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Rohm Gmbh Chemische Fabrik

Roehm Gmbh Chemische Fabrik

Roehm Gmbh & Co Kg

Heinz Gross

Gross, Heinz

Karl Funk

Hans Lorenz

Werner Siol

Heinz Vetter

Michael Meier-Kaiser

Jens-Dieter Fischer

Hartmut Schikowsky

Thomas Rhein

Thomas Sufke

Andreas Fetzer

Karl-Heinrich Schanz

Helmut Haring

Klaus E Pohlmann

Friedrich-Otto Koch

Adolf Peeck

Werner Wennemann

Roland Schuchmann

Klaus E Poehlmann

Herbert Helm

Harmut Schikowsky

Gunther Dickhaut

A parison head for discharging a parison for producing capillaries, tubes or pipes, includes a sleeve-shaped housing into which the melt is fed, and which surrounds a core on all sides with a spacing, the core being firmly clamped in the housing, and also a likewise sleeve-shaped die, which likewise surrounds the core on all sides with a spacing, wherein the housing and the die surround the core in such a way that there is a closed flow channel between the housing and the core and between the die and the core, and at the end of the flow channel a peripheral closed outlet gap is formed by the die and the core, wherein there is between the housing and the die a low-cost, quickly exchangeable, trifunctional component, which securely seals off the flow channel between the housing and the die, and with which the angle between the housing and the die and also the length of the head can be changed, while retaining the flow resistance in the region of the trifunctional component and while retaining a flow channel that is free from dead spots, and so in this way the cross section of the flow channel gap at the end of the flow channel is variable.

Parison head with trifunctional component and method for discharging a parison

The invention relates to an extrusion head and a method with which the thickness distribution of hollow bodies, for example, can be further improved. The extrusion head consists of at least one mandrel () and one nozzle (), which have a rigid geometry and therefore cannot be varied or can also be deformed flexibly in some areas and form a flow channel (), wherein the positions of the mandrel () and the nozzle () can be varied relative to one another, so that the geometry of a discharge gap (s) of the flow channel () can be varied while a melt is being discharged, wherein each head part has at least one head section with a uniform cross-sectional area in a discharge area (A) of the extrusion head, and wherein at least one head part has at least two head sections (B) and (C), each of which has a predominantly uniform cross-sectional area within the head section (B), (C), which are spaced axially apart from one another and which have mutually different cross-sectional areas.

Extrusion head and method for producing hollow bodies

A wall structure forms a fluid flow channel and includes a deformable multi-wall area for varying a cross-section of the flow channel. The wall structure comprises a homogeneous material. The wall structure is made by sequentially applying layers of a material to one another such that in a region of the wall structure corresponding to the multi-wall area layers do not adhere to one another, to form individual walls disposed adjacent one another in the direction of the thickness of the wall structure.

Wall structure having a deformable multi-walled area for varying a cross section of a flow channel

Matte-finished polymethacrylate films

The geometry of a flow channel ( ) can be varied within wide limits if at least one wall of the flow channel ( ) takes the form of a sheet stack ( ) which is pushed from the rear into the channel to a greater or lesser extent by means of adjusters ( ). The adjustment may be effected either uniformly over the entire width of the flow channel ( ) or only locally at certain points thereof. It is thus possible, while a medium is passing through the flow channel ( ), to alter form outside the flow resistance either of the entire channel or only at certain points and thus alter the entire mass flow or the mass flow distribution as desired. New processing possibilities are given by the greater flexibility of the sheet stack ( ) in relation to solid channel walls.

Method of extracting a melt strand

Apparatus for variable limitation of a flat flow channel

Adjustable throttle with flat channel cross-section

Device for extruding and smoothing plastic films

Methods and apparatus for controlling the bead height in a plastic web

Extruded, smooth finished solid sheet or film, which may have a thickness&lt;1 mm, of a thermoplastic plastic (such as polycarbonate) with a glass transition temperature &gt;50.degree. C., which under conditions of orientation displays optical birefringence, may be manufactured into a flat strip with smooth finished surfaces, to yield a strip which has characteristics as follows:

Producing extruded solid plastic sheet and film

A flat web of sizable thickness made of thermoplastic can be extruded from an extrusion die without a restrictor bar if a thickness D of a restricting passage is made smaller than a shaping distance A of die lips (4, 5), and if at least one wall of the restricting passage (6) is adjustably designed as an elastic lip (7) by adjusting elements (8), so that thickness D and distance A can be changed at the same time by actuating the adjusting elements.

Extrusion die for thermoplastic webs

Extruded, smooth finished solid sheet or film, which may have a thickness &lt;1 mm, comprised of a thermoplastic plastic (such as polycarbonate) with a glass transition temperature &gt;50.degree. C., which under conditions of orientation displays optical birefringence, may be manufactured into a flat strip with smooth finished surfaces, to yield a strip which has characteristics as follows:

Extruded solid plastic sheet or film

An extruded, smooth finished solid sheet or film of thickness &lt;1 mm is prepared from a thermoplastic plastic having a glass transition temperature &gt;50.degree. C., by extruding the plastic in the thermoplastic state through a slot nozzle to form a flat extruded strip, which is introduced into the roll gap of a roll stack having a smoothed upper roll and a lower roll, with the upper roll being maintained at a temperature below the glass transition temperature of the thermoplastic plastic and with the lower roll being maintained at a temperature in the plastic state domain of the thermoplastic plastic, and, after exiting the roll gap, the extruded strip is moved resting on a smooth-finished endless belt which passes around the lower roll, thereby smoothing the surface of the strip; and cooling said extruded strip below the glass transition temperature.

Method of manufacturing thermoplastic sheet or film

For producing a multi-extrudate of thermoplastically processable plastic, a coextrusion adapter block has a multi-part slide having a plurality of side-by-side slide sections mutually spaced in a direction transverse to the flow direction and slidably fitted in the adapter block for movement to adjustably protrude into a secondary runner for adjusting the thickness of a molten extrudate therein. A multi-layer extrudate emerging from the adapter block is further extruded in an extrusion die, and the thickness of at least one layer thereof is measured at a plurality of positions along the width thereof. The width measurements are used to control the positions of corresponding slide sections so that the layer thicknesses can be accurately controlled during an extruding operation.

Process and system for producing multi-layer extrudate

Multi-layer plastic elements containing a polycarbonate core, with a polymethacrylate layer containing a UV absorber, and modified to be impact-resistant, applied to the core, where the polymethacrylate plastic layer is composed of methacrylate copolymers, which form compatible mixtures with polycarbonate, especially the polycarbonate of bisphenol A, exhibit good adhesion between the polycarbonate and the polymethacrylate. The methacrylate copolymers are methyl methacrylate copolymers with (meth)acrylic monomers which contain carbocyclic substituents in the ester group. The protective layer containing UV absorber is applied to the polycarbonate plastic in thickness from 1 to 500 .mu.m by coextrusion or by lacquering.

Impact-resistant methacrylate protective layer for polycarbonate,

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Rossdorf, Germany

Heinz Gross