Time was when fabric technicians focused on ensuring cloths shed their creases. Now that process has been put into reverse with the launch of a new process to give garments made from Tencel, and particularly Tencel denim, the look of permanent, all-over creasing.   The finish, launched to coincide with the 10th anniversary of the fibre's launch, will be marketed under the name Scrunch. "What we were seeking was the more rugged look today's casualwear market demands," says Tencel R&D director Pat White.