Here's the challenge:
- The product is perishable;
- Its shape and configuration change daily;
- Its production envelope is only a couple of hours;
- Production delays are a given;
- Hundreds of thousands must be palletized in minutes.
Welcome to the wonderful, dynamic and competitive world of newspaper publishing. Palletizing a product that can range in shape from flat as a pancake to a giant fried egg represents a challenge for any palletizer.
"Our product had changed," explains Mike Gray, chief engineer in News International's projects department. "The number of pages per copy was going up. That increases the weight of a bundle of newspapers coming out of our strapping system."
As if the product's ever-changing dimensions were not enough, News International (London) had an additional challenge tossed into the mix by the government. A new occupational health and safety law limited the weight a worker was allowed to lift during a shift.
Designing a new system
News International Ltd., publishes some of Great Britain's better-known newspapers, including The Times, The Sunday Times, News of the World, and The Sun. News International is the U.K. subsidiary of the giant media conglomerate News Corp. (New York).
The new safety regulation was one of several challenges to manual palletizing. Increased pages meant fewer copies per bundle, which meant an increase in the number of bundles. More bundles meant employees had to work faster to position each bundle, often lifting and stretching to reach across the four-foot pallet to even out the stack.
"We had a fully manual palletizing system and weight was an issue," says Gray. "We couldn't keep up with the presses."
To comply with the weight requirements of the new labor law, the company would have to reduce the number of papers in each bundle. Smaller bundles meant the number of bundles would increase by 50 percent to ship the same number of papers. The News International logistics team at the plant near Canary Wharf in London, led by Gray and Ian Dickson, group chief engineer, knew cost would be an issue. So would space. The facility didn't have room for additional manual palletizing stations.
Careful productivity analysis and return on investment calculations led engineers to a automated system that would meet, manage and exceed the current throughput, while addressing the concerns of worker health and safety. It would also accommodate last-minute headline changes, breaking news and sports scores.
Improving the flow
The solution was an automated material handling system developed by FKI Logistex (St. Louis). "We were looking at something entirely different from the final design we went with," says Dickson. "We initially considered automating the truck-loading process. Then one of the engineers we knew introduced us to FKI Logistex, which came up with an innovative and completely different solution."
The multi-story facility in central London operates 16 printing presses, four of which are tandem presses. The old conveyor system, with serpentine loops and transfer sections, transported bundles to 12 elevated hand-palletizing and loading stations in an area known as the "van way." Here, newspaper vans drive through the building to receive full pallets.
Each palletizing station was associated with a specific press or presses. Typically, these had two workers building pallets by hand. A lift truck operator moved completed pallets to a semi-automatic stretch wrapper, where they were wrapped and loaded into a van for delivery.
The new design includes material flow management software, upgraded controls and conveyor systems, palletizers and automated stretch wrappers. Following some off-site testing, News International began with a single palletizer.
"We had one palletizer station that we installed as a trial for a year," says Gray. "Together with FKI we made adjustments to the speeds and feeds."
The final system has nearly a mile of FKI's Accumat accumulation newspaper conveyor. It also features a separate bypass conveyor called a "racetrack," which loops around the mezzanine between the printing presses and above the van way. Each subsystem of the racetrack is made up of three conveyors with four merges designed to divert product to secondary or tertiary routes. The racetrack also allows product to accumulate for short periods without slowing the presses. This allows operators the flexibility to reroute any bundle from any press to any palletizer, maximizing efficiency. The challenge was to optimize conveyor accumulation to hold product, while waiting for a new pallet to be moved into the hoist area of the palletizer.
A plastic chain conveyor carries strapped newspaper bundles to a mezzanine area between the two floors. They are then directed to one of six identical subsystems or workstations. Each subsystem has four merges (two in, two out) that feed either the palletizers or the racetrack. On a slow night, operators may route the production from three presses to a single palletizer while they perform maintenance on a subsystem. On busy nights, bundles may accumulate and then get released to whichever palletizer is free.
Each of the 12 model A881-3 palletizers can handle up to 68 bundles per minute, fast enough to keep up with the output of two or three of the 16 presses. Each of the six subsystems includes two palletizers and two fully automatic stretch wrappers. Two presses typically direct their output to one palletizer and stretch wrapper in a subsystem; the other pair of machines serve as backup in case a palletizer goes down.
Bundle layers form at the top of the palletizers, which are equipped with a sheet dispenser that inserts paper between layers of unevenly shaped bundles to make the load stable. There are 10 bundles to a layer and seven layers to a pallet.
Once loaded, the pallet travels on a transfer conveyor to the stretch wrapper associated with that palletizer. The pallet is automatically wrapped and discharged to a pickup station, where a lift truck driver loads it into a waiting van. The stretch wrappers can automatically swap an empty spool with a new roll of film in less than a minute, eliminating downtime and the need for operator intervention.
"With the older manual systems we could only stack 50 bundles to a pallet because we were constrained by manheight," says Gray. "The new palletizers allow us to increase our standard to 70 bundles to a pallet."
Process and product benefits
"The FKI system has allowed us to increase throughput by 50% while decreasing the amount of labor it takes to run the facility," says Dickson. "And while we haven't put a number to it yet, we know that we're seeing less product damage."
He adds maintenance is simpler, and the system offers a higher level of diagnostics. Importantly, the system is so reliable that News International has been able to shorten the window of production, allowing for late-breaking news and more upto-date sports scores from across Europe. "The news is timelier," says Gray. " Because we always include football scores. We don't start presses until 11 p.m. Sometimes if a game goes longer, we have to delay further. We reduce the print window by doing this, but our increased efficiency allows us to offer readers the most up-to-date information."
How do you make nice, neat pallet loads of these? Newspapers are one of the more challenging items to palletize as shown in these bundles going through sortation.
The new palletizing system at the International News facility in London has nearly a mile of newspaper conveyor and a separate bypass conveyor, called the racetrack, which loops around the mezzanine between the printing presses before reaching the palletizer.
This palletizer, in the center, can handle 68 newspaper bundles per minute.