THE MANUFACTURER'S JOIN

The blank produced by the corrugator and processed by the Printer Slotter has to be joined to make it complete before dispatch. This is done by folding over both end panels which are then secured by stitching, gluing or taping, according to the customer's requirements.

STITCHING

This is basically a simple method where the join flange and the opposite end of the case blank are joined together by metal stitches which are formed as required from a continuous reel of wire. 'the blank is folded and passed through a stitching head which cuts the wire to the right length for the material thickness, cutting-dies a 'U' shaped staple, forces this through both thicknesses of board and finally clenches it. There arc four main variations of machine for performing this function.

Table Stitchers

The scored blank is hand folded and pushed through the stitching head until the first stitch position is reached. 'A foot pedal is then used to operate the stitching action as the board is ' passed through the head. Stitches can be made one at a time for accurate work or continuously as the board is travelling through. The accuracy of stitching is completely controlled by the operator. Throughput on average size cases is 620 per hour with A crew of two girls.

Semi-automatic Stitchers

The scored blank is hand folded and pushed into the machine, but as soon as the parts to be joined enter the stitching head, the machine automatically starts to stitch at the correct spacing and also carries the blank through the machine. The operator works behind a stack of boards and as each blank is passed into the machine the stack is slightly raised by micro-switch control so that the next blank is brought into the correct position for folding and feeding. This type of machine can double the throughput of the ['able Stitchers with the same size crew, averaging 1200 cases per hour.

Automatic Stitchers

The scored blanks are loaded into a hopper from which they are kicker fed into the machine, The first operation folds the two end panels over and through 180 degrees to bring the stitch flange and opposing panel edge into position. This machine folded blank is then passed automatically through the stitching head for joining before being stacked ready for bundling. Automatic machines operate at about 2000 blanks per hour using a crew of two men. It is not economical to use automatic Stitchers on small production quantities as the set-up time is about 17 minutes.

Round Wire Stitchers or Arm Stitchers

These machines are used for joining the two ends of the blank together when the panel sizes of the blank are so small that they will not fit round the shoe of a table stitcher, This includes small cases, most stitched sleeves, and pull-through boxes, The panels to be Joined are folded round a narrow arm, adjustable for height, set below the stitching head. The stitching operation is carried out in a similar manner to the Table Stitcher with single or continuous stitching, Correct operation of this machine

for quality production depends more than any other stitching machine on the operator and her skill and experience. Even with efficient operators the average through-put is quite low, A crew of three girls is used to operate two machines, one girl bundling for both.

Gluers

These machines operate in the same way as automatic stitching machines, but instead of using stitches a continuous band of adhesive is applied to the Joining flange before folding is completed. All machines are fully automatic, the blanks being loaded into a hopper for either kicker feed, or stream feed in which the bottom of the hopper is sloped towards the machine putting the blank in A position where it is taken up by the draw rollers.

Some gluers are also fitted with Flexographic printing units, plus scoring and slotting shafts similar to the Printer-Slotter which allows a scored blank to be taken direct from the corrugator on to the Casemaking Glu-lok machine to be completed. This is subject to no