GB2144714A

GB2144714A - Heat coding plastics packaging material

Info

Publication number: GB2144714A
Application number: GB08317931A
Authority: GB
Inventors: William Peter Birkinhead; John Clark; James Chamley
Original assignee: WRAPID MACHINERY Ltd
Current assignee: WRAPID MACHINERY Ltd
Priority date: 1983-07-01
Filing date: 1983-07-01
Publication date: 1985-03-13
Also published as: GB8317931D0

Abstract

A plastics packaging material is provided, e.g. cast or orientated polypropylene, which can be printed with a heated code printer operating at 130 DEG C without being melted by the printer. Material to be sent by mail is collated and surrounded with the plastics packaging material which is then heat sealed to form an envelope (10). The envelope is printed with a code (20, 22) by means of a heated code printer and may thus be sorted in automatic sorting machines. <IMAGE>

Description

SPECIFICATION Packaging material The invention relates to packaging material, e.g.

envelopes, and in particular, but not exclusively, to envelopes used for sending advertising material, periodicals and general mailing material through the post.

Many companies, for example direct mailing companies, send advertisments, catalogues and the like to their potential customers through the post. In the past this was a time consuming operation because conventional paper envelopes were used and considerable time was required to fill and seal each envelope. The operation was even more time consuming if several different items were to be put in each envelope.

The problem was partially overcome by the introduction of polythene envelopes. Machines became available which took in polythene film, collated the necesary items to be sent, enclosed the items in the polythene film and then heat sealed the polythene at its edges. This considerably cut down the time required to fill and seal each envelope. However, polythene envelopes have a major disadvantage, namely that they cannot be used with automatic post sorting machines. Automatic sorting machines operate by reading a code which is applied to the exterior of the envelope in a series of blue dots. The dots are applied to the envelope with heat and the heat is such that when applied to polythene, the polythene melts.It has been found that such melted envelopes jam the equipment, and polythene envelopes thus require slower, manual sorting which ultimately increased the cost of postal services while at the same time slowing the services down.

It is an object of the invention to provide an envelope for postal services which has the advantages of being easily made, filled and sealed, as with a polythene envelope, but which in addition is capable of being used with automatic post sorting machines.

Accordingly, the invention provides a plastics packaging material capable of being printed with a heated code printer without being melted by the printer.

Preferably the melting point of the plastics packaging material is greater than 130 degrees Centrigrade and is preferably in the range 160-180 degrees Centigrade.

The plastics packaging material may be in the form of an envelope.

We have surprisingly found that polypropylene does not exhibit the same melting problems as polythene when used with a heated code printer, and so that plastics packaging material may be of polypropylene. Polypropylene has the additional advantage that it is less dense than polythene, and so more enclosures can be sent for the same postage as compared with polythene packaging material.

The polypropylene may be orientated polypropylene or cast polypropylene.

Material to be sent may be collated and sur rounded with the plastics which is subsequently sealed to form an envelope around the material.

The envelope may be at least partially printed e.g.

so as to alter the transparency and/or the slip characteristics of the envelope. For example, the envelope may be printed to be matt and/or white.

A transparent window may be left on a face of the envelope such that a name and address printed on the material to be sent is visible through the window.

The invention includes a method of sorting post age material comprising the steps of surrounding the material with plastics packaging material as described above, forming the plastics into an envelope around the material to be sent, and applying a code to the exterior of the plastics envelope by means of a heated code printer so that the envelope may be automatically sorted.

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 an envelope according to the invention.

Two sheets of transparent orientated polypropy lene are fed into a conventional wrapping machine.

The wrapping machine collates advertising material to be distributed and sandwiches the material to be sent in each package inbetween the two sheets of polypropylene. The two sheets of polypropylene are formed into an envelope 10 around the material by heated elements which form heat seals 12 around the edges of the polypropylene and simultaneously cut off excess polypropylene around the edges of the envelope. The machinery used is conventional and is not described in detail.

At this stage the advertising material is sealed in a transparent polypropylene envelope. The polypropylene envelope is also printed. One face of the envelope is printed white, as indicated by reference numeral 14 in the Figure. However, a transparent window 16 is left in the face to allow a name and address 18, which has been printed on the top piece of advertising material, to be easily read. Blue code dots 20, 22 are applied to the printed face of the envelope by means of a heated printer (not shown).

The blue code dots 20, 22 are those printed on an envelope by the post office to allow the letter to be sorted by automatic sorting machines. The is possible with polypropylene envelopes because the heat used to apply the blue code dots 20, 22 is not sufficient to melt the polypropylene, unlike polythene envelopes, since the heated printer is at a temperature of about 130 degrees Centrigrade and the melting point of polypropylene is between 160 and 180 degrees Centigrade. The amount of postage paid is also printed on the envelope using a franking machine.

The back face of the envelope is left transparent so that advertisements within the envelope can be seen before the envelope is opened.

The invention is not restricted to the details of the foregoing embodiment.

For example, the back face of the envelope may be printed in addition to the front face. Alternatively, both faces of the envelope may be unprinted, thus leaving a transparent envelope. Either or both of the faces of the envelope may be printed with the supplier's name or may be used to display the supplier's name, additional advertising or any other printed matter. The orientated polypropylene may be replaced with cast polypropylene or any plastics which allows blue code dots to be applied without adversely affecting the plastics.

The polypropylene envelope may be printed before the advertising material is sealed in an envelope. The white printed area may be pre-printed with a pre-paid postage or a permit number.

Preferably the envelopes are rectangular and have a minimum size of 90mm by 140mm and a maximum size of 1 20mm by 235mm. The longer side is preferably at least 1.414 times the shorter side.

Claims

1. A plastics packaging material capable of being printed with a heated code printer without being melted by the printer.

2. A plastics packaging material as claimed in claim 1, in which the melting point of the plastics packaging material is greater than 130 degrees Centigrade.

3. A plastics packaging material as claimed in claim 2, in which the melting point of the plastic packaging material is in the range 160 - 180 degrees Centigrade.

4. A plastics packaging material as claimed in any one of the preceding claims, in which the plastics packaging material is in the form of an envelope.

5. A plastics packaging material as claimed in any one of the preceding claims, in which the plastics packaging material is of polypropylene.

6. A plastic packaging material as claimed in claim 5, in which the polypropylene is orientated polypropylene.

7. A plastic packaging material as claimed in claim 5, in which the polypropylene is cast polypropylene.

8. A plastics packaging material as claimed in any one of the preceding claims, in which material to be sent is collated and surrounded with the plastics which is subsequently sealed to form an envelope around the material.

9. A plastics packaging material as claimed in claim 4, or in any one of claims 5 to 8 when dependent directly or indirectly on claim 4, in which the envelope is at least partially printed.

10. A plastics packaging material as claimed in claim 9, in which the envelope is at least partially printed so as to alter the transparency and/or the slip characteristics of the envelope.

11. A plastics packaging material as claimed in claim 9 or claim 10, in which the envelope is printed to be mattand/orwhite.

12. A plastics packaging material as claimed in claim 8, or in any one of claims 9 to 11 when dependent directly or indirectly on claim 8, in which a transparent window is left on a face of the envelope such that a name and address printed on the material to be sent is visible through the window.

13. A plastics packaging material constructed and arranged substantially as herein described, with reference to the accompanying drawing.

14. A method of sorting postage material comprising the steps of surrounding the material with plastics packaging material as claimed in any one of the preceding claims, forming the plastics into an envelope around the material to be sent, and applying a code to the exterior of the plastics envelope by means of a heated code printer so that the envelope may be automatically sorted.

15. A method of sorting postage material substantially as herein described, with reference to the accompanying drawing.