Patents Assigned to Vyskummy ustav chemickych claken
  • Patent number: 4546040
    Abstract: Cigarette filters with improved efficiency and reduced resistance to gas flow, and a method of preparing them, are disclosed. The filters are made from crimped multicomponent polypropylene polymers having microfissures on their surfaces and micropores on their cross-sections, with 5 to 7 crimps per centimeter of length, and a unit fineness of 5 to 7 dtex. The elementary fibers in the bundle have different centers of gravity, and are present in ratios of from 1:3 to 3:1 by weight. The fibers are prepared by separate melting and thermal treatment of each polypropylene polymer component, having LVI values ranging from 100 to 200 ml/g, at temperatures ranging from 230 to 330 degrees C. The difference in LVI values between the components is from 30 to 50 ml/g, and at least one of the components has a 5-20% high molecular weight fraction, by weight, with an LVI of from 400 to 450 ml/g.
    Type: Grant
    Filed: June 11, 1984
    Date of Patent: October 8, 1985
    Assignee: Vyskummy ustav chemickych claken
    Inventors: Lubomir Knotek, Jozef Peciar, Ivan Mitterpach, Jozef Hudak, Jan Simo, Jan Badura, Viliam Beseda, Frantisek Mihaly, Alexander Gregor, Jan Klisky