- August 01, 1995, Acevedo, Jennifer
In an effort to keep up with the growing demand for multipack packaging while enhancing production capability, the Bristol Division of Mead Packaging Ltd., part of the US-based Mead Corp., has purchased a new sheerer made and supplied by Strachan Henshaw Machinery (SHM), Bristol, England.
Since Mead Packaging concentrates its efforts exclusively in the field of multiple packaging, the company decided its goals of in-house flexibility, improved quality control and more efficient production would be satisfied with the installation of the new sheeter. The SHM 1700 Supertrim twin-rotary knife sheeter has enabled the company to sheet its own board on-site, thus providing the inhouse capabilities desired. The company will use the sheeter to sheet coated board from 350 gsm to 600 gsm.
"There are many advantages in bringing a sheeter onto the line," says Morgan J. Beake, Mead's manufacturing director. "It will reduce our dependence on outside contractors, give us more control over production, allow us to provide a quicker turnaround time to our customers, enable us to sheet to order and allow us to carry reduced inventory levels."
Among the features of the sheeter is a design that allows Mead to carry out reel and pallet changeovers without stopping production. As a reel of board is used up, automatic sensors feed information back to the sheeter's control system, allowing for a new splice. An overhead festoon then takes up the slack that is created as the new reel is fed through. While this is occurring, cut sheets overlap on a specially designed tape delivery that eliminates the need to waste good sheets during reel or pallet changeover.
Simultaneously, an empty pallet replaces the finished stack of sheets. The only material wasted is the board splice, which is automatically detected and sent through the reject gate for later inspection. The entire sequence continues without the machine stopping and with virtually no waste. A tension-control unit ensures that the web is kept taught and minimizes lateral movement as the board enters the cutting head.
Heavy-duty adjustable slitter stations provide optimum-performance center and edge trimming for the highest-quality square-cut sheets. Paper dust is removed with an extraction unit fitted to each slitter station.
The cutting head contains a pair of rotary knife cylinders that, when rotated, produce a true scissor cut across the web. In addition, a cyclic mechanism controls the rotation of the cylinders so that the cutting position of the knife edge is always the same speed as the web of the board. The result is a high-quality finished stack of sheets ready for printing without the need for more finishing.
Once delivered to the main production area, the sheets of board are offset-litho printed on Planeta printing presses, die-cut on a Bobst Cermatic die-cutter, creased, glued on an International straight-line gluer and folded into multipack cartons ready for delivery.
The complete process from roll to sheet is handled automatically, although manual output adjustments are easily made if necessary. The sheeter maintains virtually continuous output and reaches speeds up to 350 m/min.
The Bristol Division of Mead Packaging is reported to be Britain's only dedicated production plant for multi-pack cartons for soft drinks, brewing and dairy products. Owned by a forest products company, Mead receives most of its reels of board from this parent company's paper mills in the US. All of the board used in the company's production of multipack cartons comes from sustainable forests and is fully recyclable.