Note: Descriptions are shown in the official language in which they were submitted.
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HAGS OF EASY OPEN CONSTRUCTION
The present invention relates to bags or sacks, and in
particular to plastic bags or sacks having an improved
easily openable construction. The invention relates
additionally to such bags or sacks which are able to
stand stably and unsupported.
The bags of the present invention may be of any suitable
size from relatively small (eg about 1 litre capacity or
less) to large sacks and are very useful for, for
example, industrial processing uses within and between
factory premises, or for transporting food products
between factory and retail premises, most especially for
the food processing industry. The bags of the invention
may also be suitable as the external packaging of certain
solid and liquid consumer products (such as detergents).
The bags may also find application in home delivery
services, especially where it is sometimes necessary to
return products by post to a supplier.
Plastic bags of many different types are known, but one
particular problem has been in providing bags which
incorporate an easily openable closure and which are
easily and relatively cheaply manufactured, easy and
reliable to use and, for some uses, suitable for
containing relatively heavy materials. The present
invention seeks to provide a bag which has a closure
capable of meeting these requirements. The present
invention further seeks to provide a bag which is
additionally capable of standing upright and in a stable
manner on a surface, especially while containing a
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product which may, in particular uses, be a relatively
heavy product
The bags of the present invention are particularly
suitable for containing bulk products in the form of
powders, granules or liquids. Examples of such products
include bulk chemicals and bulk ingredients such as are
used in human and animal foodstuffs and in household
products such as washing powders and washing liquids;
foodstuffs such as prepared or partially prepared foods;
household products; and garden products such as peat or
compost. In the food industry, plastic bags and sacks
are especially used in the transport of food, ingredients
or partially prepared food products around or between
premises. In the context of this specification, bulk
product may include retail consumer products such as
liquid and solid detergents, dry foods, food ingredients
and prepared foods for which the bags of the invention
may form the external packaging. The quantity of the
bulk product which the bag is adapted to contain will
vary with the particular use and, for example, for
prepared foods, the quantity may not be very large.
The present invention also relates to bags or sacks, and
in particular to plastic bags or sacks which are able to
stand stably on a surface when containing a solid or
liquid product including in particular a relatively
heavy product.
Accordingly, the present invention provides in a first
aspect a plastic bag comprising:
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first and second side walls which together form a bag
portion having front and rear faces;
a mouth formed at the front face of the bag for access to
the interior of the bag; and
a closure flap overlying and closing the mouth and having
a region which is peelably attached to the front face;
wherein at least a portion of the closure flap may be
peeled away from the front face across the peelably
attached region to reveal the mouth, such that the front
face remains functionally intact.
In one variation of this aspect of the invention the
portion of the closure flap which may be peeled away from
the front face is defined by at least one line of
weakness extending through the peelably attached region
and along which the closure flap is torn to expose the
mouth of the bag.
An alternative, second, aspect of the invention provides
a plastic bag comprising:
first and second side walls which together form a bag
portion having front and rear faces;
a mouth formed at the front face of the bag for access to
the interior of the bag;
and a closure flap overlying and clasing the mouth and
having a region which is attached to the front face;
wherein the closure flap includes at least one line of
weakness defining a portion of the flap which does not
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include any part of the region which is attached to the
front face and which portion can be opened by tearing
along the line of weakness to expose the mouth of the
bag.
In one embodiment of these aspects of the invention the
closure flap includes a line of weakness in the form of
an arc extending from points on the closure flap
proximate the mouth towards an end edge of the closure
flap.
In order to facilitate opening of the bag, the bag
preferably includes at least one finger hole formed in
the closure flap on the above line of weakness by means
of which the closure flap may be gripped for tearing.
In another embodiment of these aspects of the invention
said portion (that is, the peelable portion of the first
aspect or the portion defined by at least one line of
weakness of the second aspect) is defined by at least two
lines of weakness in the closure flap along which the
closure flap is torn to expose the mouth of the bag.
Preferably in this embodiment the lines of weakness
terminate in one or more finger holes formed in the
closure flap, by means of which the closure flap may be
gripped for tearing. This construction facilitates
opening of the bag.
In an alternative preferred construction according to
the first aspect of the invention in the above embodiment
the lines of weakness extend from an end edge of the
closure flap to points proximate the mouth.
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Other possible constructions for the lines of weakness
and the closure flap include the following:
the lines of weakness may be substantially straight and
substantially parallel to the edges of the bag; or
5 the ends of the lines of weakness at the end edge of the
closure flap are spaced further apart than the ends of
the lines of weakness proximate the mouth; or
the ends of the lines of weakness at the end edge of the
closure flap are so spaced apart as to define a finger
tab by means of which the closure flap may be gripped for
tearing; and/or
the closure flap is sealed to the front face along
portions of its end edge extending from respective lines
of weakness to the sides of the bag.
In one particularly preferred construction, the line or
lines of weakness are so shaped that the portion of the
closure flap defined thereby adopts the shape of a
dispensing spout when torn along the line or lines of
weakness.
In a particularly preferred embodiment of the first
aspect of the invention the portion of the closure flap
which may be peeled away is attached to the front face by
means of a peelable adhesive. A hot melt adhesive is
particularly preferred. Alternatively, the portion of
the closure flap which may be peeled away may be attached
to the front face by means of a peelable heat weld or
peelable heat sealed region.
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In particularly preferred embodiments of the invention,
the lines of weakness are perforations formed in the
closure flap. Alternatively, the lines of weakness may
comprise lines where the material of the closure flap is
made thinner, or scored lines in the material of the
closure flap.
In a particularly useful embodiment of the invention, the
plastic bag further comprises a closeable region formed
at a first end of the bag for closing the bag after
filling. This construction allows the bag to be filled
from the same end as the easy-open portion and for that
end to be sealed after filling. Also, other advantageous
constructions may thus be formed at the other end of the
bag, especially constructions which will not permit
filling of the bag from that other end. The closeable
region may be closed by any suitable means. Examples of
suitable means for closing the closeable region include
heat sealing, adhesive (eg an adhesive layer initially
covered by a removable protective tape) and snap-fit
fastening means such as those extending along the width
of the closeable region and comprising a male component
on one side and a female component on the other which
components snap together to form a closure.
A further preferred embodiment of the invention provides
that the first side wall forms the front of the bag, and
the second side wall forms the rear of the bag, the said
side walls being of substantially the same length.
In a preferred construction according to this embodiment
the mouth comprises a slit formed in the front face.
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Alternatively, the bag may comprise a further line of
weakness, formed in the front face, which line of
weakness may be ruptured to form the mouth.
The closeable region may include end parts of the first
and second side walls. These end parts may, for example,
be heat sealed to close the bag after filling. In some
constructions the closeable region may further include an
end part of the closure flap, which may then also form
part of the heat seal (or other closure means).
In an alternative preferred embodiment the first side
wall forms the front of the bag, the second side wall
forms the rear of the bag and the secand side wall has an
extension beyond the bag portion. This extension can
then cooperate with the closure flap and the first side
wall in defining the mouth and forming the easily
openable closure. Thus, preferably, the closure flap
overlies a part of the first side wall and said extension
of the second side wall.
In this way, the mouth is defined by the end edge of the
first side. wall and the said end edge is revealed when
the closure flap is peeled back, thereby allowing access
to the interior of the bag.
In this construction preferably also the closeable region
includes the extension of the second side wall and an end
part of the closure flap.
Handles for carrying the bag may be formed in or near
(for example, just above) the closeable region, such as
by cutting, punching or otherwise forming suitable holes
in the first and second side walls, the extension to the
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second side wall or the closure flap (as appropriate for
the particular construction). Alternatively, separate
handles may be attached to, or near, the closeable
region.
In one more particularly preferred embodiment of the
above aspects of the invention the bag further comprises
a second flap depending by means of a boundary fold from
an edge of the mouth and extending into the interior of
the bag.
Most preferably, the second flap is attachable by means
of an adhesive to the inside face of the second side
wall. Desirably, said adhesive is a peelable adhesive.
A further preferred embodiment of the first aspect of the
invention provides that on the portion of the closure
flap which may be peeled away, any path extending from
the boundary of the said portion nearest to the mouth to
the boundary of the said portion distant from said mouth
must pass through a peelably attached region.
Also, in another preferred embodiment of the first aspect
of the invention a path along the first side wall
substantially parallel to and adjacent to the mouth lies
entirely in a peelably attached region, at least within
the peelable portion of the closure flap. These
embodiments ensure that there is an uninterrupted seal
(by means of the peelable adhesive} across the whole
width of the peelable region so that, for example, there
is no route by which powder or liquid product may escape
through the easy-open closure.
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In use of the bags of the invention it is advantageous
for the bags to be able to stand stably and unsupported
during and after filling. Accordingly, one much
preferred embodiment of the invention provides that the
bag further comprises a base portion formed at an end of
the bag distant from the closeable region and operative
to provide a substantially flat region on which the bag
may stand stably.
In a preferred construction according to this embodiment,
the base portion comprises:
a base panel connected along opposing sides thereof to
the respective first and second side walls by means of
first folds, said panel further having a second fold, co-
extensive with the width of said side walls and
substantially parallel to said first folds, said second
fold dividing the base panel into first and second panel
leaves, such that the second fold and the panel leaves
lie between said side walls with the external faces of
the panel leaves towards each other; and
mitre seals comprising a seal line extending from each
end of said second fold to each first fold, along which
seal lines the first and second side walls are
respectively joined to the base panel.
The mitre seals form mitred corners which may be removed
if necessary in order to improve the palletisation of the
bag, but this is not essential. That is to say, the bags
of the present invention may be required to be suitable
for transportation on a pallet and in order to retain the
bags on the pallet a number of bags comprising a pallet
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load are often shrink wrapped (or otherwise wrapped) on
the pallet. In bags of the prior art (without a stable,
flat base), in the absence of mitre seals, product
contained in the bag is able to fill the bag right into
5 the corners. This makes the corners stiff and sharp so
that the corners will tend to cut or tear the shrink
wrapping and/or adjacent bags. Thus some prior art bags
(without the flat base construction according to the
present invention) have included mitre seals at the
10 corners, to prevent product from passing right into the
corners. In this way, the corners, although still sharp,
are flexible and less likely to cause damage. In the
present invention, the mitre seals are an integral part
of forming the flat stable base, but may also serve to
add flexibility to the corners for improved
palletisation. Removing the mitred corners can provide a
further improvement in palletisation, but is not
essential. Similarly, where the bags of the invention
form the external packaging of consumer products, the
mitred corners can be removed to avoid sharp corners
which are inconvenient to the consumer and to allow the
bags to be more easily stacked on the shelves of shops
and supermarkets.
The preferred construction according to the invention
where the bag includes a flat, stable base portion may
alternatively be defined with the bag in its expanded
condition for filling. Thus, in this construction the
base portion comprises a generally rectangular base panel
having opposed side edges and opposed end edges and
generally triangular end wall portions each depending
along a base side thereof from a respective end edge of
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the base panel, said base panel being connected to the
respective first and second side walls by means of first
folds coincident with said respective side edges, said
triangular end wall portions having an apex positioned in
use above said base panel, and having side edges
comprising seal lines extending between said apex and
respective corners of said base portion along which the
first and second side walls are respectively joined to
the said end wall portions.
In both the former and the latter constructions, the base
panel is preferably, but not essentially, formed
integrally with the first side walls.
In the former and latter constructions according this
embodiment, preferably the seal lines (of the mitre
seals) comprise a heat weld.
Desirably the seal line of the mitre seals (as defined in
the former construction) forms an angle of between 30°
and 60° with respect to the second fold and more
especially the seal line of the mitre seals forms as
angle of 45° with respect to the second fold.
In embodiments of the invention wherein there is no
closeable region and the first and second side walls are
of substantially the same length, the mouth may
preferably be defined by the end edge of the first side
wall. This is preferably achieved by providing that the
closure flap depends from the second side wall. Most
preferably the closure flap is formed integrally with the
second side wall and depends from the second side wall
along a fold. This fold is thus most preferably
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substantially parallel to and adjacent to the end edge of
the first side wall which defines the mouth.
In constructions of the bag where there is no requirement
to provide a stable base, the bag may be constructed so
that it is openable also at an end of the bag, separately
from the easy-open closure. In this construction, the
bag is further provided with a third flap overlying and
peelably attached to the first or second side wall, which
third flap depends from the respective second or first
side wall at an end of the bag spaced apart from the
closure flap.
In an alternative definition of some of the bags of the
first aspect of the invention, the plastic bag comprises
first and second confronting side walls having
substantially coincident end boundary edges and a closure
flap overlying an end region of the first side wall,
depending from the end boundary edge of the second side
wall, including a first fold substantially parallel to
and adjacent to the end boundary edges and having a
region which is peelably attached to the first side wall,
the first and second side walls being attached along
their side edges and wherein at least a portion of the
closure flap may be peeled away from the first side wall
across the peelably attached region to expose the
interior of the bag such that the first side wall remains
functionally intact.
In an alternative definition of some of the bags of the
second aspect of the invention the plastic bag comprises
first and second confronting side walls having
substantially coincident end boundary edges; and a
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closure flap overlying an end region of the first side
wall, depending from the end boundary edge of the second
side wall, including a first fold substantially parallel
to and adjacent to the end boundary edges and having a
region which is attached to the first side wall; the
first and second side walls being attached along their
side edges; and wherein the closure flap includes at
least one line of weakness defining a portion of the flap
which does not include any part of the region which is
attached to the first side and which can be opened by
tearing along the line of weakness to expose the interior
of the bag.
For a better understanding of the invention, and to show
how the same may be carried into effect, reference will
be made (by way of example only) to the following
drawings, in which:
Figure 1 is a schematic perspective view of a bag
according to one variation of the invention;
Figure 2 is a sectional view along line A-A of Figure 1;
Figure 3 is a schematic plan view of a bag according to
another variation of the invention illustrating one line
of weakness in the closure flap;
Figure 4 is a schematic plan view of a bag according to
another variation of the invention illustrating two lines
of weakness in the closure flap;
Figure 5 is a schematic plan view of a bag according to a
further variation of the invention;
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Figure 6 is a schematic plan view of a bag according to
another variation of the invention;
Figure 7 is a section along the line D-D of Figure 6;
Figure 8 is a section along the line B-B of Figure 6;
Figure 9 is a plan view of the bag of Figure 5 in an open
condition;
Figure 10 is a plan view of the bag of Figure 6 in an
open condition;
Figure 11 is a schematic plan view of a bag according to
another variation of the invention sealable to both ends;
Figure 12 is a sectional view along the line E-E of
Figure 11;
Figure 13 is a schematic plan view of part of a bag
according to a further embodiment of the invention;
Figure 14 is a section along the line A-A of Figure 13;
Figure 15 is a view of a part of a bag according to
Figure 13 in an open condition;
Figure 16 is a schematic plan view of a bag according to
the invention incorporating the base construction of
Figures 13 to 15;
Figure 17a is a section along line F-F of Figure 16;
Figures 17b and 17c illustrate variations of the bag of
Figures 16 and 17a;
Figure 18 is a schematic plan view of a bag according to
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the invention of similar construction to the bag of
Figure 16;
Figures 19 to 22 illustrate methods of making bags
according to the invention;
5 Figure 23 is a schematic plan view of a bag according to
the invention where the mouth is not adjacent an end of
the bag; and
Figure 24 illustrates one method of making the bag of
Figure 23.
10 In this application, unless indicated otherwise, or
unless the context requires otherwise, the bags of the
invention are described and defined in relation to their
flat condition before filling. That is, the bags are
described and defined in a configuration in which the
15 side walls lie flat against each other with substantially
no gap there between. Clearly, as the bag is filled with
product, the side walls of the bag become separated and
the configuration of the bag is changed.
Figures 1 to 12 illustrate bags of a construction where
the base portion for stable standing is not required. In
these figures, the bag 200 comprises a bag portion 200A
and a closure flap 205. The bag portion 200A is formed
with a first side wall 201 and a second side wall 202.
The walls 201 and 202 are confronting in that they lie
one over the other and in these embodiments the side
walls 201, 202 are of the same length. Walls 201, 202
are joined together along their side edges 203, 204 by,
for example, heat seals (the heat seals along side edges
203 and 204 are not specifically illustrated for reasons
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of clarity). In an alternative configuration, the walls
of the bag portion may be formed as a tube so that there
is no distinct joint or seal along their sides.
The closure flap 205 overlies an end region of the first
side wall 201 and in these embodiments depends from the
second side wall 202 at the end boundary edge 206 of the
second side wall 202. The closure flap 205 may be
attached to the second side wall by means of a j oint but
in these embodiments preferably the closure flap 205 is
formed integrally with the second side wall 202 and
depends from the second side wall 202 by means of a fold
207. It can be seen that the fold 207 is then adjacent
to and substantially parallel to the end edge 209 of the
first side wall 201. (In Figures 2, 7, 8 and 12, the
spacing between the first side wall 201, and the second
side wall 202, and the closure flap 205 is exaggerated
for reasons of clarity). The end edge 209 defines the
mouth of the bag 200 when the bag is apened. An optional
second flap 208 extending into the interior 211 of the
bag 200 is attached to the end boundary edge 209 of the
f first side wall ( ie to the boundary edge of the mouth) by
means of a boundary fold 210. The end edge 222 of the
second flap 208 is illustrated by a dotted line in
Figures 5 and 6.
The closure flap 205 is adhered to the first side wall
201 by means of a peelably attached region or regions
215. The peelably attached region 215 may take a variety
of forms but preferably comprises a peelable adhesive and
most preferably a hot melt adhesive. The peelable
adhesive may be applied to either the surface of the
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first side wall 201 or the surface of the closure flap
205, or to both. Other examples of peelable adhesives
may include a pressure sensitive adhesive which comprises
two non-tacky components, a first of which is applied to
the closure flap and the second of which is applied to
the first side wall. When the two components are brought
together and pressure is applied, an adhesive bond is
formed. Alternatively the peelable adhesive may be a
permanent or non-permanent adhesive or solvent adhesive
applied to either the surface of the first side wall 201
or the surface of the closure flap 205 or both.
The region or regions of peelable adhesive 215 may be of
a number of different suitable shapes. For example, the
region 215 may occupy the whole area of the first side
wall 201 which lies underneath the closure flap 205, or
only a part of that region. Regions of peelable adhesive
may be in the form of strips or stripes extending
laterally across the first side wall or extending
diagonally or in curved (wave-like) paths. The regions
of peelable adhesive may also be intermittent across the
first side wall.
It is preferred that the region or regions of peelable
adhesive are such that it is not possible to trace a path
along the surface of the first side wall 201 from its end
boundary edge 209 (ie from the mouth) to the edge of the
closure flap 213 (ie the edge distant from the mouth)
which path does not cross a region of peelable adhesive .
Where, as described further below, only a portion of the
closure flap is peeled away, the above-mentioned path may
apply only to that portion.
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It is particularly preferred that a continuous region of
peelable adhesive is provided substantially parallel to
and adjacent to the end boundary edge 209 of the first
side wall 201 (ie adjacent to the mouth), as may be
particularly seen in Figure 5. This construction assists
in ensuring the integrity of the closure.
The region or regions of peelable adhesive 215 may also
be selected to be re-sealable, so that the bag may be re
closed after opening by means of the region or regions of
peelable adhesive 215.
For example, the transfer of permanent or non-permanent
adhesive, hot melt or solvent adhesive applied to either
the surface of the first side wall 201 or the surface of
the closure flap 205 or both may also occur on opening
the bag thereby allowing the bag to be resealed.
Alternative constructions for the peelably attached
region 215 also include the use specific adhesives whose
adhesive properties vary according to the surrounding
temperature, thereby allowing the bags to be used at
extremes of temperature. In some cases, these adhesives
may not be peelable at room temperature.
Alternative constructions for the peelably attached
region 215 also include the use of adhesives which are
frangible.
Alternative constructions for the peelably attached
region 215 include peelable heat welded and peelable heat
sealed regions. In order to provide a peelable heat weld
or heat seal, the strength of the weld or seal may need
to be weakened to some extent. This may be achieved by
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interposing some sort of contaminant between the
materials to be welded or sealed. The contaminant may be
chosen from a wide variety of materials but examples
include inks and lacquers or a third film layer which
welds less strongly to the layers of material than the
materials weld to themselves.
Referring specifically now to Figures 1 and 2, the
illustrated bag may be opened simply by peeling back the
closure flap 205 through the peelably attached regions
215 to reveal the mouth 221. In this and other
embodiments of the invention, where a peelable adhesive
is used, the adhesive is selected so that its cohesive
strength is less than its adhesive strength. Thus, in
the embodiment of Figures 1 and 2, as the closure flap is
gripped at its leading edge 213 and pulled, it is
separated from the first side wall 201 in the peelable
region 215 without substantial damage occurring to the
closure flap 205 or to the first side wall 201. Thus
neither the closure flap 205 nor the first side wall 201
is torn and although each may be somewhat distorted, any
distortion of the first side wall 201 is not significant
in terms of its function.
In this and other embodiments the optional second flap
208 assists in maintaining the integrity of the closure
when the bag 200 is filled with its contents. Second
flap 208 is effective in preventing the contents of the
bag from penetrating to an excessive extent between the
first side wall 201 and the closure flap 205 around the
region of the first fold 207, which might otherwise cause
distortion the side wall 201 and/or the closure flap 205
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so that they could become separated at the peelable
region 215. The bag closure could then be breached,
allowing the contents to leak or spill.
In particularly preferred variations of the invention the
5 closure flap 205 is provided with one or more lines of
weakness along which the closure flap 205 may be torn in
order to open the bag and expose its interior. The lines
of weakness preferably take the form of perforations in
the closure flap 205.
10 Referring now to Figures 3 and 4, a bag is illustrated
incorporating only one line of weakness. The line of
weakness 216 is in the form of an arc extending from
points W-W near the mouth and the first fold 207 through
the peelably attached region 215 towards the edge 213 of
15 closure flap 205. Line of weakness 216 defines a portion
219 of the closure flap which may be gripped and peeled
away by tearing along the line of weakness 216 to open
the bag. Preferably, the ends of the line of weakness
216 do not extend beyond the peelable region 215 towards
20 the mouth in order to preserve the integrity of the
closure and to prevent product leakage.
In order to facilitate opening of the bag, the embodiment
illustrated in Figure 4 includes a finger hole 250 by
means of which the closure flap 205 may be gripped in
order to begin tearing along the line of weakness 216.
Alternatively, a tab may be attached at a similar point
which tab may be gripped with the fingers to begin
tearing. As indicated in Figure 4, a line of permanent
adhesive 240 may be provided between end edge 213 of the
closure flap and the line or lines of weakness 216 in
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order to assist in retaining the closure flap 205 prior
to opening the bag 200.
In an alternative embodiment of the invention to that
illustrated in Figure 4 it may be desirable to refrain
from the use of adhesive in the region of the closure
flap defined by the line of weakness 216. In this case,
the closure flap 205 must be sealed to the first side
wall 201 (such as by non-peelable adhesive or heat seals)
in the area outside the portion 219, in order to provide
the necessary closure. For example, this may be achieved
by means of the line of permanent adhesive 240 and seals
at side edges 205A, 205B.
Referring now to Figures 5 to 10 variations of the bags
of the invention are illustrated in which the bags
include two lines of weakness 216A, 216B which define a
portion 219 of the closure flap which may be peeled away
along the lines of weakness to open the bag. Additional
features which may be incorporated into other embodiments
of the invention are also illustrated. In this respect,
the closure flap 205 may be sealed to the first side wall
201 at its end edge 213 by means of seals 212A, 212B
(Figure 6) and at its side edges 205A, 205B (Figure 5),
but these are not always essential. Seals 212A and 212B
are preferably heat seals, however, adhesive seals,
utilising permanent or non-permanent adhesive may also be
employed. Mitre seals 217 may be formed across the
corners of the bag, preferably by heat sealing. The
mitre seals 217 can create softer corners on the bag when
the bag is filled with product, which is preferred for
palletisation of the bags. The corners of the bag beyond
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the mitre seals 217 may be removed if desired.
Indicated in Figures 5 and 6 by dotted lines 216A, 216B
the lines of weakness extend from the end edge 213 of the
closure flap through the adhesive region 215.
Preferably, the lines of weakness 216A, 2168 do not
extend beyond the peelable region 215 towards the mouth
and the fold 207 in order to preserve the integrity of
the closure and to prevent product leakage.
When it is desired to empty the contents from the bag,
the bag is opened by gripping the closure flap 205 at the
appropriate place and peeling back the closure flap 205
or the portion 219 thereof. Specifically, in Figures 5
and 6 when the end edge 213 of the closure flap 205 is
gripped at portion 219 and pulled, the closure flap 205
tears along the lines of weakness 216A, 2168 and portion
219 is separated from the remaining parts 220 of the
closure flap 205. Especially where, as in Figure 6, the
end edge 213 of the closure flap 205 is sealed to the
first side wall 201 by means of seals 212A and 2128, the
unsealed portion 214 acts as a finger tab by means of
which the closure flap 205 can be gripped. The portion
219 can then be separated by tearing along the lines of
weakness 216A, 2168 as far as the peelable region, so
that the bag attains the open configuration as shown in
Figures 9 and 10 in which the mouth 221 is revealed.
As in the above embodiments, the peelable adhesive is
selected so that its cohesive strength is less than its
adhesive strength, so that (with reference to the
embodiment of Figures 3 to 12) as the portion 219
continues to be pulled the portion 219 is separated from
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23
the first side wall 201 in the peelable region 215
without substantial damage occurring to the portion 219
or the first side wall 201. That is, the first side wall
201 and the portion 219 are not torn (except along the
lines of weakness 216, 216A, 216B) or significantly
distorted and the first side wall 201 remains
functionally intact. When the lines of weakness have
been torn along their full length, the portion 219 can be
opened out (eg at fold 207) so that it can act as a
dispensing spout for contents of the bag dispensed
through mouth 221 farmed between first side wall 201 and
second side wall 202, as may best be seen from Figures 9
and 10. In Figures 9 and 10, various features such as
mitre seals 217 and adhesive regions) 215 have been
omitted for improved clarity.
As can be seen especially in Figures 9 and 10 the mouth
221 through which product may be dispensed from the bag
200 after opening of the closure flap 205 is defined by
the end edge, or part of the end edge 209 of the first
side wall 201, in combination with the interior face of
the second side wall 202.
Other constructions for the mouth 221 are possible.
Thus, the mouth 221 may be formed as a slit in the first
side wall 201 which slit is preferably (but need not
essentially be) close to the end edge 209. The closure
flap 205 will then overlie the slit and be peeled back
through a peelable region to reveal the slit. In this
construction, the closure flap 205 does not necessarily
have to depend from the second side wall 202 but may, for
example, include a portion beyond the slit (in the
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24
direction of tearing the closure flap) which is
permanently adhered to the first side wall. In this
latter construction, alternative means are required to
close the end of the bag beyond the slit. Such means may
include the closeable region described with respect to
later embodiments of the invention.
In Figures 3 to 10, the portion of the closure flap 205
outside the peelable portion 219, may be attached to the
first side wall 201 by non-peelable means such as, for
example, a non-peelable heat seal or a non-peelable
adhesive.
The second flap 208 may also be used to provide means for
re-closing the bag after opening. In particular, the
second closure flap 208 may be provided with a layer of
adhesive (not illustrated) which may be used to adhere
the second flap 208 to the inner face of the first side
wall 202. Depending on the intended use of the bag, the
adhesive applied to the second flap 208 may be peelable
or permanent (non-peelable). A peelable adhesive may be
employed to provide an even more secure closure for the
bag, before opening. More preferably the adhesive
(peelable or non-peelable) applied to the second flap 208
may initially be covered by a protective tape such as of
a plastics material or a coated paper. The protective
tape prevents the adhesive from adhering the second flap
208 to the second side wall 202. When it is desired to
re-close the bag, the protective tape is simply peeled
away to expose the adhesive, which may then stick to the
second side wall 202. This latter construction is
particularly advantageous when the bags of the invention
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are used for containing mail-order goods, as will be
described more fully below.
Referring now to Figures 11 and 12, a still further
variation of the invention is illustrated in which the
5 bag 200 is provided with a third flap 280 at the end of
the bag distant from the first fold 207. The third flap
may depend from the first or second side walls 201, 202
and is attached to the respective second or first side
walls 202, 201 by means such as adhesive region 300. The
10 adhesive is preferably a peelable adhesive. The third
flap 280 includes a fold 290.
In the use of this flap, goods may first of all be
inserted into the bag via initially open end 218 which
end 218 is then closed by means of the third flap 280.
15 The goods are then transported or stored as required in
the bag and, when required are accessed by peeling back
closure flap 205 or peelable portion 219, as previously
described to reveal mouth 221. If the goods need to be
repacked in the bag, such as, for example, unwanted goods
20 which are to be returned to the mail order supplier, they
may be placed in the bag again through the mouth 221.
The mouth 221 is then resealed by means of adhesive
provided on second flap 208. Additionally or
alternatively adhesive on the peelable portion 219, may
25 be used to reseal the bag. In this case, the peelable
adhesive may be resealable and/or an additional area of
adhesive may be provided on the portion 219 or on first
side wall 201, which is protected by means such as a
protective tape which tape is removed before resealing.
When access to the goods is again required, such as for
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26
returned goods at the mail order company, the bag may be
opened by peeling or tearing back third flap 280.
Referring now in particular to Figures 13 and 14, which
show the base part of a bag according to one embodiment
of the invention. The mouth, closure flap and associated
constructional details are omitted from these figures for
reasons of clarity. In these figures the bag 901 is
shown in a flat condition prior to filling. The bag 901
comprises a closure end 902 (which in the bag of the
invention will incorporate the easily openable closure),
a base panel 903, first and second side walls 904a, 904b
and side edges 905a, 905b. Side walls 904a, 904b are
joined at marginal edges 905a, 905b along their entire
length by suitable means such as heat welding and/or
adhesive and preferably by heat welding. However, in
alternative constructions, the joins may be located
elsewhere than the side edges, or, where the body of the
bags is produced in the form of a tube, may be absent.
The base panel 903 comprises a tuck defined by first
folds 909' and 909" and second fold 990. The tuck has
panel leaves or tuck leaves 906a and 906b each having two
mitred edges 907. Mitred edges 907 are mitre seals
comprising a seal line extending from each end of the
second fold 990 (that is, at point X) to the first folds
909', 909" at points Y. The mitred edges 907 thus form
internal corner boundary edges of the bag. The side
walls 904a, 904b are joined to the base panel 903 along
these seal lines which preferably comprise heat welds.
As can best be seen in Figure 14, second fold 990 and
panel leaves 906a, 906b lie between the side walls 904a,
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904b with the external faces of the panel leaves 906a,
906b towards each other.
In the illustrated embodiment the first and second side
walls 904a, 904b and the base panel 903 are unitary in
that there is no intervening joint in a path passing from
the illustrated limit of side wall 904a at the closure
end to the fold 909', the fold 990 and the fold 909" and
then to the illustrated limit of the side wall 904b at
the closure end of the bag.
In less preferred constructions, side walls 904a and 904b
may not for example be unitary in that the above defined
path may be interrupted by a joint formed for example
along fold line 990 or along or near to folds 909', 909".
When the bag is in its flat condition illustrated in
Figures 13 and 14, the mitred edge 907 preferably forms
an angle of between 30° and 60°, most preferably 45° with
respect to the second fold 990.
Figure 15 illustrates a bag part similar to that of
Figures 1 and 2, but in a substantially fully open
condition containing, or ready to receive, a product.
Side walls 904a, 904b no longer lie substantially flat
against each other as in Figures 13 and 14, but are
spaced apart from one another. In the embodiment
illustrated the side edges 904a and 904b are joined to
each other along side edges 905a and 905b. The joints
preferably comprise heat welds along the whole length of
side edges 905a, 905b although other joining means such
as adhesive may additionally or alternatively be used.
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Upper edges of side walls 904a, 904b will form the
closure end of the bag and no constructional details are
shown in this figure, for reasons of clarity. A
substantially rectangular base portion 908 (which is part
of the base panel 903) on which the bag may rest in an
upright position is defined by fold lines 909' , 909" and
910', 910" and is formed by opening out panel leaves
906a, 906b of Figures 13 and 14. Mitred edges 907 now
lie above a horizontal plane, preferably tending towards
a vertical plane, although filling of the bag may cause
the mitred edges 907 to be displaced further from the
vertical. Mitred edges 907 and fold lines 910', 910"
define upstanding generally triangular end wall portions
911a, 911b. Fold lines 910', 910" form the base side of
portions 911a, 911b and mitred edges 907 form the
remaining sides with the apex of the triangles at points
X. Thus, in the embodiment illustrated the apex of the
triangular end wall portions 911a, 911b lie above the
base portion 908 in use. Portions 911a, 911b are formed
by an opening out of the panel leaves 906a, 906b and
comprise end regions of the base panel 903. Preferably,
the mitred edges 907 form an angle of between 30° and 60°
with respect to the fold lines 910', 910". Additional
reinforcements (such as reinforcement welds or adhered
reinforcement patches) may be provided where desired such
as at points X where the welds of mitred edges 907 meet
the welds of marginal edges 905a, 905b.
The mitred corner portion 912 formed by mitred edges 907
and illustrated in dotted lines in Figure 13 may be
removed if desired for improved palletisation, but this
is not essential. If not removed, in the bag of Figure
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15 the portions 912 simply form an extra triangular layer
(not illustrated) overlying points Y-X-Y.
Thus, by means of this embodiment of the invention it is
possible to provide a bag which can stand stably in an
upright position, which is suitable for carrying heavy
and bulky materials, which is simple and cost effective
to manufacture in an automated process and which provides
excellent palletisation properties.
This variation of the invention provides a bag having an
easily openable closure portion and a stable, flat base
portion. This type of bag is particularly suited for the
transport of partially prepared food products within a
factory and of prepared food products between factory and
retail premises. An example of such a bag when complete
is illustrated in Figures 16, 17 and 18. Other suitable
uses will be readily apparent to those skilled in the
art. Features which are identical to or similar to those
of Figures 13, 14 and 15 have not been specifically
identified and will not be described again in detail.
Essentially, the bags of this embodiment of the invention
combine the stable flat base with an easily openable
closure which is the same as, or similar to, that
described above and further provide an area by means of
which the bag can be sealed after filling without
disturbing the easily openable closure.
Referring now to Figures 16 and 17a, the bag 500
incorporates a flat, stable base portion 508, the
construction of which is preferably as described with
reference to Figures 13, 14 and 15. The bag has a bag
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portion 500A comprising a first side wall 501 and a
second side wall 502. A closure flap is attached to the
first side wall 501 to form a closure over the mouth 521.
The second side wall 502 includes an extension 553 beyond
5 the bag portion 500A and so the mouth is defined by the
end edge 509 of the first side wall 501, in combination
with the interior face 502A of the second side wall 502.
The closure flap 505 is attached to the first side wall
501 in any of the ways described above which allow it, or
10 a portion of it, to be peeled back to reveal the mouth
521 while allowing the first side wall 501 to remain
functionally intact. Thus, the closure flap 505 may be
attached to the first side wall 501 by means of a
peelable adhesive, as in the first aspect of the
15 invention, or the peelable adhesive may be absent, as in
the second aspect of the invention. Most preferably, the
closure flap 505 is attached by means of peelable
adhesive 515. The closure flap 505 is preferably
tearable along lines of weakness 516, which lines 516 are
20 most preferably in the form of perforations. The bags of
this embodiment may also include a flap 528 at the
boundary of the mouth 521, which flap 528 is functionally
equivalent to the flap 208 of the previously described
embodiments.
25 In the illustrated embodiment of Figures 17a-c, the bag
is closed by means of a closeable region 550. The actual
closure may be effected by any suitable means 551, such
as adhesive or heat sealing. In the embodiment of Figure
17a, the closeable region is formed from an end part 552
30 of the closure flap 505 and the extension 553 of the
second side wall 502. The extension 553 extends beyond
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31
the bag portion 500A and is most preferably formed
integrally with the second side wall 502.
In use of the bag, the closeable region 550 is initially
open to allow the bag to be filled. When the desired
contents have been placed in the bag, the closeable
region 550 is closed by the appropriate means 551. When
access is required to the contents of the bag, the
closure flap 505, or the portion 519 thereof (in the
embodiment illustrated), is peeled back to reveal the
mouth, so that the contents may be dispensed.
Other constructions of the closeable region are possible.
For example, the first and second side walls 501, 502 may
be of the same length so that there is no extension 553.
In this case, the mouth 521 is formed as a slit or cut in
the first side wall 501 and the closure flap 505 overlies
the slit or cut. Thus, the closeable region may be
formed by end parts of the first side wall 501, the
second side wall 502 and the closure flap 505. This
construction is illustrated in Figure 17b. In another
variation illustrated in Figure 17c, the slit or cut
forming mouth 521 may be spaced further from the ends of
the side walls 501, 502 (that is, nearer to portion 508).
In this case, the closure flap 505 may also be spaced
further from the said ends 509, 510 of side walls 501,
502 and need not overlie the said ends. The closeable
region 550 may then comprise only the end regions of the
side walls 501, 502. In this variation, the closure flap
505 must be attached to the first side wall 501 on both
sides of the slit, with a portion at at least one side
being peelable or otherwise removable to reveal the slit,
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while leaving the first side wall 501 functionally
intact. In this variation as illustrated in Figure 17c,
the closure flap 505 is peelably attached by means of
peelable adhesive 515 and permanently attached by
suitable means at 554.
A further variation of the bag of this embodiment is
illustrated in Figure 18. This bag differs from that of
Figure 17 only by the provision of handles 560. These
handles may be punched, cut or otherwise formed towards
the top of the bag, preferably just above the closeable
region 550. As an alternative, separate handles may be
attached to the bag in or near the closeable region.
Methods of production of the bags according to the
invention will now be outlined, although it should be
noted that the bags of the invention are not confined to
these methods.
Initially, a method of producing the bags of Figures 1 to
12 will be described in outline, with particular
reference to Figure 19. A web 600 of plastics film is
extruded and is folded over at 601 to the configuration
shown in Figure 19A. An optional second fold 602 is then
made which will ultimately provide the optional second
flap 208 (Figures 2, 7, 8) (Fig 19B) . Next, one or more
areas of peelable adhesive 603 (such as a hot melt
adhesive) are applied to the surface of the bag (Fig 19C)
and the perforations 604 are formed (Fig 19D) which
provide the lines of weakness 216 (Figs 3, 4, 5, 6). The
portion 605 of the web 600 is then folded over and
adhered by the peelable adhesive 603 (Fig 19E). The web
600 is cut near first fold 601 to provide the open end
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606 of the bag, by means of which the bag may ultimately
be filled (Figure 19F). The web is finally sectioned
into bags of appropriate width and heat seals (or other
seals) are formed at the sides to result in the final
bag.
Two methods of production of the bags according to
Figures 16, 17 and 18 will now be described. In the
first method, illustrated in Figure 20, a web 700 is
first folded at fold 701 (Fig 20A) . A tuck 702 is then
formed from the fold 701 (Fig 20B) and mitre seals 703
are formed at the corners of the tuck portions (Fig 20C).
A portion 704 of web 700 (indicated by dotted line) is
then removed (Fig 20D) and peelable adhesive 705 is
applied to the surface of the web 700 (Fig 20E). An
additional web 706 incorporating lines of weakness 716 is
then applied to the peelable adhesive and to overlie the
area 707 of the web (Fig 20F). Finally the web is
sectioned and the resulting side edges are closed (such
as by heat sealing) to form the final bags. The parts
706 and 707 provide the closeable region 708 (Fig 20G).
In an alternative, less preferred, method illustrated in
Figure 21, the steps illustrated in Figs 21A to 21E are
the same or similar to those of Figs 20A to 20E. In the
step illustrated in Figure 21F, perforations 709 (which
form the lines of weakness 216) are formed in the part
707, which part 707 is then folded over at fold 710 (Fig
21G) and adhered to the peelable adhesive 705. The web
700 is then cut in the region of fold 710 to provide the
opening of the bag (Fig 21H). The fold 710 is so spaced
from the end of the web 700 at 711 as to allow for a
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closeable region 712 after the fold 710 has been cut off.
The web is then sectioned and the side edges sealed as
previously described in relation to Figure 20G.
In Figure 22, a method of making a bag similar to the bag
of Figures 1 to 12 is illustrated. For this bag, the
mouth is spaced from the ends of the bag, although the
method can be adapted to position the mouth nearer to the
ends of the bag.
Referring now to Figure 22, a web 750 of plastics film is
extruded and is folded over at folds 751 and 752 to the
configuration shown in Figure 22A. In Figure 22A, the
spacing of the end edges 753, 754 of the web 750 is
exaggerated for reasons of clarity. An optional third
fold forming an optional second flap depending from edge
753 or 754 may also be included. This second flap is
similar in construction and operation to the second flap
depending from fold 602 is Figure 19.
Next, one or more areas of peelable adhesive 755 (such as
a hot melt adhesive) are applied to the surface of the
bag. Adhesive 756 is also applied at the opposite side
of gap 757, which adhesive 757 may be peelable or
permanent (Figure 22B). An additional web 758 is then
applied to the adhesive regions 755, 756 to overlie (and
close) the gap 757. The additional web includes lines of
weakness 759 (Figure 22C). Finally, the web 750 is
sectioned to form individual bags and one side 760 is
sealed, such as by heat sealing or adhesive (Figure 22D).
The other end 761 is open for filling the bag and may be
closed in region 762 after filling of the bag (Figure
22E). In an alternative variation, after the step
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illustrated in Figure 22C, the web 750 may be sectioned
as in Figure 22D to form individual bags, and both the
side edges 761 and 763 may then be sealed, such as by
adhesive or heat sealing. In this variation, in order to
5 provide access to the bag for filling, the fold 752 may
be cut off (either before or after the web 750 is
sectioned). This end portion may then be closed after
filling of the bag, such as by heat sealing or adhesive.
Figure 23 illustrates another variation of the bags of
10 the invention in which the month is spaced from the ends
of the bag. Referring to Figure 23, the bag 560 includes
a flat, stable base portion 508, the construction of
which is preferably as described with reference to
Figures 13 to 15, and with reference to Figures 16 and
15 17. The bag 560. also includes a closeable region 550
which may be closed in any of the ways previously
described, after filling of the bag. The mouth 521 of
the bag 560 is in the form of a slit or gap 562. The
mouth 521 is closed by means of a closure flap 565 which
20 overlies the gap 562. The closure flap is attached to
the front face 561 of the bag by means of a region of
peelable adhesive 563 and, at the other side of the gap
562, by means of a region of peelable or permanent
adhesive 564. The closure flap includes lines of
25 weakness 566 along which the closure flap 565 may be torn
so that a portion 569 may be peeled back through the
region of peelable adhesive 563 to expose the mouth 521.
Figure 24 illustrates one method of making the bag of
Figure 23. In this method, a web 770 of plastics film is
30 extruded and is folded over at fold 771 and 772 to the
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configuration shown in Figure 24A. In Figure 24A, the
spacing of the end edges 773, 774 of the web 770 is
exaggerated for reasons of clarity. An optional third
fold forming an optional second flap depending from edge
753 or 754 may also be included. This second flap is
similar in construction and operation to the second flap
depending from fold 602 in Figure 19.
Next, a tuck 775 is formed from fold 771 (Figure 24B) and
mitre seals 776 are formed at the corners of the tuck
portions (Figure 24C). Subsequently, fold 772 is cut
away to provide an end 776 of the resulting bag open for
filling (Figure 24D). A region or regions of peelable
adhesive 777 is applied to the bag adjacent gap 778 and
adhesive regions 779 are also applied on the opposite
side of gap 778. Adhesive regions 779 may be peelable or
non-peelable. The locations of the adhesive regions 777
and 779 may be reversed if desired (Figure 24E). An
additional web 780, including lines of weakness 781, is
then applied to the adhesive regions 777, 779 to overlie
(and close) the gap 778(Figure 24F). Finally, the web
770 is sectioned to form individual bags and the side
edges are sealed, such as by heat sealing or adhesive.
After filling of the bag, the open end 776 may be closed
by suitable means in closeable region 782.
