Method for introducing additives into an extruder
AssigneeE. I. Du Pont de Nemours and Company
InventorWilliam A. Fintel
Life of this patent
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Abstract
This invention relates to a method for controlling the introduction of additives, in the form of a plurality of strands, to a cutter. The strands are cut into pellets, and the pellets are fed to an extruder for making thermoplastic shaped articles. The feeding of the strands to the cutter and extruder involves feeding the strands through a metering device and calculating the feed rate, velocity, and delta position for each strand per feed interval in order to obtain the desired amount of additive in the resulting thermoplastic article.
Claims14
A method for introducing additives into an extruder for making thermoplastic shaped articles comprising the steps of feeding additives in the form of a plurality of strands to a cutter, wherein each strand is cut into pellets, and then feeding said pellets to the extruder, wherein the feeding of the strands to the cutter is controlled by the steps comprising:
- a) calculating a feed rate for each strand, said feed rate being different for at least two of the strands;
- b) calculating a velocity for each strand, said velocity being the same for each strand;
- c) calculating a delta position for each strand per feed interval, said delta position being different for at least two of the strands;
- and
- d) feeding each strand at the calculated velocity for the time needed to move the calculated delta position per feed interval.
Dependencies are inferred from the claim text.