Polypropylene materials are among the most versatile and commonly used thermoplastics in the world today. Commercial grade polypropylenes are typically produced using either a Ziegler-Natta or metallocene catalyst mechanism in a polymerization process. Many industries, such as the packaging industry, utilize these polypropylene materials in various manufacturing processes, such as extrusion, injection molding, thermoforming, and blow molding to create a variety of finished goods.
Within the packaging industry, there are a number of unique applications that ideally require strong and substantially clear polymers. Medical articles, food storage containers, and other products that can readily be formed by thermoforming and blow molding techniques are either in direct contact with blood or other bodily fluids or with food or other items that are to be ingested or taken into the body. Thus, it would be desirable to use polymers having high clarity and strength and a very low extractables content for these applications. Accordingly, there is a need for Ziegler-Natta polypropylene blends having improved thermoforming and blow molding characteristics while retaining outstanding toughness, stiffness, strength, and clarity for demanding food or drug packaging applications, especially for cold temperature end use applications.