An air ring has a main body including a plenum through which pressurized air enters the air ring, the main body including a generally circular interior that is unobstructed vertically above the main body. A generally circular forming-cone assembly is received in the generally circular interior of the main body, and includes at least one annular lip defining a passage through which pressurized air from the plenum exits the air ring for impingement upon the polymer tube. A plurality of fasteners secure the forming-cone assembly in the interior of the main body, the fasteners and forming-cone assembly being unobstructed vertically above the air ring, wherein the fasteners are accessible from vertically above the air ring and the forming-cone assembly is removable from the main body by vertical lifting without removal of other components from the air ring.

A method for post-tempering a film tube extruded by a blown film line includes: ejecting the film tube in a haul-off direction along a longitudinal axis of the blown film line by a blow head; blowing cooling gas onto the film tube relative to the haul-off direction downstream of the blow head to solidify the film tube at a frost line; post-tempering the film tube by a post-tempering unit having a plurality of adjustable blowing elements downstream of the frost line for blowing tempering gas onto the film tube; adapting a diameter of a feed-through opening formed by the blowing elements to a diameter of the film tube by adjusting the blowing elements; measuring the actual temperature of the film tube downstream of at least one of the blowing elements; and regulating the temperature of the film tube to a target temperature by blowing tempering gas onto the film tube.

The present invention relates to an apparatus for producing inline stretched tubular foils by the blowing process, having a blown foil system comprising an extruder, a blowing head, a cooling ring, a calibrating basket, a flat laying unit and a reversing turret haul-off, having a stretching system for monoaxially stretching the laid flat foil in the machine direction and with a first thinness control system which operates segmented control zones in the cooling ring to form thinness sections so that, during stretching, a foil is produced with a thickness profile having the smallest possible deviations from the medium foil thickness over the complete foil width. To increase the accuracy and speed of the first thinness section control system, a second thinness section control system is provided which controls two opposing heat sources between the calibrating basket and the flat laying unit and which can be connected to the first thinness section control system.

A melt cooler for a blown-film installation with a film-tube guide, wherein the film-tube guide has a central passage for a film tube that passes through the melt cooler during the operation of the blown-film installation, wherein the melt cooler has a cooling-fluid guide, which is designed to deliver cooling fluid introduced into the cooling-fluid guide to the film tube that passes through the melt cooler during the operation of the blown-film installation, wherein the cooling-fluid guide has a manifold, which has a cooling fluid outlet for delivering the fluid, and the cooling fluid outlet delivers the cooling fluid to the passage. An installation for moulding plastics, especially a blown-film installation or flat-film installation or some other installation designed for producing a film web, with a treatment section, and a melt cooler. A method for cooling a melt of a film tube of a blown-film installation with a melt cooler.

A tempering device for tempering a film tube extruded in a haul-off direction above a frost line includes: several guide segments distributed around a longitudinal axis parallel to the haul-off direction of the film tube and forming a central guide opening for guiding the film tube along the longitudinal axis, the guide segments being adjustable transversely to the longitudinal axis for adjusting the diameter of the guide opening; a guide roller for each guide segment, the guide roller being adjustable together with the guide segment and configured to guide the extruded film tube; and a nozzle section associated with the guide roller, which is adjustable together with the guide segment. The nozzle section has a blow-out nozzle for blowing out a tempering gas in the direction towards the longitudinal axis. The nozzle section is arranged relative to the longitudinal axis in at least partial radial overlap with the guide roller.