NEW YORK — Metallocene polyethylene resins can compete with flexible PVC films in some medical applications, according to a recent study by Dow Chemical Co.'s Films Group. However, about two-thirds of the medical market remains off-limits to metallocene PE and requires PVC, particularly in applications that need autoclave sterilization, said Bruce Lipsitt, development leader for technical service and development of films at Dow. PVC will remain widely used, he said.
``PVC works very well and it is very inexpensive and it is very well-established,'' Lipsitt said. ``It has a broad range of properties.''
Metallocene PE films offer an alternative for companies worried about legislative or regulatory challenges to PVC, including any fallout from the Environmental Protection Agency's dioxin reassessment expected in July, he said.
Metallocene PE is more expensive than PVC but its toughness and density, which is about 30 percent lower than PVC, allow for thinner walls that do not sacrifice structural integrity, the Dow study said.
Metallocene resins can be used in applications such as collection bags, drainage systems and inflatable devices.
The study compared two grades of metallocene PE with two medical grades of PVC, and examined how they performed in liquid collection bags. The metallocene products demonstrated ``similar or superior results'' in physical properties and improvements of more than 50 percent over PVC films in elongation, toughness, tear strength and puncture resistance tests, the study said.
The study was presented at an April conference and released June 3 at the Medical Design & Manufacturing East '97 show in New York.