The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of one or more enclosures with one or more respective cavities that directly receive a portion of cooling gas emanating from one or more associated cooling elements. Each enclosure includes a port containing a variable exhaust device and optional flow buffer, acting to maintain a pressure differential between the cavity and an adjacent inside volume of the molten film tube, adjustable to optimize molten film tube stability cooling element efficiency and spaced apart dimension between cooling elements. Significant increases in production speeds are achieved with improved film quality over an increased range of tubular film sizes, down to a minimum size which occurs when operating at zero internal to molten film tube pressure.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of a divergent cooling element with a divergent cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube and providing an expelled cooling gas (i) in a path opposing the flow of the molten film tube toward a first exit gap and (ii) in a path with the flow of the molten film tube toward a second exit gap. A minimum gap between the divergent cooling interface and the molten film tube occurs at the first exit gap and/or the second exit gap. Advantageously, the divergent cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency. Additionally, multiple cooling elements can preferably be arranged in a stackable configuration to achieve higher throughput rates. Operation is characterized by improved film holding forces without the presence of high noise levels or detrimental vibration, flutter, and drag. Additionally, employing simplified single air delivery channels, and a stackable design, significantly reduces complexity and manufacturing costs.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of one or more enclosures with one or more respective cavities that directly receive a portion of cooling gas emanating from one or more associated cooling elements. Each enclosure includes a port containing a variable exhaust device and optional flow buffer, acting to maintain a pressure differential between the cavity and an adjacent inside volume of the molten film tube, adjustable to optimize molten film tube stability cooling element efficiency and spaced apart dimension between cooling elements. Significant increases in production speeds are achieved with improved film quality over an increased range of tubular film sizes, down to a minimum size which occurs when operating at zero internal to molten film tube pressure.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of a divergent cooling element with a divergent cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube and providing an expelled cooling gas (i) in a path opposing the flow of the molten film tube toward a first exit gap and (ii) in a path with the flow of the molten film tube toward a second exit gap. A minimum gap between the divergent cooling interface and the molten film tube occurs at the first exit gap and/or the second exit gap. Advantageously, the divergent cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency. Additionally, multiple cooling elements can preferably be arranged in a stackable configuration to achieve higher throughput rates. Operation is characterized by improved film holding forces without the presence of high noise levels or detrimental vibration, flutter, and drag. Additionally, employing simplified single air delivery channels, and a stackable design, significantly reduces complexity and manufacturing costs.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of one or more enclosures with one or more respective cavities that directly receive a portion of cooling gas emanating from one or more associated cooling elements. Each enclosure includes a port containing a variable exhaust device and optional flow buffer, acting to maintain a pressure differential between the cavity and an adjacent inside volume of the molten film tube, adjustable to optimize molten film tube stability cooling element efficiency and spaced apart dimension between cooling elements. Significant increases in production speeds are achieved with improved film quality over an increased range of tubular film sizes, down to a minimum size which occurs when operating at zero internal to molten film tube pressure.

The invention relates to a blown film line for generating a blown film with at least one extruder for generating at least one melt strand, at least one distribution tool for converting the at least one melt strand into a circulating melt layer, an outlet nozzle for outputting the at least one melt layer, wherein this melt layer forms the blown film, and at least one device for subjecting the blown film to at least one fluid stream, in particular an air stream, for cooling the blown film. At least one pressure-providing device is furnished, with which the blown film may be brought to the device for subjecting the blown film to a fluid stream by means of at least one overpressure and/or one underpressure.

The invention relates to a blown film line for generating a blown film with at least one extruder for generating at least one melt strand, at least one distribution tool for converting the at least one melt strand into a circulating melt layer, an outlet nozzle for outputting the at least one melt layer, wherein this melt layer forms the blown film, and at least one device for subjecting the blown film to at least one fluid stream, in particular an air stream, for cooling the blown film. At least one pressure-providing device is furnished, with which the blown film may be brought to the device for subjecting the blown film to a fluid stream by means of at least one overpressure and/or one underpressure.

A method of forming a blown film comprising extruding a molten composition through a die opening to form a film; wherein the molten composition comprises at least one polyethylene and within the range from 0.10 wt % to 10 wt % of a cyclic-diene terpolymer by weight of the composition; causing the film to progress in a direction away from the die opening; cooling the film at a distance from the die opening, the distance adjusted to effect the properties of the film; and isolating a blown film therefrom.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of a divergent cooling element with a divergent cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube and providing an expelled cooling gas (i) in a path opposing the flow of the molten film tube toward a first exit gap and (ii) in a path with the flow of the molten film tube toward a second exit gap. A minimum gap between the divergent cooling interface and the molten film tube occurs at the first exit gap and/or the second exit gap. Advantageously, the divergent cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency. Additionally, multiple cooling elements can preferably be arranged in a stackable configuration to achieve higher throughput rates. Operation is characterized by improved film holding forces without the presence of high noise levels or detrimental vibration, flutter, and drag. Additionally, employing simplified single air delivery channels, and a stackable design, significantly reduces complexity and manufacturing costs.

A method of forming a blown film comprising extruding a molten composition through a die opening to form a film; wherein the molten composition comprises at least one polyethylene and within the range from 0.10 wt % to 10 wt % of a cyclic-diene terpolymer by weight of the composition; causing the film to progress in a direction away from the die opening; cooling the film at a distance from the die opening, the distance adjusted to effect the properties of the film; and isolating a blown film therefrom.