IES59845B2 - Manufacturing paperboard blanks - Google Patents

Description

Manufacturing paperboard blanks The invention relates to a method for manufacturing paperboard blanks .

There are several steps involved in the manufacture of paperboard blanks . It is known to have dedicated machines 5 for taking a paperboard sheet and forming, in one machine, a limited range of paperboard blanks for cartons. Such machinery, however, is not only expensive but also limited because it must be run at very high speeds on large quantity runs for efficiency.

This invention is directed primarily towards providing a method for manufacturing a paperboard blank in a cost efficient manner. In particular, the invention is directed towards providing a method which may be used for manufacturing a wide range of different size, shapes and 15 quantities of paperboard blanks.

According to the invention there is provided a method for manufacturing a paperboard carton blank comprising the steps of:feeding rectilinear sheets of paperboard to an 20 infeed; creasing the sheets in a desired pattern; cutting away part of the creased sheet to form a blank; stacking the blanks thus formed; applying glue to a flap of the blank; - 2 folding the blank about the creases to engage a mating part of the blank with the glue on the flap; , stacking the glued blanks in a well to cure the adhesive; delivering glued blanks from the well to an outfeed hopper; counting the glued blanks in the outfeed hopper; delivering a preset number of glued blanks from the stack along a conveyor to a transfer station; delivering the stack of glued blanks from the transfer station; squaring the stack of glued blanks, and strapping the stack.

In a preferred embodiment of the invention, the method includes the step of driving the conveyor to the transfer station in synchronisation with an outfeed roller of the delivery conveyor.

Preferably, the conveyor to the transfer station is of a flexible material to accommodate the stack.

In a preferred embodiment of the invention, the transfer conveyor comprises at least two spaced-apart flexible · drive belts between the transfer station and the outfeed roller, the outfeed roller driving the drive belts to 9 deliver the stack to the transfer station.

In one embodiment of the invention, the transfer station comprises a transfer conveyor which is driven to deliver the stack for squaring and strapping.

Preferably, the transfer conveyor comprises a plurality of 5 transfer rollers and the method includes the step of driving the transfer rollers to deliver the stack for squaring and strapping.

In a preferred embodiment of the invention, part of the blank is cut-away by forming slots in the blank.

In one embodiment of the invention, the method includes the step of printing indicia on the sheets prior to creasing.

Preferably, the method includes the step of applying a load to the creased and cut blanks as they are being 15 stacked. In this case, preferably the load is applied by at least one spring loaded arm which presses down on the cut and creased blanks as they are being stacked.

The invention also provides paperboard blanks whenever manufacturing by the method of the invention.

The invention will be more clearly understood from the following only with which:- description thereof, given by way of example reference to the accompanying drawings in Fig. 1 is a plan view of a typical sheet of 25 paperboard material used in the method of the v invention; Fig. 2 is a plan view of the sheet of Fig. 1 formed into a creased and slotted blank; Fig. 3 is a perspective view of part of a slotting , apparatus used in the method of the invention; a Fig. 4 is a plan view of another apparatus used in the method of the invention; Fig. 5 is a side elevational view of part of the apparatus of Fig. 4; Fig. 6 is a side view of a detail of the apparatus of Fig. 5; Fig. 7 is a perspective view of a detail of the apparatus of Fig. 5; and Fig. 8 is a perspective view of part of the apparatus of Fig. 5.

In the method for manufacturing a paperboard carton blank according to the invention, rectilinear sheets 1 of paperboard material are fed to a machine which first prints indicia on the sheet at desired locations and in desired patterns and colours. The printed sheet is then creased by feeding it through creasing rollers which form transverse creases 2 in the sheet. Longitudinal creases 3 may be either preformed into the sheet 1 or may be formed using additional creasing rollers. The creased and printed sheet is then passed between pairs of opposed slotting rollers 5 which form slots 6 in the sheet 1 including a side flap 7. As the printed, creased and e slotted blanks are delivered from the slotter rollers 5, they are stacked on a bed 10. To maintain the blanks in V position on the bed 10, a load is applied to the uppermost blank in the stack by a pair of arms 12 which are typically of spring steel material and extend downwardly from a support 14 to engage the uppermost sheet in the stack. The arm 14 is fixed to a support arm 15 which is slidably mounted in a bracket 16 for adjustment of the arm 15 and hence the load applying legs 12 into a desired 5 position engaging the stack. The arm 15 is moved to accommodate different sizes of sheets. The legs 12 may also be moved up and down the arm 14 as required.

Referring particularly to Fig. 4, the printed, creased and slotted blanks 25 are loaded onto a gluing machine 21 10 having a gluing station 20 which applies a strip of glue to the flap 7 of the blank 25. Side portions 23 of the blank 25 are then folded towards one another so that the glued flap 7 engages a mating face of the other side portion 24 of the blank 25. After folding the folded 15 blanks 25 are delivered into a well 30 to allow the glue to cure. From the well 30, the blanks are stacked at 31 and the lowermost blanks in the stack 31 are delivered to an out feed stacking area 33 in which the blanks are counted and a stack 34 of the folded blanks is driven by a belt 35 to a transfer conveyor 37. The transfer conveyor 37 delivers the stack 34 of blanks to a transfer holding station 38 from which the stack 34 is delivered to a squaring and strapping machine 40. Stacks 34 of strapped folded blanks being delivered from the machine 40 for storage. The transfer station 38 includes a transfer conveyor comprising a plurality of transfer rollers 45 which are driven by a drive motor 46 for driving the stack 34 into the squaring and strapping machine 40.

The transfer conveyor 37 in this case comprises a conveyor 30 of flexible material, in this case three spaced-apart flexible belts 48 which are trained around guide rollers 49, an outermost outfeed roller 50 of the gluing and folding machine and a roller 51 adjacent the transfer conveyor rollers 45.

The stack 34 passes to the transfer conveyor under the control of an upper load applying conveyor 55 which is biased by counterweights 56.

In use, printed, creased, slotted and glued blanks 25 are folded as described and the flat folded blanks are delivered away from the outfeed roller 50 by the flexible drive belts 48 to the transfer station 34. If an operator monitors any quality defects or blockages in the machine, the transfer drive motor 46 may be stopped and the fault 10 corrected before the stacks 34 are fed to the squaring and strapping machine 40.

The invention provides a cost efficient method of manufacturing folded paperboard blanks in a wide range of sizes and in a manner which allows the machinery to be 15 optimised for maximum output even for relatively low volume runs .

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims (5)

1. A method for manufacturing a paperboard carton blank comprising the steps of:- feeding rectilinear sheets of paperboard to an infeed; creasing the sheets in a desired pattern; cutting away part of the creased sheet to form a blank; stacking the blanks thus formed; applying glue to a flap of the blank; folding the blank about the creases to engage a mating part of the blank with the flap; glue on the stacking the glued blanks in a well to cure the 15 adhesive; delivering glued blanks from the well to an outfeed hopper; counting the glued blanks in the outfeed hopper; delivering a preset number of glued blanks from the stack along a conveyor to a transfer station; delivering the stack of glued blanks from the transfer station; squaring the stack of glued blanks, and strapping the stack.

2. A method as claimed in claim 1 including the step of driving the conveyor to the transfer station in synchronisation with an outfeed roller of the delivery conveyor, preferably the conveyor to the transfer station is of a flexible material to accommodate the stack, preferably the transfer conveyor comprises at least two spaced-apart flexible drive belts between the transfer station and the outfeed roller, the outfeed roller driving the drive belts to deliver the stack to the transfer station.

3. A method as claimed in any preceding claim wherein the transfer station comprises a transfer conveyor which is driven to deliver the stack for squaring and strapping, preferably the transfer conveyor comprises a plurality of transfer rollers and the method includes the step of driving the transfer rollers to deliver the stack for squaring and strapping, preferably part of the blank is cut-away by forming slots in the blank, preferably the method also includes the step of printing indicia on the sheets prior to creasing, preferably the method includes the step of applying a load to the creased and cut blanks as they are being stacked, typically the load is applied by at least one spring loaded arm which presses down on the cut and creased blanks as they are being stacked.

4. A method substantially as hereinbefore described with v reference to the accompanying drawings.

5. A paperboard blank whenever manufactured by a method as claimed in any preceding claim.