| 摘要 |
A composite cup, including an inner container of thermoplastic material bonded to an outer container of fibrous material, is provided with a rounded lip which tends to stay tightly rolled after formation, thereby strengthening the cup and facilitating the placement of a lid on the cup. After forming the cup, the inner thermoplastic material is trimmed off beyond the edge of the outer fibrous material. The projecting thermoplastic material tends to overlap the fibrous material and impede the absorption of moisture by the cut edge of the fibrous material. After the rolled edge of the cup is formed, shrinkage forces in the projecting thermoplastic material help to retain the edge of the cup in a tightly rolled configuration.
|
