Patent Publication Number: US-7707804-B2

Title: Method of wrapping a soap bar

Description:
The present application is a divisional of U.S. patent application Ser. No. 10/486,890, filed on Feb. 11, 2004, which has issued as U.S. Pat. No. 7,428,965, and which claims the benefit of U.S. Provisional Application No. 60/313,199, filed Aug. 17, 2001, the entireties of which are hereby incorporated by reference. 

   FIELD OF THE INVENTION 
   This invention relates to wrappers for shaped soap bars. More particularly, this invention relates to a single plastic wrapper for a shaped generally rectangular soap bar. 
   BACKGROUND OF THE INVENTION 
   Soap bars are produced in various shapes. These range from round, to square, to rectangular to elliptical and variations on these shapes. Some soap bar shapes are easy to wrap while others present a measure of difficulty. Square, rectangular and circular shaped bars are relatively easy to package. They can be wrapped in a single relatively thin plastic film folded at the ends and heat sealed. These also can be packaged in a flow wrap. In this type of wrapper, the ends are fin sealed rather than being folded and sealed. However, elliptical shaped bars and generally rectangular shapes having curved edges and curved primary surfaces present packaging difficulties in other than flow wrap packaging. Examples of generally rectangular soap bars are shown in U.S. Des. 345,817; U.S. Des. 346,241; U.S. Des. 348,539 and U.S. Des. 348,541. These design patents are incorporated herein by reference. These have a rectangular-like shape having main top, bottom, side and end surfaces that are curved. Further, the transition of one surface to another surface is curved. The soap bars are rectangular-like but with non-planar top, bottom and front and rear connecting surfaces. The end surfaces may have a flat area for sealing but otherwise usually are curved. This includes ovoid shaped soap bars since they also have an elongated type of structure. The transition from one surface to another surface preferably also is curved. This curving gives the soap bar a pleasing, aesthetic shape. Such soap bars are described herein as generally rectangular shaped soap bars. 
   In order to wrap such bars so that they have a substantially rectangular shape, a stiffener reinforcing element is conventionally used to shape the package. The stiffener reinforcing element is a piece of relatively stiff material such as paperboard, paperboard coated with plastic or plastic that is wrapped laterally around the soap bar with the ends of the soap bar being open. Then, the soap bar and the stiffener reinforcing element are surrounded by a wrapper which is folded at its ends and the flaps of the folds heat sealed, one to the other. There also is a longitudinal seal of the film on the bottom surface of the package. A problem in the use of a stiffener reinforcing element is that it requires the handling and use of two films. The stiffener reinforcing element film and the wrapper film. The packaging process and cost can be reduced with the use of only one film, the wrapper film. That is, the stiffener reinforcing element films is deleted. It has been found that this can be done if a particular wrapper film is used. This film will be sufficiently stiff to provide a rectangular shape to the packaged soap bar, but yet be able to be readily folded and sealed to produce the package. 
   BRIEF DESCRIPTION OF THE INVENTION 
   It has been found that a reinforcing element stiffener is not required if a plastic wrapper of about 60 micron to about 180 micron is used, and preferably about 90 micron to about 150 micron. This plastic can be of a monolayer or laminate multilayer construction. Such a plastic has a sufficient thickness to form and maintain a generally rectangular shape, but yet a thickness where the film can be folded to form the end side panels without the need for optional fold enhancement techniques. Preferably, it will be a thermoplastic film or thermoplastic coated paper or paperboard to aid in the sealing of the film. In such a wrapping of soap bars, there also is a longitudinal lap seal on the lower surface of the package with the end seals having folds and the folds sealed. These usually are heat seals since thermoplastic films are used. An adhesive can be used to form such heat seals in conjunction with the thermoplastic film. 
   The films of this invention have a Taber stiffness of more than about 5 to form the package and are sufficiently flexible so that end panels can be formed and sealed. Preferably the Taber stiffness is about 8 to 20. A preferred film is biaxially oriented polypropylene. This can be a monolayer or a multi-layer of two or more layers. However, any other sealable plastic surface films having similar Taber stiffness can be used. These usually will have a thickness in the 60 micron to 180 micron range. However, it is the stiffness that primarily will control use. The films should have a Taber stiffness of about 7 to 20 which is equivalent to that of about 60 micron to about 180 micron biaxially oriented polypropylene film. 
   In order to form a more effective bottom longitudinal overlapping seal on the soap bar package the soap bar should have a planar area on its bottom surface. The bottom surface can have curved surfaces and sections but at least one area should be planar. Further this planar area should be adjacent to the area where the bottom overlapping seal is to be made. That is, the overlapping edges of the film should be adjacent to the planar area of the bottom of the soap bar. The seal plate or band will hold the overlapping film edges against the planar area of the bottom surface of the soap bar to effect the bottom seal of the soap bar package. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a of a generally rectangular soap bar. 
       FIG. 2  is a top plan view of the soap bar of  FIG. 1 . 
       FIG. 3  is a bottom plan view of the soap bar of  FIG. 1 . 
       FIG. 4  is a perspective view of the packaged soap bar of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention although useful with many objects will be described with regard to a soap package that does not require a stiffener to wrap generally rectangular soap bars and will be set out in more detail with reference to the preferred embodiments. A generally rectangular soap bar is one described above that has an elongated rectangular-like shape inclusive of an ovoid shape, with main surfaces that are curved and preferably curved in the transition from one main surface to another. Examples are shown in the above U.S. Design patents which have been incorporated herein by reference. It is an aesthetically pleasing shaped soap bar and one that is relatively easy to grip and to use. However, it is difficult to package in other than a carton, flow wrap, or two component package that requires both a stiffener sheet laterally around the soap bar and a wrapper that fully encloses the soap bar. 
   It has been found that a one piece package can be used to package soap bars and other objects that are generally rectangular in shape. A single plastic or plastic coated paper or paperboard film having a thickness of about 60 microns to about 180 microns, and preferably about 90 microns to about 150 microns, a Taber Stiffness of more than about 5, and preferably about 7 to about 20 m can be used. This is an average Taber Stiffness for both directions. This film is sufficiently stiff to form a rectangular-like package for the soap bar or other object. This film can be plastic, paper or paperboard with or without a plastic coating and can be opaque, translucent or transparent. Further it can be colored or tinted and/or printed with a decoration and/or information about the product. 
     FIG. 1  is a depiction of an embodiment of a generally rectangular soap bar  10 . It has a compound curved top surface  12 , a left end surface  16 , a right end surface  14  and a front surface  18 . This soap bar is further depicted in  FIGS. 2 and 3 .  FIG. 2  is a top plan view with this view also showing the compound curve of the top surface of the soap bar. Also shown in this view is side  20 .  FIG. 3  is a bottom plan view of the soap bar. This shows side surfaces  18  and  20  and end surfaces  14  and  16 . Each of these is shown to have a compound curvature. Further side surface  18  and  20  have scalloped, dished out areas  30  and  32 . These scalloped areas extend into bottom surface  28 . The bottom surface  28  except for the scalloped areas  30  and  32  is planar. It is this planar area of the bottom surface which will assist in the forming of the longitudinal seal on the film that is used to form the seal on the longitudinal edges that are overlapped on the bottom surface in the packaging of soap bars. It is conventional to have a seal longitudinally across the bottom of a soap bar package. At the soap bar ends, the film is folded and sealed. The seals are made by heat sealing the film material to itself, or by activating an adhesive on the surface of the film. Both are conventional techniques for sealing films and are used in making seals on soap bar packages. 
     FIG. 4  shows the soap bar of  FIG. 1  that is packaged in a 104 micron biaxially oriented polypropylene film. The soap bar  10  is packaged within the wrapper  40 . The wrapper has a top surface  42 , longitudinal side surface  43  and end surface  45 . The end surface has fold over seals formed by folded sections  34 ( a ) and  34 ( b ) that are overlayed by folded sections  36 ( a ) and  36 ( b ). Longitudinally across the bottom of the package is a seal of the overlapping edges of the film that is folded over on the bottom. The side folds and seals and the bottom seals are conventional in wrapping soap bars. 
   As noted above, the film for the package can be comprised of paper, paperboard or plastics, including combinations of these materials. This includes plastic/plastic laminates, plastic/paper laminates, plastic/paper/plastic laminates, plastic/paperboard laminates and plastic/paperboard plastic laminates. The useful plastics are primarily thermoplastics and include polyethylenes, polypropylenes, ethylene-propylene copolymers, polyesters such as polyethylene terephthalate, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, ethylene vinyl compound copolymers, polystyrenes, and acrylnitrile-butadiene styrene copolymers. Economics dictate the preferred use of thermoplastics such as polyethylenes and polypropylenes, and more preferably biaxially oriented polypropylene. The films are formed by conventional and known processes.