Effect of Skin Layer on Strength of Foamed Plastics

• Published in: Kanazawa Kogyo Daigaku Zairyo Sisutemu (Materials Systems) Vol. 27; no. 3; pp. 49 - 53
• Main Authors: Shimbo, Minoru, Nakano, Susumu, Misawa, Akihiro
• Format: Journal Article
• Language: Japanese
• Published: 01.01.2008
• ISSN: 0286-6013

This study focused on the skin layers as an improvement of strength, and examined the generation method of skin layers and its effect on mechanical properties such as strength and rigidity of foamed plastics. Concretely, polystyrene resin (PS), polycarbonate resin (PC), and polyvinylchloride resin (PVC) were used and the generation of the skin layers was tried to these resins under various foaming conditions in the batch type foaming process. The obtained foamed plastics with skin layers were carried out three-point bending test and the effect of the skin layers on the strength characteristic was investigated. Consequently, the followings have been clarified. (1) The thickness of the skin layers can be controlled by change of the dispersing time after the blowing agent was saturated and foam temperature and it can be enlarged by lowering the foam temperature, and lengthening the dispersing time. (2) Though the specific strength of foamed plastics without skin layers decreases in from 20% to 30% compared with that of unfoamed plastics, by adding the skin layers, specific strength equal With unfoamed plastics can be obtained. And, the thickness of skin layers contributes to the strength improvement with from 7% to 8% of the thickness of specimen. (3) Though the specific rigidity of foamed plastics without skin layers decreases in from 40% to 50% compared with that of unfoamed plastics, it improves with an increase in the skin layers. And specific rigidity can be maintained with 70% to 80% of unfoamed plastics by adding the skin layers of from 7% to 8% of the thickness of specimen.