System for the improved introduction of a separating device and blown film line, as well as a method for the production and supply of at least two plastic film webs in a blown film line

A blown film line for the production and supply of several film webs made of plastic with:

• a blow head from which a film tube can be extruded wherein the film tube can be conveyed along a transport direction;
• a flattening device which is arranged downstream of the blow head and by means of which the film tube can be flattened as a double-layer plastic film;
• a separating device which is configured in such a way that the flattened film tube can be separated into two separate film webs;
• a system, for improved introduction of the separating device into the flattened film tube, comprising:
• a cutting device for cutting through only a first tube side of the film tube, wherein the cutting device has at least one cutting element for effecting a severing cut on the film tube;
• and
• an opening device arranged downstream of the cutting device and upstream of the separating device in a transport direction of the film tube for opening the flattened film tube along the severing cut to facilitate inserting the separating device into the flattened film tube, wherein the opening device includes at least one opening element configured to move from a position outside the flattened film tube to pass through the severing cut;
• a control unit for causing the film tube to move along the transport direction;
• and
• two winding points, wherein a film web can be fed to each winding point.

A method for producing and providing at least two film webs of plastic comprising the following:

• extrusion of a film tube,
• cutting of only a first tube side of the film tube via a cutting device for cutting through only a first tube side of the film tube, wherein the cutting device has at least one cutting element for effecting a severing cut on the film tube,
• flattening the film tube to form a double-layer plastic film,
• opening of the flattened film tube along the severing cut of the first tube side via an opening device arranged downstream of the cutting device and upstream of a separating device in a transport direction of the film tube, wherein the opening device includes at least one opening element configured to move from a position outside the flattened film tube to pass through the severing cut, and
• separation of the flattened film tube into two separate film webs via the separating device.