Process and apparatus for production of plastics containing additives
AssigneeWerner & Pfleiderer
InventorBernhard Scheuring
Life of this patent
Estimating the term…
Abstract
A process and apparatus for the production of plastic material containing an additive in which the plastic material is supplied into a mixing tank to undergo vigorous mixing therein and the mixed plastic material is discharged by an extrusion screw at the bottom of the tank into a conveying cylinder in which the extrusion screw extends. The mixed plastic material is conveyed by the screw in the conveying cylinder for discharge of the plastic material at a discharge outlet. The plastic material is heated in the conveying cylinder to achieve melting of the plastic material and the additive is supplied to the melted plastic material within the conveying cylinder so that the additive is thoroughly mixed with the melted plastic material before discharge thereof at the discharge outlet.
Claims12
A process for the production of plastic material containing an additive, said process comprising,
- providing a mixing tank having a rotatable extruder screw at a bottom of the tank, said extruder screw extending from said tank into a conveying cylinder which is connected to said tank,
- supplying plastic material into said conveying cylinder at an inlet spaced from the mixing tank,
- conveying the plastic material in said cylinder, by said extruder screw, towards said mixing tank,
- heating the plastic material in said conveying cylinder to melt the plastic material therein and supply the melted plastic material to said mixing tank,
- introducing additive into said mixing tank to mix the additive with the melted plastic material in said mixing tank,
- reversing the direction of rotation of said extruder screw to advance the now mixed additive and melted plastic material from said mixing tank into said conveying cylinder in a direction opposite the direction of travel of the plastic material when the plastic material traveled from said inlet to said mixing tank, and
- advancing the mixed additive and plastic material in said conveying cylinder to a discharge outlet thereof.
Apparatus for producing plastic material containing an additive comprising a mixing tank for receiving a measured amount of an additive to be mixed with a plastic material, a rotatable extruder screw in said tank, a conveying cylinder extending from said mixing tank with said extruder screw extending therein, said conveying cylinder having a discharge outlet spaced from said mixing tank, said conveying cylinder further having an inlet for supply of plastic material between said mixing tank and said discharge outlet, means for rotating said extruder screw in opposite directions of rotation, said extruder screw, in one direction of rotation, advancing the plastic material supplied at said inlet through said conveying cylinder to said mixing tank, means for supplying heat to the conveying cylinder between said mixing tank and said inlet for heating the plastic material to melting temperature as the plastic material is conveyed from said inlet to said mixing tank, and means for supplying a measured amount of an additive to said mixing tank for mixing the additive with the melted plastic material introduced into the mixing tank, said extruder screw than being driven in reversed direction of rotation to convey the plastic material with the additive mixed therein through the conveying cylinder to said discharge outlet.
Dependencies are inferred from the claim text.