Apparatus for producing a curly puff extrudate

DETAILED DESCRIPTION The proposed invention comprises introducing the extrudate as it exits the extruder die into a containment tube or other peripheral containment vessel that is generally axially oriented with the flow path of the extrudate and has a diameter that approximates the intended diameter of each curl.
A slight pressure, force, or resistance is then applied on the extrudate downstream of the glass transition point.
This resistance causes the extrudate to "back up" and, in essence, coil inside the peripheral containment vessel.
The resistance can be accomplished by any number of means.
For example, a blocking element can be placed in front of the containment tube, either outside of or integral to the tube.
A hole can be drilled in the containment tube and either a pressure applied or a vacuum applied through such hole, either of which need only be of such magnitude to effect a change in the resistance on the extrudate sufficient to begin the coiling process.
A blocking flap under spring tension can also be used, or any number of small obstructions or means of applying a force on the extrudate.
Such a device can be easily fitted to the exit of an extruder die at one end and to a circular extruder face at the other end, thereby allowing for a simple and inexpensive retrofit to existing machinery and allowing for face cutting.
Changes in the containment vessel and changes in the method of applying resistance can be used to adjust the pitch and diameter of the curl.
Economically high throughput rates can be achieved, thus allowing for efficient utilization of existing extruder production lines without requiring additional extruders to maintain line production rates.
The above as well as additional features and advantages of the present invention will become apparent in the following written detailed description.