CPC Subgroup
B31B 70/146 Full Title
Making flexible containers, e.g. envelopes or bags > Cutting, e.g. perforating, punching, slitting or trimming (cutting window openings B31B70/83)
B31B 70/146 Making flexible containers, e.g. envelopes or bags > Cutting, e.g. perforating, punching, slitting or trimming (cutting window openings B31B70/83)