Kautex Textron Gmbh & Co. Kg

Joachim Eckhardt

Thomas Froitzheim

Gerd Wolter

David Schenkel

Dirk Eulitz

Harald Lorenz

Matthias Borchert

Timo Kramer

Matthias Franke-Maintz

Timo Krämer

The invention relates to an annular die on an extrusion head for producing tubular or sheet-like preforms with an arcuate die gap and with a melt channel delimited by a mandrel and a die body, the cross-sectional profile of the melt channel being variable by way of adjusting elements, the annular die according to the invention being distinguished by the fact that the outer circumference of the melt channel is at least partially delimited directly by at least one radially adjustable slide, that the slide is formed by a number of segments that can be adjusted together from at least one first position into at least one second position, and that the segments in each position form a respectively closed arc portion of the delimitation of the melt channel, the radius of the arc portion being different according to the position of the segments.

Annular die and method for extrusion

The invention relates to an annular die () on an extrusion head for producing tubular or sheet-like preforms with an arcuate die gap and with a melt channel () delimited by a mandrel () and a die body (), the cross-sectional profile of the melt channel () being variable by way of adjusting elements, the annular die according to the invention being distinguished by the fact that the outer circumference of the melt channel () is at least partially delimited directly by at least one radially adjustable slide (), that the slide () is formed by a number of segments that can be adjusted together from at least one first position into at least one second position, and that the segments in each position form a respectively closed arc portion of the delimitation of the melt channel (), the radius of the arc portion being different according to the position of the segments.

The invention relates to a method for the production of hollow bodies from thermoplastic plastic. The method comprises the extrusion of at least two sheet-like preforms consisting of thermoplastic plastic, the introduction of the preforms into a preferably multipart molding die with a molding cavity which at least partially defines the contour of the hollow body to be manufactured, and the shaping of the preforms inside the die, using a vacuum and/or gas pressure in the first heat of the material. The method is distinguished in that at least two preforms to be shaped into a hollow body and to be connected are extruded successively, that is to say sequentially, in time and are shaped simultaneously.

Method for the production of hollow bodies from thermoplastic plastic

The invention concerns a process for the production of hollow bodies of thermoplastic material by extrusion blow molding. In the process according to the invention continuous extrusion of at least two preforms in web form of plasticized material is effected by means of a plurality of extrusion devices. The preforms are jointly shaped to form a hollow body in the still plastic condition, that is to say in the first heat, within a multi-part tool forming a mold cavity. In that case a wall thickness profile is imparted to at least one preform during the extrusion operation independently of the respective other preform by continuous nozzle gap adjustment during the extrusion operation.

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Bonn, Germany

Joachim Eckhardt