8 tips on how to make your packaging lines more flexible: here are some ideas—both new and proven—on how you can accommodate more variety in your operations

Food & Drug Packaging, April, 2005 by John Henry

Prior to the '60s, the Coca-Cola bottling plant manager's job was easy. Coke came in a single flavor and a single 6-ounce glass bottle and line flexibility was not an issue. Today, Coca-Cola comes in more than 140 flavors, containers and sizes. The modern plant manager needs to be flexible as an eel to accommodate them all. Most of you are probably facing similar pressures as the market demands more and different products. Here are eight ideas that can help make your packaging lines more flexible.

1 Changeover

The biggest single cause of downtime in most plants is the time spent changing from one product or package to another. Reducing changeover times brings a number of benefits including increased production and increased capacity. As products proliferate, changeovers become more and more frequent--and thus more critical.

Reducing changeover times can seem a daunting task. In reality, most changeover reduction is a result of many small, simple improvements. Some of these improvements are made to the equipment, such as reducing tool usage. Other improvements are the result of organizational improvements, such as training and documentation.

2 Robots

After decades of promises, robots are finally becoming practical for general packaging use. Robots are replacing humans in operations like case packing and palletizing. Robots can often do several tasks at the same time, such as packing product into the case then placing the case on a pallet or taking mixed products from a single conveyor and separating them onto multiple pallets.

"The robot's great flexibility allows them to readily replace human operators on dangerous or dirty jobs," says Ed Goldman, senior vice-president of Foster-Miller Inc. He cautions, however, "There is a tradeoff between flexibility and reliability. The greater the variety of tasks that a robot is expected to perform, the greater the likelihood that it will falter occasionally. End of arm grippers are especially important and must be carefully designed."

3 Servo motors

In the past several years there has been an explosion in the use of servo motors in packaging. Cartoners that used to have one drive motor with mechanical linkages may now have a dozen or more servo motors. Complex speed and motion profiles can be readily programmed for each function. Minor adjustments (for component variance) or major changes (for package size changeover) can now be done quickly and easily from a touchscreen.

4 Inline printing

Many techniques are available which allow packagers to print at the point of manufacture. Thermal, thermal transfer, continuous ink jet, laser and hot stamping are a few in common use. Traditionally, they have been used for variable data such as lot codes. In other applications, they are used for primary product identification.

As speed and quality improve, inline coders/printers are increasingly being used for primary labeling. A hair dye producer required over 80 different labels to cover all the color and country variations. After years of fighting with label inventory, they developed a generic label with no color info. A laser mounted on the labeling machine prints the color info immediately prior to application. Their label stock-keeping units (SKU's) have gone from more than 80 to 1.

5 Pucks

Pucks are plastic cups which hold the container during packaging operations. They are common in the cosmetic and aerosol industries but almost unheard of elsewhere. The great advantage of pucks is that, from the line's point of view, the bottle size and shape does not matter. Additionally, pucks are often less expensive than a set of change parts required to run additional sizes.

6 Pigs for cleaning

Pigs aren't found only on the farm. Pigs are rubber plugs that are forced through process piping squeegeeing the walls along the way. Benefits are improved and faster cleaning, as well as more efficient recovery of residual product from the piping.

Pigs may be the first step in a clean-in-place (CIP) processor. When similar products are being run, a simple pass with a pig may be all the cleaning required. The succeeding product can push the pig through the piping. The pig then serves not only to clean but to separate the two products. Sensors detect when the pig arrives at the end of the line and automatically actuate valving to allow non-stop product flow.

7 Modular machines with docking stations

Modular machine designs allow them to be more readily adapted as products change. Krones' new high-speed rotary labeler is a good example. It uses a wheeled stand to mount the various labeling heads. These stands then dock to the main machine. Changing from a pressure-sensitive to a cold glue label is as simple as swapping out the module. The benefits are that it allows changeover of label type and product to be accomplished externally, while the labeler continues to run.

8 Line layout

Ignacio Munoz, general director of AutoPak Engineering, talks about the impact of line layout on flexibility in this era of lean manufacturing. "U-shaped packaging lines maximize space usage and create ergonomic advantages because they minimize distances between machines," he says. "Well designed conveyor systems should allow for repeatable accurate positioning of guide rails through mechanical stops or position feedback. Accurate and repeatable control of conveyor speed is also a must."