A packaging material capable of having a desired sealing strength with ease and a packaging bag using such material are provided. A packaging material, which serves as either one of a first and a second packaging materials to be heat-sealed to each other, includes a sealing portion. This sealing portion...http://www.google.es/patents/US7040483?utm_source=gb-gplus-sharePatente US7040483 - Packaging bag with weak sealed duct
