high density polyethylene

...Thin polyethylene with a low degree of polymerization has long been used as a wax, but with the development of thicker, more crystalline polyethylene with a high degree of polymerization, its applications as molded products have expanded greatly. It is a milky white, translucent thermoplastic resin, and depending on its properties it can be divided into soft low density polyethylene (abbreviated as LDPE) and hard, tough high density polyethylene (abbreviated as HDPE). As will be described later, the manufacturing process is different for each, with the former being called high pressure polyethylene and the latter being called low and medium pressure polyethylene.

*Some of the terminology explanations that mention "high density polyethylene" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…低重合度のものは古くからワックスとして利用されていたが，高重合度，結晶性のものが得られるようになって成形品として用途が大きく広がった。乳白色，半透明の熱可塑性樹脂であるが，その得られる特性によって，柔らかい低密度ポリエチレンlow density polyethylene(略号LDPE)と，硬くて強靱（きようじん）な高密度ポリエチレンhigh density polyethylene(略号HDPE)とに分けられる。後述するようにそれぞれ製法が異なり，前者は高圧法ポリエチレン，後者は低･中圧法ポリエチレンと呼ばれる。…

※「high density polyethylene」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報