A bending apparatus for corrugating a sheet-like material can comprise a support member, a feed mechanism, a bending member, a hold-down member, and a driving mechanism. The support member can comprise a support surface with corrugations. The feed mechanism can be configured to feed the support member in increments of one pitch of the support member corrugations. The bending member can be configured to reciprocate between a retracted position and an actuated position mating with a corrugation on the support surface so material laying on the support surface is bent along the support member corrugation. The hold-down member can be configured to be reciprocated between a retracted position and an actuated position holding the material against the support surface. The drive mechanism can be configured to sequentially reciprocate the bending member and the hold-down member so the hold-down member presses down the material and the bending member bends the material.