UNITES EMBALLEES SOUS FILM ETIRABLE POUR ARTICLES SOUPLES

STRETCH WRAPPED UNITS FOR FLEXIBLE ARTICLES

Abrégé français

Unité (10) composée d'un ensemble (11) d'au moins deux emballages souples (12) sensiblement parallélépipédiques, lesdits emballages (12) contenant des articles souples comprimés (14) enfermés dans un sachet souple (13), lesdits articles comprimés (14) ayant été comprimés de 20 à 70 % de leur volume non comprimé dans un sens de compression C, ledit ensemble (11) présentant une face supérieure (15), une face inférieure (16), une face avant (17), une face arrière (18) et deux faces latérales (19, 10). L'invention est caractérisée par le fait que ladite unité (10) comprend un film plastique étirable à froid (21) situé en position contiguë à au moins une partie d'au moins quatre faces consécutives (15, 16, 17, 18, 19, 20) dudit ensemble (11) et que ledit film plastique étirable à froid (21) est fixé non adhésif à ladite face supérieure (15), à ladite face inférieure (16), à ladite face avant (17), à ladite face arrière (18), ainsi qu'auxdites faces latérales (19, 20) dudit ensemble (11).

Abrégé anglais

A unit (10) comprising an array (11) of at least two substantially
parallelepipedal flexible packs (12), said packs (12) comprising compressed
flexible articles (14) encased in a flexible bag (13), said compressed
articles (14) having been compressed to between 20 percent and 70 percent of
their uncompressed volume in a direction of compression C, said array (11)
comprising a top face (15), a bottom face (16), a front face (17), a back face
(18) and two side faces (19, 20) characterised in that said unit (10)
comprises a cold stretchable plastic film (21) disposed adjacent at least a
part of at least four consecutive faces (15, 16, 17, 18, 19, 20) of said array
(11) and said cold stretchable plastic film (21) non-adhesively attaches to
said top face (15), said bottom face (16), said front face (17), said back
face (18) and said side faces (19, 20) of said array (11).

Revendications

6
What is claimed is:
1. A unit comprising an array of at least two substantially parallelepipedal
packs,
said packs comprising compressed flexible articles encased in a flexible bag,
said
compressed articles having been compressed to between 20 percent and 70
percent of
their uncompressed volume in a direction of compression C, said array
comprising a
top face, a bottom face, a front face, a back face and two side faces wherein
said unit
comprises a cold stretachable plastic film disposed adjacent at least four
consecutive
faces of said array and said cold stretchable plastic film non-adhesively
attaches to
said top face, said bottom face, said front face, said back face; and said
side faces of
said array.
2. A unit according to claim 1 wherein said faces of said array not covered by
said cold stretchable plastic film remain exposed to the environment.
3. A unit according to claim 1 wherein said cold stretchable plastic film is
disposed adjacent said top face, said bottom face, said front face, said back
face and
said side faces of said array and sealed to form a closed unit.

Description

CA 02253457 1998-11-02
WO 97/41045 PCT/US97/07093
1
STRETCH WRAPPED UNITS FOR FLEXIBLE ARTICLES
Field of the invention
The invention relates to an array of packs, comprising compressed
flexible articles encased in flexible bags, which are stretch wrapped
with a cold stretchable plastic film and sealed to form a rigid stretch
wrapped unit.
Description of the prior art
It is widely known in the art to pack an array of flexible packs
comprising compressed flexible articles encased in flexible bags in
cardboard cases of fixed dimensions for ease of handling, storage and
transport. The space inside these cases cannot be fully utilised because
of the tolerances imposed by the variations in the pack dimensions
resulting from the production processes and the usual automatic
mechanical packaging systems. Furthermore, due to the deviations in
the pack dimensions resulting from the packing of compressible flexible
articles into flexible bags, the cardboard cases need to be over-
dimensioned. As a consequence of this over-dimensioning, arrays of
packs on the bottom of pallets are. incapable of supporting the imposed
loads when pallets of products are stacked or grouped three pallets
high. Therefore, the cardboard cases must be designed to support the
extra loads.
An array of packs of compressed flexible articles can also be wrapped in
a plastic film. The plastic film can comprise relatively inexpensive
materials such as polymeric films or thermoplastic films. Such materials
reduce the severity of the disposal problem from an environmental
standpoint both with respect to the amount of wrapping material
required and the disposabitity/degradability of the particular wrapping
material. In addition, plastic film is lighter and more flexible than
cardboard, which is heavy, requires space and has less flexibility for
storage since it is rigid and in use continues to occupy the same amount
of space even when nearly empty.

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Prior art developments include US 5,049,423, which discloses
thermoplastic films and more particularly, thermoplastic films having
properties making them especially suitable for use as stretch wraps for
various foodstuffs, rolls of carpet, liquid containers etc. in various
bundling and palletising operations. The load of the pallet may be
bundled by stretch wrapping a film several times around the articles to
be palletised. The document focuses on the properties of the
thermoplastic film.
EP 0 294 339 A2 discloses a machine for packaging a plurality of
articles, either loose, collected on a tray or inside a container, within a
cold stretchable or a semi-stretchable type of film web. The machine
includes a stretching device which prevents shrinking of the central
region of the film in the longitudinal direction, a wrapping device and a
complete sealing unit which seals the film ends while the film is still
under tension. The invention takes advantage of the elastic memory of
the fifm web to tightly enclose the packaged articles rather than using
the compressibility of the articles to form a rigid stretch wrapped unit.
DE 33 41 897 A1 discloses a process developed by the Hagemann
company which results in a stretch wrapped product. The machine
wraps articles in pre-stretched film, which contracts at a later stage.
The film is drawn from a reeling device under tension and continuously
wound in a spiral fashion around the conveyor belt and reels to form a
tube, whose end is drawn off. The machine can wrap loosely stacked
articles in continuous action and single articles can be handled. The
invention does not teach a stretch wrapping process which exploits the
compressibility of an array of packs of flexible articles.
Therefore, the prior art does not teach a wrapping system which is
independent of the fixed dimensions of the outer cases, which exploits
the compressibility of an array of packs of flexible articles and which
allows the possibility of sealing the sides of the array of packs to form a
completely closed unit.

CA 02253457 2002-08-02
3
Object and summary of the invention
An object of an aspect of the present invention is to produce a rigid and
stable unit by
stretch wrapping an array of flexible packs of disposable absorbent diapers,
sanitan
articles, incontinent pads or briefs, bandages and the like, with a cold
stretchable
plastic film.
In an aspect of the present invention, cardboard is eliminated as a packaging
material
by making use of a plastic film, which is stretch wrapped around four
consecutive
faces of an array of flexible packs. This has subsequently led to several
benefits
namely, units that are more stable and that are capable of sustaining higher
load
carrying capacities; a reduction in the overall weight of the units to be
handled, stored
and transported; a decrease in the level of waste packaging material; and an
improved
and optimised pallet fit during handling, storage and transport operations.
In accordance with an object of an aspect of the invention, a unit comprising
an array
of at least two substantially parallelepipedal packs is provided. The unit has
a top
face, a bottom face, a front face, a back face and two side faces and
comprises a cold
stretchable plastic film, which is disposed adjacent to at least four
consecutive faces
of the array of packs. The cold stretchable plastic film non-adhesively
attaches to the
faces of the array. Two options exist: either the faces of the array not
covered by the
cold stretchable plastic film can be left exposed to the environment or the
cold
stretchable plastic film can be made wide enough to cover the remaining two
faces of
the array and can be sealed to form a closed unit by a variety of means.
In accordance with another aspect of the present invention, there is provided
a unit
comprising an array of at least two substantially parallelepipedal packs, said
packs
comprising compressed flexible articles encased in a flexiblf: bag, said
compressed
articles having been compressed to between 2t) percent and 70 percent of their
uncompressed volume in a direction of compression C, said array comprising a
top
face, a bottom face, a front face, a back face and two side faces wherein said
unit
comprises a cold stretachable plastic film disposed adjacent at least four
consecutive

CA 02253457 2002-08-02
3a
faces of said array and said cold stretchable plastic film non-adhesively
attaches to
said top face, said bottom face, said front face, said back face and said side
faces of
said array.
Brief description of the drawings
The invention will be described hereinafter with reference to the following
drawings:
Figure 1 shows a pack comprising compressed flexible articles encased in a
flexible
bag;

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4
Figure 2 is a perspective view of an array of five packs and a cold
stretchable plastic film disposed adjacent to four consecutive faces of
the array.
Detailed description of the invention
Figure 1 shows a pack 12 comprising compressed flexible articles 14
encased in a flexible bag 13. The substantially parallelipedal packs 12
are arranged in an up-on-base configuration. Other configurations such
as flat-on-face and up-on-side are also possible. The compressed
flexible articles 14 may comprise disposable absorbent diapers, sanitary
articles, incontinent pads or briefs, bandages and the like. The flexible
articles 14 are compressed to between 20 and 70 percent of their
uncompressed volume in a direction of compression C. In particular,
figure 1 shows a diaper pack 12 comprising between one to fifty
disposable absorbent diapers 14 and a plastic bag 13 with a thickness
ranging from 20 to 120 micrometres. A method for the compression
packing of disposable absorbent diapers into flexible bags has been
described in detail in the following patents US 4,934,535, US
4,966,286, US 5,022,216,
US 5,050,742 and US 5,150,561.
As is displayed in figure 2, the packs 12 are arranged in the form of an
array 11 before transport and storage. An array 11 usually comprises
at least two substantially parallelipedal packs 12. More specifically,
figure 2 shows a perspective view of a substantially covered array 11
comprising five substantially parallelepipedal packs 12 of the type
shown in figure 1. The stretch wrapped array forms the unit 10. For
the purposes of transport and storage, a number of units 10 can be
stacked or grouped in a plurality of configurations to form a case on a
pallet such that a load can be applied to a top panel or to a side panel
of the case with the direction of the load being perpendicular to the
direction of compression, which is around the circumference of the
case. The units are less compressible in directions perpendicular to the
direction of compression.
In figure 2, the unit 10 comprises a top face 15, a bottom face 16, a
front face 17, a back face 18 and two side faces 19, 20 and a cold

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stretchable plastic film 21, which is disposed adjacent to at least four
consecutive faces of the array 11 of packs 12. Three stretch wrapping
configurations are possible with permutations, namely the cold
stretchable film 21 can be disposed adjacent to the top face 15, the
back face 18, the bottom face 16 and the front face 17; the side face
7 9, the top face 15, the remaining side face 20 and the bottom face 16;
or the back face 18, the side face 20, the front face 17 and the
remaining side face 19. The cold stretchable plastic film 21 non-
adhesively attaches to all the faces 15, 16 17, 18, 19, 20 of the array
11. The faces 15, 16 17, 18, 19, 20, depending on the selected
stretch wrapping configuration, not covered by the cold stretchable
plastic film 21 remain exposed to the environment. tn figure 2, in
particular, the cold stretchable plastic film 21 is wrapped around the
side face 19, the top face 15, the remaining side face 20 and the
bottom face 16.
The cold stretchable plastic film 21 can also be disposed adjacent to the
top face 15, the back face 18, the bottom face 16, the front face 17
and the side faces 79, 20 of the array 11 to form a completely closed
unit 10.
The preferred film 21 is a cold stretchable polyethylene film, which is a
plastic film that after being stretched exhibits the property of elastic
memory. Such a property enables the film to return substantially to its
starting dimensions. The preferred thickness for the cold stretchable
film 21 ranges from 15-60 micrometres and it can be stretched in an
elongation range from 80-150 percent. The cold stretchable film 21
may either be transparent, white or coloured and in addition, it may
comprise graphical indicia, which can also be coloured. By tightly
stretch wrapping the cold stretchable film 21 around the array 11 of
packs 12, the stability of the array 11 is improved without resulting in a
deterioration of the substantially parallelepipedal shape of the array 11.
Furthermore, a strong and rigid outer casing for the array 11 is created,
which guarantees stability.

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