Method and machine for producing a single-walled or multi-walled tubular thermoplastic body
AssigneeBodo Richter
InventorGünter Richter
Life of this patent
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Abstract
In a method for producing at least a single-walled tubular thermoplastic body in a machine, a nozzle head extrudes at least one tubular preform. The preform is expanded to a predefined dimension in a transverse direction and to a predefined shape in an expansion process using an expanding mandrel, the preform remaining open at the top and bottom. When the at least one preform has cooled off, the expanding mandrel is changed into a non-expanded state and the at least single-walled tubular body is removed from the machine.
Claims15
A method for producing at least a single-walled tubular body from thermoplastic material in a machine,
- in which at least one tubular preform is output from the nozzle head of an extrusion device,
- the at least one tubular preform is guided vertically downwards,
- the at least two-part hollow mold having one of a corrugated profile or a cup profile is arranged around the at least one tubular preform,
- the at least one tubular preform is expanded in an expansion process by an expanding mandrel having one of corrugated expanding elements or expanding elements provided with cups, the expanding mandrel being arranged centrically to the nozzle head to a predefined dimension in a transverse direction and to a predefined shape, wherein the at least one tubular preform is pressed against one of a corrugated profile ort a cup profile of the hollow mold and the at least one tubular preform adopts the shape of one of the corrugated profile or the cup profile by applying one of a vacuum to the hollow mold or compressed air to the expanding mandrel, the preform remaining open at the top and bottom,
- after cooling the at least one tubular preform, the expanding mandrel is moved into a non-expanded state,
- and in which afterwards the at least single-walled tubular body is removed from the machine.
a. A method for producing a triple-walled tubular body in which a first preform is output and is expanded by a first expanding mandrel with smooth expanding elements,
- b. afterwards, a second preform is output concentrically to the first preform and is expanded by a second expanding mandrel with one of corrugated or cup-shaped expanding elements so far that it welds to the still warm first preform at contact points,
- c. and afterwards, a third preform is output concentrically to the second preform and is expanded by a third expanding mandrel with smooth expanding elements so far that it welds to the still warm second preform at contact points, and in which the three preforms are cooled off,
- d. wherein the third preform is pressed against one of a corrugated profile or a cup-shaped profile of the second preform and the third preform adopts the shape of one of the corrugated profile or the cup profile by applying one of a vacuum to the hollow mold or compressed air to the third expanding mandrel.
A machine for producing at least a single-walled tubular body from thermoplastic material,
- in which at least one tubular preform is output from the nozzle head of an extrusion device,
- the at least one tubular preform is guided vertically downwards,
- the at least two-part hollow mold having one of a corrugated profile or a cup profile is arranged around the at least one tubular preform,
- the at least one tubular preform is expanded in an expansion process by an expanding mandrel having one of corrugated expanding elements or expanding elements provided with cups, the expanding mandrel being arranged centrically to the nozzle head to a predefined dimension in a transverse direction and to a predefined shape, wherein the at least one tubular preform is pressed against one of a corrugated profile or a cup profile of the hollow mold and the at least one tubular preform adopts the shape of one of the corrugated profile or the cup profile by applying one of a vacuum to the hollow mold or compressed air to the expanding mandrel, the at least one tubular preform remaining open at the top and bottom,
- the expanding mandrel moves into a non-expanded state after cooling the at least one tubular preform.
Dependencies are inferred from the claim text.