2026 Volume 65 Issue 2 Pages 151-158
What we consider “common sense” today can be replaced by a new “common sense” once new principles or insights are discovered and widely accepted by the majority.
Traditionally, the significant deterioration in the physical properties of waste plastics compared with virgin materials has been attributed to chemical degradation involving irreversible polymer chain scission. As a result, research on mechanical recycling had stagnated completely. In contrast, we were the first in the world to propose the “Physical Degradation and Physical Regeneration Theory,” which demonstrates that the primary cause of property deterioration is actually a physical phenomenon arising from internal structural variations retained from molding history, and that plastics can indeed be regenerated through sufficient melt relaxation treatment. Based on this theory, we also designed an extruder equipped with a resin retention section and verified its functionality.
By establishing this theory as the new “common sense,” a highly advanced, multi cycle plastic resource circulation society can become a natural reality.
