Apparatus and method for feeding a powdery material to a plasticized, pressurized polymer
AssigneeW Bar E, Incorporated
InventorRichard H. Skidmore
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Abstract
Means and method are provided for feeding through a feed port, to a plasticized polymer mass, a powdery material which contains entrapped air. An extruder is used having an entrance for feeding the polymer, and having a rotating worm, transporting the polymer from its entrance to a polymer exit; means are provided forming an entrance port for the powdery material downstream of the polymer entrance, and positive vent means are provided in the housing upstream of the powdery material entrance but downstream of the polymer entrance for drawing out the air, to prevent entrapped air or volatiles from fouling the powder feed port.
Claims10
In an apparatus for feeding, to a plasticized polymer mass, a powdery material which contains entrapped air, the combination which comprises:
- a. an extruder having an entrance for feeding said polymer, and having an elongated worm arranged for rotation in a housing and having worm flights arranged to transport said polymer from said entrance to a polymer exit formed in said housing,
- b. means forming an entrance port for said powdery material together with its entrapped air, downstream of said polymer entrance, and
- c. vent means in said housing upstream of said means (b) but downstream of said polymer entrance and sealed therefrom.
In a method for feeding, to a polymer mass, a powdery material which contains entrapped air, the steps which comprise feeding the main polymer feed and heating and plasticizing it, and forming it into a polymer seal within said housing, feeding the powder additive together with its entrained air into the housing at a point downstream of said polymer material seal, into contact with the plasticized polymer mass at the location of the point of introduction of said powdery material, whereby substantial quantities of said powdery material mix with the plasticized polymer mass and move downstream together, releasing from said housing, at a point upstream of the point of introduction of the powdery material, the air initially contained within said powdery material, and moving said air from said housing.
Dependencies are inferred from the claim text.