Abstract:
There is provided an improved two-ply sterilization wrap and a method for using the improved sterilization wrap to sterilize an article. The wrap is made of a single sheet of sterilization material. The sheet is folded forming at least one fold. The folded sheet forms first and second overlapping panels and two layers of sterilization material. Preferably, the panels are bonded to each other. The folded single sheet provides two layers of sterilization material covering the article to be sterilized.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to sterilizing articles utilizing sterilization wrap. More particularly, it relates to sterilization wrap having two plies of sterilization material.  
           [0002]    Reusable medical instruments must be sterilized prior to each use. Normally, these instruments are sterilized by steam or ethylene-oxide. In order for the instruments to remain sterile after the sterilization procedure, the instruments must be wrapped in a material called “sterilization wrap”.  
           [0003]    The most common type of sterilization wrap is a three-ply laminate consisting of a layer of melt blown polypropylene sandwiched between two layers of spun bond polypropylene. The wrap includes bond points all across the face of the material so that the material is held together, i.e., laminated. This three-ply material is commonly referred to as “SMS”, which is short for spun bond—melt blown—spun bond. Most hospitals specify SMS as the sterilization wrap to be used because SMS is sufficiently porous to permit steam and ethylene-oxide to penetrate through the material to the surgical instruments, but has filtration properties sufficient to prevent the passage of most pathogens therethrough.  
           [0004]    In most hospitals, there is a protocol which requires surgical instruments to be wrapped with two separate sheets of SMS so that in the event one sheet becomes torn, there is a redundancy which will maintain the sterility of the surgical instruments. The wrapping of surgical instruments with two separate sheets of sterilization wrap obviously is labor intensive in that the nurse must first place the instruments on one sheet of sterilization material and wrap the instruments, and then place the wrapped package on another sheet of sterilization material and wrap the instruments again.  
           [0005]    In an attempt to reduce the labor required to provide dual wrapping of surgical instruments, Kimberly-Clark Corporation has developed a product called “One Step Sterilization Wrap”. One Step Sterilization Wrap is made by bonding two separate sheets of sterilization wrap together. The Kimberly-Clark One Step product is described in U.S. Pat. Nos. 5,635,134 and 5,688,476. However, because the One Step wrap requires separate sheets to be bonded together, manufacturing costs are substantially increased. In addition, it requires precise alignment of the two separate movable sheets during the bonding process.  
           [0006]    Thus there is a need for a sterilization wrap which provides two layers of protection, yet is inexpensive to manufacture and is easy to use.  
         OBJECTS OF THE INVENTION  
         [0007]    It is therefore one object of this invention to provide an improved two-ply sterilization wrap.  
           [0008]    It is another object of this invention to provide a two-ply sterilization wrap which is inexpensive to manufacture and is easy to use.  
           [0009]    It is still another object of this invention to provide an improved method for sterilizing an article utilizing an improved two-ply sterilization wrap.  
         SUMMARY OF THE INVENTION  
         [0010]    In accordance with one form of this invention, there is provided a sterilization wrap made from a single sheet of sterilization material. The sheet has first, second, third and fourth edges. The sheet is folded in half forming first and second overlapping panels and two layers of sterilization material. The fold runs from the third edge to the fourth edge. Because of the fold, the first edge is adjacent to the second edge and thus two layers of sterilization material are provided for an article to be sterilized by using a single sheet of sterilization material. The two panels may be affixed together along the first and second edges.  
           [0011]    In addition, the third edge includes first and second portions and the fourth edge also includes first and second portions. The first panel may be also affixed to the second panel by bonding the first portion of the third edge to the second portion of the third edge, and by bonding the first portion of the fourth edge to the second portion of the third edge. In addition, the two panels may be affixed together by bonding adjacent to the fold.  
           [0012]    In accordance with another form of this invention, there is provided a two-ply sterilization wrap made from a single sheet of sterilization material. The sheet is folded in half forming first and second overlapping equally sized panels. Each panel has edges. The first panel is bonded to the second panel so that the edges of the first panel remain adjacent to the edges of the second panel.  
           [0013]    In accordance with another form of this invention, there is provided a two-ply sterilization wrap made from a single sheet of sterilization material. The sheet includes two folds. The sheet includes first, second, third and fourth edges. The first edge is adjacent to the second edge, and the third and fourth edges are opposite from one another. The folded sheet forms two adjacent equally sized panels. The first and second edges form an overlapping region. The first and second edges are bonded together along the overlapping region. The third edge includes first and second adjacent portions, and the fourth edge includes first and second adjacent portions. The first portion of the third edge may be bonded to the second portion of the third edge, and the first portion of the fourth edge may be bonded to the second portion of the fourth edge.  
           [0014]    In accordance with another form of this invention, there is provided a method for sterilizing an article, including the steps of providing an article, wrapping the articles with sterilization wrap which is formed in accordance with one or more of the above described designs, and applying sterilization conditions to the wrapped article.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    The subject matter which is regarded as the invention is set forth in the appended claims. The invention itself, however, together with further objects and advantages thereof may be better understood in reference to the accompanying drawings in which:  
         [0016]    [0016]FIG. 1 is a plan view of the sterilization wrap in accordance with this invention, but prior to being folded;  
         [0017]    [0017]FIG. 2 is a plan view of the sterilization wrap of FIG. 1, but after having been folded, in accordance with this subject invention;  
         [0018]    [0018]FIG. 3 is another embodiment of the invention shown in FIG. 2;  
         [0019]    [0019]FIG. 4 is an alternative embodiment of that shown in FIG. 2;  
         [0020]    [0020]FIG. 4A is an alternative embodiment of that shown in FIG. 2;  
         [0021]    [0021]FIG. 5 is an alternative embodiment of that shown in FIG. 2;  
         [0022]    [0022]FIG. 6 is an alternative embodiment of that shown in FIG. 2;  
         [0023]    [0023]FIG. 7 is an alternative embodiment of that shown in FIG. 2;  
         [0024]    [0024]FIG. 8 is a perspective view of the embodiment of FIG. 3 having materials to be sterilized in preparation for wrapping;  
         [0025]    [0025]FIG. 9 is a side elevational view of the embodiment of FIG. 1 viewed from Lines  9 - 9 ;  
         [0026]    [0026]FIG. 10 is a right side elevational view of the embodiment of FIG. 2;  
         [0027]    [0027]FIG. 11 is a right side elevational view of the embodiment of FIG. 4;  
         [0028]    [0028]FIG. 12 is a perspective view of an alternative embodiment of the invention;  
         [0029]    [0029]FIG. 13 is a plan view of an alternative embodiment of FIG. 12;  
         [0030]    [0030]FIG. 14 is a side elevational view of the embodiment of FIG. 12 viewed from Lines  14 - 14 ;  
         [0031]    [0031]FIG. 15 is an alternative embodiment of that shown in FIG. 14;  
         [0032]    [0032]FIG. 16 is an alternative embodiment of that shown in FIG. 12. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    Referring now more particularly to FIG. 1, there is provided single sheet  10  which is made of sterilization material, which is preferably a three-ply laminate having a layer of melt blown polypropylene sandwiched between two layers of spun bonded polypropylene, referred to as SMS. A side elevational view showing the melt blown layer  12  sandwiched between spun bonded layers  14  and  16  is shown in FIG. 9. The layers  12 ,  14  and  16  are laminated or fixed together by a series of closely spaced small bond points consisting of ultrasonic welds. For simplicity, so as not to be confused with other bond points which are used for different purposes describe below, these SMS bond points are not shown. SMS is commercially available from Kimberly-Clark Corporation.  
         [0034]    Sheet  10  includes first edge  22 , second edge  24 , third edge  26  and fourth edge  28 . Third edge  26  includes a first portion  30  and a second portion  32 , which are equal in length, and fourth edge  28  includes a first portion  34  and a second portion  36 , which are also equal in length.  
         [0035]    The single sheet of sterilization material  10  is folded in half along the fold line indicated by dotted line  18  from third edge  26  to fourth edge  28 . The resulting folded article becomes two-ply sterilization wrap  20 , as indicated in FIG. 2. Sterilization wrap  20  includes two equally sized panels  38  and  40  having first edge  22  which is aligned with and is adjacent to edge  24 . First portion  30  of edge  26  is aligned with and is adjacent to second portion  32  of edge  26 . First portion  34  of edge  28  is aligned with and is adjacent to second portion  36  of edge  28 . As shown in FIG. 2, a single sheet two-ply sterilization wrap has been formed by simply folding an elongated sheet of sterilization material in half. However, it is preferred that the two panels  38  and  40  be bonded together. The preferred method of bonding is ultrasonic bonding which will result in bond points. Alternatively, hot melt glue, heated knife or wire, laser, water jet, or mechanical embossing may be used. Preferably, the central portions  41  and  43  of panels  38  and  40  are not bonded together.  
         [0036]    When the phrase “edges are bonded together” is used herein, it should be understood that the bonding may occur on the material adjacent to the edges, or on the edges themselves.  
         [0037]    In one embodiment, shown in FIG. 3, the sheets are bonded together by a plurality of bond points  42  which are formed by ultrasonic bonding using a known procedure. These bond points  42  are provided along edges  22  and  24  so that the panels  38  and  40  are bonded together only along edges  22  and  24 .  
         [0038]    [0038]FIG. 4 shows an alternative embodiment, which includes a plurality of bond points  44 , which are provided along first portion  34  of edge  28  and second portion  36  of edge  28 , and a plurality of bond points  46 , which are provided along first portion  30  of edge  26  and second portion  32  of edge  26 .  
         [0039]    [0039]FIG. 4A shows an alternative embodiment, which includes the bond points  44  and  46 , and also includes bond points  42  along edges  22  and  24 , i.e., a combination of the embodiments of FIGS. 3 and 4.  
         [0040]    [0040]FIG. 5 shows a modified version of the embodiment of FIG. 3, whereby a plurality of bond points  48  are provided by bonding along the fold line  18  so that the two panels  38  and  40  will stay together along fold line  18 .  
         [0041]    [0041]FIG. 6 shows another alternative embodiment to that of FIG. 4, which also includes bond points  48  along fold line  18 , as well as bond points  44  and  46  described above, but omits the bond points along edges  22  and  24 .  
         [0042]    [0042]FIG. 7 shows yet another alternative embodiment which includes bond points  42 ,  44 ,  46  and  48  on all of the edges and the fold of the two-ply sterilization wrap.  
         [0043]    [0043]FIG. 8 shows the single sheet two-ply sterilization wrap embodiment of FIG. 3 having articles  50  to be sterilized placed thereon in preparation for wrapping. Article  50  is wrapped by sterilization wrap  20  in a known fashion. Tape is placed over the wrapped article and the wrapped articles  50  are subjected to sterilization conditions, such as steam or ethylene-oxide. The other embodiments of the invention described herein may also be used to wrap article  50  for sterilization.  
         [0044]    [0044]FIGS. 12 through 14 show still another embodiment of the invention. Sterilization wrap  52  includes two plies  54  and  56 , which is preferably made from the SMS sterilization material shown in FIG. 9. The sterilization wrap  52  is also made of a single sheet of sterilization material, but has been folded twice, namely, at folds  58  and  60  so that edge  62  overlaps edge  64  forming an overlap zone  66 . The edges  62  and  64  are bonded together along overlap zone  66 , preferably by ultrasonic bonding, resulting in bond points  68 . The two folds  58  and  60  form first panel  70  and second panel  72 , which are equal in size and which completely overlap one another. The third edge  74  of the single sheet includes first portion  76  and second portion  78 . First portion  76  and second portion  78  of third edge  74  are adjacent to one another. As shown in FIG. 13, the first portion  76  of edge  74  and the second portion  78  of edge  74  may be bonded together, again, by using ultrasonic bonding, thereby forming bond points  79 . Likewise, the first and second portions of the fourth edge  80  may also be bonded together in an identical fashion.  
         [0045]    As shown in FIG. 15, the bond points  68  may also provide bonding between panels  70  and  72 . That is, the bond  68  may go all the way through to panel  72 , which will help stabilize the sterilization wrap.  
         [0046]    [0046]FIG. 16 shows still another embodiment of the invention, which is similar to that shown in FIG. 13, except that the article is only bonded along the third edge  74  and the fourth edge  80 , as shown by bond points  82  and  84 , i.e., there is no bonding along the overlap of edges  62  and  64 . Alternatively, the embodiments of FIGS. 12 and 16 could be combined, as shown in FIG. 13, so that the overlap of edges  62  and  64  are bonded as well as edges  74  and  80 . By using the embodiments shown in FIGS. 4A, 7 and  13 , there are no loose, i.e., unsealed, edges. By sealing all edges, the fiber and particle generation often associated with untreated edges of SMS is reduced.  
         [0047]    The sterilization wrap assembly of the subject invention is easy to manufacture in that it is simply cut into the rectangular shape shown in FIG. 1 and folded into two equal sized panels in the shape shown in FIG. 2. Once the sheet  10  is cut, only a single sheet is used during the manufacturing of the sterilization wrap. Preferably, the two panels are bonded together by ultrasonic welding, which is commonly used to manufacture SMS. Thus there is no need for the nurse to handle two separate sheets of sterilization wrap, nor is there a need for the manufacturer to handle two separate sheets of sterilization wrap and bond the two separate sheets together.  
         [0048]    From the foregoing description of the preferred embodiments of the invention, it will be apparent that many modifications may be made therein. It will be understood, however, that the embodiments of the invention are an exemplification of the invention only and that the invention is not limited thereto. It is to be understood, therefore, that it is intended in the appended claims to cover all modifications as fall within the true spirit and scope of the invention.