Background of the Invention
[0001] This invention relates to a carton erected from a blank of stiff, but foldable, board
material which blank incorporates the precursor of a tear strip permitting the carton
to be erected into a first closed condition to contain a product (preferably of a
flowable nature that can be dispensed by pouring from the carton) but on actuation
of the tear strip can be converted into an opened carton for ready dispensing of the
contents.
[0002] It is expected that a carton in accordance with the invention will find many commercial
applications but it has been specifically designed for the retaining in moisture-proof
conditions and the subsequent dispensing of seeds.
Summary of the Invention
[0003] According to one aspect of the invention a carton erected from a blank of stiff,
but foldable, board material has a bottom, a top, and side faces delimited by corners
and the top, the top being provided with the precursor of a hinge extending across
one corner of the carton from a first line of weakness in one face to a second line
of weakness in another face, said lines of weakness being interconnected by the precursor
of a tear strip formed in at least said one face and said another face whereby on
actuation of the tear strip a closure cap is formed from the top which can hinge between
open and closed positions about said precursor of the hinge.
[0004] Conveniently, the carton is of right parallelepipedic form and the precursor of the
tear strip runs from a pull tab adjacent one corner of the carton to a cut formed
in the next adjacent side face intermediate the corners that define that side face.
[0005] Suitably the lines of weakness in the side faces extend parallel to the corners and
in a preferred arrangement one line of weakness is located at or adjacent to one corner
and preferably extends down to the pull tab. Either or both lines of weakness can
be a cut or a partial cut.
[0006] Suitably the top is formed from overlain flaps forming extensions of the side faces,
the precursor of the hinge being formed as a line of weakness along at least one of
said flaps.
[0007] To ensure that when the cap is lifted, following actuation of the tear strip and
hinging about the said hinge, the retaining effect of the two side faces is not destroyed,
it is desirable to form the two side faces involved in the creation of the cap, at
least in part, as double layers, only the outer layer of which is torn by the actuation
of the tear strip.
[0008] Conveniently the tear strip is created from at least one length of reinforcing tape
adhered to or incorporated in,the board material. For manufacturing convenience, straight
lengths of tape can be employed in a right parallelepipedic carton which lengths extend
through each of the four side faces and the two double layers provided to supplement
the faces torn during opening of the carton, the extent of the tearing open being
limited by a cut formed through this reinforcing tape or tapes in the vicinity of
the second line of weakness.
[0009] The bottom of the carton can similarly be formed from overlain flaps forming extensions
of the side faces.
[0010] The invention also extends to a blank of stiff, but foldable, board material from
which the carton can be erected.
[0011] A particular advantage of the invention is that it enables a blank of board material
to be partially erected into a knocked-down carton which can be supplied to users
as a finished flat blank merely requiring erection by folding in bottom-forming flaps
prior to filling and closing of the top subsequent to filling. Erection and filling
can be effected using automatically operating machinery.
[0012] A variety of different forms of stiff, but foldable, board material can be employed
to fabricate a carton in accordance with the invention but a preferred material is
double-faced corrugated board, the tear strip incorporating two parallel longitudinally
splittable reinforcing tapes one located between layers of the corrugated board and
another located on the inside of the inner layer of the board, since experience has
shown that tapes of this design will create a very clean tear when they are actuated.
[0013] Suitably the pull tab is cut as a tapered piece of board material whose narrow end
overlies a central part of two parallel splittable tapes.
[0014] To provide a moisture resistant wall to the carton, the facing sheet of double-faced
corrugated board destined to be innermost on erection of the blank into a carton can
be provided with a moisture-proof barrier layer (e.g. of a plastics material) . A
sandwich construction of paper/moisture barrier/paper can be used as the inner facing
sheet or a barrier layer can be adhered to a paper facing sheet as the board material
is being formed on a corrugator.
Brief Description of the Drawings
[0015] The invention will now be further described, by way of example, with reference to
the accompanying drawings, in which:-
Figure 1 is a plan of a blank for erecting into a carton in accordance with the invention,
Figure 2 shows the closed carton created from the blank of Figure 1,
Figure 3 shows a first stage in the opening of the carton of Figure 2,
Figure 4 shows the carton of Figure 1 fully opened and ready to dispense contents,
Figure 5 shows a first stage in the erection of the carton of Figure 2 from the blank
of Figure 1,
Figure 6 shows a further stage in the erecting procedure,
Figure 7 shows the finished blank knocked down flat ready for supply to an end user,
and
Figure 8 shows the pull tab of Figures 1 and 2 in greater detail.
Description of Preferred Embodiments
[0016] Referring to Figure 1, this illustrates a pre-cut pre-creased blank 10 of stiff,
but foldable, double-faced corrugated fibreboard material as seen from the inside
and comprises a front panel 11, a first side panel 12, a rear panel 13, a second side
panel 14, a secondary front panel 15 and a secondary partial side panel 16 joined
side-by-side by parallel crease lines (shown in Figure 1 as dashed lines) which will
define the corners of the eventually erected carton. The direction of the flutes in
the intermediate web of the three web board material is indicated by the arrow A in
Figure 1.
[0017] The bottom of the carton is created by integral end flaps 11a, 12a, 13a and 14a and
the top of the carton is created by integral end flaps 11b, 12b, 13b and 14b, these
end flaps being delimited from the respective panels 11 to 14 by further crease lines
also shown dotted.
[0018] Extending completely across the width of the blank 10 is a reinforcing tape 17 which
terminates in the front panel 11 in a pull tab 18. The tape 17 is cut at the point
20 in the side panel 12 at the location of a line of weakness 24 which extends from
the cut 20 to the top of the panel 12 where it meets an inclined line of weakness
21, the purpose of which will be further described. The top flap 14b also includes
an inclined line of weakness 22.
[0019] Figure 2 shows a carton 30 erected from the blank of Figure 1 and Figures 5 and 6
show how this erection is effected, it being noted that the secondary front panel
15 completely underlies the front panel 11 and the secondary side panel 16 partially
underlies the first side panel 12. These secondary panels 15 and 16 are not clearly
evident in the erected but unopened carton shown in Figure 2 although the panel 15
can just be seen at the edge of the panel 11 behind the pull tab 18. Following folding-over
of the blank in the manner shown in Figures 5 and 6 and a gluing together of lower
regions of the secondary panels 15 and 16 to the outer panels 11 and 12 via the glued
areas shown at 29 in Figure 5, the blank 10 forms a knocked-down format 10A as shown
in Figure 7 and in this form can be delivered to a user.
[0020] The user then opens out the format 10A and folds in the flaps 12a, 11a, 13a, 14a
to create a rectangular bottom to the carton and fills the carton with the product
through the then-open top. The top is now closed by folding-in the upper flaps in
the sequence 14b, 11b, 13b, 12b and adhering at least regions on the underside of
flap 12b to flap 14b. In the erected condition of the carton 30 as shown in Figure
2, lines 21 and 22 are collinear and define the precursor of a diagonal hinge extending
across the top of the carton from the corner at which the pull tab 18 is located to
the region on the side panel 12 where the cut 20 is formed at the lower end of the
line of weakness 24.
[0021] It will be readily apparent from an examination of Figures 3 and 4 how the carton
is opened by actuating the tear strip using the pull tab 18. Figure 3 shows the tear
strip 19 partially removed and Figure 4 shows how, on its complete removal, a triangular
cap 23 is created from the top which can be lifted by folding back to expose the contents.
The purpose of the secondary walls 15 and 16 is now readily apparent, these acting
to prevent spillage of contents until the carton 30 is tipped, usually with the exposed
corner lowermost, to provide a true dispensing operation of the contents.
[0022] The preferred material for the tape 17 is SESAME (Trade Mark) tape, this being a
longitudinally splittable fibrous tape that can be incorporated in corrugated fibreboard
material as the material is made on the corrugator. Desirably two lengths of this
tape are provided one above the other (see Figure 8), one length 17a being located
on the back of the front facing web 10a of the corrugated board material used for
the blank 10 of Figure 1 and the other length 17b being located on the back of the
rear facing web 10c. The corrugated central web is shown at 10b. With this arrangement
one tape length (17a) is hidden in the laminations of the board material and is thus
invisible from the intended front face of the board material while the other tape
length (17b) is visible when viewing the inside face of the carton. The pull tab 18
is cut into the blank 10 in such a way that the cuts defining it only partially sever
both tape lengths at the inner narrow end of the pull tab 18, so that when the tab
18 is pulled away from the panel 11 a narrow central strip 17c is torn out of both
lengths of tape 17a and 17b leaving a clean cut in all three webs 10a, 10b and 10c
of the board material from the location of the tear tab 18 through to the cut line
20. To facilitate grasping of the tab 18 it can project slightly proud of the rest
of the edge of the front panel 11 as shown in Figure 8.
[0023] The cap 23 can be opened and closed many times about the hinge formed by the lines
21 and 22 so that partial dispensing of the carton contents can also be undertaken
many times. The ears 14c shown provided on the flap 14b are an optional feature but
when provided create a finger tab for facilitating opening of the carton 30.
[0024] The cutting away of one corner of the flap 11b facilitates the hinging of the cap
23 about the hinge lines 21, 22.
[0025] The flap 12b can be of the same height as flap 14b in which case the line of weakness
21 extends all the way up to the left-hand top corner of the flap 12b.
[0026] A suitable pourable material for containment in the carton is seeds and to protect
these from moisture ingress the board material from which the blank 10 is stamped
can be rendered moisture-proof (e.g. by coating, laminating (for example with MELINEX
(TM)) or using, as the inner liner 10c of the board, a polythene-lined paper or a
paper/polythene/paper sandwich. A thin polythene barrier layer suitable for incorporation
in such a sandwich is that known under the Trade Mark PARATEN.
[0027] Moisture protection is particularly important in the case of seeds provided with
an insecticidal coating based on pva. Prior art cartons to contain coated seed (e.g.
sugar beet seeds) have used a separate moisture-proof bag contained within a fibreboard
carton but by using a carton in accordance with this invention which has been made
from board material moisture-proofed on its inner facing surface in the manner described,
the use of a separate bag can be dispensed with making the seeds more readily available
for use when required without impairing the protective coating on the seeds which
gives them a (near) 100% germination success rate.
[0028] Where contents as small as seeds are packaged in a carton according to the invention
it can be desirable to apply adhesive to that area 29 of flap 16 which is closest
to the free edge thereof so that it extends the full length of the flap 16 and thus
bonds the flap 16 to the flap 12 above the line of the tape 17 to the right of the
cut 20 shown in Figure 5.
[0029] Moisture proofing of board material with a layer of MELINEX (TM) or PARATEN (TM)
does not interfere with the actuation of the tear strip required to create the openable
cap 23.
[0030] In one practical example 100000 sugar beet seeds each protected with a pva layer
dusted with insecticide/fungicide could be housed in a parallelepipedic carton of
308 mm x 193 mm x 121 mm.
1. A carton erected from a blank of stiff, but foldable, board material having a bottom,
a top, and side faces delimited by corners and the top, the top being provided with
the precursor of a hinge extending across one corner of the carton from a first line
of weakness in one face to a second line of weakness in another face, said lines of
weakness being interconnected by the precursor of a tear strip formed in at least
said one face and said another face, whereby on actuation of the tear strip a closure
cap is formed from the top which can hinge between open and closed positions about
said precursor of the hinge.
2. A carton according to claim 1, in which the carton is of right parallelepipedic form
and the precursor of the tear strip runs from a pull tab adjacent one corner of the
carton to a cut formed in the next adjacent side face intermediate the corners that
define that side face.
3. A carton according to claim 1 or claim 2, in which the lines of weakness in the side
faces extend parallel to the corners of the carton.
4. A carton according to claim 3, in which one line of weakness is located at or adjacent
to one corner.
5. A carton according to any preceding claim, in which the two side faces involved in
the creation of the cap, at least in part, are formed as double layers, only the outer
layer of which is torn by the actuation of the tear strip.
6. A carton according to any preceding claim, in which the tear strip is created from
at least one length of reinforcing tape adhered to, or incorporated in, the board
material.
7. A carton according to claim 6, in which said at least one length of tape extends through
each of the four side faces and the two double layers provided to supplement the faces
torn during opening of the carton, the extent of the tearing open being limited by
a cut formed through the or each reinforcing tape in the vicinity of the second line
of weakness.
8. A carton according to any preceding claim partially erected into a knocked-down carton
which can be supplied to users as a finished flat blank merely requiring erection
by folding in bottom-forming flaps prior to filling and closing of the top subsequent
to filling.
9. A carton according to any preceding claim, in which the board material incorporates
a moisture-resistant barrier layer.
10. A blank of stiff but foldable board material for erecting into a carton as claimed
in any one of the preceding claims.