Abstract: A method for using the quantity of heat output from an extrudate during a cooling operation in an extrusion process, wherein a fluid, in particular air, is guided along the extrudate and/or through the die counter to an extrusion direction, at least some of the heat from the extrudate and/or the die is transmitted to the fluid, the heated fluid is supplied from a first sub region of a process chain, comprising at least one die, a calibrating and cooling device and a take-off apparatus, via a connecting region, preferably consisting of at least one connecting pipe, to a second sub region of the process chain, comprising at least one suction apparatus. In the connecting region, an extraneous fluid can be added to the heated fluid in order to reduce the actual temperature of the heated fluid at least below a predetermined maximum value before said fluid is supplied to the second sub region of the process chain.

Abstract: An extrusion head for an extrusion apparatus can include a spider for supporting a central mandrel. A high volume reservoir can be mounted to the spider on a downstream side of the spider. The central mandrel can extend longitudinally into the high volume reservoir. The high volume reservoir can have an axially straight annular conduit with a length L and an outer diameter OD. The annular conduit can have an L to OD ratio of about 1:1. A set of dies can be mounted downstream of the high volume reservoir, whereby the high volume reservoir reduces pressure and promotes homogenization of molten polymer flowing therethrough, before reaching the set of dies.

Abstract: The extrusion head including a conduit with a central mandrel extending within the conduit for supporting an inner die portion of a set of dies that has inner and outer die portions. An upstream spider and a downstream spider are included, and each have webs supporting the central mandrel at axially spaced apart positions. The webs of the upstream and downstream spiders can have web portions that are axially offset from each other to promote mixing of polymer flowing through the conduit.

Abstract: A spider for an extrusion apparatus located upstream from a die, through which a profile is extruded. The spider can have an outer housing with a central flow passage therethrough. An inner hub can be positioned within the central passage for supporting an inner portion of the die. At least one spider leg can be secured to the outer housing and the inner hub, and support the inner hub within the central passage. The at least one spider leg can recess radially rearwardly outwardly in the downstream direction such that molten polymer flowing through the central passage flows around the at least one spider leg, separating and rejoining together earlier in inner radial regions close to the inner hub than in outer radial regions close to the outer housing for reducing spider lines on inside surfaces of extruded profiles.

Abstract: A spider for an extrusion apparatus located upstream from a die, through which a profile is extruded. The spider can have an outer housing with a central flow passage therethrough. An inner hub can be positioned within the central passage for supporting an inner portion of the die. At least one spider leg can be secured to the outer housing and the inner hub, and support the inner hub within the central passage. The at least one spider leg can recess radially rearwardly outwardly in the downstream direction such that molten polymer flowing through the central passage flows around the at least one spider leg, separating and rejoining together earlier in inner radial regions close to the inner hub than in outer radial regions close to the outer housing for reducing spider lines on inside surfaces of extruded profiles.

Abstract: A spider for an extrusion apparatus located upstream from a die, through which a profile is extruded. The spider can have an outer housing with a central flow passage therethrough. An inner hub can be positioned within the central passage for supporting an inner portion of the die. At least one spider leg can be secured to the outer housing and the inner hub, and support the inner hub within the central passage. The at least one spider leg can recess radially rearwardly outwardly in the downstream direction such that molten polymer flowing through the central passage flows around the at least one spider leg, separating and rejoining together earlier in inner radial regions close to the inner hub than in outer radial regions close to the outer housing for reducing spider lines on inside surfaces of extruded profiles.

Abstract: An extrusion head for an extrusion apparatus can include a spider for supporting a central mandrel. A high volume reservoir can be mounted to the spider on a downstream side of the spider. The central mandrel can extend longitudinally into the high volume reservoir. The high volume reservoir can have an axially straight annular conduit with a length L and an outer diameter OD. The annular conduit can have an L to OD ratio of about 1:1. A set of dies can be mounted downstream of the high volume reservoir, whereby the high volume reservoir reduces pressure and promotes homogenization of molten polymer flowing therethrough, before reaching the set of dies.

Abstract: The extrusion head including a conduit with a central mandrel extending within the conduit for supporting an inner die portion of a set of dies that has inner and outer die portions. An upstream spider and a downstream spider are included, and each have webs supporting the central mandrel at axially spaced apart positions. The webs of the upstream and downstream spiders can have web portions that are axially offset from each other to promote mixing of polymer flowing through the conduit.

Abstract: Supporting device for a plastic profile (2), in particular for a plastic pipe, in a calibration device which has a supporting region (1), in which it supports the plastic profile (2), wherein the contour (3) in the supporting region (1) is adapted to the contour of the plastic profile (2). According to the invention, provision is made in that the contour (3) in the supporting region (1), in particular the radius (4), can be changed. Furthermore, the invention relates to a process for changing a supporting region of a supporting device, in which the position of one or more series-arranged supporting devices with continuously changeable supporting region are changed as a function of a predetermined theoretical diameter such that the predetermined diameter is produced.

Abstract: An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar and an outer collar, and webs radially joining the inner collar and outer collar. The webs can be arranged twisted and/or offset in radial direction.

Abstract: An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar, an outer collar, and a middle collar, each of the collars being radially joined by webs to the particular adjoining collar. Each interior web and exterior web, relative to the middle collar, can form a web pair, the webs of the web pair being arranged to overlap at least partially in the radial direction in a particular embodiment.

Abstract: In a co-extrusion system, a primary extruder is connected to a primary flow director to direct the solid melt from the primary extruder to the co-extrusion assembly. A secondary extruder is connected to a secondary flow director to direct the melt from the secondary extruder to the co-extrusion assembly. A co-extrusion assembly produces simultaneous co-extruded melts without any significant pressure change in the melt. Dies shape the co-extruded melts to a desired shape.

Abstract: An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar and an outer collar, and webs radially joining the inner collar and outer collar. The webs can be arranged twisted and/or offset in radial direction.

Abstract: An extrusion die includes an inner die portion having a male form. The male form has a male complex shape with peaks and a valley. An outer die portion is included having a female form. The female form has a female complex shape with peaks and a valley which corresponds to the male complex shape of the male form. The female complex shape surrounds and is separated from the male complex shape by a gap. Flowable material is capable of being extruded through the gap between the male and female complex shapes to form a hollow profile. An adjustment mechanism is included having an outer member which surrounds the outer die portion. At least eight adjustment screws are threaded through the outer member and engage the outer die portion at equidistant angular locations.

Abstract: There is provided a plastic extrusion sizing tube having a cylinder with a split along its length to allow for radial expansion and reduction of the sizing tube. The cylinder has holes to allow an extrusion within the cylinder to be drawn to the cylinder by a vacuum outside the cylinder. The cylinder also has extensions on opposite sides of the split with an adjustment screw connecting the extensions. The diameter of the cylinder can be expanded or reduced when the adjustment screw is turned in respective directions. A set screw can be connected to one of the extensions. The diameter of the cylinder can be expanded or reduced when the set screw is turned in respective directions. The diameter of the cylinder can be locked in a desired position when the adjustment screw and the set screw are turned in the same direction. The adjustment screw and the set screw can be located in a flange at one end of the cylinder. The holes in the cylinder can be slots.

Abstract: In a co-extrusion system, a primary extruder is connected to a primary flow director to direct the solid melt from the primary extruder to the co-extrusion assembly. A secondary extruder is connected to a secondary flow director to direct the melt from the secondary extruder to the co-extrusion assembly. A co-extrusion assembly produces simultaneous co-extruded melts without any significant pressure change in the melt. Dies shape the co-extruded melts to a desired shape.

Abstract: An adjustable extrusion die shapes a melt into a non-circular cross-sectional profile form. The wall thickness of the profile is adjustable by moving two adjustment plates orthogonal to each other and transverse to the flow of the melt. Movement of each adjustment plate is restricted to prevent rotation relative to a melt-shaping bushing.

Abstract: An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar, an outer collar, and a middle collar, each of the collars being radially joined by webs to the particular adjoining collar. Each interior web and exterior web, relative to the middle collar, can form a web pair, the webs of the web pair being arranged to overlap at least partially in the radial direction in a particular embodiment.

Abstract: There is provided a plastic extrusion sizing tube having a cylinder with a split along its length to allow for radial expansion and reduction of the sizing tube. The cylinder has holes to allow an extrusion within the cylinder to be drawn to the cylinder by a vacuum outside the cylinder. The cylinder also has extensions on opposite sides of the split with an adjustment screw connecting the extensions. The diameter of the cylinder can be expanded or reduced when the adjustment screw is turned in respective directions. A set screw can be connected to one of the extensions. The diameter of the cylinder can be expanded or reduced when the set screw is turned in respective directions. The diameter of the cylinder can be locked in a desired position when the adjustment screw and the set screw are turned in the same direction. The adjustment screw and the set screw can be located in a flange at one end of the cylinder. The holes in the cylinder can be slots.

Abstract: An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar and an outer collar, and webs radially joining the inner collar and outer collar. The webs can be arranged twisted and/or offset in radial direction.