PROCESS FOR PRODUCING PIPE BY BIAXIAL ELONGATION

• Main Authors: TARAIYA, Ajay,Kumar, SOLIMAN, Maria
• Format: Patent
• Language: English; French; German
• Published: 03.07.2024
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BLASTING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PIPES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THERMAL INSULATION IN GENERAL; TRANSPORTING; WEAPONS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

The invention relates to a process for producing a biaxially oriented pipe, comprising the steps of: a) forming a polyethylene composition into a tube, wherein the polyethylene composition comprises a bimodal or a multimodal high-density polyethylene (HDPE) and b) stretching the tube of step a) in the axial direction and in the peripheral direction to obtain the biaxially oriented pipe, wherein step b) is performed at an axial draw ratio of 1.1 to 3.2 and an average hoop draw ratio of 1.1 to 2.0 or step b) is performed at an axial draw ratio of 1.1 to 1.9 and an average hoop draw ratio of 1.1 to 2.0, and wherein step b) is performed at a drawing temperature which is 1 to 30° C. lower than the melting point of the polyethylene composition.