US 5,679,380 A · Underwater pelletizing die plate

Abstract

In an underwater pelletizing die plate or an extruder for the pelletizing of thermoplastics, the front face of the die plate, which is provided with a wearing protection layer and over which pass the pelletizing knives, being disposed under water, and heat isulation means being provided on the pelletizing die plate, good axial insulation is to be achieved, accompanied by uniform temperature distribution in the radial direction, it being provided to this end that an insulating layer is disposed between the external upper side of the actual pelletizing die plate and the wearing protection layer, the wearing protection layer being positioned, relative to the insulating layer, with radial play and without axial pressure or with little axial pressure, respectively.

Claims16

Dependent claims

An underwater pelletizing die plate for an extruder that pelletizes thermoplastics, said die plate comprising

said pelletizing die plate defining a plurality of die plate holes extending through a face of said pelletizing die plate,
an insulating layer on said face, said insulating layer having a plurality of insulating die holes aligned with said die plate holes,
a wear protection layer on said insulating layer, said wear protection layer having a plurality protection layer die holes aligned with said insulating die holes, said protection layer die holes being larger than said insulation die holes,
mounting means mounting said wear protection layer on said insulating layer, and wherein when said wear protection layer is cooled radial displacement of said wear protection layer towards the center of said wear protection layer takes place relative to said insulation layer and said die plate.

1 more element

In a pelletizing extruder that has an underwater pelletizing die plate and a cutting head having pelletizing knives spaced from said pelletizing die plate to pelletize an extruded material, said die plate

said pelletizing die plate defining a plurality of die plate holes extending through a face of said pelletizing die plate,
an insulating layer on said face, said insulating layer having a plurality of insulating die holes aligned with said die plate holes,
a wear protection layer on said insulating layer, said wear protection layer having a plurality protection layer die holes aligned with said insulating die holes, said protection layer die holes being larger than said insulation die holes,
mounting means mounting said protection layer on said insulating layer, and wherein when said wear protection layer is cooled radial displacement of said protection layer towards the center of said wear protection layer takes place relative to said insulation layer and said die plate.

1 more element

Dependencies are inferred from the claim text.

Underwater pelletizing die plate

Life of this patent

Underwater pelletizing die plate

Life of this patent

Abstract

Claims16