Dr. Heiko E. Schenck is a polymer chemist and is the segment leader for healthcare applications and convenience at DuPont in Europe. He holds a degree in Chemistry from the University of Mainz/Germany.

After four years at IBM Heiko started 1989 with DuPont in Germany working in sales and marketing. In the following six years at the European Technical Center in Geneva the major focus was on development and marketing of tie layer polymers. The assignment included supervision of the technical team and responsibility for rigid packaging application and extrusion. In this period 15 new products for multilayer structures have been developed to commercial level as well as new peel seal concepts based on Polyolefines. In 1999 Heiko returned to Germany  and took the lead for medical and pharmaceutical packaging applications in DuPont to which global account management and the lead for convenience packaging applications was added in 2001.

Ethylencopolymers are widely used in medical applications like forming webs, colostomy bags, urine bags and tubing. In addition to the well known and established copolymers we see more and more compounded products and terpolymers, which are generated buy using a third monomer in the polymer.

The comonomer level in the final polymer has a significant influence on all the key properties of the product. Taking EVA (Ethylen-vinyl-acetat) as an example increasing VA monomer level is reducing the crystallinity and the melting point. As a consequence the seal initiation temperature is lowered, the optical properties are improved as well as the flexibility. The product is getting tougher at the same time. Along with the higher monomer level the polarity is increased which corresponds to high frequency weldability and better adhesion to polar substrates. On the processing side handling is becoming more critical due to tackiness and thermal stability. The lower melting point may limit the application temperature. A higher monomer level is weakening the mechanical properties like stiffness.

Acid modified products like Acid-copolymers (ACRs) and Ionomers (SURLYN®) improve hot tack, oil resistance and stress crack resistance with increasing monomer level. In specific with Ionomers at strong improvement of mechanical properties like toughness, stiffness and puncture resistance goes along with a high monomer level and increased neutralization. This special class of polymers (by grade) is listed in the US drug master file (DMF) and is in line with the pharmacopoeia.