Oriented polymeric products

US6053214A · kind A · utility

Assignee

• Uponor, Inc. · GB

Inventors

• Michael Sjoberg · Malung, SE
• Jan Rydberg · Houjie, CN
• Nils Yngve Lundequist · Virsbo, SE
• Lars Hoving · Hagfors, SE
• Hans Martin Tony Josefsson · Sandhult, SE
• Stig Lennart Agren · Borås, SE
• Bjorn Axel Roland Olsson · Alingsås, SE
• Jyri Jarvenkyla · Viinijärvi, FI

Key dates

• Filing date: Jul 28, 1998
• Grant date: Apr 25, 2000
• Expiry date: Jul 28, 2018

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29L2023/22
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A continuous method of extruding an oriented plastic article of improved strength. A chemically reactive polymer, monomer or other compound is included in the matrix material(s) and a (multilayer) parison is extruded or melt formed having built-in thermoplastic orientation caused by shear or caused by elongational flow. A reaction can be activated in the molten state thereof by additional heat resulting in a cross-linked structure or at least the mobility of the molecules being reduced, resulting in a longer relaxation time which makes the freezing of permanent orientation possible. The soft matrix can be stretched while still hot in the hoop and/or axial direction. Then, the product thus obtain is calibrated and cooled in an oriented state.