Guide element for a tubular film

Abstract

A guide element for a tubular film which is produced by blown film extrusion. The guide element includes a support structure having guides secured to the support structure and acting upon the circumference of the tubular film. The support structure includes a plurality of support limbs that are articulated to each other and that are received so as to be adjustable relative to each other by adjusting drives. At least one guide for the tubular film is secured to each support limb.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates to a guide element for a tubular film manufactured by the blown film extrusion process, having a support structure with guides that are fastened to the support structure and that act on the circumference of the tubular film.[0003]2. Discussion of Related Art[0004]In the manufacture of plastic films by the so-called blown film extrusion process, the melted mass of thermoplastic plastic manufactured by at least one extruder is extruded from an annular exit opening of a die and blown into a tube, which is then folded by a so-called flattening device into a double-layered film web, conveyed between squeezing rollers, and then supplied to a winding device.[0005]In the simplest case, the flattening device is of two flattening elements, which are arranged in diametrically opposite regions of the tubular film and are adjustable at an acute angle in relation to each other, similar to an inverted V or an A,...

AI Technical Summary

Benefits of technology

The invention proposes a flattening device for tubular films that has guide elements with adjustable support legs and guide means for the tubular film. The guide elements can be adjusted in various ways to adapt to the contour of the tubular film as it passes through the flattening device. The guide elements can be fastened to the support legs with separate adjusting drive units, allowing for precise adjustment. The flattening device can be used in a lateral guide device with two lateral guide elements and can also have a guide blade to guide the edge fold of the tubular film. The adjustment of the support legs can be done with high precision using spindle drive units or other suitable drive units. The technical effects of this invention include improved flattening of tubular films, better lateral guidance, and more flexible adjustment options.

Problems solved by technology

This can lead to problems with regard to product stability, freedom from wrinkles, and the like.

Because of the straight arrangement of the brushes, rollers, or strips used as guides for the tubular film, though, which has up to now been the default arrangement in the prior art, it is only possible to provide an insufficient point-by-point contact.

Particularly in reversing movements of the flattening device and / or a withdrawal device for the tubular film, which is situated after the squeezing rollers, the film starts to form slight wrinkles that run all the way through the completed roll and reduce the quality.

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