成形加工
Online ISSN : 1883-7417
Print ISSN : 0915-4027
ISSN-L : 0915-4027
23 巻, 5 号
選択された号の論文の22件中1~22を表示しています
目次
巻頭言
解説:医療を支える機能性高分子材料と成形加工
AWPP 2010 in ベトナム報告
講座
技術報告
海外だより
会議・見本市だより
知りたい・見たい・訪ねたい 成形加工の元気な仲間
論文
  • 船木 章, 蔵谷 祥太, 山田 敏郎, 金井 俊孝
    2011 年 23 巻 5 号 p. 299-305
    発行日: 2011年
    公開日: 2011/05/26
    ジャーナル フリー
    To improve the transparency of isotactic polypropylene sheets, multilayer extrusion was conducted using a resin with lower melt viscosity for the surface layers than one for the core layer. By using multilayer extrusion, the number of spherulites near the surface decreased dramatically and the internal haze of the sheet was improved. The number of spherulites of the sheet cross-section and the internal haze were closely correlated to each other. Each distribution on the flow velocity, shear rate and shear stress in a die lip section was calculated using a finite element method. The shear stress in the sheet thickness direction was reduced when the resin with lower melt viscosity was laminated on both surfaces, and then it was surmised that the stress induced crystallization was considerably restrained in these layers. Furthermore, the cooling simulation in a belt quenching process was conducted, and the prediction formula was derived by multiple regression analysis, using the number density of spherulites as a response variable, and both the plateau area time of the temperature in each thickness direction and shear stress as independent variables, respectively. As a result, the number density of spherulites in various surface layer ratios was predicted using obtained regression formula, and the optimization of the multilayer composition to obtain higher transparency was proposed.
feedback
Top