Forming filled continuous plastic rod such as plastic cigarette filter rod filled with a tow of cellulose acetate

Abstract

Abstract A METHOD WITH WHICH A CONTINUOUS LENGTH, TUBULAR ARTICLE FILLED WITH A GAS OR LIQUID PERVIOUS FILLER MATERIAL SUCH AS A TOW FILLED PLASTIC CIGARETTE FILTER ROD IS FORMED BY EXTRUDING PLASTIC AS A SHEATH AROUND AN ADVANCING BLOOMED TOW OF FIBROUS FILTER MATERIAL, HEAT FROM THE PLASTIC EXTRUDATE BEING UTILIZED IN THE COURSE OF THE FORMING OPERATIONS TO ACCELERATE CURING OF A PLASTICIZER IMPREGNATING THE TOW. A CROSSHEAD TYPE EXTRUSION DIE IS UTILIZED FOR THE FORMING OPERATION AND IS PROVIDED WITH A CENTRAL TUBE EXTENDING LONGITUDINALLY THEREIN FOR RECEIVING THE ADVANCING TOW AND ISOLATING IT FROM THE MOLTEN PLASTIC WITH WHICH THE EXTRUDATE IS FORMED, THE LATTER ENTERING THE DIE LATERALLY AND ISSUING FROM THE MOUTH THEREOF AS A CONTINUOUS TUBULAR SHEATH WHICH MAKES FIRST CONTACT WITH THE TOW AT A DISTANCE DOWNSTREAM OF THE DIE MOUTH. THE EXTRUDATE ON LEAVING THE CROSSHEAD DIE IS THEN SEIZED BY PASSING IT THROUGH A COOLING CHAMBER WHEREIN THE EXTERNAL DIMENSION OF THE PLASTIC SHEATH IS ACCURATELY CONTROLLED WITHIN PREDETERMINED LIMITS.

Inventors

• 👤 R Thomson
• 👤 J Osmalov
• 👤 G Mathe

Bibliographic Details