In a recent case, Teashot v. Green Mountain Coffee, the Federal Circuit affirmed that Green Mountain Coffee’s K-Cups do not infringe Teashot’s disposable tea pods. T-Shots products is a sealed pod made of water-permeable material (essentially tea wrapped in coffee filter paper). K-Cups, on the other hand are made of impermeable material and must be punctured in order to brew coffee. Teashot’s argument was that the pods become “water-permeable” once punctured. The courts did not agree with this argument.
Read Dennis Crouch’s review of the case here for more details. You can also read the decision here.