GB1559472A

GB1559472A - Containers

Info

Publication number: GB1559472A
Application number: GB2803675A
Authority: GB
Original assignee: Paget R A
Current assignee: Paget R A
Priority date: 1976-10-04
Filing date: 1976-10-04
Publication date: 1980-01-16

Description

(54) IMPROVEMENTS IN OR RELATING TO CONTAINERS (71) I, RAYMOND ARTHUR PAGET, a British subject of 21 Gordon Avenue, St. Margarets, Twickenham, Middlesex, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement :- This invention relates to containers and, more particularly, to a container in the form of a bag or envelope.

According to the present invention there is provided a container in the form of a bag or envelope comprising :- two panels of heat sealable material heat sealed together along adjacent side edges to form opposite side seams and define an opening, an area of pressure sensitive adhesive on a surface of one of the panels opposite a surface of the other of the panels and adjacent said opening, and a releasable cover strip of heat sealable material covering said adhesive area, said cover strip extending into the side seams and being weakened adjacent said side seams, so that on severing portions of said cover strip from adjacent portions thereof in said side seams and peeling said portions from the adhesive on the said one of the panels, the opening is closed by pressing the other of said panels into contact with the adhesive.

The invention will now be described, by way of example only with reference to the drawings which accompanied the provisional specification in which :- Figures I to 6 show in cross section six stages respectively of a method of manufacturing a container according to the present invention, Figures 7 to 12 show in plan view the six stages of Figures I to 6 respectively, Figure 13 is a perspective view of an empty unused container manufactured according to the method shown in Figures I to 12, Figure 14 is a perspective view of the container shown in Figure 13 but filled with papers and showing a protective strip being removed, and Figure 15 is a perspective view of the container shown in Figures 13 and 14 but sealed in a closed condition.

Referring now to the drawings, a container I is made from a preprinted web 2 (Figs. I and 7) of high or low density thermoplastics material such as polyethylene, polypropylene or polyvinyl chloride. The web is folded longitudinally so that one longitudinal edge registers with the other longitudinal edge (Figs. 2 and 8) thereby forming two layers 3 and 4. As shown in Fig. 3, the free edge of the upper layer 3 is folded back upon itself to expose a margin 5 of the lower layer 4 (Figs. 3 and 9).

A strip of pressure sensitive adhesive 6 then is applied to the margin 5 (Figs. 4 and 10) and the adhesive is subsequently covered by a cover strip web 7 of thermoplastics material having a release coating on the surface thereof nearest the adhesive (Figs.

5 and 11). The folded portion of the upper layer 3 then is folded back onto the cover strip web 7 (Figs. 6 and 12) and the layers 3 and 4 are welded together by means of a pair of spaced parallel hot wires extending transversely of the longitudinal axis of the web 2 as shown diagrammatically in chaindotted lines in Fig. 12. In each operation, the wires melt the plastics material of the web 2 thereby cutting through the material. and simultaneously welding the layers 3 and 4 together to form the container I having side seams 8 and 9 and a bottom fold 10. The operation is repeated after the web, folded as shown in Figs. 6 and 12, has been advanced incrementally towards the hot wires. In this manner, a plurality of containers I is formed from the web 2.

It will be appreciated that the width of each container I will be determined by the spacing of the hot wires and that the depth of each container will be determined by the width of the web 2.

In the example illustrated in the accompanying drawings, the web is preprinted so that when it is converted into containers I, the containers have a printed border)) of constant width (Figs. 13 to 15).

Each container) therefore has front and back panels 12 and 13 of substantially equal area (Fig. 13), side seams 8 and 9 and a bottom fold 10. On the inside surface of the panel 13 is a band 6'of adhesive extending in a margin 5'of the container, the margin extending at the top of the container parallel to the bottom fold 10. There is a cover strip 7'having a release coating which is pressed onto the adhesive band 6'with the release coating in contact with the adhesive.

Each container I has a printed border ! 1 on each of the panels 12 and 13, the border being of constant width.

When a container) has been filled, the cover strip 7'is peeled off (Fig. 14) and the front and back panels 12 and 13 are squeezed together in the margin 5'and sealed due to the adhesive band 6'.

The cover strip 7'since it is made of thermoplastics maferial, will be sealed in the side seams 8 and 9 of the container 1 and it may be difficult to remove the ends of the strip to peel the strip off the adhesive band 6'. To reduce the possibility of this occurring, the cover strip web 7 is provided with groups of parallel lines of weakening extending transversely of the longitudinal axis of the cover strip web the groups being spaced a distance corresponding to the width of the containers 1.

In this manner, if movement of the cover strip web 7 is phased with movement of the web 2 the groups of parallel lines of weakening will coincide with the seams 8 and 9 of the containers 1. When a cover strip 7'then is to be removed from a container, the main portion of the cover strip 7'can be broken away from the portions welded in the seams 8 and 9.

The cover strip web 7 is drawn from a reel located above the web 2 and pressed into contact with the adhesive strip 6.

Instead of first coating the web 2 with the adhesive strip 6 and then applying the cover strip web 7 to the adhesive strip, the adhesive may be precoated on the cover strip web 7 and the combined strip 7 and adhesive 6 then may be applied to the web 2.

In this case, it would be necessary to provide the cover strip web 7 with a releasable protective strip to protect the adhesive 6 when the cover strip web is wound into a reel. The adhesive 6 therefore would need to have greater affinity for the cover strip web 7 than for the protective strip.

In the foregoing examples, the container is made of synthetic plastics materials which are thermoplastics. It will be appreciated, however, that a container according to the invention may be made of other material, such as paper, which is coated with thermoplastics material, at least on the surfaces of the front and back panels facing one another, so that the panels can be heat sealed together to form side seams of the container.

Claims

WHAT I CLAIM IS :- 1. A container in the form of a bag or envelope comprising :- two panels of heat sealable material heat sealed together along adjacent side edges to form opposite side seams and define an opening, an area of pressure sensitive adhesive on a surface of one of the panels opposite a surface of the other of the panels and adjacent said opening, and a releasable cover strip of heat sealable material covering said adhesive area, said cover strip extending into the side seams and being weakened adjacent said side seams, so that on severing portions of said cover strip from adjacent portions thereof in said side seams and peeling said portions from the adhesive on the said one of the panels, the opening is closed by pressing the other of said panels into contact with the adhesive.
2. A container as claimed in Claim I wherein the adhesive is pre-coated on the cover strip and the cover strip is applied by the said adhesive to the surface of the said one of the panels prior to formation of said side seams.
3. A container as claimed in Claim I or Claim 2 wherein the panels are of paper coated with thermoplastics material.
4. A container in the form of a bag or envelope substantially as hereinbefore described and as illustrated in the drawings which accompanied the provisional specification.