GB2163408A

GB2163408A - Packaging material

Info

Publication number: GB2163408A
Application number: GB08421665A
Authority: GB
Inventors: William Peter Birkenhead; John Clark; James Chamley
Original assignee: WRAPID MACHINERY Ltd
Current assignee: WRAPID MACHINERY Ltd
Priority date: 1984-08-25
Filing date: 1984-08-25
Publication date: 1986-02-26
Also published as: GB2163408B; GB8421665D0

Abstract

A package comprises cast polypropylene 16 and orientated polypropylene 14 heat sealed together. The polypropylene may be in the form of sheets, peripherally heat-sealed together at 18 about a greetings card 10. <IMAGE>

Description

SPECIFICATION Packaging material The invention relates to packaging material, and in particular to polypropylene packaging material.

It is known to wrap articles, for example greeting cards, wool and other articles, in cast or orientated polypropylene and to seal the package by heat sealing along the edges of the polypropylene. Furthermore our co-pending U.K. Patent Application No.

8317931 discloses that polypropylene is suitable for use as material for an envelope which can be printed with a heated code printer without melting. In that co-pending Patent Application cast or orientated polypropylene is positioned around material to be sent and is then heat sealed.

Orientated polypropylene is particularly suitable for use where the packaged article is to be on display, for example in the case of a greetings card, since orientated polypropylene particularly clear, unlike cast polypropylene, which tends to have a slightly "milky" appearance.

Furthermore orientated polypropylene has a slightly more crisp, rigid feel to it than cast polypropylene. It therefore provides a package having a better and smarter feel to it than the slightly floppy feel which is provided by the more stretchable cast polypropylene.

Unfortunately however, when two layers of orientated polypropylene are heat sealed together, the seal is relatively weak.

We have now discovered, somewhat surprisingly, that orientated polypropylene can be very effectively heat sealed to cast polypropylene and so it is possible to provide a package which has the advantages of a package made entirely of orientated polypropylene, but also has strong and effective seals.

Accordingly, the invention provides a package comprising cast polypropylene and orientated polypropylene heat sealed together.

The invention makes it possible to provide a package which is strong, has strong seals, and which is particularly suitable for display purposes, since the relatively clear and crisp orientated polypropylene can be used in those areas where it is desired that the contents of the package be clearly visible.

The cast polypropylene can be used in those areas of the package where display is not so important.

In order to provide a package having effective strength, the cast polypropylene may be made slightly thicker than usual, with the orientated polypropylene being made slightly thinner than usual, while maintaining approximately the same weight.

Preferably the cast polypropylene comprises a sheet.

Preferably the orientated polypropylene comprises a sheet.

An article may be positioned within the package, and the article may comprise a greetings card.

The package may be for use with a heated code printer.

The invention includes a method of packaging an article, comprising packaging the article in a package formed from cast polypropylene and orientated polypropylene heat sealed together.

The cast and orientated polypropylene may be positioned around the article and then heat sealed together to enclose the article.

Alternatively the cast polypropylene and orientated polypropylene may be heat sealed together to form an envelope or bag, the article subsequently being inserted into the bag through an open mouth of the bag. The mouth of the bag may then be subsequently closed, for example by heat sealing, adhesive, or by means of an adhesive label.

By way of example, a specific embodiment of the invention will now be described, with reference to the accompanying drawing, in which: Figure 1 is a plan view of one face of a greetings card inside a package according to the invention; and Figure 2 is a cross-sectional view looking in the direction of arrows ll-ll of Figure 1.

The drawing illustrates a greetings card 10 which is sealed within a polypropylene envelope 12. The envelope comprises a sheet 14 of orientated polypropylene and a sheet 16 of cast polypropylene. The two sheets are sealed together with heat seals 18 extending around the whole of the periphery of the sheets. In order to wrap the card in the polypropylene sheets, one sheet is placed on either side of the card. The sheet 14 of orientated polypropylene is positioned to lie over the face of the card which is to be displayed, since the orientated polypropylene is clearer and crisper than the cast polypropylene.

Heating elements (not shown) then form seals 18 around the edges of the polypropylene sheets and simultaneously cut off excess polypropylene around the edges of the envelope or bag 12 thus formed.

The process may be carried out on a wrapping machine, whose mode of operation is conventional.

The invention is not restricted to the details of the foregoing embodiment. For example an openmouthed bag or envelope may be formed, into which the greetings card is subsequently inserted.

The bag or envelope may be formed by sealing sheets of polypropylene together along three sides, leaving an opening on the fourth side. The fourth side may have a sealing flap. The greetings card may then be inserted into the envelope or bag and the flap can be folded over and sealed by any suitable method, for example heat sealing, adhesive, or by the attachment of an adhesive label. The fact that a particularly strong heat seal can be provided between cast polypropylene and orientated polypropylene is particularly useful when articles are to be inserted into preformed bags or envelopes since the insertion process often puts a strain on the heat seals, particularly at the edges of the mouth of the bag or envelope.

The package need not be in the form of an envelope or bag. The package may be in any form required to package the desired goods. The material to be wrapped need not be flat, but can be of any shape, and may for example comprise wool, fruit, or vegetables. The package may be used in the sending of direct mail, particularly since, as disclosed in our co-pending U.K. Patent Application No. 8317931, such a package may be printed with a heated code printer without melting.

Claims

1. A package comprising cast polypropylene and orientated polypropylene heat sealed together.

2. A package as claimed in claim 1, in which the cast polypropylene comprises a sheet.

3. A package as claimed in claim 1 or claim 2, in which the orientated polypropylene comprise a sheet.

4. A package as claimed in any one ofthe preceding claims, in which an article is positioned within the package.

5. A package as claimed in claim 4, in which the article comprises a greetings card.

6. A package as claimed in any one of the preceding claims, adapted for use with a heated code printer.

7. A method of packaging an article, comprising packaging the article in a package formed from cast polypropylene and orientated polypropylene heat sealed together.

8. A method as claimed in claim 7, in which the cast and orientated polypropylene are positioned around the article and then heat sealed together to enclose the article.

9. A method as claimed in claim 7, in which the cast and orientated polypropylene are heat sealed together to form an envelope or bag, the article subsequently being inserted into the bag through an open mouth ofthe bag.

10. A method as claimed in claim 9, in which the mouth of the bag is subsequently ciosed by heat sealing, adhesive, or by means of an adhesive label.

11. A package constructed and arranged substantially as herein described, with reference to the accompanying drawings.