| 摘要 |
PROBLEM TO BE SOLVED: To provide a composite cup having a paper cup member arranged up to a back side of a flange by forming a pre-curl at the top of the paper cup, putting the paper cup in an injection forming mold, and injecting a molten plastic. SOLUTION: A composite cup 10 made mainly of paper is formed in such a manner that a paper cup formed by integrating, in a winding and clamping manner, a bottom board and a barrel part formed out of a laminate material whose both sides or inside face is laminated with a plastic layer is put in an injection forming mold. The plastic layer of the paper cup and a molten plastic having heat seal property are injected. Around the top of the barrel part 11, a plastic ring 15 and a protective material 16 of a superposed part 11a of the barrel part 11 are formed. At the same time, at the bottom end of the protective material, a protrusion (k) and a protective material 14 of a connecting part 17 of the barrel part 11 and the bottom board 12 are integrally formed. In this case, a pre-curl (p) is formed on the top of the barrel part of the paper cup. |
