Melt-sealing device for extruders for the processing of thermoplastic polymers or rubber
AssigneeHermann Berstorff Maschinenbau GmbH
InventorsFriedrich-Otto Behrens, Ulrich Proossler, Jurgen Voigt
Life of this patent
Estimating the term…
Abstract
A melt-sealing device for extruders for thermoplastic polymers or rubber for sealing off the gear unit side against high-melt pressure, in which sealing is effected by the configuration of the extruder screw which includes an intake section, a compression section having a channel depth that decreases in the conveying direction, a metering section with a constant screw channel depth, a smooth annular melt channel section, and a blister element with an annular gap for the sealing melt.
Claims4
A melt-sealing device for extruders for the processing of thermoplastic polymer or rubber for sealing off a gear unit side of a conveying screw against high melt pressures within an extrusion chamber defined by the screw and an extruder housing, wherein the conveying screw has a screw configuration which comprises the melt-sealing device and which includes:
- an intake section for receiving material pellets and conveying said pellets in a conveying direction toward an extrusion outlet, said intake section being formed with an intake liner with a feed opening for pellets, said feed opening being provided with an insulating sleeve to prevent agglomeration of the pellets,
- a compression section having a screw channel depth that decreases in the conveying direction,
- a metering section with a constant screw channel depth,
- a smooth annular melt channel section devoid of screw channels and having a channel depth and a minimum length of half the diameter of the screw, and
- a blister element downstream of said annular melt channel section in the conveying direction, said blister element having a peripheral surface which defines with said extruder housing an annular gap through which the melt passes.
Dependencies are inferred from the claim text.