Hosokawa Alpine Aktiengesellschaft

Hosakawa Alpine Aktiengesellschaft

Bernd Bayer

Lothar Klimek

Holger Niemeier

Hans-Peter Schüle

Georg Scharpf

The thickness profile of a film tube manufactured using a film blowing process is regulated using a control system consisting of segmented control zones and at least at two measuring units for the film thickness such that the specified target film thickness profile exhibits deviations from a uniform film thickness in the form of one or two thin spots opposite each other, which serve to compensate for film thickness changes across the film width which occur during the monoaxial orientation in machine direction so that a film web is produced as a result of orientation whose thickness profile has as few deviations as possible from the target thickness across the entire width of the film web, the final film should exhibit a thickness profile where the thickness increase from the middle of the film to the edges is as minor as possible and the flatness of the film is improved.

Process and equipment to regulate the thickness of oriented tubular film that is manufactured in a film blowing process

In the case of a device to permit the monoaxial length change of film webs in machine direction, which comprises at least one processing gap delimited by two rolls via which a film web is routed in machine direction, whereby the first roll in film transport direction exhibits a first peripheral speed and the second roll in film transport direction exhibits a second peripheral speed, in order to produce film webs with low transverse neck-in as well as reduced edge build-up and to improve the flatness of the film web.

Device and process to permit monoaxial changes in the length of film webs

An internal cooling tower for a film blowing line with one or more superimposed cooling air nozzles designed such that the entrainment of droplets consisting of low-molecular components of the raw material that diffuse during the film blowing process from the film into the flow of cooling air is prevented. This is achieved in that at the height of the nozzle gap, the top surface of the cooling air nozzles has a grooved contour both on the inside and the outside.

Internal cooling tower for film blowing lines

The invention relates to a process to regulate the film thickness of tubular film manufactured using a film blowing process, wherein the film is laid flat and repositioned using an oscillating take-off unit and subsequently monoaxially oriented in machine direction using an orientation unit. This process produces a film whose thickness profile has as few deviations as possible from the average film thickness across the film width. This result is achieved by setting the film thickness profile of tubular film produced with a film blowing line such that after orientation and as a result of deviations during orientation, a film thickness profile develops that is uniform across the entire film width.

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Bobingen, Germany

Bernd Bayer