In an aspect, a biaxially oriented pipe has a thickened end portion. The end portion has the same inner diameter as the biaxially oriented pipe and has a larger thickness than the biaxially oriented pipe. The end portion is made of the same thermoplastic polymer composition as the biaxially oriented pipe.

The invention relates to a process for producing a biaxially oriented pipe by a) forming a polyethylene composition into a tube, wherein the polyethylene composition comprises high density polyethylene (HDPE) and a second polyethylene selected from linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and a combination of LLDPE and LDPE and b) stretching the tube of step a) in the axial direction and peripheral direction to obtain the biaxially oriented pipe.

The invention relates to a process for producing a biaxially oriented pipe by a) forming a polyethylene composition into a tube, wherein the polyethylene composition comprises high density polyethylene (HDPE) and a second polyethylene selected from linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and a combination of LLDPE and LDPE and b) stretching the tube of step a) in the axial direction and peripheral direction to obtain the biaxially oriented pipe.

The present invention discloses a system and a method for manufacturing fittings and connections for biaxially-oriented plastic tubes in an integral way from straight preformed tubes, with the possibility of adjusting and distributing the thicknesses as well as adjusting the specific stretching in the different areas of the fittings, allowing them to be reinforced or optimized during the method itself and without causing an increase in the production time or an increase in the raw material used, such that it allows for the manufacture of fittings of different geometric shapes (curves, tapers, couplers, branches, etc.)

The present invention discloses a system and a method for manufacturing fittings and connections for biaxially-oriented plastic tubes in an integral way from straight preformed tubes, with the possibility of adjusting and distributing the thicknesses as well as adjusting the specific stretching in the different areas of the fittings, allowing them to be reinforced or optimized during the method itself and without causing an increase in the production time or an increase in the raw material used, such that it allows for the manufacture of fittings of different geometric shapes (curves, tapers, couplers, branches, etc.)

Methods for preparing oriented polymer tubes, such as biodegradable polymer tubes suitable for in vivo use, are provided herein. The disclosed methods provide alternatives to the typical extrusion/expansion methods by which oriented polymeric tubes for such uses are commonly produced. Advantageously, the disclosed methods can provide more homogeneous molecular orientation of crystallizable polymers within the tube walls, which can endow such polymeric tubes with enhanced strength (e.g., resistance to compression) and toughness.

Methods for preparing oriented polymer tubes, such as biodegradable polymer tubes suitable for in vivo use, are provided herein. The disclosed methods provide alternatives to the typical extrusion/expansion methods by which oriented polymeric tubes for such uses are commonly produced. Advantageously, the disclosed methods can provide more homogeneous molecular orientation of crystallizable polymers within the tube walls, which can endow such polymeric tubes with enhanced strength (e.g., resistance to compression) and toughness.

A method and system for stretching a length of Teflon (PTFE) tubing where a mandrel is fully inserted therein requires firmly supporting and tensioning the PTFE tubing at ends thereof and grabbing the supported tubing at two adjacent locations at the center thereof and sliding and gripping with grippers from the center towards the two ends thereby stretching and pulling the length of PTFE tubing.

A method and system for stretching a length of Teflon (PTFE) tubing where a mandrel is fully inserted therein requires firmly supporting and tensioning the PTFE tubing at ends thereof and grabbing the supported tubing at two adjacent locations at the center thereof and sliding and gripping with grippers from the center towards the two ends thereby stretching and pulling the length of PTFE tubing.

Biaxially oriented tubular blown film stretching machine by isostatic pressurized water is a simultaneous biaxial stretching process, invented to stretch a high crystalline tubular blown film substrate with heterophasic structure to form a microporous film substrate, especially for microporous polypropylene film. The system comprises sequential sets of variable speed nip rolls, a temperature control water tank, and a water pump unit. The sequential sets of variable speed nip rolls used to stretch the tubular blown film substrate in machine direction, while hot water is pumped and confined inside the tubular blown film substrate creating an isostatic pressure in bubble, lead to an orientation stretching in transverse direction.