Note: Descriptions are shown in the official language in which they were submitted.
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Hang Bags
Field of the Invention
This invention relates to the construction and
production of a hang b~g, that is to say a bag formed of
thermoplastic material in which goods rnay be packaged and
provided with a hanger by which the bag may be hung from
a peg in order to display the goods. In particular the
inven~ion relates to a hang bag formed of shrinkable film
and provided with an improved hanger construction.
Backqround of the Invention
Food and other goods are frequently packaged for
retail pur~oses in shrinkable film that is then shrunk
around the goods. The film may initially be in the form
of a bag in which event this is open at one end to permit
the insertion of the goods and is then heat sealed and
shrunk around the goods. It is often desirable to be
able to hang the bag containing t~e goods from a peg, for
instance a hook or the peg of a pegboard, for display in
a supermarket. Tt is therefore necessary to provide
hanger means by which the bag can be hung from a hook.
The hanger means can be an external hanger into which the
bag fits, for instance a cone-shaped cut out of paper or
other material. Preferably however the bag includes
hanger means as part of the bag.
In one system a strap or hook is permanently secured
to the bag. For instance in United States patent
3,207,300 a strap is heat sealed to a bag.
~nfortunately it is difficult to obtain an adequately
reliable seal hetween many externally applied straps and
bags. Also it is not easy to construct the strap so
that it can be sealed to the bag and will readily stand
away from the bag, to permit easy hanging on a peg,
during use.
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6~536-559
In German GBM 8224353.0 thls problem ls overcome by
forming the strap of non-shrinkable material so that when the bag
is shrunk around the goods the strap stands clear of the bag.
However it is still necessary ~o take par~icular precautions if an
adequa~e seal is to be achieved between the strap and the bag.
In another system the hanger means comprises a hole
punched in the bag material at one end of the bag. Unfortllnately
the bag material is liable to tear around the hole. Localised
tearing can be minlmised by providing a metal or plastic eyelet as
reinforcement around the hole but it is inconvenient to secure
this reinforcement and the sheet material between the
reinforcement and the filled part of the bag is still liable to
tear.
It is therefore an object of the invention to provide a
hang bag comprising a bag of shrinkable fllm in whlch goods may be
packaged and provlded with lmproved hanger means. In partlcular
lt ls an object o~ the invention ko provide a bag wher~in the
hanyer means are easily and convenlently incorporated into khe bag
and can have high strength. A further objeck cf the invention is
an improved way of making a hang bag having improved hanger means.
SummarY of the Invention
A hang bag according to the invention comprises (1) a
body portlon in which goods may be packaged and that is a double
side weld bag formed of shrinkable film that is folded at a fold
to define front and rear panels that are sealed along each slde
and that can be sealed across the end distant the fold and the
external surfaces of which have been corona treated, and (2) a
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64536 559
hanger portion that extends at the said fold away from the body
portion and ~hat comprises a face layer of heat-shrinkable ~ilm
that is laminated to and extends from the said face panel, a rear
layer of heat-shrinkable fllm that is laminated to and extends
from the said rear panel, and a relnforclng member of non-æhrlnk
film that is laminated between ~he two said layers and that
includes or can include a perforation by which the bay may be hung
from a peg and wherein the entire inwardly facing surfaces of the
said face and rear layers have been corona treated and both
surfaces of the non-shrinkable film have been CQrona treated,
whereby the lamination of facing, corona treated, surfaces is
improved.
After insertion of the goods in the body portlon the
panels are also sealed across the end distant from the fold. The
said face and rear layers of shrinkable fil~ securely extend from,
respec~ively, the sald face and rear panels as a result of being
laminated to the~e panels and exkending from them.
In another aspect the invention a hang bag is made b~ a
method comprlsiny providing a flattened double-side weld bag
having face and rear panels and formed by folding the shrinkable
material about a fold and that haæ corona treated outer faces,
providing a face layer of shrinkable fllm ~hat is corona ~rea~ed
on its rear surface, providing a rear la~er of shrinkable film
that is corona treated on its face surface, providing a
reinforcing non-shrinkable film that is corona treated on both
surfaces, providing an assembly of the shrinkable film layers
substantially co-extensive wlth each other and with the
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64535-~59
relnforcing film sandwiched between ~hem at one end and with the
side weld bag sandwiched between them at the other end with the
said Pold of the side weld bag adjacent the reinforcing film, and
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laminating the faciny corona treated surfaces of the
assembly.
The invention also provides filled hang bags wherein
goods are packaged in a hang bag as described above and
~he body portion is shrunk around the goods and sealed
around its entire periphery.
Description of the Drawinys
The invention may be better understood by reference
to the accompanying drawings which show one example of
the invention and wherein
~ igure l is a plan vi~w of a hang bag according to
the invention;
Figure 2 is a cross-section on the line II-II in
Figure l (not to scale); and
Figure 3 is a plan view of the bag shown in Figure l
after filling, shrinking and heat sealing.
Description of the Preferred Embodiments
The hang bag shown in the drawings comprises a body
portion l and a hanger portion 2. The body portion l is
formed of front and rear panels 3 and 4. Each of the
panels is formed of heat shrinkable film 5. These
panels are sealingly joined across the width of the end 6
closest to the hanger portion.
It is particularly preferred that the body portion
should be a double-side weld bag, in which event the bag
is formed by folding the sheet material 5 upon itself to
define the front and rear panels 3 and 4 and this fold
serves as the join at the end 6. The assembly of the
side weld bag is then completed by heat sealing the faces
of the panels 3 and 4 to one another along the sides of
the panelsj- to form side welds 7 and 8. This heat
sealing is generally effected before the goods are
packaged in the bag, the bag being left, before usel open
at the remaining end 9 to permit the insertion of the
goods that are to be packaged in the body.
In an alternative, and less preerred, construction
other forms of body portions 1 may be utilised. For
instance the body portion may be formed of a single side
seal bag~ Thus instead of having a side weld 7 that
side of the bag may be provided by a fold in the sheet
material and the end 6 and the opposite side 3 may be
sealingly joined by heat welding, end 9 again being left
open.
Broadly, the body portion when flat will normally
consist of substantially rectangular front and rear
panels that are sealingly joined (either as a result of
welding or as a result of folding a continuous sheet
material) across one end and along two sides, with the
intention that the remaining end can be heat sealed, so
as to complete sealing of the entire periphery, after the
goods that are to be packaged have been inserted into the
bag.
The hanger portion extends at the end 6 away from
the body portion 1 and comprises a face layer lO of
shrinkable film extending away from the face panel 3, and
a rear layer 11 of shrinkable film extending away from
the rear panel 4.
The hanger portion also includes a reinforcing
member 12 that is secured between the layers lO and 11.
This reinforcing member 12 is provided with a perforation
13 by which the bag may be hung from a peg. This
perforation may be in the reinforcing member 1 before it
is sandwiched between the layers lO and 11, in which
event they must subsequently be perforated in the same
place, but more usually the perforation is formed after
laminating-the layers lO, 12 and 11. It may be provided
by any convenient piercing or punching means. It may be
provided while the bag is flat or it may be provided
after the bag has been filled with the goods that are to
be packaged. For instance the perforation may be formed
by `forcing the hanger portion of a filled bag on to a
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spike from which the bag is to be hung for display
purposes.
It is necessary that the layers lO and 11 should
extend securely from, respectively, the face panels 3 and
4 in order that the hanger portion does not pull away
from the body portion. When, as is preferred, the body
portion comprises a double side weld bag the secure
extension of the layers from the panels can be achieved
by laminating film 14 of which the layers are formed to
the material 5 of which the panels are formed over a
substantial length of the body portion. Generally the
film 14 is laminated to the film 5 over a length of at
least one quarter, usually . at least one third and
sometimes at least one half of the length of the body
portion from the end 6 towards the end 9.
In a less preferred construction, when the body
portion is a single side seal bag, the secure extension
of .the face and rear layers can be provided by a
continuation of the sheet material 5 beyond the end 6.
For` instance a double layer of sheet material 5 may
extend over the entire desired length of the hang bag, a
transverse seal may be provided between the layers at 6
to provide the end of the body portion and the
reinforcing member 12 may be sandwiched between the
2S layers. Securement of the reinforcing member 12 between
the layers is preferably promoted by corona treatment.
In the.preferred constructionJ .using a double side
weld bag as illustrated in Figure 1, lamination of the
face and rear layers to, respectively, the face and rear
panels is promoted by corona treatment. The reinforcing
member is .preferably formed of non-shrinkable film and
the securement of this between the face and rear layers
is also preferably promoted by corona treatment.
Preferably the face and rear panels 3 and 4 are
subjected :to corona treatment either over their entire
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area or over the part that is to be laminated with sheet
material 14. This sheet material is corona treated over
its entire inner surface. The reinforcing film 12 is
corona treated over its two outer surfaces. All the
facing corona treated surfaces are laminated to one
another. Thus sheet 14 is laminated to sheet material 5
over a substantially part of the length of the bag
extending from the end 6, the sheet material 14 is
laminated to the upper and lower surfaces of the
reinforcing member 12 and the adjacent faces of the layer
15 are laminated to one another at the end of the hanger
portion 15.
The corona treatment may be conducted after laying
the various components cf the hang bag in position as
shown in, for instance, Figure 2 or the individual
components may be subjected to corona treatment and then
brought together and laminated. The corona treatment
and lamination may be conducted in known manner using
apparatus and methods as described in, for instance,
~nited States patent specifica~ions 3,346,480, 3,823,061
or 4,120,716. Alternatively a system as described in
U.S. patent specification 3,900,538 may be utilised.
The provision of a double side weld bag as shown in
the drawings may be conducted in conventional manner, for
instance as described in U.S. patent specification
no.4,276,330. ~lternatively a bag having a single side
weld 8, a transverse weld 6 and a fold 7 may be provided
in known manner.
The bag is generally manufactured and supplied flat,
as shown in Figures 1 and 2 (but with or without the
perforation -13) and the user then fills it with the goods
to be packaged, for instance sausagemeat or other
foodstuffs, and then causes shrinking of the bag to a
tight fit around the foodstuffs and heat sealing of the
end 9, as shown at 16, all in conventional manner. ~he
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extent to which the hanyer portion will also shrink will
depend upon the relative strengths of the reinforcing
film 12 and the face and rear layer~ 10 and 11.
Generally the reinforcing film 12 is resistant to
shrinking and distortion in which event it will, as shown
in Figure 3, undergo little or no reduction in
dimensions. For instance-there may be some small folds
as shown diagrammatically at 17 or the dimensions of the
hanger portion may remain unchanged.
The shrinkable film of which the body portion is
made may be any thermoplastic heat shrinkable film having
properties suitable for packaging of the goods that are
to be enclosed in the body portion. Often it is a
laminate. It may include a vapour impermeable barrier
as one of its layers. Particularly suitable material
is described in United States patent no.3,741,253.
Typically it is 0.005 to 0.05 mm thick, often 0.01 to
0.03 mm th-ck. The face and rear layers 10 and 11 may
be of the same thermoplastic heat-shrinkable material or,
if they are laminated on to the body portion as shown in
Figure 2, they can if desired be of different
heat-shrinkable material. Typically they will then be
of a single ply material.
The reinforcing film 12 is preferably formed of
non-shrink film, for instance of polyethylene or
polypropylene, and typically it is 0.02 to 0~2 mm thick,
often about 0~05 to 0.1 mm thick.
Although the hanger portion is shown as being
rectangular and of the same width as the body portion it
can be of a lesser or greater width and, in particular,
it can be s-haped, for instance as shown by the dashed
lines in Figure 1. The layers 10 and 11 and
reinfoxcement 12 may be shaped before lamination or the
hanger may be cut to shape after lamination.
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As a result of the invention it is possible, for the
first time, easily to provide a hang bag having a strong
and very securely attached hanger and that is readily
accessible and does not tend to cling to the body
portion.
The hang bag may be provided with decoration or
informative printing in conventional manner.
Conveniently however such printing is on the shrinkable
film extending bevond the body portion, i.e., on the
layers lO and/or 11. This film may be surface printed
or reverse printed, and thus printing may be trapped
between the film 14 and either the film 5 or the film 12.
