A flexible die head for continuously extruding pipe may have a flexible ring mandrel (112). A second, open end (120) of the ring mandrel (112) near the die exit may be continuously and resiliently formed to a non-circular shape whilst extruding the pipe so as to provide an extrudate profile to counter slump in plastic pipe forming. Symmetric and asymmetric shapes may be formed by the ring mandrel (112). The second end (120) may be flexed or otherwise distorted by use of a flexing means (122). The ring mandrel (112) may also be necked in a circumferential portion to order to further improve the forming of non-circular shapes.

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.

A film forming apparatus includes a die device which extrudes a molten resin in a tube shape to form a film and a controller which controls the die device. The die device includes an inner peripheral member which defines an inner periphery of an annular discharge port, an outer peripheral member which surrounds the inner peripheral member and defines an outer periphery of the discharge port, and an adjustment portion which applies a load to at least one of the inner peripheral member and the outer peripheral member to elastically deform the at least one of the inner peripheral member and the outer peripheral member and change a radial width of the discharge port. The controller controls a thickness of the film with the load applied by the adjustment portion.

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.

The invention relates to an annular die (1) on an extrusion head for producing tubular or sheet-like preforms with an arcuate die gap and with a melt channel (4) delimited by a mandrel (2) and a die body (3), the cross-sectional profile of the melt channel (4) 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 (4) is at least partially delimited directly by at least one radially adjustable slide (5), that the slide (5) 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 (4), the radius of the arc portion being different according to the position of the segments.

An apparatus produces plastic tubes by extrusion with an extruder, a pipehead being attached to the extruder in production direction, having a base material with at least one mandrel and a sleeve, a melt channel between the mandrel and the sleeve, the melt channel shaped to aid flow in production direction at least at the mandrel's end and at the sleeve's end, the mandrel and sleeve being adjustable backwards and forward relatively to one another, the outer surface of the mandrel and/or the inner surface of the sleeve at least partially has a material that allows for a higher sliding quality than the base material. The outer and/or the inner surface (i) has a coating either unvaried, or whose sliding quality constantly improves, or whose sliding quality alternately improves and worsens, in the production direction, or (ii) is partially coated, or (iii) the mandrel and/or sleeve fronts are coated.

A method and device for adjusting the concentricity of a die component of an extrusion assembly relative to a tip component in a manner that minimizes time and effort. The concentricity adjusting extrusion device includes an extrusion die body assembly including a die subassembly and a body, a die tip module and an adjustment sleeve subassembly; wherein said adjustment sleeve subassembly adjusts the concentricity of the die subassembly relative to the die tip module.

An extrusion nozzle for making tubular preforms has a mandrel extending along a vertical axis, an annular and stationary nozzle body spacedly radially surrounding the mandrel, and a holding ring having an upper end axially slidable in the nozzle body, braced axially downwardly against the nozzle body, and having a lower end spaced radially inward from shiftable limitedly radially relative to the nozzle body. A nozzle ring has an upper end axially slidable in the holding ring, is braced axially downwardly against the nozzle body, and has a radially deflectable lower end forming an annular extrusion gap with the mandrel. A first positioner engages the lower end of nozzle ring and is operable to radially deflect this lower end. A second positioner engages radially with the lower end of the holding ring or with the nozzle ring for radially deflecting same.

An extrusion nozzle for making tubular preforms has a mandrel extending along a vertical axis, an annular and stationary nozzle body spacedly radially surrounding the mandrel, and a holding ring having an upper end axially slidable in the nozzle body, braced axially downwardly against the nozzle body, and having a lower end spaced radially inward from shiftable limitedly radially relative to the nozzle body. A nozzle ring has an upper end axially slidable in the holding ring, is braced axially downwardly against the nozzle body, and has a radially deflectable lower end forming an annular extrusion gap with the mandrel. A first positioner engages the lower end of nozzle ring and is operable to radially deflect this lower end. A second positioner engages radially with the lower end of the holding ring or with the nozzle ring for radially deflecting same.

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 (1) and one nozzle (2), which have a rigid geometry and therefore cannot be varied or can also be deformed flexibly in some areas and form a flow channel (3), wherein the positions of the mandrel (1) and the nozzle (2) can be varied relative to one another, so that the geometry of a discharge gap (s) of the flow channel (3) 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.