[0001] THE PRESENT INVENTION relates generally to a tear tape opening system for a carton
or package formed of corrugated board and more particularly it relates to such a system
wherein the edge produced by the opening system at the outside surface of the outside
liner board of the corrugated board packaging material is evenly torn without any
unevenness therealong resulting from the tearing operation.
[0002] A similar type of opening system is disclosed in our European Patent Application
No. 88301122.3, published as EP 0278751, entitled "A tear tape opening system". In
this referenced application, there is disclosed a tear tape opening system for use
with packages formed of kraft paper, paper board or corrugated board. The major benefit
derived from the invention the subject of EP 0278751 is to provide reinforcing along
the tear line or lines in the outside surface of the material forming the package,
so as to prevent uneven tearing or delamination of the outside surface of the material
forming the package at or along the tear line. The system disclosed in this prior
application consists of a tear tape in the form of hot melt coated tape or string
adhered along the inside surface of the package material, along the desired tear line
of the opening system, together with a tear guide system consisting of one or a plurality
of tapes arranged on the outside surface of the package material along the desired
line of tear and which guides the tear produced by the tear tape so as to prevent
uneven tearing of the package forming material. Furthermore, in connection with packages
formed of corrugated board, this prior application teaches, in addition to disposing
the tear guide system on the outside surface of the corrugated board, that it is possible
to arrange the guide tape or tapes on the inside surface of the outside liner and
that it is possible to provide the tear tape on the inside or outside surface of the
inside liner board.
[0003] In connection with employing the tear tape opening system according to the above-identified
application, with a package or carton formed of corrugated board, it is not possible
to utilise a hot melt coated tape for the tear guide system on the outside surface
of the corrugated board since these tapes are applied at the doublebacker section
of the corrugation forming machine or corrugator when the outside liner is incorporated
in the formation of the corrugated board. The outside liner is incorporated in the
corrugated board with the use of hot plates which press the outside liner against
the flutes of the corrugating medium and the heat activates the adhesive on the flutes
to thereby adhere the outside liner thereto. Thus, if a hot melt coated tape were
also applied at this point, the heat of the hot plates would cause the hot melt to
soften and smear, resulting in an unsightly package and unworkable tear guide system.
Alternatively, as indicated in the prior application, the tear guide tape can be
applied in the form of a hot melt coated tape to the inside surface of the outside
liner at the doublebacker of the corrugator. However, in this latter application when
the tear tape is pulled through the corrugated board, the outer surface of the outside
liner at the tear line may become unevenly torn since there is no reinforcement at
the outer surface to reinforce the edge of the tear. This drawback is particularly
problematic where the outside liner is coated for the purpose of accepting printing
thereon, since this coating tends to flake and become broken when torn through by
the tear tape. Because of the poor results obtained in such an opening system for
a carton or package formed of corrugated board relative to the unevenness of the edges
along the tear line, the carton itself is too unsightly to be utilised in a consumer
display of the product. Therefore, a retailer must go through the labour intensive
operation of unpacking the carton and stocking the store shelves.
[0004] It is, therefore, a primary object of the present invention to provide a tear tape
opening system for establishing an opening in a carton or package formed of corrugated
board, whereby the edge of the tear line at the outside surface of the outside liner
of the corrugated board is reinforced so as to be stabilised during the opening procedure
to result in an even torn edge therealong and to also provide a reinforced torn edge
for the resulting open container.
[0005] The above object is accomplished in accordance with the present invention by providing
a tear tape opening system for creating an opening in a package or carton formed of
corrugated board wherein the corrugated board consists of an outside liner, an inside
liner and a corrugating medium thereinbetween, wherein the outside liner has outside
and inside surfaces and the inside liner has outside and inside surfaces, and the
inside surfaces of the outside and inside liners face the corrugating medium. The
tear tape opening system according to the present invention includes a tear tape adhered
to the outside surface of the inside liner along the desired line of opening and a
paperbacked hot melt coated tape, wider than the tear tape, adhered to the outside
surface of the outside liner along the desired line of opening so as to guide the
tear formed by the tear tape and reinforce and stabilize the edges of the tear along
the outside surface of the outside liner. By the utilisation of a paperbacked hot
melt coated tape for the tear guide system, the tape is capable of being applied to
the outside surface of the outside liner of the corrugated board during the incorporation
of the outside liner in the corrugated board. Thus, the paperbacked hot melt coated
tape is applied in the doublebacker segment of the corrugator board forming machine
and the paperbacking prevents the hot melt coated tape from being directed contacted
by the hot plates and resulting in the melting and smearing thereof.
[0006] An embodiment of the invention is described below, by way of example, with reference
to the accompanying drawings, wherein:-
FIGURE 1 is a perspective view of a carton having the tear tape opening system embodying
the present invention;
FIGURE 2 is a perspective view of the carton of Figure 1, subsequent to being opened
by the tear tape opening system with the sections of the carton shown exploded and
the product therein arranged in a consumer display;
FIGURE 3 is a perspective view of a panel of the carton of Figure 1, showing the tear
tape opening system therein;
FIGURE 4 is a schematic view of a portion of the machine utilised in the formation
of corrugated board; and
FIGURE 5 is a perspective view of the tear guide tape utilised in the tear tape opening
system of the carton of Figure 1.
[0007] Now turning to the drawings, there is shown in Figure 1 a carton, designated 10,
having a horizontally disposed tear tape opening system 12 passing circumferentially
throughout the periphery thereof and dividing the carton into a lower section 14 and
an upper section 16. Thus, lower and upper sections 14 and 16, respectively, can be
separated from each other as shown in Figure 2 and the lower section utilised as a
tray for the product 18 packaged in carton 10 in a consumer display. However, in order
for lower section 14 of carton 10 to be utilised together with the product 18 contained
in the carton in such a consumer display, the tear line 20 of lower section 14 resulting
from the operation of the tear tape opening system 12 must be straight and even without
any tears or breaks in the outside surface of the outside liner of the corrugated
board.
[0008] Turning now to Figure 3, therein is shown a corrugated board panel, designated 22,
of carton 10 having outside and inside liners 24 and 26 respectively, and corrugations
or corrugating medium 28 thereinbetween. Tear tape opening system 12 consists of a
tear tape 30 adhered to the outside surface of inside liner 26 along the desired opening
line and a tear guide tape, designated 32, adhered to the outside surface of outside
liner 24 of panel 22. In order to operate the tear tape opening system, the user grasps
pull tab 34, formed by die cut 36, and pulls in the direction indicated by the arrow.
Tear tape 30 is thereby caused to rip through inside liner 26, corrugations 28 and
outside liner 24. Tear lines 20 are guided in each section of panel 22 by means of
guide tape 32 which lacks weft strength so that outside liner 24 is caused to tear
substantially evenly, resulting in even tears along tear lines 20.
[0009] In Figure 4 there is shown the doublebacker section, designated 38, of a corrugated
board-forming machine where inside liner 26 adhered to the flutes of one side of corrugating
medium 28 is fed between pressure rolls 40 and hot plates 42, and outside liner 24
is applied to the opposing flutes of corrugations 28 by roller 44. Thus, outside liner
24, corrugations 28 and inside liner 26 are sandwiched between pressure rolls 40 and
hot plates 42. Upstream from the doublebacker section (not shown), an adhesive is
applied to the flutes of corrugations 28, which is heat activated so that when the
three elements pass between pressure rolls 40 and hot plates 42, the outside liner
is firmly adhered to corrugations 28. Tear tape 30 is conveniently applied to the
outside surface of inside liner 26 by feeding it into the nip between inside liner
26 and pressure rolls 40. Tear tape 30 may be anything which has the ability to tear
such as a hot melt coated tape or string, or pressure sensitive tape. As can be seen
from Figure 4, there is no problem created by having the tear tape a hot melt coated
tape or string since the tape is not exposed to hot plates 42, which are disposed
on the opposite side of the corrugated board being formed between pressure rolls 40
and hot plates 42. Preferably, tear guide tape 32 is fed into the nip between outside
liner 24 and roller 44, so that it is disposed on the outside surface of outside liner
24. In such a case, however, it should be noted that, as pointed out above, if tear
guide tape 32 is a hot melt coated tape, the hot melt will be melted by the hot plates
42 and thus smear the outside of outside liner 24. In order to overcome this problem
and still take advantage of the benefits of having tear guide tape 32 applied to the
outside surface of outside liner 24, it has been found that applying a paper backing
to the hot melt coated tape on the outside surface thereof, will insulate the hot
melt coated tape so that hot plates 42 are not in direct contact with the hot melt
of tape 32. Thus, as clearly seen in Figure 5, tear guide tape 32 consists of a hot
melt coated tape 46 having a paperbacking 48 applied to one side thereof.
[0010] While only a single embodiment of the present invention has been described and shown,
it is obvious that many changes and modifications may be made thereunto without departing
from the spirit and scope of the present invention as defined by the accompanying
claims.
[0011] The features disclosed in the foregoing description, in the following claims and/or
in the accompanying drawings may, both separately and in any combination thereof,
be material for realising the invention in diverse forms thereof.
1. A tear tape opening system for establishing an opening having an even tear line
in a package or carton formed of corrugated board, the corrugated board having an
outside liner, an inside liner, and corrugations therein between, the outside and
inside liners each having outside and inside surfaces, the inside surfaces of the
outside and inside liners facing and being adhered to the corrugations, said tear
tape opening system comprising:
a tear tape adhered to the outside surface of the inside liner of the corrugated board
along the desired line of opening; and
a tear guide tape adhered to the outside surface of the outside liner of the corrugated
board along the desired line of opening superimposed in projection on said tear tape,
said tear guide tape consisting of a hot melt coated tape adhered to the outside surface
of the outside liner and having a paper backing thereon.
2. A tear tape opening system as claimed in claim 1, wherein the tear tape and the
tear guide tape extend circumferentially throughout the periphery of the carton so
that when a opening is established by the tear tape opening system, the carton is
separated into two sections at least one of which is suitable for consumer display
of the product packaged in the carton.
3. A tear tape opening system as claimed in claim 2, wherein at least the tear tape
edge corresponding to the tear line of the carton section of the consumer display
underlies said tear guide tape.
4. A tear tape opening system as claimed in claim 1 or claim 2, wherein the tear guide
tape is wider than the tear tape and overlies both edges of the tear tape.
5. A method of producing a tear tape opening system for establishing an opening having
an even tear line in a package or carton formed of corrugated board, the corrugated
board having an outside liner, an inside liner, and corrugations thereinbetween, the
outside and inside liners each having outside and inside surfaces, the inside surfaces
of the outside and inside liners facing and being adhered to the corrugations, the
method comprising:
adhering the tear tape to the outside surface of the inside liner of the corrugated
board along the desired line of opening by feeding the tear tape into the nip between
the pressure rolls and the inside liner which is adhered to the flutes of one side
of the corrugating medium in the doublebacker of the corrugator forming machine; and
adhering the tear guide tape to the outside surface of the outside liner of the corrugated
board along the desired line of opening by feeding the tear guide tape into the nip
between the outside liner and the roller pressing the outside liner into contact with
the flutes of the side of the corrugating medium opposite the inside liner, the tear
guide tape being formed of a hot melt coated tape having a paper backing thereon to
prevent the heat from the hot plates from melting the hot melt.