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.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process. Embodiments of the present disclosure provide a unidirectional cooling element having a unidirectional cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube. The unidirectional cooling element operably expels cooling gas in a path with the flow of the molten film tube toward an exit gap formed between the unidirectional cooling interface and the molten film tube. The minimum gap between the unidirectional cooling interface and the molten film tube occurs at the exit gap, and advantageously, the unidirectional cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency.

The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling.

The invention relates to a cooling device for plastic tubular films. In order to increase the cooling capacity of a known cooling device while simultaneously reducing bubble instabilities, the operating distance between the support air unit and the film bubble can be adjusted using at least two driven lifting elements, wherein the lifting elements are coupled together via a coupling element such that the lifting elements produce the same displacement distance upon adjusting the operating distance.