Coffee Capsule Lines Extraordinaire

Many marketers of single-serve coffee capsules today still rely on a cup that is thermoformed of polystyrene and includes a layer of EVOH for oxygen barrier purposes. A paper filter goes into the capsule to keep grounds from getting into one’s coffee cup. The third component, a foil lid, is heat sealed into the cup. In the brewing machine, one needle punctures the lid and another punctures the bottom of the cup. Hot water flows into the cup through the hole in the lid. Out through the bottom of the cup flows freshly brewed coffee.

The single-serve coffee capsule has been widely criticized because polystyrene is rarely if ever recycled. That’s why Green Mountain Keurig is in the middle of a transition out of polystyrene to an injection-molded PP/EVOH cup, a transition it hopes to have complete by 2020.

Patented cup
The coffee capsule now in use is patented. Not only can it be thermoformed more efficiently and at higher throughput than its injection-molded predecessor, it weighs 2.6 g instead of 6.8. And the EVOH barrier layer keeps the coffee fresher than the oxygen absorber in the previous cup was able to. Shelf life is two years.
Line Four
we chose to focus on Line Four, which was producing 24-count cartons that were being case-packed four cartons per case. An operator removes a slug of 100 cups from the corrugated case in which they arrive and places it in a flighted incline conveyor. Up at the top of the machine, the slugs drop from the incline conveyor into a second flighted conveyor, this one being horizontally oriented. Its six flights position the six slugs in front of six capsule magazines from which capsules are denested and placed into the six-across filling machine. When these magazines require fresh slugs of capsules, the horizontal flighted conveyor holding the six fresh slugs pivots to a vertical position so that the slugs drop neatly into the six magazines. Then the cycle repeats itself. An operator can fill this denesting system with enough capsules to last about an hour and 12 minutes before he needs to replenish it again.

Meanwhile, at the bottom of the six capsule magazines, capsules are picked by vacuum cups mounted on tooling driven. The capsules are drawn down into the six-across pockets of the carrier mechanism that takes them through a number of operations. With each stroke of the servo-driven picking device, mechanical fingers separate the bottom cup to be picked from the nested ones above it so as to simplify the task of cleanly picking it and placing it into its assigned pocket.