Claims
- 1. A method for the formation of a liquid retaining recess in the bottom support surface of a foamed thermoplastic food tray which comprises, sequentially, (a) compressing said surface with a hollow punch member; (b) penetrating said compressed surface with said punch thereby forming a permanent recess in said surface and (c) removing said punch member from said recess, said recess being characterized by having a greater cross-sectional area at its base portion than at its top portion.
Parent Case Info
This is a division of application Ser. No. 371,819, filed June 20, 1973, now abandoned.
US Referenced Citations (6)
Divisions (1)
|
Number |
Date |
Country |
Parent |
371819 |
Jun 1973 |
|