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US 8,297,964 B2Granted
Cleaning of extrusion dies
AssigneeE. I. Du Pont de Nemours and Company
InventorDelmer Ray Pettitt, Jr.
Life of this patent
Estimating the term…
Abstract
Extrusion dies may be cleaned, especially of so-called die drips, by passing a wire over the die orifices in the vicinity of the exit face of the extrusion die. The operation of the extrusion operation is not affected by the passing of the wire through the stream(s) of the extrudate, and so the extrusion operation need not be shut down for the cleaning process. The process is especially useful for cleaning dies through which polymers are extruded.
Claims20
A process for cleaning a die of an extruder,
- the extruder having
- a die out of which polymer extrudate flows and
- having
- an exit face and one or more extrusion orifices, each orifice having a cross section;
- and
- a rigid wire having
- a diameter that is no more than 20 percent of the maximum dimension of the cross section of any of the one or more extrusion orifices,
- wherein the rigid wire:
- is in the vicinity of and oriented in a plane parallel to the exit face of the die and parallel to the one or more extrusion orifices,
- the process comprising:
- moving a wire across the exit face of the die and the one or more extrusion orifices of said die thereby dislodging polymer extrudate from the exit face without breakage of, or interruption of, the polymer extrudate flowing out of the die.
8 more elements
A process for the extrusion of a substance, comprising:
- providing an extruder having
- a die out of which polymer extrudate flows and having an exit face and one or more extrusion orifices,
- and
- a rigid wire having a diameter that is no more than 20 percent of the maximum dimension of the cross section of any of the one or more extrusion orifices
- wherein the rigid wire is in the vicinity of and oriented in a plane parallel to the exit face of the die and parallel to the one or more extrusion orifices
- moving a wire across the exit face of the die and the one or more extrusion orifices of said die thereby dislodging polymer extrudate from the exit face without breakage of, or interruption of, the polymer extrudate flowing out of the die.
3 more elements
An apparatus, comprising:
- an extruder having
- a die out of which polymer extrudate flows and
- having
- an exit face and
- one or more extrusion orifices,
- each orifice having a cross section;
- and
- a rigid wire having
- a diameter that is no more than 20 percent of the maximum dimension of the cross section of any of the one or more extusion orifices,
- wherein the rigid wire:
- is in the vicinity of and oriented in a plane parallel to the exit face of the die and parallel to the one or more extrusion orifices;
- moves across the exit face of the die and through polymer extrudate flow;
- and
- dislodges extrudate from the exit face without breakage of the polymer extrudate flowing out of the die or interruption of polymer extrudate flow.
11 more elements
Dependencies are inferred from the claim text.