Abstract A method and apparatus for making filter means of a type which is constructed to provide elongated, high-surface area, cavities defined on opposite sides of a relatively thin wall formed of filtering material with only the ends of the filter means contacting an overwrapped outer tube thereby presenting maximum available surface area of the material from which the products are formed to the smoke for filtration is disclosed. A tow of a suitable filtering material is passed through an air nozzle containing a mandrel centered therein, the tow thereby achieving a uniformly random, but tubular, configuration and then through a steam-curing station followed by an air-curing station. The formed rod is then again steam cured and passes to a crimping device which imparts a particular configuration thereto. The crimped rod is then again air cured, wrapped, and cut. In another embodiment, an addition material may be added by means either of a printing applicator device or a pulsating nozzle device.
The method of claim 1 wherein said segments defined in step (d) include parts of a plurality of crimped portions of said inner element and parts of a plurality of uncrimped portions of said inner element, including the step of further subdividing said segments to provide filter elements having an inner member defined by part of only one crimped portion of said inner element and part of only one uncrimped portion of said inner element, and an outer member formed by part of said outer element.
Claim 2
Dependent Claim
53 words
The method of claim 1, wherein said filtering material is formed into an axially elongated, hollow, inner element as defined in step (a) by passing said filtering material through air nozzle means having elongated mandrel means axially disposed therein, through steam jet means having mandrel extending thereinto, and then through air jet means.
Claim 3
Dependent Claim
37 words
The method of claim 1, wherein said inner element is crimped as defined in step (b) by passing the same through steam jet means, through heated crimping means comprising crimping wheels, and then through air jet means.
Claim 4
Dependent Claim
22 words
The method of claim 1 further including the step of applying a second filtering material to said axially elongated, hollow, inner element.