UHMWPE

Materials of Construction - UHMWPE
March 13, 2003

Common Name	UHMWPE
Chemical Name	Ultra High Molecular Weight Polyethylene
Trade Names	RCH 1000 (Hoechst’s early trade name for UHMWPE) Hostalen GUR 1020 (Type 1) (manufactured by Hoechst/Ticona, Inc.) Hostalen GUR 1050 (Type 2) (manufactured by Hoechst/Ticona, Inc.) 1900H (Type 3) (previously manufactured by Basell Polyolefins, now discontinued)
General	Ultra-high molecular weight polyethylene (UHMWPE) is a unique polymer with outstanding physical and mechanical properties. For the past 40 years, UHMWPE has been used in orthopedics as a bearing material in artificial joints. Each year, about 1.4 million joint replacement procedures are performed around the world. Despite the success of these restorative procedures, UHMWPE implants have only a finite lifetime. Wear and damage of the UHMWPE components is one of the factors limiting implant longevity. UHMWPE comes from a family of polymers with a deceptively simple chemical composition, consisting of only hydrogen and carbon. However, the simplicity inherent its chemical composition belies a more complex hierarchy of organizational structures at the molecular and supermolecular length scales. At a molecular level, the carbon backbone of polyethylene can twist, rotate, and fold into ordered crystalline regions. At a supermolecular level, the UHMWPE consists of powder (also known as resin or flake) that must be consolidated at elevated temperatures and pressures to form a bulk material. Further layers of complexity are introduced by chemical changes that arise in UHMWPE due to radiation sterilization and processing.
Specifications	ASTM D4020 Standard Specification for Ultra-High-Molecular-Weight Polyethylene Molding and Extrusion Materials ISO 11542-1 gives a range of viscosity numbers that defines the viscosity of UHMW-PE grades. The viscosity numbers are determined in accordance with ISO 1628-3.
Application	General Bearing material in artificial joints Sulphuric Acid Plants Weak acid pumps (i.e. Wernert)


Sulphuric Acid on the Web^TM	Technical Manual	DKL Engineering, Inc.