Medical Plastic Data Service Magazine



Our 31st Year of Publication
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Ethylene Vinyl Acetate Polymers For Advancing Healthcare




Ethylene vinyl acetate (EVA) has a long and successful history of innovation in medical packaging, medical devices, and pharmaceutical applications. In fact, EVA has been an innovative force in those applications for over 40 years and continues demonstrating its value in applications presenting everincreasing challenges. New solutions are required to support continued innovations that improve patient healthcare.


This article will examine the evolutionary role of EVA innovation in diverse applications ranging from its early use in parenteral applications for delivery of life-saving medications to cryogenic storage bags for stem cells used in the field of cell therapy.


The molecular architecture of EVA lends itself to the creation of innovative solutions to some of healthcare’s most challenging and complex problems. Case studies will provide an illustration of each of these applications.




We are living at a time when healthcare is undergoing exciting new developments and innovations. The medical device industry and the pharmaceutical industry are developing innovative products which can provide better patient care and improved quality of life.


Also, and of no surprise, the two industries have applications in common as well as areas of uniqueness. For example, an intravenous (IV) bag containing drugs illustrates where a medical device and pharmaceutical product work together in support of patient needs. For an application where a medical device and a pharmaceutical product work independently of one another, consider a sleep apnea device versus a tablet containing an API. Here, the sleep apnea device does not contain a pharmaceutical product and the tablet is associated with a medical device.


Ethylene vinyl acetate (EVA) has been used for many years in both industries and has historically been an important enabler of innovation. Today and moving into the future, EVA continues to be an enabling innovation in established and emerging fields. An overview of EVA polymers will describe the unique characteristics that make EVA suited for a range of unique applications in healthcare.




Ethylene vinyl acetate copolymers are made using two monomers: ethylene and vinyl acetate (VA). The polymerization may take place by either autoclave or tubular reactors. Figure 1 illustrates the polymerization.


Figure 1. Polymerization of EVA


The percent of VA incorporated into the polymer backbone can vary from 0 to 40. At 0% the polymer is essentially low-density polyethylene. As VA content is increased, the polymer becomes more flexible and transparent. EVA polymers with VA content higher than 40 percent tend to become a handling challenge from a commercial pelletized perspective. The melting point of the EVA is influenced by the vinyl acetate content. As VA content increases, the melting point decreases. Figure 2 illustrates the
linear relationship.

Figure 2. Melting point versus VA%


EVA has been commercially used for over 40 years in medical device applications, beginning with medical tubing. Uses of EVA in healthcare continue to expand, as the following case studies will demonstrate.

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