A Modified Classical Nucleation Theory for Plastic Foam Processing

This paper elucidates a modified Classical Nucleation Theory (CNT) that considers the effects of stress variations and existence of microvoids in plastic foaming processes. The stress effect has been incorporated into the CNT by a local pressure variation term that describes the dynamic conditions of industrial plastic foaming processes (e.g., extrusion foaming, injection foam molding). Also, the free energy barrier equation has been modified to include nucleation events from existing gas clusters. Both phenomena have been observed experimentally via in-situ plastic foaming visualization to confirm the modified theory. Combining the stress and preexisting gas clusters considerations, the modified CNT described in this paper improves the traditional CNT in describing cell nucleation phenomena in plastic foaming processes.

Analysis of Environmentally Friendly Packaging Materials in Modern Packaging Design

Nowadays, “green and environmental protection” is the theme of the social development. Therefore, packaging waste has become a prominent environmental problem that should be solved as quickly as possible. In such background condition, the research and application of environmentally and friendly packaging materials gets more and more important and urgent. Corn plastic, oilseed plastic, straw container, renewable foam plastic, foaming plant fiber and other environmentally friendly packaging materials are in line with the requirements of the times. But what we cannot forget is that when catering to the trends of times, our packaging design has to also inherit the essential traditional culture in the use of the material. Only in this way can we stand among the nations of the world.