DE1704864A1 - Process for the continuous production of endless, helically curved plastic hoses or dams - Google Patents

Description

Naturin plant in Weinheim, March 28, 1967

Becker & Co. ON 444

Process for the continuous production of endless, helically curved plastic hoses or intestines

The invention relates to a method for the production of so-called coronary casings. It is understood to be round and helically curved Intestines (as they are present on the carcass). These are preferred in the production of certain types of sausage.

All attempts to make these coronary intestines from synthetic materials, such as ZoB. Producing polyamides led to unsatisfactory results, only skin fiber casings can so far be produced in the shape of a wreath. The manufacture of hide fiber skins, the un ter the brand name NATURIN commercially available, can be made of the literature - for example, the German patents 686 391, 684 and 638 585 - will be removed.

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A skin fiber mass opened up by suitable pretreatment - today also known as NATURIN mass - is processed by a annular gap between a jacket tube and a rotating core mounted in it zen cally in the form of an endless, however straight hose. This hose can - if desired - be wound helically onto an endless mandrel will. If the intestine is sprayed in this state with tanning agents such as wood smoke distillate or glyoxal, hardening occurs, whereby the spiral shape (coronary intestine) is stabilized.

In the process outlined above, only a natural product is produced - the skin fiber or NATURIN mass - in a coronary intestine convicted.

It is also already known to make thermoplastic masses from annular Expressing columns. The corresponding process is known in the art as the blown film blown process. (Please refer e.g. plastic technical dictionary by A.M. Wittfoht, Volume 2, Garl Hansen Verlag, Munich 1959 - copy is included).

In the blow molding process, a thermoplastic mass emerges from an annular gap, which in turn is in the so-called blow head is stored. The blow head consists of an inner core or mandrel that is surrounded by the blow head jacket or blow head housing.

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The annular gap in the die is in with a screw press Connection through which continuously hot thermoplastic mass, e.g. 225 ° C hot polyamide, into the ring-shaped and gap-shaped channel is pumped in «Inside the blow head wall is located also a hole through which air can be supplied.

After leaving the annular and gap-shaped canal, the falls emerging, still very hot mass in the form of a hose. This hose is at a distance of about 1 to 2 m above the Exit gap passed through a pair of nip rollers. At the same time, some air is blown through the hole in the blow head mandrel » This expands the still very hot and soft hose ο As the pair of squeeze rollers allows the air to escape in the Hose and the blown air cannot escape downwards either, is the part of the hose which is just between the exit plane of the gap and the pair of nip rollers, constantly filled with air.

This air cushion has the task of maintaining the original, small diameter of the hose emerging from the annular gap expand about three times. The hot hose cools naturally on the way between the blow head and the pair of nip rollers away.

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The cooling is supported by a ring that is at a distance 3 to 5 cm above the exit level of the annular gap »The hose must run through this ring» This ring again has a fully encircling slot on its inside through which air can flow is blown on all sides perpendicular to the outer surface of the inflating hose »

When a constant amount of thermoplastic is pressed out of the ring slot in the blow head per unit of time and the take-off speed of the hose as well as the temperature and the amount of air exiting over the "air ring" is also constant, then the hose will reach its maximum diameter just above the "air ring" o This remains - because the between. Blow head trapped air and nip rollers cannot escape - also constant;

If you want to increase the expansion, i.e. the ultimate pressure gauge of the plastic «™ hose, you still have to have a little more air over the bore feed in the blow head »

In this way, straight endless hoses are also produced. Most of the time you cut them open afterwards to get a film. »But you have plastic tubing like this also already filled with sausage mixture

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The aim of the invention is now to produce a uniform
curved endless hose according to a modified one
Blown film blow molding process,

Such endless helical tubes can then be cut into shorter pieces, which can then be used as coronary intestines are ο

In order to better understand the invention described below,
it must be noted that with the known blown film blow molding process, the exit plane of the thermoplastic material from the annular gap in the die and the plane in which the air exiting the slot in the air ring runs strictly parallel to each other »

However, if you tilt the air ring a little, then both planes enclose an angle. At this moment, the external cooling takes place at various distances above the exit plane of the thermoplastic material from the slot in the die. On the side on which the cooling begins later than on the opposite side, the mass remains plastic longer
at the same time the one emerging from the ring slot in the blow head
The hose is constantly under tension (the rotating pinch rollers pull the hose out of the ring slot, so to speak),
consequently, the softer side is stretched more than the opposite

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opposite, the temperature of which is noticeably lower due to the earlier blowing on.

The same effect can of course not only be achieved by tilting the air ring o It is also possible to split the air ring in two Split halves at different distances, but offset by 180 to each other, above the exit plane of the thermoplastic Let out of the ring slot in the blow head, be arranged »

The decisive factor in the process according to the application is that the one emerging from an annular slot and still very hot and under Tension standing hose is cooled asymmetrically with simultaneous inflation of its diameter.

The curving endless inflated tube then becomes continuous Via numerous - arranged in the form of a semicircle - auxiliary rollers. After a semicircular or multiple revolutions, the hose passes a squeeze roller, pair o Each roller here preferably has a cone shape (d »h" the diameter at the left end is less than that at the right when the bowel is curved in the manner shown in enclosed drawing). Of course, when the curved casing passes through a conventional pair of rollers, it still forms

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folds in the nip, which in turn - at least partially - allow the trapped air to escape and thus the were disrupting continuous production.

After passing through the conical pair of rollers, the now air-free, spiral or helically curved endless casing wound onto a supply roll.

The process according to the application can be varied in that the dorm in the blow head is not - as usual - centrically, but rather eccentrically. In this case the exiting hose has different points at 180 offset points Thicken immediately upon exiting the ring slot. In this way, the curvature effect can be increased.

The accompanying FIG. I shows schematically an embodiment of the invention. In the screw 1, polyamide is heated to about 230.degree heated up and fed to the blow head 2. From the ring slot 3 the polyamide emerges in the form of a tube (shown in green for clarity). The usual closed air ring is now divided into two semicircular halves 4 and 5 (shown in blue for clarity), which are in different levels above the exit plane 3% 3 "of the polyamide mass from the ring slot are mounted. FIG. II shows a view of the half-ring 4 into which air enters via the supply line 6. These Air emerges from a layer on the inside of the half-ring 4

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genes slot again and hits - essentially vertically

- on the outer wall of the inflating plastic tube 7.

The half ring 5 is constructed like the half ring 4. However, he is closer to the exit plane 3 ', 3 "and also offset from the half-ring 4 by 180 °.

Since the air from the half-ring 5 hits the right-hand side (in FIG. I) of the inflating plastic tube earlier than the air from the half-ring 4 to the left side of the plastic tube, the latter curves to the right.

In the inflated state (the air required for inflation was pumped in via a supply line * located in the blow head 2, but not shown), the intestine is fed to the squeezing mechanism via auxiliary rollers 8 (FIG. 1). As can be seen in FIG. III, the latter consists of two conical rollers 9 'and 9 ^W · After passing through the squeezing mechanism 9, the casing is flat and curved. To the inflated and flattened intestine in Figure I.

- which is a side view - to be able to distinguish, were Curved lines are drawn in the inflated part of the curved bowel and straight lines in the flat part.

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FIG. IV shows an eccentric diagrammatically in section and in level Storage of the dome in the blow head. The plastic hose emerging in this embodiment has a larger one on the left Thicknesses than right on »If such a tube is curved according to FIG about the same thickness, because the initially thicker side was also stretched the most »

FIG. V shows, in section and in a top view, schematically the usual concentric mounting of the dome in the blow head. The plastic tube exiting in this embodiment initially has the same thickness - that is, immediately above the exit plane 3 ¹ , 3 ″ of the slot 3. If such a tube is curved according to FIG the greater stretching took place, thinner wall thickness than on the side that was not stretched as much.

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Claims (4)

- ίο - claims 1. Process for the continuous production of endless, helical curved plastic tubing or intestines by pressing out a hot plastic mass from one in one Blow head mounted ring slot with simultaneous supply of a metered amount of air via a line in the blow head and retaining this supplied amount of air in the hose by means of squeezing rollers, characterized in that the expanding hose is asymmetrically cooled before reaching its final and largest diameter. 2. The method according to claim 1, characterized in that the asymmetrical cooling by means of a tilted air ring is carried out. 3. The method according to claim 1, characterized in that the asymmetrical cooling is carried out by means of two half rings 4 »5, which are arranged in different levels and offset by 180. 4. The method according to claim 1 and 3, characterized in that the curving intestine arranged over in the form of a semicircle Auxiliary roles 8 is performed before he has the connected Air-retaining squeezing mechanism 9 reached. 209811/1359 5c Method according to claims 1 to 4 »characterized in that 9 ¹ » 9 ^{n is} squeezed off by means of conical rollers. 20981 1/1359