GB2113611A

GB2113611A - Envelope

Info

Publication number: GB2113611A
Application number: GB08300653A
Authority: GB
Inventors: Ragnar Winberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-01-11
Filing date: 1983-01-11
Publication date: 1983-08-10
Also published as: GB2113611B; GB8300653D0; SE426045B

Abstract

The object of the present invention is to provide at low cost an envelope both with a large transparent side and which can be used in conventional envelope filling machines. This is arrived at by making the envelope of two pieces of paper of which one forms the closure flap (7) of the envelope. Both pieces of paper (1, 7) are positioned close to each other and a plastics film (9) is welded to the edge area (11) of the closure flap adjacent to the folding for line and to the paper adjacent to the side edges (3, 4) thereof. <IMAGE>

Description

SPECIFICATION Envelope The present invention relates to an envelope and to a method for the manufacture thereof.

Window envelopes have been known for a long time. In such an envelope an address on the contents is visible through the window.

This window is either made of plastics or commonly of special treated paper. The window is normally rather small and the purpose thereof is to show only the address. Traditional window envelopes are often expensive.

Within the last few years, it has been more and more common to wrap for example advertising material in plastic film which then completely encloses the content. Wrapping occurs in special machines which are very large and very expensive and, therefore, exist only in a limited number.

It has a long time been a desire with all the manufacturers having an envelope filling machine, to be able to use a cover which is cheap, makes the content clearly visible and may be used in conventional envelope filling machines without modifications thereof.

The object of the invention is to provide an envelope meeting these desires.

According to one aspect of the invention there is provided an envelope comprising at least two pieces of paper and at least one plastics film, a first said piece of paper having a straight edge substantially parallel with the lower limit of the envelope, two straight side edges substantially perpendicular to the lower limit and defining lateral limits of the envelope and an upper edge which is substantially parallel with the lower limit adjacent the side edges and which defines the upper limit of the envelope, a second said piece of paper which acts solely as a closure flap and has a straight edge spaced apart from but lying close to the upper edge of the first piece of paper parallel with the bottom edge, and a first said plastics film completely covering the area between the side edges of the envelope and a narrow strip of the second piece of paper, the first plastics film being welded to the first piece of paper in a narrow area adjacent to the side edges and being welded to the second piece of paper.

Preferably the lower edge of the first piece of paper defines the lower limit of the envelope and the first plastics film is welded to the first piece of paper in a narrow area adjacent to the lower edge thereof.

According to another aspect of the inven .ion there is provided a method of manufacturing envelopes of the first aspect, comprising the steps of providing, on each side and close to a wide intermediate web containing paper in a width substantially corresponding to that of two envelopes and running in the manufacturing direction, a respective narrower paper web which later will form the closure flaps of the envelopes, providing a web of plastics film adjacent the three webs, which overlaps the entire intermediate web and a narrow edge on each of the narrow paper webs, welding the plastics film web to the intermediate web and the narrow webs and cutting the webs to provide the separate envelopes.

Alternatively the "intermediate" web may correspond to the width of only one envelope and be provided with a narrow paper web along one edge only.

To help understanding of the invention, various embodiments thereof will now be described with reference to the accompanying drawings in which: Figure 1 illustrates an envelope according to the invention; Figure 2 illustrates the envelopes slightly opened and in section along the line A-A in Fig. 1; Figure 3 illustrates in principal a method of manufacturing the envelope of Fig. 1; Figure 4 illustrates a second envelope according to the invention Figure 5 illustrates the second envelope slightly opened and in section along the line B-B in Fig. 4; Figure 6 shows a third envelope according to the invention; and Figure 7 illustrates the third envelope slightly opened and in section along the line C-C in Fig. 6.

The envelope shown in Figs. 1 and 2 incorporates a first piece of paper 1. This piece of paper is substantially rectangular in shape. It has a straight unbroken lower edge 2 and two side unbroken edges 3 and 4 perpendicular thereto and an upper edge 5.

The upper edge 5 is parallel with the lower edge adjacent to the side edges, but has a curved intermediate portion 6.

A second piece of paper 7, forming the closure flap of the envelope, has a straight unbroken edge 8 which when the envelope is flat is positioned close to the upper edge 5 of the first piece of paper.

A transparent plastics film 9 which completely covers the area between the side edges of the first piece of paper, is welded to this piece of paper 1 in the area 10 close to the lower edge and side edges thereof. The plastics film covers a narrow area 11 on the second piece of paper 7 and is welded thereto at this area. It has been shown that a width of 2 mm for the welding seams is sufficient.

When the envelope lies with the plastics film against a planar table, the closure flap 7 is easy to fold along an imaginary folding line in the narrow area defined between the first and second pieces of paper. The folding is easily accomplished in the soft resilient plastics film and the substantially more stiff pieces of pa per provide with their edges 5 and 8 control for the folding. This is of vital importance for use of the envelope in an envelope filling machine. A closure flap of plastics film alone is not usable in such a machine, neither is an envelope made merely of plastics film.

The closure flap is conventionally provided with an adhesive stripe 1 2 activated by wetting in water. There is a printed rectangular area 1 3 on the outer side of the plastics film.

This area has postal functions. The printed area may be continuous and then extend over the entire length of the envelope.

During filling, the strain tending to cause splitting of the welding is great at the uppermost part of the side edges. Therefore, in certain cases it may be appropriate to provide the first piece of paper 1 and even the second piece of paper 7, with welded plastics layers in the areas of the folding line for the flap and along the side edges of the envelope. The plastics reinforcement may also cover the entire length of the envelope and be welded thereon in the form of a plastics strip, e.g. 10 mm wide. During manufacture, the plastics reinforcement may be incorporated before the 1st station described below in respect of Fig.

3 and even before the paper web is cut to an intermediate web 1 4 and lateral webs 1 5 and 1 6. Also the plastics film 9 itself may be reinforced just beneath the upper edge thereof, e.g. by making it thicker here.

The second envelope of Figs. 4 and 5 differs from the envelope of Figs. 1 and 2 primarily in that one side of the envelope comprises, instead of paper alone, a piece of paper 27 and a plastics film 28 welded thereon. Also, on the closure flap there is a postal print 29.

The envelope of Figs. 6 and 7 differs from the envelope of Figs. 4 and 5 primarily in that one side of the envelope comprises two pieces of paper 30 and 31 and an intermediate plastics film 32 instead of one piece of paper 27 and a plastics film 28.

A fourth embodiment of an envelope according to the invention may be realized by making a rectangular punching (e.g.

40 x 100 mm) in the first piece of paper 1.

This punching may be covered by a strip of plastics film on the inner side of the envelope, thus forming an address window. The strip may have the same length as the envelope and may be secured to the piece of paper 1 by welding along a narrow (e.g. 2 mm) area on each side of the window. The narrow areas are parallel with the bottom edge of the envelope. The plastics film strips are at their ends melted together with the plastics film 9 and the piece of paper 1 at the transverse welding 22, see below. The closing flap of this envelope may be provided with a postal print 29 as in Fig. 4. The postal print and the address are thus, when the envelope is closed, found on the same side, whilst the opposite side of the envelope may be transparent across its entire surface.

Envelopes according to Figs. 1 and 2 may be manufactured from a roll of paper the width of which is similar to that of two envelopes and two closing flaps. The paper may be fed during e.g. 0,5s, whereby as much paper is fed as corresponds with two envelope lengths. Thereafter, treatment occurs at a number of stations Si S,...S, during 0,5s, whereafter new feeding is carried out.

In Fig. 3, the paper web is cut longitudinally before the 1 st station S, such that a wide intermediate web 14 is provided, with on each side thereof, close thereto, a narrow lateral web 15 and 16.

In the 1st station S" a punching 17 is made in the intermediate web for each envelope. This punching has for its object, as in most other envelopes, to somewhat facilitate handling of the contents of the said envelope.

This punching is not necessary however, and may be excluded.

In the 2nd station 82, the plastics film 1 8 from a roll is placed on the three paper webs in such a manner that it completely covers the wide intermediate web 14 and narrow edge areas 19, 20 on the lateral webs 15, 16.

In the 3rd station S3, welding of the plastics film with the intermediate web and both the lateral webs occurs. Welding is carried out by pressing a heated welding jaw against the material webs. The engaging surface of the welding jaw is in Fig. 3 indicated with oblique lines and designated 21. The finished surfaces are designated with 22 and are of exaggerated width in Fig. 3.

In the 4th station S4, a punching 23 is carried out to give the closing flaps 24 a tapered shape at their side edges. In this station, it is arranged that the material web is cut lengthwise in the middle during feeding.

The cut is designated 25.

In the 5th station S,, the material is fed; here two lengths of an envelope at the time.

In the 6th and last station S6, cutting 26 occurs perpendicular to the manufacturing direction, whereby finished envelopes are separated. Here, the closure flap is openly protruding outwards. Of course, the envelopes may also be delivered with the closure flap folded over. This folding over may occur at the 5th station S5 when the material is fed.

Instead of making two envelopes in width, as in Fig. 3, the manufacture may of course be arranged such that only one line of envelopes is produced. Then, two paper webs and a plastics film web are required. Hereby, the longitudinal cut is deleted but otherwise, the manufacture is similar to that of two envelopes in width.

The shape of the envelopes may of course vary such that e.g. the sides are made longer than the lower edge of the envelopes. The postal print may be deleted or provided in another position. The plastics film may be made of a thermoplastic, e.g. ethylene or propylene, but may also comprise a laminate of plastics films of which the innermost is a thermoplastic film. The paper may be untreated or treated with plastics. The method of manufacture may also be based upon the principal of rotation. The envelope and method described above are only examples within the scope of the present invention as defined in the following claims.

Claims

1. An envelope comprising at least two pieces of paper and at least one plastics film, a first said piece of paper having a straight edge substantially parallel with the lower limit of the envelope, two straight side edges substantially perpendicular to the lower limit and defining lateral limits of the envelope and an upper edge which is substantially parallel with the lower limit adjacent the side edges and which defines the upper limit of the envelope, a second said piece of paper which acts solely as a closure flap and has a straight edge spaced apart from but lying close to the upper edge of the first piece of paper parallel with the bottom edge, and a first said plastics film completely covering the area between the side edges of the envelope and a narrow strip of the second piece of paper, the first plastics film being welded to the first piece of paper in a narrow area adjacent to the side edges and being welded to the second piece of paper.

2. An envelope as claimed in claim 2, wherein the lower edge of the first piece of paper defines the lower limit of the envelope and the first plastics film is welded to the first piece of paper in a narrow area adjacent to the lower edge thereof.

3. An envelope as claimed in claim 2, wherein the first piece of paper is provided with a window.

4. An envelope as claimed in claim 1, wherein the side of the envelope including the first piece of paper has the area between the lower edge of this piece of paper and the lower edge of the envelope completely or partially covered by plastics film.

5. An envelope as claimed in any preceding claim, wherein the first plastics film has a postal print.

6. An envelope as claimed in any one of claims 1 to 4, wherein the closure flap is provided with a postal print.

7. An envelope as claimed in any preceding claim, wherein the first piece of paper is reinforced with plastics material in the areas at the uppermost part of the side edges.

8. A method of manufacturing envelopes as claimed in claim 1, comprising the steps of providing, on each side and close to a wide intermediate web containing paper in a width substantially corresponding to that of two envelopes and running in the manufacturing direction, a respective narrower paper web which later will form the closure flaps of the envelopes, providing a web of plastics film adjacent the three webs, which overlaps the entire intermediate web and a narrow edge on each of the narrow paper webs, welding the plastics film web to the intermediate web and the narrow webs and cutting the webs to provide the separate envelopes.

9. A method of manufacturing envelopes as claimed in claim 1, comprising the steps of providing, close to a wide web containing paper in a width corresponding to that of the envelopes and running in the manufacturing direction, a narrower paper web which later will form the closure flaps of the envelopes, providing a web of plastics film adjacent the two webs, which overlaps the entire wide web and a narrow edge on the narrow paper web, welding the plastics film web to the wide web and the narrow web and cutting the webs to provide the separate envelopes.

1 0. An envelope substantially as hereinbefore described with reference to Figs. 1 and 2 or Figs. 4 and 5 or Figs. 6 and 7 of the accompanying drawings.

11. A method of manufacturing envelopes substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.