Blown-form identification in a blown film system

Patent metadata

Field	Value
Publication number	US-12544967-B2
Application number	US-202117921819-A
Country	US
Kind code	B2
Filing date	Apr 28, 2021
Priority date	Apr 28, 2020
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

The invention relates to a blown film system for producing a film tube made of plastics material, comprising: an annular nozzle, out of which a plastic melt having a closed cross-section can be brought; a take-up device, by means of which the plastic melt can be drawn up from the direction of the annular nozzle so as to form the film tube; an air-provision device, which is downstream of the annular nozzle when viewed in the transport direction of the film tube and by means of which an amount of air can be provided; and a calibration device, which is downstream of the annular nozzle when viewed in the transport direction of the film tube and surrounds the film tube and by means of which the outer circumference of the film tube can be delimited. At least one detector is contained that has a plurality of detection elements, by means of which electromagnetic radiation emitted or reflected at various points of the film tube can be detected, such that at least one planar region and/or contoured region of the film tube can be detected with regard to characteristic properties, wherein the detector comprises at least 32 detection elements.

First claim

The invention claimed is:

1 . A blown film line for the production of a film tube made of plastic, the blown film line comprising:
an annular nozzle from which a plastic melt with a closed cross-section is discharged; an extraction device with which the plastic melt is extracted from the direction of the annular nozzle, forming the film tube; an air supply device downstream of the annular nozzle, as seen in the transport direction of the film tube, with which an air quantity is supplied; and a calibrating device that, viewed in the transport direction of the film tube, engages around the film tube and by means of which the outer circumference of the film tube is limited; and wherein the blown film line further comprises at least one detector with several detection elements, with which electromagnetic radiation emitted or reflected from different points of the film tube is detected, so that at least one surface region and/or one contour region of the film tube is detected with regard to one or more characteristic properties, wherein the detector comprises at least 32 detection elements.

2 . The blown film line according to claim 1 ,
wherein at least one swivel arrangement is provided such that the detector is swiveled in the circumferential direction of the film tube.

3 . The blown film line according to claim 1 ,
wherein at least one second detector is to be provided, which is arranged offset from the first detector in the circumferential direction of the annular nozzle.

4 . The method according to claim 1 , wherein the one or more characteristic properties are: temperature, temperature distribution, surface shape, contour, three-dimensional shape, molecular orientation, thickness, thick spots, thin spots, dots, scratches, foreign bodies, or any combination thereof.

Assignees

• Windmoeller & Hoelscher

Inventors

• Hehmann Ingo
• Ventker-Stegemann Marco
• Bembenek Michel

Classifications

• B29C48/912

  of tubular films · CPC title

• B29C48/89

  Internal treatment, e.g. by applying an internal cooling fluid stream · CPC title

• B29C55/28

  of blown tubular films, e.g. by inflation {(extrusion moulding of tubular films B29C48/03)} · CPC title

• B29C48/0018

  combined with shaping by orienting, stretching or shrinking, e.g. film blowing (B29C48/0017 takes precedence) · CPC title

• B29C2948/92123

  Diameter or circumference · CPC title