As of 2015, polyethylene terephthalate and high-density polyethylene are among the most commonly used plastics for cases. Polyethylene terephthalate is typically used in pliable casings for cooking oils, bottled water and peanut butter jars. High-density polyethylene is used in molded plastic cases such as display cases, storage cases and carrying cases.Continue Reading
Polyethylene terephthalate, usually called PET or PETE plastic, is a durable thermoplastic that resists radiation, chemicals, weather and abrasion. Although generally recognized as safe, cases made from this plastic can leak hormone-manipulating substances into their contents when used repeatedly or kept in perpetual high temperatures, according to Reuseit.com. For this reason, PETE plastic is used for single-use products and should not be reheated or refilled. Casings made from PETE plastic are generally translucent, and they can be either clear or pigmented.
High-density polyethylene, or HDPE plastic, is a sturdier plastic than PETE plastic. Cases made of HDPE resist impact, chemicals and ultraviolet rays. HDPE plastic is able to resist temperatures between -100 and 80 degrees Celsius, and HDPE cases are also water resistant. This makes HDPE ideal for repeated use cases such as display or protective cases for electronics, playing cards or documents. Containers made from HDPE usually have a more non-translucent or opaque appearance.Learn more about Manufacturing