Image Number 5 for United States Patent #5439124.
A closure unit for a container for storing and handling flowable products is made from at least two different thermoplastic materials, the different materials fulfilling different functions. A basic thermoplastic material (A.2) is used for sealing against the container (G.2), and an area made of another different thermoplastic material (B.2,C) is provided to fulfill additional sealing functions, to increase mechanical stability, to have a reduced permeability, and to provide increased elasticity for additional opening and closing and/or absorption characteristics. The closure unit is produced by a multimaterial injection molding process, so that contact surfaces between the different thermoplastic materials can be interconnected by reversible or irreversible positive engagement and/or by more or less pronounced melting into one another. The closure unit is in two parts and comprises a pouring part (1.2) and a closure part (2.2), or is in one part. The two-part closure unit is produced in a single operation in a closed state.