A tape applicator configured for applying a tape to a carton (e.g., for sealing and/or assembling the carton). The tape applicator may include an edge folder assembly having an edge folder roller operatively coupled to a support member that allows the edge folder roller to rotate around the support member. The edge folder assembly may also include an alignment assembly (e.g., a self-alignment assembly) that allows the edge folder roller to move axially along the support member. The alignment assembly may comprise one or more biasing members (e.g., springs, or the like) and/or one or more restraining members (e.g., washers, or the like) to aid in allowing the edge folder roller to rotate and/or move axially with respect to the one or more support members in order to account for shifting of the tape transversely through the tape applicator.