English
November 5, 2026
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At PACK EXPO, coffee roasters asked us how to set up their bag format so the packaging machine runs at its best. The answer starts long before the machine: get everyone to the table while the format can still change.
At PACK EXPO in Chicago, one question came up again and again: “How do I optimize my packaging format for optimum performance?” We promised a proper answer. Here it is, from our engineering team and our PackLab.
Most bag formats start in marketing. That makes sense, because the bag is what the shopper sees. But every dimension chosen there also sets how fast the packaging machine runs, how precisely it doses and how much film it uses. Once the format is fixed, those limits are fixed too. Most of what follows applies to ground coffee, which is dosed by an auger. Whole beans are filled differently and are only partly bound by these limits; we come back to them below.
Brand teams often ask for a tall, slim bag with a large front panel. For ground coffee, the machine pulls the other way. An auger positioned inside the forming tube doses the coffee, and, above all on a four-corner-sealed bag, the narrow side of the bag decides how large that auger can be. A larger auger fills faster. A slimmer bag needs a smaller auger, and the machine runs slower.
Smaller augers do dose more precisely, but only for small fill weights. So there is no rule of thumb that fits every bag. The right cross-section depends on your coffee, your bag style, your valve and your fill weight. We calculate it for each project.
Bag style. For ground coffee, a block-bottom bag with a center seam leaves the auger the most room. A four-corner-sealed bag needs a rectangular forming tube and leaves less.
Valve. An inside valve needs a valve channel in the forming tube. That channel takes room from the auger on the narrow side, and the slimmer the bag, the more output it costs. The valve protects your coffee, so this is no argument against it. It is an argument for deciding on valve and bag format together, and early.
Rectangle, not square. The wide side of the bag must be clearly longer than the narrow side. Where the film layers overlap at the seams, a square bag cannot be sealed tight. A square footprint looks efficient on paper and fails at the seal.
Bag length. Your coffee’s bulk volume decides how much film each bag needs. The machine’s geometry caps how tall the bag can be. Coffee that settles a lot can also mean more film per bag. How much depends on the machine and on how the coffee is compacted before sealing — one more reason to test the format with your coffee. When we sample your coffee, we see how far it settles and can set the bag length accordingly. That can save film.
Every format on the machine. If one machine runs several formats, each format usually gets its own auger. But the auger position stays the same for all of them, which makes it a compromise across every format. One unusual format can therefore limit the auger for every other bag. Plan the whole format family, not one bag.
Different densities on one machine are fine, as long as we know about them before the design starts. When we sample your products, we set the bag length so your most voluminous coffee fits. From there we size the doser and forecast your output. For your other coffees, the bag length can differ. What drives the design of the bucket chain and your secondary packaging is the fill level, or pack height. There is a lower limit too: if the pack falls below a certain size, it no longer runs in the bucket chain.
Whole beans are a different story. They run on a different dosing setup: through the auger with different parts if the machine also fills ground coffee, or through a net weigher if it fills beans only. Either way, the auger limits above do not apply in the same way. Ground coffee also doses more precisely than whole beans. For ground coffee and whole beans alike, the relative standard deviation of our dosing units is below 1%. Volume still matters with beans, though: bulk volume and pack height set the bag length and how the pack runs in the bucket chain, just as with ground coffee.
A format that is perfect for the packaging machine can be a poor fit for your cases and your pallet. The pallet pattern follows the bag, so logistics needs a say before the format is fixed.
If you know your existing formats, your film, your cases and your pallet, bring those too.
In our PackLab, we test your coffee and your film under lab conditions as close to your line as possible, before your design is final. You see what your format means for output, dosing accuracy and film use while it is still easy to change. The cheapest moment to change a bag format is before anyone has printed it.
We would love to hear your opinion, questions or comments.
