Abstract: Method of manufacturing a food container or cover includes the steps of: forming a paperboard article from pulp and/or other vegetable fiber material; coating front surface or back surface of the paperboard article with heat sealable thermoplastic resin; forming foldout pieces for connecting adjacent sidewall pieces at four corners of the paperboard article; and forming the food container or cover by hot-pressing the paperboard article thus obtained between a pair of male and female press dies. One mutually opposed pair of the sidewall pieces is configured to be erected before the other mutually opposed pair of the sidewall pieces. The V-shaped foldout pieces include a V-shaped foldout portion shorter than portions that are adjacent to both side portions on the foldout piece, and the V-shaped foldout piece is overlapped or stuck to an adjacent one side of the foldout piece or sidewall piece.

Abstract: Method of manufacturing a food container or cover includes the steps of: forming a paperboard article from pulp and/or other vegetable fiber material; coating front surface or back surface of the paperboard article with heat sealable thermoplastic resin; forming foldout pieces for connecting adjacent sidewall pieces at four corners of the paperboard article; and forming the food container or cover by hot-pressing the paperboard article thus obtained between a pair of male and female press dies. One mutually opposed pair of the sidewall pieces is configured to be erected before the other mutually opposed pair of the sidewall pieces. The V-shaped foldout pieces include a V-shaped foldout portion shorter than portions that are adjacent to both side portions on the foldout piece, and the V-shaped foldout piece is overlapped or stuck to an adjacent one side of the foldout piece or sidewall piece.

Abstract: A low cost method of commercially manufacturing a food container of practical strength from vegetable-fiber material includes the steps of: forming aboard of a predetermined size from pulp and at least one kind of vegetable fiber material other than the pulp; coating the board with thermoplastic resin having a heat sealing property; providing for forming the folding portions for connecting adjacent sidewall pieces at four corners of the board; and hot-pressing the board thus obtained using a pair of press dies to form the food container, the pair of dies being composed of female die and male die, wherein one of the pairs of opposing sidewall pieces is arranged to be erected prior to the other pair of opposing sidewall pieces and four corners are bonded correspondingly each other by a hot press process in order to form the container.

Abstract: A method of commercially manufacturing at low cost a vegetable-fiber-material made food container of practical strength includes the steps of: forming a board of a predetermined size from pulp and at least one kind of vegetable fiber material other than the pulp; coating the board with thermoplastic resin having a heat sealing property; providing cuts at four corners of the board to form sidewall pieces; and hot-pressing the board thus obtained using a pair of press dies to form the food container, the pair of dies being composed of female die and male die, wherein one of the pairs of opposing sidewall pieces is arranged to be erected prior to the other pair of opposing sidewall pieces and four corners are bonded correspondingly to each other by a hot press process in order to form the container.