Multifaceted Evaluation of Changes in Physical Properties of Recycled Plastics by Advanced Recycling Process and Influencing Microstructural Changes (Part 1): Example of Application to Container/Packaging-Derived Recycled Polyethylene

User Benefits

- Evaluation of changes in the microscopic physical structures in plastic during molding is possible by multifaceted measurements using general-purpose instruments. - It is possible to understand the physical properties of plastics and the factors that influence those properties.

Introduction

In response to heightened awareness of decarbonization and a recycling society in recent years, initiatives for plastic recycling are advancing worldwide. However, multiple issues have been pointed out in product applications of recycled plastics, including deterioration of mechanical properties and thermal properties, odor, estimation of life, variations in product quality, and the cost balance. Among those problems, deterioration of mechanical properties is recognized as a problem that requires improvement in many industries because it is directly related to the safety and stable quality of products. The causes of deterioration of mechanical properties are considered to be degradation of the used plastic and the effects of foreign substances. Conventionally, the effect of chemical changes was believed to be the major factor in degradation, but more recently, the results of research at Fukuoka University have revealed that not only chemical changes, by also physical changes have a large effect. One principal cause of this physical changes is considered to be changes in the microscopic physical structures in plastics. A molding technology for physical property improvement of the plastic by an advanced recycling process developed by researchers at Fukuoka University has attracted attention as a technique for controlling these microscopic physical structures. In this report, a multifaceted evaluation was carried out to determine whether the advanced recycling process improved the physical properties of recycled plastic and the factors responsible for that improvement.

July 22, 2025 GMT