A cushioning conversion machine converts a sheet stock material into a relatively lower-density cushioning dunnage product. An exemplary sheet stock material includes two sheets that each overlap a common side of another sheet and are connected to respective lateral edges of the other sheet. The conversion machine includes a forming assembly having a former for shaping and randomly crumpling the sheet material, a set of adjustable guide members to guide the crumpled sheet material to a feeding assembly downstream of the forming assembly, and a severing assembly downstream of the feeding assembly that separates discrete lengths of cushioning. The severing assembly includes a window frame passage that guides the crumpled sheet material to an outlet during operation of the feeding assembly and constrains the crumpled sheet stock material during operation of the severing assembly.

A conversion apparatus is provided herein. The conversion apparatus includes a cutting member having an edge configured for cutting the dunnage material. The conversion apparatus also includes a biasing member that is located adjacent to the cutting member such that the dunnage material passes between the biasing member and the cutting member. The biasing member operably contacts the dunnage material thereby biasing the dunnage material against the cutting member. The position of the biasing member relative to the cutting member is such that in response to the dunnage material being retracted back into the conversion apparatus the cutting member begins to sever the dunnage material, but in response to the dunnage material traveling in the dispensing direction the cutting member does not begin to sever the dunnage material due to the relative position.