DE6918241U - DEVICE FOR THE PRODUCTION OF BLOWN TUBE FILMS. - Google Patents

Description

• · «tVtfv · *« *

• · · · · ·· «errs r · _r · r ·

DR.-ING. EUGEN MAIER PATENT ADVOCATE STUTTGART

A 1o 868
2. Mti 1969
i - me

Costruzioni Heocaniche Luigi Sandera S.-n.jL. Corso Semplona, 12o - BUSSO ARSIZIO (Varese), Italy

Device for the production of blown tubular films

The innovation relates to a device for the production of "Obiasenen tubular films. Gate directions of this ax normally have an extruder cylinder into which the plastic to be processed is introduced in order to be fed by means of the screw to the blow head, which is provided with an air supply and an annular nozzle through which the hose is extruded.

A 1o 668

May 2nd 1969

i - me - 2 -

Foil folded and fed to a winding device.

The "in such devices occurring main disadvantage Desteht in the RaupenMldung during the extrusion process, which" leads in the finished film tube to the annular Terdickungen, engaged in the subsequent operations, such as when printing, welding and cutting, extremely detrimental.

To avoid this disadvantage, it has already been proposed a relative rotational movement between the The extruder cylinder and the die-head assembly and the tubular film to carry out, whereby the thickness differences over the entire tube circumference are distributed and a completely cylindrical finished tubular film is obtained.

For example, in Swiss patent specification 381 418 a “? Device described and illustrated in which such relative rotational movement is provided is. In this device, the entire extruder, i.e. not just the extruder barrel and the

A 1o 868 2nd time 1969

i - me - 3 -

The die head, but also the drive and feed position of the extruder are rotatably mounted · This solution however, it obviously leads to a construction of the device that is not very robust and, on the other hand, is structurally complex, relatively expensive and required continuous control and maintenance.

Afgäbe the innovation is a device for the production of completely cylindrical blown To realize tubular films, which has a simple and robust structure, cheaper than in terms of cost is the aforementioned known device and does not require continuous and careful maintenance.

The task that has been set becomes thereby through the innovation gjslöst that the assembly formed from the extruder cylinder and the blow head is continuously rotated in one direction of rotation independently of the screw and of the stationary base, so that only this assembly and the hopper connected to it rotates continuously in one direction of rotation, during the base the device and the parts attached to it remain stationary.

A 1o 868
?., May 1969

i - me - 4 -

In this way, not only is an extremely robust, by no means complicated and not excessively expensive construction of the device achieved, but its mode of operation is extremely favorable, since the distribution of the differences in thickness over the circumference of the hose is apparently best when the extruder cylinder with the die is uniform and always rotates in the same direction of rotation with respect to the extruded tubular film. If desired, however, the continuous rotation in one direction of rotation can be replaced by an alternating back and forth rotation .

An embodiment of the device according to the innovation is explained in more detail below with reference to the single figure of the drawing.

The device has a base 1 in which the shaft 5 of the extruder can be rotated with a vertical axis is mounted and which includes the gear 2 driven by a belt drive 3-4 for driving the shaft 5. The extruder screw 6 is located in the cavity 7 of the vertical extruder cylinder 8, which is on his the upper end of the blow head 9 with an annular gap 1o tsaws, wel-

A 1o 86Θ

May 1969

i - me - 5 -

rather, is provided with an air supply, not shown. The feed triohter 11 is also attached to the extruder cylinder 8, through which the plastic to be processed enters the cavity 7 of the extruder cylinder is introduced · The extruder cylinder 8 is rotatably mounted on the base 1 and is on the part of one on the Motor H attached to base 1 rotated about its vertical axis via a chain drive 12 - 13 « On the extruder cylinder 8, a turntable 15 is also attached, which carries a control center 16 and which is provided with a downwardly bent edge that protects the chain drive.

During operation, the shaft 5 of the extruder screw 6 is set in rapid rotation by the belt drive 3 - 4, whereby the screw 6 conveys the plastic introduced from the funnel 11 through the extruder cylinder 8 to the blow head. From the ring nozzle 1o des Blow head 9 exits the tubular film 17, which is put together by means of the take-off rollers 18 and into one Vetch} - 19 is wound up.

The beads of the extruded tubular film and thus the

ι · «ι

A 1o 868 2nd time 1969

i - me - 6 -

unwanted annular thickenings are caused by the Slow rotation of the extruder cylinder δ and the blow head 9 evenly over the vetch! ”Spread out. Piping caused by the motor H rotation of the extruder cylinder 8 can indifferently clockwise or counterclockwise and, if desired, it can also be done by alternating rotation in both directions of rotation be replaced. It is noteworthy that after the initial inflation of the tubular film, the one attached to the blow head Air supply is removed, since it is no longer necessary to admit additional blown air, so that the rotation of the extruder cylinder with the blow head is not hindered.

Claims (2)

Il ■ · A 1o 868 May 2nd 1969 - me - 7 - Protection claims ο device for the production of blown tubular films, consisting of a base, an extension cylinder, a blow head, a loading part, an air supply and a screw rotatable in the extruderaylinder, characterized that the from the extruder cylinder (8), the blow head (9) and the feed part (11) existing assembly continuously with respect to the base (1) and the rotating extruder screw (6) is rotated. ο Device according to claim 1, characterized that the extruder cylinder (8) is arranged perpendicular to the base (1) «,