NZ242878A - Method of filling a laminated container to eliminate bulging - Google Patents

Description

PATENTS FORM NO. 5 Fee No. 4: $260.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 242878 Dated: 22nd May 1992 CONTAINERS AND METHODS OF FILLING SAME \VE Trigon Industries Limited, a New Zealand company of 317 Sunset Road, Mairangi Bay, Auckland, New Zealand hereby declare the invention for which We pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: fc N f ' . > t s 4 This invention relates to improvements in and relating to laminated containers.

Containers formed from blanks are well known and well addressed within the prior art. Similarly, containers formed from blanks which comprise a stiff material laminated to a flexible material such as plastics film are also known (eg: US Patent Specification No. 3332599; US Patent Specification No. 4930906: New Zealand Patent Specification No. 206030; New Zealand Patent Specification No. 195457; New Zealand Patent Specification No. 242879). This kind of container has been used for the storage of solid materials and non-liquid flowable materials. We have recently experimented with the use of such containers for flowable materials.

The particular container described in our New Zealand patent specification no. 231103 has been trialled with success but it has also become apparent that a number of modifications to filling methodology and structure will be required in order to meet customers requirements.

The container described in New Zealand patent specification No. 231103 is a thin-walled container and as with any other thin-walled container when it is filled with flowable liquid material the sides tend to bulge which detracts from appearance and may cause storage and handling problems, particularly if the product is subsequently frozen.

The container described in New Zealand patent specification No. 231103 is a top filled container and is characterised by having an inwardly protruding bottom wall with a bisecting foldline and two hinged sides. The container can be self-erecting or mechanically erected. Self-erection will occur when the container is placed on a surface and filled with flowable material as the bottom wall straightens drawing the side walls into a rectilinear configuration in sympathy with the straightening of the bottom wall. Alternatively, the application of mechanical pressure to the side seams will result in a sympathetic straightening of the bottom wall. We have discovered that the mechanical characteristics of this container can he taken advantage of to solve the problem of bulging which occurs when the container is filled with a flowable material.

It is an object of the present invention to provide a method of filling a container of the type described.

Further aspects and advantages of the present invention will become apparent from the ensuing description.

According to one aspect of the present invention there is provided a method of filling a container which is characterised by a bottom wall having a bisecting fold line and side walls having fold-lines on the same plane as the fold-line of the bottom wall said method comprising the steps of: - (a) filling the container to a predetermined level, (b) partially collapsing the container so that a head space is substantially reduced or eliminated, (c) sealing the container.

According to another aspect of the present invention in the partially collapsed condition the bottom wall of the container extends upwardly in an inverted V-formation.

According to another aspect of the present invention in the partially collapsed condition opposite side walls of the container extend outwardly in a V-formation. 2 4 H 7 8 According to another aspect of the present invention the partially collapsed condition is effected by a mould having tapered inner walls.

According to another aspect of the present invention the partially collapsed condition is effected by a set of jaws which can be operated to squeeze the side walls of the container.

According to another aspect of the present invention the container is further characterised by having two opposite substantially triangular closure flaps and two opposite substantially rectangular closure flaps extending from the side walls at the open end of the container and sealing the container is preceded by the further step of folding the triangular closure flaps downwardly and folding the rectangular closure flaps downwardly to overlie at least one of the triangular closure flaps.

According to another aspect of the present invention both of the triangular closure flaps can be folded inwardly prior to overlaying the rectangular closure flaps.

According to another aspect of the present invention one of the triangular closure flaps can be folded inwardly and one outwardly with the outwardly facing closure flap being usable as a pouring spout.

As a result of this method, when the container is released and placed on a surface the weight of the product re-expands the base of the carton creating an internal vacuum which is such that sides of the carton are pulled inwards substantially eliminating bulging. \ k. fi t' A* -± V11 APR 199 Aspects of the present invention will be described by way of example only and with reference to the accompanying drawings in which: Figure 1: is a perspective view of a container in accordance with aspects of the present invention, and Figure 2 and 3: are diagrammatic long sections of the container of Figures 1, and Figure 4 and 5: show filling steps for the container of Figure 1 in accordance with aspects of the present invention, and Figure 6 and 7: are top views of possible closure configurations for the container of Figure 2.

With respect to the drawings a container in accordance with the present invention is largely as described in New Zealand patent specification No. 231103. Such containers are characterised by a bisected bottom wall 1 and two hinged side walls 2 and plain walls 2A, the basic form of construction, collapsed and erect conditions of the container being fully described by New Zealand patent specification No. 231103.

In the container illustrated an open end 3 is modified and is provided with an extended section of plastic film 4 stiffened by side flaps 5 and triangular end gussets 6. If the end gussets 6 are pushed towards each other the side flaps 5 are drawn downwards to overlie the end gussets and the extended section of plastic film 4 is also drawn together and is conveniently disposed for sealing of the open end to take place.

Figures 4 and 5 of the drawings illustrate the method of steps by which a container described can be filled with a flowable liquid material and sealed 2 4 £ 8 eliminating the side bulges discussed previously. The possible steps are to fill the container to a level "A" leaving a head space 10 (Figure 4) and to subsequently partially collapse the container manually, mechanically or with the use of a mould or other means so that the bottom wall 1 is held in an inverted V-shaped configuration and the head space 10 is substantially eliminated (see Figure 5) and then to seal the container whilst it is in the partially collapsed condition. The pre-filling step (Figure 4) may be eliminated and empty containers placed in a mould or moulds as in Figure 5 in some instances. When the container is released and placed on a surface the weight of the produce re-expands the base 1 of the carton creating an internal vacuum which pulls in the side sections substantially eliminating bulging.

The method of closure of the open end of the container illustrated by Figure 1 presents the options illustrated by Figures 6 and 7. One alternative is to fold both gussets 6 inwardly so that the side flaps 5 are drawn downwards over the gussets and then to seal the package at 11 utilising the extended plastic portion 3.

Another alternative, which creates a spout, is to inwardly fold one of the gusset sections 6 and to outwardly fold another gusset section 12 prior to sealing the opening with the outwardly extending gusset section 12 providing basis for a pouring spout. The spout section may or may not be reinforced by stiff material can be strapped or otherwise fixed to the adjacent side 2 of the container and when it is desired to use the contents of the container the peaked end of the gusset can be cut off with scissors or a knife or ruptured and the contents poured from the spout which is created. 9 '/ 7 Q C "r ! / Q Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope.

Claims (6)

WHAT WE CLAIM IS:

1. A method of filling a container which is characterised by a bottom wall having a bi-secting fold line and side walls having fold-lines on the same plane as the fold-line of the bottom wall said method comprising the steps of: - (a) filling the container to a predetermined level, (b) partially collapsing the container so that a head space is substantially reduced or eliminated, (c) sealing the container.

2. A method as claimed in claim 1 wherein, in the partially collapsed condition the bottom wall extends upwardly in an inverted V-formation.

3. A method as claimed in claim 1 wherein, in the partially collapsed condition opposite side all extend outwardly in a V-formation.

4. A method as claimed in claim 2 or claim 3 wherein, in the partially collapsed condition is effected by a mould having tapered inner walls.

5. A method as claimed in claim 2 or claim 3 wherein, in the partially collapsed condition is effected by a set of jaws which can be operated to squeeze the side walls of the container.

6. A method as claimed in claim 1 wherein, the container is further characterised by having two opposite substantially triangular closure flaps and two opposite substantially rectangular cl6sure flaps 242 s 78 extending from the side walls at the open end of the container and sealing the container is preceded by the further step of folding the triangular closure flaps downwardly and folding the rectangular closure flaps downwardly to overlie at least one of the triangular closure flaps. The method of claim 6 wherein both of the triangular closure flaps are folding inwardly prior to overlaying the rectangular closure flaps. The method of claim 6 wherein one of the triangular closure flaps is folded inwardly and one outwardly with the outwardly facing closure flap being usable as a pouring spout. TRIGON INDUSTRIES LIMITED by their Attorneys JAMES & WELLS 1: AT l] 1095