A method and system for processing a heated flexible sheet, with oppositely facing surfaces, that is advanced in a processing path. A first cooling roll has a first peripheral surface for contacting one of the sheet surfaces. A second cooling roll has a second peripheral surface for contacting the other sheet surface. The system is configured so that the first and second cooling rolls are selectively movable in relationship to each other in a manner, other than by moving one or both of the first and second cooling rolls towards or away from the flexible sheet, between: a) a first relationship wherein the first sheet surface is caused to engage the first peripheral surface over a first circumferential extent as the flexible sheet is advanced in the processing path; and b) a second relationship wherein the first sheet surface is caused to engage the first peripheral surface over a second circumferential extent that is different than the first circumferential extent as the flexible sheet is advanced in the processing path.

A calibration device for a calibration, in particular wet calibration of an extrusion device is provided. The calibration device comprises a calibrating element which includes an opening for guiding through a profile produced by means of an extrusion die of the extrusion device and at least one rotatable guide roller which is in contact with the profile when the profile is guided through the opening. The calibration device further comprises at least one separate bearing element insertable into a cutout of the calibrating element, via which the guide roller can rotatably be mounted on the calibrating element.

Disclosed are plastic products from a recycled plastic mix of unidentified, unclean and unsorted mixed plastic waste made with a system comprising thermal and mechanical processing of the recycled plastic waste using continuous extrusion foaming, two-phase cooling, continuous metering of the pulling strength and automatic adjustment of the pulling speed and extrusion speed.

Disclosed are plastic products from a recycled plastic mix of unidentified, unclean and unsorted mixed plastic waste made with a system comprising thermal and mechanical processing of the recycled plastic waste using continuous extrusion foaming, two-phase cooling, continuous metering of the pulling strength and automatic adjustment of the pulling speed and extrusion speed.

An air ring comprises a circular plenum in fluid communication with a source of pressurized air. An upper and lower annular lips are in fluid communication with the plenum through upper and lower channels and are arranged to supply air to the blown film bubble. A plurality of vanes are disposed in the upper channel and extend radially inwardly from the plenum to the upper annular lip. The vanes divide the upper channel into a plurality of radially extending channel segments. Each vane has a selected length and a distal end proximal the upper annular lip, the distal end being spaced from the upper annular lip no greater than about 20% of the length of the vanes. A powered plunger extends between the vanes of each of the channel segments to vary the cross-sectional area of the channel segments.

An air ring comprises a circular plenum in fluid communication with a source of pressurized air. An upper and lower annular lips are in fluid communication with the plenum through upper and lower channels and are arranged to supply air to the blown film bubble. A plurality of vanes are disposed in the upper channel and extend radially inwardly from the plenum to the upper annular lip. The vanes divide the upper channel into a plurality of radially extending channel segments. Each vane has a selected length and a distal end proximal the upper annular lip, the distal end being spaced from the upper annular lip no greater than about 20% of the length of the vanes. A powered plunger extends between the vanes of each of the channel segments to vary the cross-sectional area of the channel segments.

A ram extrusion apparatus including a die having several thermal zones, a hopper for introducing a granular polymer resin to the die, and a ram for moving the granular polymer resin through the thermal zones of the die and out from an outlet end thereof at a temperature above the crystalline melt temperature of the polymer resin. The hopper may be designed to deliver the polymer resin into a resin inlet of the die in a plurality of specifically metered amounts which may vary across a width of the resin inlet end of the die. The apparatus may further include one or more finishing tables positioned after the outlet end of the die for receiving and moving the extruded resin away from the outlet end of the die so that there is no backpressure on the extruded resin, and which provide compression force and even cooling to the extruded resin.

A ram extrusion apparatus including a die having several thermal zones, a hopper for introducing a granular polymer resin to the die, and a ram for moving the granular polymer resin through the thermal zones of the die and out from an outlet end thereof at a temperature above the crystalline melt temperature of the polymer resin. The hopper may be designed to deliver the polymer resin into a resin inlet of the die in a plurality of specifically metered amounts which may vary across a width of the resin inlet end of the die. The apparatus may further include one or more finishing tables positioned after the outlet end of the die for receiving and moving the extruded resin away from the outlet end of the die so that there is no backpressure on the extruded resin, and which provide compression force and even cooling to the extruded resin.

This invention relates to a polymeric pipe, and more particularly a polymeric pipe where the pipe comprises a crosslinked polyolefin formed from extruded polyolefin comprising a photoinitiator and a reactive extrusion species. More particularly, this invention relates to the manufacturing of plastic pipes and tubing by utilizing co-rotating twin screw extrusion combined with photo-induced crosslinking, of thermoplastic polymers such as polyethylene, to produce PEX pipes and tubing.

This invention relates to a polymeric pipe, and more particularly a polymeric pipe where the pipe comprises a crosslinked polyolefin formed from extruded polyolefin comprising a photoinitiator and a reactive extrusion species. More particularly, this invention relates to the manufacturing of plastic pipes and tubing by utilizing co-rotating twin screw extrusion combined with photo-induced crosslinking, of thermoplastic polymers such as polyethylene, to produce PEX pipes and tubing.