Patent ID: 7207159

Claim:
An unsealing method for unsealing a packaging structure for a liquid container, wherein said liquid container includes a liquid containing portion accommodating liquid, and a liquid supply portion for supplying the liquid to an outside and an air vent for fluid communication with an ambience, wherein said packaging structure includes a covering member for covering and sealing said liquid supply portion and said air vent, said covering member including an air vent sealing portion for sealing said air vent, a liquid supply portion sealing portion for sealing said liquid supply portion, and a connecting region for covering a connecting side of said liquid container, in which said connecting region connects said air vent sealing portion and said liquid supply portion sealing portion, wherein said liquid supply portion sealing portion effects non-adhering sealing for said liquid supply portion, and said connecting region provides a resistance against unsealing of said liquid supply portion, wherein said liquid container is substantially in the form of a rectangular parallelopiped shape substantially constituted by six sides, including a first pair of opposite sides and a second pair of opposite sides which are vertical in use of said liquid container, wherein said air vent and said liquid supply portion are disposed in opposite ones of said first pair of opposite sides, wherein said covering member has a first region and a second region covering opposite ones of said second pair of opposite sides and which connect the side having said air vent and the side having said liquid supply portion, respectively, wherein said first region and said second region respectively include a first resistance generating portion for generating resistance against unsealing and a second resistance generating portion for generating resistance against the unsealing, whereby said liquid supply portion, said air vent, said first resistance generating portion and said second resistance generating portion are disposed at different sides of said six sides, respectively, said method comprising: a step of unsealing said air vent at said air vent sealing portion; a step of separating, in a direction toward said liquid supply portion from one of said second pair of opposite sides, said first resistance generating portion from the side of said liquid container where said first resistance generating portion is provided; a step of unsealing said liquid supply portion at said liquid supply portion sealing portion where said liquid supply portion is sealed by the non-adhering sealing; and a step of separating, in a direction toward said air vent from the other of said second pair of opposite sides, said second resistance generating portion from the side of said liquid container where said second resistance generating portion is provided.