Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02269652 1999-04-22
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fIELD Of THE INVENTION
The invention relates to s bag and a method of forming a bag which can be
opened
easily.
BACKQROUND Of THE INVENTION
Seated bags are often used for storing and transporting materials such ss
,~ peat moss, clay, fertilizer, pet food and the like. 'To remove the contents
of the bag
-it is necessary to open the bag using 8 knife or other instrument.
It is well-known to provide bag8 which may be opened easily and safely
without using a knife. United States Patent 6,375.930 to Tani describes an
easily
op~nable synthetic resin bag comprising s bag body having front and rear
walls. A
tear string with sn ear portion is heat sealed on the inner side of the rear
wall along
an opening tine. To open the bag the asr portion is gripped and pulled away
from
the bag taking the tear string with it to open the bag along the opening line,
United States Patent 6,118,140 to Hirashima also describes a bag having a
tear string heat sealed on the inside of one of the walls of the bag. The bag
also
includes means to keep the tear string on the bag body after the bag is
opened.
The arrangements described a above are suitable for bags made of a thin
materia) such as plastic film or paper which is easy to tear. Where the bag is
made
of ~ heavier material such ss synthetic resin and fibrous material such as
hemp,
glass fiber, asbestos and the like the bag is more difficult to tear and the
arrangements described above do not work so wef t.
SUMMARY Of THE INVENTION
In broad terms the invention comprises a bag having st least one side wall. At
(east one of the at least one side walls includes a separable opening strip
defined
and bounded by a frangible boundary. Most frequently, the frangible boundary
is
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formed by weakening the side wall of the bag along two substantially parallel
edges
that are substantially equal in length and along a joining segment to join the
edges
at one and. There are, of course, numerous possible alternative configurations
including, far example, having the frangible boundary comprise a pair of
convergent
edges the join at one end to form a "V", in which case the joining segment
would
not be necessary.
~' - A method aspect of the invention includes the steps of providing a
material
-from which to form the bag; forming the bag such that it has at least one
side wall;
and forming in the at feast one aide wall a frangible boundary to define a
separable
opening strip.
BRIEF DESCRIPTION OP THE DRAWiN~38
The invention wilt be further described with reference to the accompanying
drawings in which:
FIG. 1 is a prospective view of one fomn of the bag having a vertical
separable opening strip bounded by a frangible boundary;
FIG 1 A is a view of a cylindrical bag having a separable opening strip
bounded by a frangible boundary;
FIGS. 1 B through 1 E illustrate verioue configurations ~ of the frangible
boundary defining the separable opening strip;
FIG. 2 is a prospeotive view of another form of the bag having a vertical
separable opening strip bounded by a frangible boundary;
FIG. 3 is a prospective view of one form of the beg having two horizontal
separable opening strips;
FIG. 4 is a prospective view of another form of the bag having two horizontal
separable opening strips;
FIG. 6 is a side elovation view of the bag shown in FIO. 1,
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a preferred embodiment of a bag having a
separable opening strip 10 (hereinafter, the "bag i0"). The particular
embodiment
of the bag 10 shown in the figures has opposed side wells 14 and 1B. It will
be
appreciated that the bop 10 may also have additional stde walls 18 en'd/or a
bottom
wall 20 interposed between side waNs 14 and 16. Furthermore, a bag 10 having a
.
,' single Bide wail is possible where, for exempla, a single cylindrlcel side
wall 22 is
-provided with top and bottom wails 24 end 26 ea shown in FIG. 1 A, in any
event,
the number of wells the bag 10 has is not particularly pertinent as will be
mare fully
appreciated further in the description. The beg 10 is preferably formed from a
synthetic resin and fibrous material such as hemp, glass fiber, asbestos or
the like
and suitable for storing and transporting peat moss, clay, fertilizer, pet
food and the
like. It is also preferred that the bag 10 be waterproof so as to inaulata its
contents
from moisture originating from sources external to the beg 10.
Tha wall 14 of the bag 10 in FIGS. 1 and 2 through 5 is bounded by four
boundsries 14s, 14b, 14o and 14d. In the case of a cylindrical well 22 as
shown
in FIG. 1 A, there may only be two boundaries 22a end 22b; however, for
purposes
of illustrating the principles of the invention, reference is made to the wall
14 which
has four boundaries. The point to be eppraclatsd further in this dssoriptlon
with
regard to the location of a separable opening strip 30 is that it is
preferably located
entirely within the boundaries of a single well no matter how many boundaries
thst
wall has. The wall 14 is provided with a saparebla opening strip 30 bounded by
a
frangible boundary 34. Tha frangible boundary 34 is located within the
confines of
the borders l4s,b,o and d of side wall 14. Although designations of
orientafion
such as top and bottom ere entirely arbitrary, for the purposes of clarity,
border
14a is regarded as the top border; 14b, the left border; 140, the right border
and
14d, the bottom border. The frangible boundary 34 is formed preferably by
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weakening the wall 14 along a path that includes two substantially parallel
elongated edges 38 and 37 having first ends 38a and 37a end second ends 38b
and 37b, respectively. The edges 38 and 37 are joined by a joining segment 40
that joins the edges 3B and 37 at at feast one of each of their ends. For
example,
the joining segment 40 may join ends 38b and 37b as shown in Fl4. 1, ends 38a
and 37a or a joining segment 40 may join both sets of ends 38a and 37a and 38b
end 37b as shown in FIG. 1 B.
- As shown in FIG. 1, the edges 38 and 37 of the frangible boundary 30 are
preferably substantially equal in length and aligned with one another on the
wall 14.
The weakening of the wall 14 to create the frangible boundary 34 is preferably
accomplished by perforating the wall 14 along a path that defines the shape of
the
frangible boundary 34. However. 'rt will be appreciated that the wall 14 could
be
weakened in other ways including by applying one or more score lines or one or
more cuts to define the frangible boundary 34. Furthermore, depending on the
material from which the beg 10 is fabricated, a weakened region defining the
frangible boundary 34 could be formed contemporaneously with the formation of
the plastic sheet from which wall 14 is made. For example, if the bag 10 were
fabricated from a heavy plastic, the frangible boundary 34. oouid be formed
right in
the sheet of plastic as the sheet of plastic is being formed.
The frangible boundary 34 defining the separable opening strip 30 may be of
numerous configurations. It has previously been stated that the preferred
configuration includoa two substantially parallel edges 36 and 37 joined by a
joining
segment 40 that joins the edges 38 and 37 at at (east one of each of their
ends
3Ba end 38b and 37a and 37b. While the preferred Joining segment 40 is V-
shaped
ae shown in FIG. 1, other possible shapes include semi-circular or simply a
straight
line segment extending perpendicularly between edges 38 and 37, for oxample,
as
shown in FIGS. 1 C end 7 D, respectively. Furthermore, although there are
certain
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advantepes to aligning the edges 36 and 37 in substantially parallel
alignment, it is
not essential to so align them; for instance, they could be linear, but
converge
themselves and join to form a V-shaped frangible boundary 30, in which case
the
joining segment 40 would be unnecessary. See FIG. 1 E.
. The bag 10 may further comprise a strip of taps 60 adhered to the side wall
14 by a suitable, known adhesive 64. As shown in FiG. 1 and others, the tape
60
may cover and overlap the separable opening strip 30, and extend in all
directions to
-the outside of the frangible boundary 34. Preferably, the tape 60 is formed
of a
flexible plastic material that is water impermeable, and includes an sdhssive
64 that
is water resistant, so as to prevent water from entering the beg 10 through
the
frangible boundary 34. Furthermore, the tape 60 and the adhesive 64 by which
it is
adhered to the bag 10 should be resistant to high and low temperatures so as
to be
capable of preventing moisture tram entering the bag 10 under various
anvirqnmental
conditions such as might be incurred outdoors.
The tape BO may further comprise a pull-tab 68 extending outwardly from the
wall 14, as particularly shown in FIG. 5. Ths preferred pull-tab 68 is of the
same
width as the tape 60 and may be formed of paper or cellophane. Alternatively,
the
pull-tab 68 may comlxiae a section of the taps 60 which is not adhered to the
wall
14. As shown in FIG. 1, it is preferred that the tape 60 be oriented so that
the pull-
tab 68 is adjacent the joining segment 40 of the frangible boundary 34, where
applicable. Where there is no joining segment 40. it is prefsrrod that the
pull-tab 68
be adjacent to the point where the edges 3d and 37 of the frangible boundary
34
converge. If the edges 3B and 37 are joined at both sets of their ends 38a and
37a
and 38b and 37b, either by joining segments 44 or by convergence, a pull-tab
68
may be provided adjacent either or both sets of ends 36a end 37a and 38b end
37b.
To open the bag 10 using separable opening strip 30. the pull-tab 68 is
gripped
and pulled outwardly from the wall 14. As the pull-tab 18 is pulled away from
the
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wall 14, the strip of tape fi0 separates from the wall 14. The separable
opening strip
30, however, remains adhered to the tape 60 and separates from the wall 14
along
the frangible boundary 34 creating an opening in the bag 10 between the edges
38
and 37. Optionally, to facilitate this aspect of the invention, the tape 60
could ba
adhered or otherwise attached to the separable opening strip 30 by means of a
stronger adhesive such as glue, for example, than the adhesive by which the
~' Temaindar of the tape 60 is adhered to the side wall 14 to the outside of
the frangible
-boundary 34.
it is envisaged that the orientation, placement end number of separable
opening strips 30 may be altered. Figure 7 shows a vert~cal~y onentea
separaa~e
opening strip 30 having a tape 80 in which the pull-tab 68 is located above
the
separable openin8 strip 30. As shown in Figure 2, the pull-tab 68 may be
placed
below the separable opening strip 30.
Figures 3 and 4 show a eltametive arrangements in which the separable
opening strip 30 is positioned horizontally across the side wall 14 of the beg
10. In
Figure 3, the pull-tab 68 of the strip of tape 60 Is positioned to the Isft of
the
separable opening strip 30 whereas in Figure 4, the pull-tab 68 is positioned
to the
right of ~e separable opening strip 30. As shown in both Figures 3 and 4, the
side
well 14 maY be provided with a plurality (at Isast twal separable opening
strips 30.
tt will be appreciated that tha number of separable opening strips 30 may
exceed two, and that the separable opening strip(si 30 may be poattloned along
the
top of tha bag or the base wall of the bag as an addition or en alternative to
one or
more of the side walls.