Container assembly, closure cap for container assembly, container for container assembly, method for manufacturing a container assembly

A container assembly comprising a container and a closure, wherein:

• the container is made of a crystallisable polymer material and comprises a neck portion that has an inner neck surface and outer neck surface and defines an outlet opening of the container, the neck portion being configured for receiving the closure in a closed state of the container assembly;
• the closure includes a closure cap and a tamper ring connected to the closure cap when the container assembly has never been opened,
• the closure cap is made of a crystallisable polymer material and has an inner cap surface with which the outer neck surface of the neck portion is in contact when the container assembly is in a closed state, the closure cap being matched to the neck portion of the container to cover the outlet opening when the container assembly is in the closed state;
• the crystallizable polymer material of the inner cap surface of the closure cap with which the outer neck surface of the neck portion is in contact when the container assembly is in a closed state is crystallized more than an outer cap surface;
• and
• a degree of crystallinity of the inner cap surface of the closure cap is between 10% and 80%.