DE1222656B - Extrusion process and multicolor extrusion press for applying a cover to an extruded body - Google Patents

Description

Extrusion process and multicolor extrusion press for applying a Wrapping on a strand-shaped body The invention relates to a method and a device for applying a coating to a strand-shaped body, in particular a metal wire.

Here there is often the need to, at certain intervals, the change the visible color of the envelope. So show z. B. Telephone cables are known a large number of individual conductors, which differed according to the color of their sheath will. There must therefore be a way to produce such different colored cables exist, the externally visible color of the applied coating during the To change the manufacturing process, in such a way that the respective desired lengths of wrapped Cable material can be obtained in the various desired colors.

In the currently known extrusion presses you now have to change the color to change in the course of the application of a coating, shut down the machine and their extrusion units in all their parts, namely housing, screw conveyor and pressure nozzle, clean, which is tedious, complicated and expensive, because the all material in the machine is lost and the machine during for the required cleaning time.

In the mentioned case the telephone cable with many details where a variety of colors is required, this process must be repeated so many times that the output of the machine is often down to less than half of the theoretical Performance drops.

There is therefore a need for a method and an apparatus by means of which, for example, an insulation covering in a metal wire desired color can be applied and a rapid change of color this wrapping without interrupting the operation of the machine and with a minimum allow losses of wire material and cladding material.

The invention thus relates to a method for applying a casing on a strand-like body, especially a metal wire, in which in certain The visible color of the envelope is changed at intervals; intended by the invention the disadvantages of the known extrusion processes described are avoided.

For this purpose it is provided according to the invention that one in on known way by means of at least two extrusion units at the same time applies at least two concentric coating layers of different colors, and that in the desired time of color change the relative position of the two Wrapping layers reversed by switching the material flows to the order places.

In a simple manner, according to the invention, a practically sudden one is thus achieved Transition from the color of the previously outer covering layer to the color of the previous one allows inner wrapping layer. In the event that the inner wrapping layer is in front the color transition does not already have the desired new color, is according to a preferred embodiment of the method according to the invention provided that one Preparing the material with the new color before switching the inner layer supplies, while initially applied unchanged the outer layer in the previous color will.

From a practical point of view, two layers are most often used, whose relative position only needs to be reversed, so that the inner position to the outer one becomes, whereby the color of this inner layer is only visible at the moment of this reversal and if necessary be prepared in the corresponding extrusion unit can. At the moment of reversal, a mixed color from the two colors occur; however, this phenomenon occurs only over a short wire length so that only a small amount of wire and wrapping material is lost and in each If there is no need to clean the machine and thus shut down.

The invention also relates to a multicolor extruder for implementation of the method according to the invention, wherein the multicolor extruder in itself known way an extruder with at least two along the path of the to be wrapped strand-shaped body has application sites arranged at a distance from one another, those of at least two extrusion units that are assigned to them and operate at the same time are charged with the coating material and have concentric coating layers apply the strand-like body to be wrapped.

According to the invention, the device is designed so that between a switching element is provided for each extrusion unit and the application points is, through which each of the application points optionally with each of the extrusion units is connectable.

Extrusion presses for the production of enclosures from two concentric ones Locations are known per se.

In a known embodiment, both layers of the envelope are on one and the same place already in a concentric arrangement of one and the same Squeezed out nozzle or from several, concentrically arranged nozzles, the squeezing out opening however, viewed along the running direction of the part to be wrapped, on the same Place lies; such devices are for the purposes of the present invention obviously unsuitable.

It's also already an extruder with two lengthways along it the path of the part to be wrapped known at a distance of the application points, which of associated extrusion organs with the appropriate coating material are charged and produce concentric layers of wrapping. With this well-known Arrangement is, however, each application point firmly with an extrusion member tied together; switching is not planned.

For the method according to the invention this is also known device not suitable.

According to a preferred embodiment of the invention it is provided that the switching elements are designed as multi-way rotary valves; connect the slides according to their respective rotary position, the outlet line of the associated extrusion unit with one of several delivery lines leading to the individual application points.

Another advantageous embodiment of the invention consists in that each switching element accessible from the outside, closable cleaning lines having.

The switching of the material flows from the extrusion units to the individual order points is expediently carried out at the same time and in a corresponding manner Assignment to each other; according to a preferred embodiment of the invention is to for this purpose a transmission is provided for the joint actuation of the switching elements.

The reversal of the relative position required to change the color the two covering layers can either be used without interrupting the operation of the plant to be made; alternatively, the passage of the strand-shaped to be enveloped Body can be temporarily interrupted to carry out the switchover. - It should also be mentioned that if more than two concentric layers are applied, the majority color extrusion press to have as many extrusion units as layers would have; however, it is readily apparent that the connection of one of the extrusion units becoming visible at the point furthest forward along the part to be wrapped which produces the color squeezed out by this extrusion unit; the present The invention therefore only needs to be described with reference to two extrusion units to become; any further extrusion units that may be present can be considered equivalent are viewed, insofar as their color is basically not visible on the outside is.

Further advantages and details of the invention emerge from the following description of an embodiment using a multicolor extruder with two extrusion units based on the drawing. In this FIG. 1 one Representation in section along one of the continuous wire and the axes of the two Extrusion units containing plane, Fig. 2 is a partial view in section along the line II-II in FIG. 2.

As can be seen in the drawing, they are in a common housing 1 of a multicolor extruder, which is used for wrapping or wrapping a in the direction of the arrows 1 continuous strand-like body, for example a metal wire F, two extrusion units 3 and 4 are provided. In the illustrated Embodiment they are opposite one another, one in each case axial extension of the other lying, arranged. However, you might as well also arranged at an angle to one another, inclined to one another or offset if only their emission under the same or similar conditions - as shown - he follows. The two extrusion units are driven by gears 5 and 6, respectively a common shaft 7 driven by a common motor 8.

There are two orders between these two extrusion units set 9 and 10, from which the material conveyed by the two extrusion units is applied coaxially to the wire F.

The two layers 11 and 12 and that from the two application sites 9 and 10 of material applied around the wire F are necessary in terms of quantity the same, since the two extrusion units 3 and 4 have the same delivery rate, as can be seen from the description of the mode of operation below.

At the end of each extrusion unit there is a reusable rotary valve 13 and 14 are provided, each of which has two channels 15, 16 and 17, 18 of such an arrangement has that each extrusion unit optionally to one of the two application points promotes and is isolated from the other, and vice versa. In other words and as from Fig. 2, the two multi-way rotary valves 13 and 14 are above a gear 9 coupled to one another in such a way that the two extrusions always promote a constant total amount of material, but each extrusion unit each promotes to a different job site than the other.

The channels that the extrusion units with the application sites 9 and 10 connecting are substantially equal in length to account for any discrepancy between those exiting at the two order points Material quantities to avoid. As can be seen from FIG. 2, there is a cleaning system for each application point provided by means of closable lines 20 and 21, respectively.

The operation of the device is described below; Provided that the material on the outside is sufficiently opaque and the inner layer does not show through, the outer layer has the desired color while the inner layer can be any color.

In the case shown, the extrusion unit 3 supplies the outer layer 11, via the channel 15 of the slide 13, which conveys to the application point 10. During this time, the extrusion unit 4 promotes through the channel 18 of the slide 14 with any color to the application site 9, this color because it forms the inner layer, is not visible. In this position, the job site 9 do not get in connection with the extrusion unit 3, since the channel 16 of the Slide 13 is closed; accordingly, the extrusion unit 4 cannot are in connection with the application point 10, since the channel 17 of the slide 14 is also closed.

You can therefore choose any length, for example 10,000 m, in Apply one and the same exterior color to the wire F using the extrusion process, without worrying about the simultaneously from the order point 9 in the form of the inner layer 12 Take care of leaking paint. Only when a change in the color of the outer layer and The intended transition to a third color must be prepared in preparation for the reversal the third color of the new outer layer is introduced into the housing of the extrusion unit 4 without, however, the slide 3 and 14 would first be thrown over. While this preparatory operation mixes the two colors, i. H. the color the old inner layer and the third color of the coming outer layer until finally the new color progressively displaces the old one and finally it is complete replaced. Since this change takes place in the inner layer, it is not from the outside visible. The wire length F passing through during this time is therefore almost without Meaning; however, it should at least correspond to the length, which is noted corresponds to the time required for a complete color change.

As soon as this preparation is finished, bring the multicolor extruder on for a moment to stand and the position of the multi-way rotary valve 13 reverses and 14 in such a way that the extrusion unit 3 is now via the channel 16 and the Slide 13 comes in connection with the application point 9 and that accordingly the extrusion unit 4 via the channel 17 of the slide 14 with the order place 10 came into contact. During this time, the cleaning lines 20 or 21 to be opened, possibly in the lines and in the order points to deposit even remaining material. Because this volume of material is extremely is minor, the process takes a short time and the waste is meaningless.

The cleaning lines 20 and 21 are then closed and the The multicolor extruder starts up again and covers the following length of wire F. in the extrusion process, now the extrusion aggregate 4 the new color as Outer layer applies, while the conveyed by the extrusion unit 3 old outer paint now forms the inner layer and is no longer visible.

Of course, the color reversal can even be done without stopping the press take place; only the waste increases a little, since a certain amount of wire will have an envelope with a mixture of colors. In this case mentioned above the rotary valve 13 and 14 must be operated synchronously by means of the gear 19 and the Length of the lines connecting the extrusion units to the application sites are kept constant so that the total amount of material applied in the extrusion process remains the same. In this case, the cleaning lines 20 and 21 can be seen can be omitted as the cleaning material is now part of the wire wrap forms.

Claims (8)

Claims: 1. Extrusion process for applying a coating on a strand-shaped body, in particular a metal wire, in which in certain The visible color of the envelope is changed at intervals, characterized in that that in a known manner by means of at least two extrusion units at the same time at least two concentric wrapping layers of different colors applies and that at the desired time of the color change the relative position of the two coating layers by switching the material flows to the application points reverses. 2. extrusion process according to claim 1, characterized in that one in the event that the inner wrapping layer is not already the desired new one Has color, preparing the material before switching the inner layer with the new color, while initially unchanged the outer layer in the previous color is applied. 3. extrusion process according to claim 1 or 2, characterized in that that the reversal of the relative position of the two covering layers required for the color change is made while the strand-like body to be enveloped is continuous continues. 4. extrusion process according to claim 1 or 2, characterized in that that to undertake the reversal of the relative position required to change the color of the two enveloping layers, the movement of the stream-shaped body to be enveloped interrupted. 5. Multicolor extrusion press to carry out the process according to a of the preceding claims with at least two along the path of the to be wrapped strand-shaped body spaced from each other application sites that of at least two extrusion units that are assigned to them and operate at the same time are charged with the coating material and have concentric coating layers apply the strand-like body to be enveloped, characterized in that between each extrusion unit (3 or 4) and the application points (9 or 10) one switching element each - (13 or 14) is provided through which each the application points (9 or 10) optionally with each of the extrusion units (3 or 4) is connectable. 6. Multicolor extrusion press according to claim 5, characterized in that that the switching elements are designed as multi-way rotary valves (13 or 14). 7. multicolor extrusion press according to claims 5 or 6, characterized in that that each switching element (13 or 14) is connected from the outside common, lockable cleaning lines (20 or 21, Fig. 2). 8. Multicolor extrusion press according to one or more of the claims 5 to 7, characterized by a gear (19, Fig. 2) for common actuation the switching elements (13 or 14). Documents considered: German Auslegeschrift No. 1,082,043; Belgian Patent No. 531,375; U.S. Patent No. 2695422.