India: Insulation Dosage System

You’d be hard pressed to find a project with a more international scope than a new portable insulin dosage system: designed in the UK, with components from Europe and Asia, precision tooling carried out in Taiwan, final testing performed in Holland and intended for use in India.

Expected to dramatically advance diabetes treatment in India by offering quick and easy insulin dosage, the system’s key component is a reusable plastic pen — no bigger than a marker — manufactured entirely from DuPont materials.

Project supervisor Industrial Design Consultancy (IDC), of Berkshire, England, selected DuPont’s Delrin acetal homopolymer resin for manufacture of the clutch tube and locking sleeve, and Zytel nylon resin for the drive shaft, inner housing, thumb pad and piston rod cap.

“For the intricate system of ratchets and gears in the pen’s delivery mechanism, Delrin delivers dimensional stability in combination with resistance to creep,” said IDC’s manag-ing director, Stephen Knowles. “And since many mechanical movements must occur in an exact sequence, we chose Zytel for its combination of very high impact strength, elastic modulus and tensile strength.”

A final DuPont material, Crastin PBT polyester resin, is used for the pen’s dose dial and clip. These parts had initially been specified in Zytel, but testing revealed that the nylon would absorb too much moisture from India’s hot and sticky climate — bad news for dosing accuracy. “DuPont was able to ship us samples of Crastin to Thailand for testing within a week, and we found it to be the perfect alternative,” Knowles said.

E.I. DuPont Company (Mississauga, Ont.); www.plastics.dupont.com;905-821-5193