By Patrick Raleigh UT On-line news editorMaitland, Canada- DuPont Canada Inc. is to shutdown the Invista spandex fibre manufacturing plant at Maitland, Ontario, with the loss of up to 85 jobs, the company announced 12 April. The Canadian firm linked the closure of the 40-year-old spandex operation to the imminent sale of Invista to Koch Industries Inc., as well as to a global rationalisation plan by parent group DuPont."This restructuring will ensure that we are positioned for sustainable growth and future success following the sale of DuPont's Invista division to Koch Industries," said Doug Muzyka, DuPont Canada president and CEO, in a press statement. "