A method for determining sagging of melt of a tube extruded in an extrusion device includes structuring a measuring device to rotate about the tube. The measuring device is configured to measure a wall thickness of the tube over a circumference of the tube and determine a wall-thickness profile over the circumference of the tube from the measured wall thicknesses. The wall-thickness profile includes a frequency and an amplitude. The method further includes determining a sagging of the melt from at least one of (i) the frequency and (ii) the amplitude of the wall-thickness profile.

An extrusion film-forming apparatus includes: a die that extrudes a molding material from a slit-shaped extrusion outlet; a die lip drive mechanism that changes a slit width of the extrusion outlet; and a control device that controls the die lip drive mechanism, in which during the extrusion of the molding material, the control device controls the die lip drive mechanism to temporarily decrease the slit width of the extrusion outlet for cutting the extruded molding material.

The invention relates to a method for calibrating adjusting means (120) for adjusting a nozzle slot (112) of a discharge nozzle (110) for a film track (FB) on a flat film machine (100), comprising the following steps: specifying a calibration position (KP) for the adjusting means (120), performing a controlling intervention to change the adjusting position (SP) of the adjusting means (120), acquiring the reaching of the calibration position (KP) of the adjusting means (120).

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.

The invention provides an appartus for adjusting the thickness of a resin film exiting an extrusion lip of a blown film extruder, the apparatus comprising: a gear motor configured to provide a rotational movement in any one of two directions; an actuation unit connected with a first side to the gear motor and with a second side to the extrusion lip, wherein the actuation unit is configured to convert the rotational movement of the gear motor into an axial movement, and wherein the actuation unit is further configured to adjust a local width of the extrusion lip by the axial movement for adjusting the thickness of the resin film exiting the extrusion lip of the blown film extruder.

A method for producing reels of plastic film by cast extrusion process is described. The steps include causing the film to flow from an extrusion head slit, adjusting its thickness, drawing the exiting film with an internally cooled roll, winding the film downstream of the roll to form reels of film, measuring the thickness of the film and adjusting the thickness of the film based on the thickness measurements provided by the thickness measuring device. The method further includes measuring a reference quantity of the film reels produced, comparing the reference quantity measured value with a design value of the reference quantity corresponding to the design value of the thickness of the film and if the measured value is different from the design value of the reference quantity, acting on adjustment means and/or on the thickness measuring device to obtain a desired film thickness.

The present invention relates to a multilayer system F1 comprising: a layer C1 comprising at least one polypropylene, an adhesive layer Ad made up of a hot-melt self-adhesive composition CA, and a layer C2 comprising at least one polypropylene, said multilayer system F1 comprising at least 80% by weight of polypropylene or a mixture of polypropylenes relative to the total weight of said system. The invention also relates to the use of said system F1 for producing a recycled item.

A laminate (110) of polypropylene films (100), a luggage shell (120) constructed of the laminate (110), a method (200) of making the laminate (110), and a method (280) of making the luggage shell (120) are provided. The films (100) include a core (102) and at least one outer layer (104). The laminate (110) includes a plurality of films (100). The laminate (110) may be formed by laminating a plurality of films 100 under predetermined pressure, temperature, and time conditions. The shell (120) may be formed by deep drawing a sheet of laminate (110) while applying heat and tension to the laminate (110).

The present disclosure relates to a method and an extrusion line in which an additive content, in particular, a carbon black content, can be determined inline during extrusion of an extrusion product. For this purpose, an initial measurement is carried out in which a layer thickness and a refractive index of the extrusion product are determined, whereupon a continuous in-line measurement of the current additive content is carried out by a stationary radar measuring device. Thus, the layer thickness is set and the additive content is determined directly by the radar measuring device and controlled by setting the additive feed rate, in particular as a close-loop control.