US 2997224 A
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Description (OCR text may contain errors)
A g- 1961 F. B. STANNARD 2,997,224
PACKAGING CONTAINER Filed Nov. 5, 1958 FOPPA'S 7' B- STANNAED BY a Wed A'ITORNEYJ 2,997,224 PACKAGING CONTAINER Forrest B. Stannard, N. High St., Clinton, Conn. Filed Nov. 5, 1958, Ser. No. 772,137 6 Claims. (Cl. 22953) This invention relates to packaging containers, such as preformed bags or wrappings formed about the articles to be packaged.
The principal object of the invention is to provide a bag or wrapper construction which possesses controlled breathing properties. More specifically, within the broad objective, is the provision of a construction which will permit eflicient sterilization of the contents of the bag or wrapper after the bag or wrapper has been sealed, and which will maintain the contents of the package in a sterile condition.
A further object is to provide a construction and method which is adaptable to a wide variety of packaging forms and procedures and which is also adaptable to the use of a substantial range of wrapping materials including polyethylene film and similar plastic films.
Another object is to provide a construction and method which permits economical manufacture, and utilization of conventional machinery for forming, filling and closing the package, or otherwise accomplishing the enclosure of the article in the protective covering.
Other and further objects will be made apparent in the disclosure of the accompanying drawing and in the following specification and claims.
Many articles or materials which it is desirable or necessary to package and sell in a sterilized condition deteriorate under heat sterilization and many wrapping or packaging materials also deteriorate or are destroyed when subjected to sterilizing temperatures. The existence of either one of these conditions precludes heat sterilization of the contents after the package is sealed, and the pre-sterilization of an article or material prior to its enclosure in a wrapper or bag requires that the container filling, closing and sealing or wrapping and sealing operations be carried out under sterile conditions, usually a diflicult and costly procedure, if the sterility of the article or material is to be preserved.
Gaseous sterilization, while meeting many objections of heat sterilization still has required that the sterilizing gas be introduced into the package before sealing since conventional wrapping materials are either impervious to the sterilizing gases, or equally pervious to contaminating air and other vapors.
By the construction of the invention these limitations tates Patent on the sterilization of the contents of a sealed package by the gaseous method are overcome.
Broadly the invention provides the wall of the bag, wrapper or other container with a portion which is pervious to the passage of sterilizing gases but prevents the entrance of germs.
In the accompanying drawing:
FIG. 1 is a fragmentary plan view of a web of material, embodying the invention and from which bags, wrappers or other forms of packaging enclosures may be formed;
FIG. 2 is a generally perspective view of a bag embodying the invention;
FIG. 3 is a sectional View substantially on line 3-3 of FIG. 2; and
FIG. 4 is a diagrammatic view illustrating one manner of employing the construction of FIG. 1 to form, fill and seal a bag as a continuous operation.
Referring to FIG. 1 a web, or sheet, of polyethylene, or other moisture, gas and germ impervious material is indicated at 10. A relatively narrow portion of the sheet or web 10 is provided with an overall coating of heat and 2,997,224 Patented Aug. 22, 1961 pressure sensitive adhesive material as indicated at 11. Within the area 11 the web is provided with a plurality of openings as indicated at 12. These openings may take various shapes and forms but for reasons hereinafter made apparent they are spaced longitudinally of the web. Also, as later pointed out, the openings 12 may be varied in size and shape depending on the nature of the material or articles to be packaged.
A web or strip 13 of gas permeable paper is superposed on the web or sheet 10 to overlie the adhesive area 11. The web 13 is of a width to at least cover the openings 12 and is preferably at least substantially coextensive transversely with the area 11. Web 13 extends the full length of web or sheet 10. When sterilization of the contents of the container is desired the web 13 will take the form of a germproo-f paper.
Germproof paper is a dense paper, characterized by its ability to permit the passage of gases while excluding the passage of germs. Germproof papers are commercially available, examples being Stock #3930-CK manufactured by Clairmont Paper Company and Grade #1627 made by Merrimack Paper Company.
Alternatively strip 13 may take the form of a gas permeable paper which has been treated with a suitable germicide.
The strip 13 is heat sealed, or otherwise permanently secured to the web or sheet 10 along relatively narrow lines 14, transversely outwardly of the openings 12, the portion of strip 13 intermediate the lines of seal 14 being left freely separable from the underlying perforated portion of the web 10.
The assembly described is economically made in web form as a continuous operation. The web 10 is continuously advanced past means which applies the band of adhesive 11, past means for punching the openings 12, or otherwise renders the portion of the area 11 inwardly of its edge portions permeable to gases, and past means which position the web 13 over the area 11 and past means which heat seals or otherwise permanently secures web 13 to web 10 along the lines 14. The composite web, generally indicated at 15, may then be wound into rolls or cut into sheets depending on the packaging procedure in which it is to be used.
One form of container is shown at 16 in FIGS. 2 and 3. In the formation and use of the container 16 the composite web 15 is run through conventional folding means, not shown, to form a flat tube having, if desired, inwardly extending side gussets 17, the edges of the web 10 being overlapped and permanently sealed together at .18 to form the tube, as generally indicated at 19. The opposing walls 20 and 21 of the tube, including the gusset portions 17 may then be sealed or otherwise secured to each other along a spaced transverse zone 22 and the tube cut at one side of zone 22, as indicated at 23, FIG. 2, to provide an open ended bag, which, when filled, may be closed at its open end by a transverse seal line 24.
The overall coating of the area 11 with the adhesive permits the sealing of the paper strip 13 to the underlying portion of web 10 simultaneously with the sealing of the opposing plastic surfaces and by the same instrumentalities, while the spacing of the openings longitudinally of the strips permits location of the seal to assure continuity of the sealed surfaces while keeping the transverse width of the line of seal to a minimum.
Alternatively the composite web 15 may be cut into sheets and fed to conventional bag forming machines which form square-bottom or other types of bags. Similarly the web may be fed to various types of wrapping machines which cut sheets from the web, or receive precut sheets, and fold them around articles and seal the overlapping edges and folds to provide a sealed wrapped lap-sealed around a hollow mandrel 25 below the end of which the so-formed tube is transversely sealed by a vertically reciprocating clamping means 26. Material or articles are introduced through the hollow mandrel and enclosure thereof completed by the succeeding transverse sealing operation, the packaging being completed by severing the tube along a line as 27 centrally of the seal at 26. This packaging procedure is exemplified in the disclosure of United States Patent No. 1,986,422.
The package formed by any of the above, or other, procedures is characterized by a capacity for breathing, and for gaseous sterilization of its contents after the package has been formed, if sterilization is desired. The sterilizing gas can enter the package through the germproof paper strip 13 and openings 12 to effect sterilization of package contents and excess pressure, if any, built up in the package is later equalized by escape of excess gases by the same route. The sheet being impervious to liquids and gases as Well as germs or other microorganisms, protects the contents from subsequent contamination, while germs and other contaminating microorganisms are barred from entrance through openings 12 by the germpro'of strip 13.
The invention thus makes possible the sterlization of articles after packaging in containers formed mainly of transparent plastic sheeting or films (such as polyethylene) which are impervious to gases and which are incapable of withstanding sterilizing dry heat or autoclaving without damage. The invention provides in general a package which has the capacity to breathe and makes possible the economical sterile marketing of many articles desirably sold in transparent containers, such as cotton balls, minor bandage items and the like, which because of the cost of sterile packaging procedures have heretofore been frequently sterilized, if at all, only prior to packaging.
While the invention has a special utility in extending the use of polyethylene film to sterile packaging it will be understood that its advantages are not limited to that material, but extends to coated papers, foils and other materials which are impervious to moisture and gases and which for various reasons may be found preferable for packaging specific articles or materials desirably sterilized after packaging.
While as shown the gas-permeability is imparted to the area 11 of the otherwise gas impermeable sheet 10 by apertures involving the removing of material it will be understood that if found desirable such permeability may be imparted by piercing or cutting which does not remove material, or by other treatment which renders the area 11 sufliciently permeable to gases for breathing or sterilizing purposes.
What is claimed is:
1. A sheet construction for forming package wrappings and containers which comprises a length of sheet material substantially impervious to gases and moisture and having an area of restricted width, extending from one edge to the opposite edge thereof, provided with an overall coating of heat and pressure sensitive adhesive, said area of the sheet being provided with a plurality of spaced openings, and a strip of flexible sheet material, having a limited capacity to transmit gases and moisture and at least coextensive with said area, heat sealed along its side edge portions to the side edge portions only of said area, whereby packages and containers formed therefrom are provided a limited capacity for breathing.
2. A sheet construction as in claim 1, said length of sheet material being polyethylene film.
3. A sheet construction as in claim 1, said strip of sheet material being germproof.
4. A sheet construction as in claim 3, said length of sheet material being polyethylene film.
5. A sheet construction for forming package wrappings and containers which comprises a length of sheet material substantially impervious to gases and moisture except along an area of restricted width extending from one edge to the opposite edge thereof, said area being provided with an overall coating of heat and pressure sensitive adhesive, and a strip of sheet material, having a limited capacity to transmit gases and moisture and at least coextensive with said area, heat sealed along its side edge portions to the side edge portions only .of said area, whereby packages and containers formed therefrom are provided with a limited capacity for breathing.
6. A container comprising a flat tube formed of sheet material substantially impervious to gas and moisture except along an area of restricted Width extending from one end of the tube to the other, said area being provided with an overall coating of heat and pressure sensitive adhesive, and a strip of sheet material, having a limited capacity to transmit gases and moisture and at least coextensive with said area sealed thereto along its side edge portions, the opposing walls of the tube including said strip being transversely heat sealed together along one end, whereby the container is provided a limited capacity for breathing.
References Cited in the file of this patent UNITED STATES PATENTS 2,386,157 Barthen Oct. 2, 1945 2,634,856 Perkins Apr. 14, 1953 2,647,334 Wilsher et a] Aug. 4, 1953 2,664,358 Eichler Dec. 23, 1953