Back to results
US 6,474,966 B1Granted
Slot die for producing webs of a foamed plastic material
AssigneeBerstorff GmbH
InventorFriedrich-Otto Behrens
Life of this patent
Estimating the term…
Abstract
A slot die for producing webs of a foamed plastics material, into which die plastics material which has been plasticized under elevated pressure in an extruder and charged with a blowing agent enters, and through the die gap of which the plastics material is extruded by foaming. The die gap is formed by a pair of rollers mounted in a laterally sealed manner in the slot die. This achieves the effect that an advantageous formation of outer layers already occurs ahead of the die gap before the start of foaming.
Claims2
A slot die for producing webs of a foamed plastics material, comprising:
- a housing;
- and a pair of rollers arranged in the housing so as to form a die gap through which plasticized plastics material is channeled under such a pressure that foaming of the plastics material only occurs after it leaves the die gap, the pair of rollers being mounted in a laterally sealed manner in the housing of the slot die so as to prevent a pressure drop in the plasticized plastics material before it leaves the die gap, the rollers of the pair of rollers being frustoconical and displaceable axially with respect to each other so that the thickness of the die gap is set.
Dependencies are inferred from the claim text.