The present disclosure relates to methods and apparatuses for mechanically bonding substrates together. The apparatuses may include a pattern roll including a pattern element protruding radially outward. The pattern element includes a pattern surface and includes one or more channels adjacent the pattern surface. The pattern roll may be positioned adjacent an anvil roll to define a nip between the pattern surface and the anvil roll, wherein the pattern roll is biased toward the anvil roll to define a nip pressure between pattern surface and the anvil roll. As substrates advance between the pattern roll and anvil roll, the substrates are compressed between the anvil roll and the pattern surface to form a discrete bond region between the first and second substrates. As such, during the bonding process, some yielded substrate material flows from under the pattern surface and into the channel to form a channel grommet region.