This invention is concerned with packaging processes and apparatus and more particularly with the packaging of powdered or granular products intended for transportation and possible repackaging before those products are purchased by an end consumer.

Granulated products such as milk powder are traditionally packaged 1n a sealed plastics inner container, fabricated from polyethylene, or a laminate of suitable plastics, and the so packaged milk powder then further packaged for transportation by the insertion of the plastics powder container into a second outer container usually fabricated of strong paper which may be laminated, the paper being usually in the vicinity of 85 grams per square metre strength, the paper then being coated with a heat sealable plastics material. It 1s necessary to so package products such as miIk powder, firstly because such products suffer deterioration 1f exposed to oxygen which might permeate the packaging in which those products are contained, and secondly because products may be transported by road and/or ship to end destinations and it 1s a requirement of transportation that vermin such as cockroaches, insects and dust dirt etc are unable to penetrate the packaging and pollute the contents of the inner bag.

Currently, milk powder and like granulated products are packaged by use of purpose designed machinery which introduces the powdered material to a first plastics container fabricated by the machinery. The plastic Inner container 1s then manually inserted Into a second outer container fabricated by other machinery and perhaps purchased from an outside source. The outer container is, of course, sealed, either by heat sealing or otherwise, before transportation of the powder and Its Inner and outer containers is undertaken.

It Is an object of this invention to simplify the conventional packaging of powdered materials.

This Invention 1n one broad form provides a method of packaging granulated material wherein a roll of packing material comprising a first layer of plastics or laminated plastics material adapted to form an inner package within which such powdered material might be contained, interleaved with a second material which may be paper, plastics or other material coated with a thermoplastics lining adapted to form an outer container, is presented to a forming station wherein a portion of said plastics material is formed Into a receptacle, closed at one end for receiving a predetermined quantity of said powdered material and, simultaneously or

otherwise, said second material is formed into a second receptacle located around said first receptacle, said second receptacle also being closed at one end, powder is introduced in predetermined quantity to said first receptacle, said inner and outer receptacles then being heat sealed at their upper ends to form a package wherein said powder 1s contained within said first plastics container and said inner plastics container is wholly retained within said outer container.

The preferred method of sealing the outer container to the Inner plastics container is by way of heat sealing, the plastics inner lining of the laminated material of which the outer container 1s formed, having a lower sealing force with the plastics material of the Inner container than the sealing force between the Inner plastics walls of the inner container. With this arrangement, the outer container may be shed or stripped from the Inner plastics container by simple pulling which breaks the weaker seal between the outer container and the Inner plastics container without breaking the seal by which the walls of the Inner plastics container are joined.

In a further embodiment of this Invention, the outer material laminate container may be sealed separately from the Inner container so that there is no physical seal between the walls of the outer container and any part of the inner container.

The accompanying drawing depicts conventional packaging apparatus utilized to pack granulated materials such as milk powder 1n a plastics container.

In the drawing, packing material stock reel 1 is a single roll of dual layers of Inner and outer container material. The inner material is usually a barrier laminate and the outer layer of protective material Is a plastics coated paper, or other plastics coated material although many plastics materials will suffice for the purpose of providing package 9, the choice of plastics material depending on the nature of the contents intended for the final package and the strength requirements of the packaging material, along with cost.

Dual wound plastics sheeting from roll 1 is passed over tension rollers 2 and forms film track 3 which 1s advanced to forming shoulder 4. The plastics material thereafter is fed into forming tube 5 and a side seam established in the plastics material by longitudinal sealing jaw 6. A belt draw off system 7 is provided to advance the so sealed plastics material to cross seal jaws 8 where heat is applied to an end portion of the plastics tube to form a heat sealed bottom to the prospective inner and outer

contai ers 9. At this stage, a predetermined quantity of milk powder or other granulated material is advanced through forming tube 5 into the receptacle formed by the sealed tube of plastics material closed at its bottom by heat sealing jaws 8. After this quantity of powder is introduced to the receptacle of plastics material, belt draw off system 7 advances that receptacle through cross seal jaws 8 which then operate to seal the receptable at its upper end to form the inner and outer container 9 with powder material enclosed therein.

Conventionally, sealed powder containing containers 9 are then hand packed into outer containers of laminated paper material, these outer containers being first in receptacle form with a sealed bottom end. Once a container 9 has been introduced into such an outer container, the outer container is itself heat sealed at its upper end either to the upper closure end of container 9 or therebeyond. Another conventional method of achieving a package with a re oveable outer is to have pre made bags with an inner liner pre assembled. This forces the packer to purchase pre made bags.

The current invention provides a modification of the conventional packaging arrangement wherein packing material stock reel 1 is not merely of plastics or laminated plastics material with a view to formation of a single container 9. Reel 1 is replaced by an interleaved reel, this Interleaved reel comprising a first sheet of the plastics coated material which is conventionally utilized to form the outer container of the above described packages. This first sheet, of laminated paper material coated with a heat sealable plastics material is provided with a covering sheet of the conventional plastics or laminated plastics material of reel 1. These two sheets are rolled together so as to be interleaved and the reel used to replace reel 1. When this replacement reel is unrolled over tension rollers 2, film track 3 incorporates a double layer of material, a first layer of coated material for formation of the outer package, superimposed on which is a sheet of plastics material adapted to form the inner container 9. This double layered sheet arrangement is fed through forming tube 5 and longitudinal seams placed in both the plastic sheeting adapted to form inner container 9 and the coated material sheeting adapted to form the outer container of the packaging arrangement. Both inner and outer sheets are then provided with bottom heat seals at cross seal jaws 8 and the inner receptacle filled with a predetermined quantity of granulated material .

Thereafter, both inner and outer containers are sealed at their upper

ends, the apparatus thus producing a package wherein granulated material 1s contained within an inner plastics container which in turn 1s retained within an outer coated material container, the entire exercise having been completed on the one piece of equipment, without the necessity for hand packaging of the inner container within the outer container or the purchase of pre made bags.

It is estimated that adoption of the technique described above in accordance with this Invention will halve the current cost of packaging by virtue of saving in process steps and the utilization of extraneous equipment for the separate formation of the outer container.