Author(s)

Keisuke Maeda¹, Koji Yamada², Kazushi Yamada^1*, Masaya Kotaki^3,4, Hiroyuki Nishimura¹

¹Department of Advanced Fibro Science, Kyoto Institute of Technology, Kyoto, Japan.
²Osaka Municipal Technical Research Institute, Osaka, Japan.
³Center for Fiber and Textile Science, Kyoto Institute of Technology, Kyoto, Japan.
⁴Kaneka US Material Research Center, Kaneka Americas Holding, Inc., TX, USA.

Thin-wall injection molded parts have been paid much attention to the lightweight saving from viewpoints of natural resources saving. In the injection molding, skin-core structure can be found in the parts. This skin-core structure affects the property of completed injection molding parts (bulk property) even if in thin-wall injection molding. However, there is a few research about the relationship between bulk property and internal property distribution in the injection molding specimen. In this study, thin-wall injection molded parts of polypropylene (PP) were prepared by 4 different molecular weight and molecular weight distribution to reveal the relationship between bulk property and property distribution. These characteristics were investigated by using tensile test, fracture toughness characterized by Essential Work of Fracture (EWF) method for bulk property and film tensile test by sliced sample for tensile property distribution. The property distribution test results revealed that the highly bulk property sample had thicker highly mechanical property layer on its surface.

Molecular Weight, Molecular Weight Distribution, Fracture Toughness, Property Distribution, Thin-Wall, Injection Molding

Maeda, K. , Yamada, K. , Yamada, K. , Kotaki, M. and Nishimura, H. (2016) The Relationship between Bulk Property and Property Distribution in Thin-Wall Injection Molded PP at Different Molecular Weight and Molecular Weight Distribution. Advances in Materials Physics and Chemistry, 6, 1-8. doi: 10.4236/ampc.2016.61001.