| 摘要 |
1478719 Dielectric heating to bond tows BAUMGARTNER PAPIERS SA 17 Sept 1974 [24 Sept 1973] 40364/74 Heading D1R [Also in Divisions A2 and H5] A tow 19 of filamentary dielectric material is wrapped in an endless belt 15 and the belt and tow passed through a stationary tube 16 situated in at least one resonant cavity having an electric field of frequency 3 x 10<SP>8</SP> to 3 x 10" Hz directed parallel to the axis of the tube. The bonded fibre rod 24 produced is usable without a paper wrapping as a cigarette filter. Preferably a beat activatable binder is added to the filamenets before they are formed into a tow 19. Microwaves generated at 1 are absorbed by load impedance 7. Each of the cavities 3, 4 and waveguide 6 are tuned by the degree of insertion of bars 17, 17' of dielectric material. Tube 16 may be of polytetrafluoroethylene or quartz and belt 15 may be of polytetrafluoroethylene, optionally reinforced by glass fibres, or a nylon fabric. Belt 15 and the bonded tow are cooled by circulating cold air at 23 to form rod 24 which is separated from the belt and cut into sections for use as filters. Belt 15 may be further cooled at 26 before returning to the inlet of funnel 20. In an alternative embodiment endless belt 15 may pass and return through both coolers 23 and 26 thus permitting the belt to be removed from the apparatus without cutting it. |
