US3381884A - Packages - Google Patents

Description

y 7, 1968 M. J. HERRITTY 3,381,884

PACKAGES Filed April 14, 1966 3/4 FIG. I x

M/CHAEJL JI'HEEE/TTY INVENTOR BY 92m wi TTO/ENEY United States Patent C) 3,331,884 PACKAGES Michael John Herritty, Haywards Heath, near Lindfield, England, assignor t Monsanto Chemicals Limited, London, England, a British company Filed Apr. 14, 1966, Ser. No. 542,556 Claims priority, application Great Britain, June 16, 1965, 25,421/65 2 Claims. (Cl. 229-51) ABSTRACT OF THE DISCLOSURE A package having a closure of sheet thermoplastic which is folded back on itself to form a line of weakness for easy opening.

This invention relates to packages, and in particular to a new kind of package that can be readily opened when required.

Thermoplastic sheets, especially biaxially orientated resin sheets, are becoming increasingly used in such applications as packaging, where their properties have facilitated the introduction of mass production techniques. Packages made from thermoplastic sheets are in many cases strong, light and durable; however, in some instances their strength can be a disadvantage, since it makes the package difficult to open. A novel type of package which can readily be opened when required has now been developed.

It is a principal object of the present invention to provide a package which can be readily opened.

It is another object of the present invention to provide a package made using thermoplastic sheet which can be readily opened.

It is a further object of the present invention to provide method and means to carry out the above objects.

This invention will in part be obvious and will in part appear hereinafter.

The invention comprises a package having a closure made from a sheet of thermoplastic material of which a portion is folded back upon itself twice so as to form a lap defining a line of weakness along which the sheet can be torn so as to open the package when required.

FIG. I is a sectional side View of a tray covered by sheet material having a folded overlap.

FIG. II is a top plan view of the tray shown in FIG. I.

FIG. III illustrates a package completely enclosed with sheet material having a folded overlap.

FIG. IV illustrates the use of the present invention in a sachet.

Referring to the drawings and more particularly to FIGS. I and II, a package which comprises a tray 1, which may be a vacuum formed from a plastic such as polystyrene, having heat-sealed to it a transparent lid 2 comprising a sheet material such as biaxially orientated polystyrene, folded in two places 4 and 5 to form a lap 3. The lap is held down at its ends 6 and 7 by the seal in such a manner that a finger can easily be inserted under it near the middle so as to tear the lid away from the tray.

The invention has been specifically illustrated With reference to a tray container having a sealed-on lid, but many other types of package can be provided with a closure in accordance with the invention. Two further examples are shown in FIGS. III and IV. FIG. III shows in perspective a film-wrapped container such as is used for biscuits, etc., which is provided with a lap on all four sides, while FIG. IV shows a sachet of the type which is often used to contain shampoo, having a lap across one corner. The above description and particularly the draw- "ice ings are set forth for the purpose of illustration only and not for the purpose of limitation.

Moreover, the invention has been described with reference to a package, which can be empty or already filled with the substance to be packed, but the invention also includes a part or component (of a package) comprising a sheet of thermoplastic material of which a portion is folded back upon itself twice so as to form a lap. Thus for example the lap might be part of a lid which is sealed to a container after the latter has been filled.

Preferably the thermoplastic sheet from which the closure is made is a synthetic resin sheet, particularly a transparent sheet of biaxially orientated resin. Other suitable resins are polyolefins such as polyethylene, or polypropylene; styrene copolymers, for instance styreneacrylonitrile copolymers; polyacrylates, polymethacrylates, polycarbonates; polyvinyl chloride; and polyethylene terephthalate. Thermoplastic cellulose derivatives such as for example cellulose acetate or cellulose triacetate can be employed if desired.

The thermoplastic sheet is normally relatively thin, for instance having a thickness of between 0.0002 and 0.010 inch, particularly between 0.0005 inch and 0.004 inch. A sheet of thickness 0.001 is often convenient to use.

The folded lap in the closure can be produced by any suitable means. For instance, blanks can be cut and then folded separately, or the lap can be produced mechanically in a roll of the material using web fed equipment either by intermittent folding and creasing across the web, or by continuous folding and creasing by passing through rollers.

Where the closure is sealed to another part of the container the seal can be effected in a variety of ways, for instance by heat-sealing, impulse-sealing or ultrasonic sealing; or by the use of a solvent or an adhesive. Particularly suitable methods are those described in British patent specifications Nos. 922,388, 14,577/62 and 18,560/ 63. A counter-part of the latter British patent specification was filed in the United States Patent Ofiice on Apr. 20, 1964, and was given Ser. No. 361,262.

The present invention serves to extend the use of thermoplastic sheets to many packaging applications where strength and easy opening of the package are important.

It is obvious that many variations may be made in the products and processes set forth above without departing from the scope of this invention.

What is claimed is:

1. A package comprising a container and a closure for the container made from a sheet of thermoplastic material of which a portion is folded back on itself twice to form a lap, said lap being sealed at its edges to the container so that a finger may be inserted under the lap to initially tear the closure away from the container along the sealed edges of the closure, the surfaces of the folds of the lap within the sealed edges being substantially free of attachment to each other, said lap within its sealed edges extending substantially in the plane of the remainder of the sheet material.

2. A package according to claim 1 in which the thermoplastic material is a transparent sheet of biaxially oriented polystyrene.

References Cited UNITED STATES PATENTS 3,166,234 1/1965 Amberg 22 9-S1 JOSEPH R. LECLAIR, Primary Examiner.

R. PESHOCK, Assistant Examiner.

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