US 3061091 A
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Description (OCR text may contain errors)
1962 M. A. WICHMAN 3,061,091
FOOD PACKAGE Filed June 5, 1961 2 Sheets-Sheet 1 Fig. l
Oct. 30, 1962 M. A. WICHMAN 3,061,091
FOOD PACKAGE Filed June 5, 1961 2 Sheets-Sheet 2 United States Patent Office 3,%l,fi9l Patented Oct. 30, 1962 3,061,091 FOOD PACKAGE Merle A. Wichman, Appleton, Wis, assignor to American Can Company, New York, N.Y., a corporation of New Jerse y Filed June 5, 1961, Ser. No. 114,993
1 Claim. (Cl. 206-78) This invention relates to a package having the contents enclosed in a transparent container which is reinforced and supported by a suitably cut and folded sheet material. The package according to this invention is especially adapted for packaging sliced cheese, meats and the like for display in food stores.
Sliced food products, such as cheese and meats, are customarily packaged in a transparent sheet material ernploying a vacuum to withdraw the air from the package to prevent deterioration of the packaged commodity. After the air is withdrawn and/ or an inert gas employed to replace the air, the transparent sheet material is sealed around its entire perimeter to give an essentially hermetically sealed package. Since neither the packaged product nor the packaging material gives substantial support or rigidity to the finished package, the package is usually enclosed or reinforced by a folded sheet material such as paperboard.
Previous packages, such as that exemplified in U.S. Patent No. 2,802,569, have presented problems in regard to the sealing together of the folded sheet material and the hermetically sealed transparent material. Customarily, the folded sheet material is coated with a suitable heat-sealable adhesive which is activated for sealing purposes by heating bars. Unless the heating bars which apply heat through portions 27 and 28 of the package shown in the patent are located in far enough towards the window 21, a good seal is not effected. Since the heat must penetrate through the board to activate the heat-scalable adhesive, the heaters must be at a relatively high temperature for rapid scaling to take place. This high temperature necessary for sealing tends to cause a scorching or burning of the transparent material either detracting from the appearance of the finished package and/ or breaking the hermetic seal enclosing the packaged product.
This invention provides a package having the contents enclosed in a hermetically sealed transparent sheet mate rial reinforced and supported by a folded paperboard blank. The transparent sheet material and the blank can be readily heat-sealed together by adhesive-activating heaters located in close proximity to the perimeter of the exposed transparent sheet material without burning or scorching. The structure of the blank employed not only prevents burning and/ or scorching by the heater but also serves to hold the transparent sheet material in position within the blank while the sealing is effected.
Further details, advantages and objects of the invention will be apparent from the following specification and appended drawings wherein:
FIGURE 1 is a plan view of a reinforcing blank suitably cut out to form a window opening,
FIGURE 2 is a perspective disassembled view of the transparent container and reinforcing blank,
FIGURE 3 is a plan view of the bottom of the package partially completed with the blank folded upon itself with the transparent container shown in phantom outline,
FIGURE 4 is a plan view of the bottom of the completed package with the transparent container shown in phantom outline,
FIGURE 5 is a perspective view of the completed package with the transparent container shown in phantom outline, and
FIGURE 6 is a sectional view of the completed package taken along line 66 of FIGURE 5 With the transparent container shown in phantom outline.
Referring to FIGURE 1, the reinforcing or supporting blank A is made of flexible material, such as paperboard. The blank is divided by score lines 10, 11 and perforation lines 12-15 into hingedly connected panels, tabs and lips including bottom panel 20, top panels 21, lips 22, 23, tabs 24, 25 and sealing panel 26. The blank A is cut out to provide a window 16 whose perimeter comprises the edges of top panels 21, lips 22, 23, and tabs 24, 25. The blank is preferably provided with a suitable heat-scalable adhesive film on its surface in the mottled areas indicated in FIGURE 1.
FIGURE 2 shows both the reinforcing blank and the transparent container prior to assembling. The transparent container B contains a stack 43 of cheese, sliced meat and the like. The container may be made of suitable fiexible transparent heat-scalable materials, such as cellophane having a heat-scalable coating, polyethylene film, rubber hydrochloride film and the like. The container B may be made for example of a sheet of transparent material of suitable dimensions which is enfolded or Wrapped about the stack and the extending marginal portions 40, 41 and 42 are then heat sealed by the application of suitable heat and pressure to provide a hermetically sealed transparent container. The container may be suitably evacuated before being hermetically sealed or the air in the container may be displaced by an inert gas, such as nitrogen or carbon dioxide before being sealed.
The transparent container B is dropped into contact with the reinforcing blank A so that the stack 43 passes through the window opening and extends therethrough. The contours and dimensions of the window are such as to snugly receive and fit the base of the stack portion 43. As the stack passes through the window opening 16, tabs 24 and 25 are bent downwardly about perforation lines 14, 15 to lie in contact with the sides of the stack portion. Next the sealing panel 26 is folded inwardly about its edge defined :by score line 11 and perforation line 13 to lie superposed on marginal portion 41 of the transparent container as shown in FIGURE 3. The bottom panel 20 is infolded about score line 10 and perforation line 12 to lie superposed on sealing panel 26 as shown in FIGURE 4.
The lips 22, 23 and tabs 24, 25 make possible the required degree of sealing. As is readily apparent from FIGURE 5 the lips and tabs extend at a substantial angle to the plane of the reinforcing blank and at some point are in contact with the side of the stack of the enclosed product. The tabs 24, 25 are forced out of the plane of the blank when the stack is inserted. Not only the insertion of the stack but also the inward folding of the panels adjacent the lips 22, 23, namely 20 and 26, forces the lips to assume a position which is at a substantial angle to the plane of the blank. The lips 22, 23 tend to follow the folding of the adjacent panels to a certain degree since the lips are relatively small in comparison to the panels to which they are connected. The upstanding lips and tabs act as shields protecting the transparent sheet material from the heat of the heater or sealing bars. During the sealing step, the inner edges of the heating bars coincide with the lines connecting the lips and flaps to the respective adjacent flaps.
After the completion of the folding steps, heat and pressure are applied to the bottom of the package in the areas denoted by 30, 31 and 32 as adhesive bearing. Simultaneously heat and pressure are also applied to the upper surfaces of the package in the areas denoted as adhesive hearing. The application of heat and pressure not only seals the overlying surfaces of the reinforcing blank together, but also seals the blank and transparent container together in the adhesive bearing areas. Thus bottom panel 20 becomes sealed to sealing panel 26 while the marginal portions of top panels 21 extending beyond the transparent container are sealed to bottom panel 20 as shown in FIGURE 5.
The degree of heat employed to activate the adhesive on'the blank is greater than the amount that would be necessary to activate the adhesive if it were immediately adjacentthe heating elements. Random heat losses due to the increased distance between the heating surface and the adhesive whichis to be activated plus the fact that the heating is through a layer of paperboard requires either a longer dwell time for the heating elements in contact with the blank or else the use of a higher temperature. Since the higher degree of heat required would scorch or burn the transparent sheet material if nothing were interposed between the sheet material and the heating elements, some protection such as the upstanding lips 22, 23 and tabs 24, 25 is essential. The lips and tabs serve not only to protect the container material but also to maintain the shape of the stack. Lips 22, 23 prevent the bottom edge of the stack from overlapping the outer confines of the folded reinforcing blank thus protecting the thin container material from ripping, etc.
FIGURE 6 shows in cross-section the structure of the completed package. The marginal portions 40, 41 and 42 of container B are interposed between and sealed to the marginal portions of top panels 21, bottom panel 20 and sealing panel 26 of the reinforcing blank. The lips 22, 23 define the edge of the stacked product in the transparent container. The folding in of the sealing panel 26 first, gives an uninterrupted printing surface on the lastly adhered bottom panel 28. If desired, sealing panel 26 could be made of the same dimensions as bottom panel 20 to impart increased rigidity to the finished package.
The package according to the present invention can be made of a minimum amount of materials for efiectively and economically packaging many commodities,
such as comestibles as well as nonedible articles which it may be desired to display in package form. It is to be understood that the details of the invention as described are merely illustrative and not necessarily restrictive. The contour and dimensions of the componentsmay be greatly varied. Windows of various shapes and sizes may be provided of various designs. Such modifications and changes are intended to be included within the scope of the present invention.
A reinforced display package comprising a transparent container having a container portion and opposed extended marginal portions at two sides thereof and a reinforcing paperboard blank suitably cut to provide a window opening through which said container portion upwardly extends, top panels adjacent said opening forming the upper surface of said blank, a bottom panel hingedly connected to said top panels forming the lower surface of said blank and whose outer edges are approximately coextensive with those of the top panels, a pair of upstanding opposed lips connected to the bottom panel along the side edges thereof and connecting said top panels along opposite sides of said window opening, a pair of upstanding opposed tabs hingedly connected to said top panels along the other opposite sides of the window opening, said lips and taps being essentially in contact with the container portion extending upwardly through the window opening to protect said container from degradation by heat during the sealing of said package, said marginal portions of said container being disposed between and adhered to the top and bottom panels of said reinforcing blank.
References Cited in the file of this patent UNITED STATES PATENTS