     The wrapping material  38  is then sealed (the sealing process is preferably but not necessarily performed under a partial vacuum) and the resulting compressed block  36  is removed from the chamber  14 . Preferably, the block  36  is again wrapped with wrapping material  38  (i.e., the compressed block of garments  36  is double wrapped) and the outer wrapping  38  is then sealed (preferably heat sealed); alternately, the block  36  may be heat sealed or otherwise sealed after its initial compression. More preferably, the second application of wrapping material  38  is in the form of a gusset to assist in the retention of the preferred block shape. The resultant package  40  has the shape of an orthorhombic (preferably rectangular) parallelepiped and retains that shape during shipping and storage. In one preferred embodiment, the package  40  has dimensions of about 16×14×12 inches and has a mass of about 11 pounds.  
         [0023]     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. It is understood that the embodiments have been shown and described in the foregoing specification in satisfaction of the best mode and enablement requirements. It is understood that one of ordinary skill in the art could readily make a nigh-infinite number of insubstantial changes and modifications to the above-described embodiments and that it would be impractical to attempt to describe all such embodiment variations in the present specification. Accordingly, it is understood that all changes and modifications that come within the spirit of the invention are desired to be protected.