Patent ID: 9730469
Date: 2017-08-15
CPC Classifications: A24D

Claim:
1. A method of producing a tobacco smoke filter or filter element comprising: heat treating a continuously advancing longitudinally extending preformed strand of material; cooling the heat treated continuously advancing longitudinally extending preformed strand of material; and forming a longitudinally extending outer layer of tobacco smoke filtering material around the continuously advancing longitudinally extending preformed strand of material subsequent to said cooling, to form a continuously advancing rod comprising the longitudinally extending preformed strand of material and the longitudinally extending outer layer of tobacco smoke filtering material engaged around the longitudinally extending preformed strand of material; wherein the preformed strand is formed at least 15 minutes before the longitudinally extending outer layer of tobacco smoke filtering material is formed around the continuously advancing longitudinally extending preformed strand of material; and in which the continuously advancing longitudinally extending preformed strand of material is under tension during the heat treatment.