DE3735279C2 - - Google Patents

Description

The present invention relates to a method for color coding of plastic or rubber insulated wires of electrical cables and lines in which the marking by A colored insulating mixture is extruded.

In cable technology it is generally known that individual wires according to their function in the assembled State differently. So you have already (DE-AS 10 80 646) the marking of the Plastic existing insulation electrical conductors so performed that only surface parts of the insulation are continuously sprayed in colored mass. For this serve additional extruders with the help of which Spray head into the one in the mouthpiece Insulating material continuously colored insulating material is introduced. Aside from being mechanical heavily used cables the stored color strips, because of their different composition Represent foreign bodies in the insulating layer, Notch effects can be one of them inhomogeneous insulation not suitable for all cases where with higher voltage stress on the insulation must be expected. That is obviously the reason for the fact that the known method for the production of  Telephone wires are used where there is homogeneous insulation is not necessary for electrical reasons.

Essentially the same applies to a known one Multiple extrusion press (DE-AS 12 10 547), which serves the labeling options for plastic products by multiplying that any number of colored thread lines is embedded in the insulation. A controlled perforated disc is used for this purpose one or more strips of paint in the insulation be injected. This in the insulation material embedded strips are neither electrical nor mechanically portable if the respective cable or each line increased mechanical and electrical Is exposed to stress.

Methods are also customary in which the respective Wire mix the appropriate color pigments added will. The manufacturing effort is considerable since Completion of a colored wire in the required Length the manufacturing line must be stopped. Act it the wires to be manufactured are also those whose insulation is networked, for example during the Pass through a continuous networking system (CV system), the colored and manufactured must crosslinking core are still heated. Only then can the entire system is opened and that is still in the extruder and Color in the extruder head by a neutral one Mixture pushed out or by introducing the next Color mixture are pressed out. Closing the Head, setting up the injection mold and that Center the conductor in the molded material further necessary steps until the vein with the different colored insulation can be driven continuously. At the end of this production length, the same steps are followed as described necessary to match one wire length with the to mark next color etc.  

All of these for a smooth production process necessary steps in processing and each Color changes are time consuming and costly Manufacturing facility is often blocked. In addition to that Driving out a driven color mixture and for Feed in the new color mix as well as for each Setting up the plant consumes a lot of material first just ejected, then collected and finally, usually for inferior jobs, processed becomes.

Attempts to stop in the manufacturing facility Extruder a new color mixture immediately afterwards Entering the previously processed leads to the production a transition vein lost for sale with from one color to the next alternating marking.

The invention is therefore based on the object Possibility of finding time and costly Avoid set-up times and save mix material.

This object is achieved according to the invention by that on a first colored the same for all veins Insulating layer, a distinctive colored second Insulating layer in the form of a thin closed shell extruded and both insulation layers together be formed, the time of the beginning and End of extrusion of the characteristic insulating layer in Depends on the respective cable or line length and / or the time of provision of the characteristic insulating mixture is controllable.

This measure allows optimal use of existing ones Materials that makes the distinctive insulation mix only a fraction of the share for all veins same color insulation mix. This is why also a short-term color change possible, so that this Process exactly in time to the length to be manufactured can be coordinated.  

The insulation mixture of the same color for all wires and the colored in the respective marking color Insulation mix contribute to the electrical insulation of the live conductor. It can therefore be beneficial be, especially if the effort for the Mixing is in the foreground for which solid color insulation and the distinctive Insulation mix to use the same basic materials. It comes however, insists on saving material costs without Losses in production quality have to be accepted then you can also continue the invention proceed in such a way that the characteristic insulating mixture is a higher insulation compared to the same colored insulation and / or extrusion quality.

As already stated, the distinctive Insulation mix only a fraction of that for all wires same colored insulation mix per extruded length turn off. In other words, it's for them Implementation of the invention is particularly advantageous proven if the wall thickness of the characteristic layer 0.01 to 0.10 mm, preferably 0.03 to 0.06 mm.

The possibility of one is decisive for the invention short-term color change with simultaneous  Material savings and set-up time savings.

To perform this procedure a device with at least one characterizing Insulating compound leading and the extrusion head for the insulation of the same color with additional extruders with controllable blocking element at the extruder outlet. Across from which is the main mass flow of the same color Extruder leading the insulating mixture can another extruder for the characteristic mixture in the Dimensions are kept small, the connection is accordingly without problems.

The locking member expediently has a closed State of the vacant opening for the characteristic insulation mixture. The locking member in The simplest form can be a so-called chick, which in the Transition area to the extrusion head of the single color Insulating mixture leading extruder is arranged and in the closed state a passage opening for im Insulating material inside to the outside releases. This opening is crucial for the exact color change. Because only when the new color mixture prepared in the further extruder in the blocking member is switched and the passage opening so that the color mixture is introduced into the main extruder and over the same colored insulation as thin Additional layer formed.

Possesses, as in continuation of the invention also provided the device two extruders for the characteristic insulation mixtures, then you will proceed advantageously so that both extruders to the same feed channel can be connected. One of them Blocking element assigned to extruder outputs then permits at the same time the infeed of one characteristic Insulation mixture in the extruder for the same color  Isolation mixture and the discharge of a residual amount of second distinctive insulation mixture outside. In in this case, the locking member is expedient easy handling to train as a rotary valve.

For applying the distinctive mixture to the same colored insulation mixture within the One becomes extruder head because of the small Distribution of pending colored masses a so-called Place the displacement tool in the spray head. This contributes to further improvement of the method according to the invention at.

Embodiments of the invention are explained in more detail with reference to FIGS. 1 to 3.

Fig. 1 shows a schematic embodiment of a main extruder 1 with the spray head 2 and the tool 3 spray. This leads the insulation mixture of the same color for all wires. An additional extruder 4 for the characteristic color mixture is connected to the spray head 2 and as close as possible to the injection tool 3 ; 5 denotes the extruder hopper into which the respective colored mixture is entered.

FIG. 2 shows an additional extruder 6 for the colored insulating mixture on an enlarged scale compared to FIG. 1, the extruder screw is designated by 7 . This additional extruder 6 has the outlet bore 8 , which opens into the transition 9 to the spray head 10 . In the outlet bore 8 , the locking member 11 , for. B. in the form of a so-called. Chick having a bore 12 which leads to the outside. The transition 9 to the spray head 10 can be closed from the outside by the slide or screw arrangement 13 if colored mixtures are not introduced by the additional extruder 6 .

The wire of a power cable with a single-color insulation mixture which is passed through the spray head in the main extruder is characterized in color in that the outlet bore in the additional extruder 6 is released and the colored mass flow is fed into the transition 9 to the spray head 10 . Precisely timed with the length to be manufactured, the blocking member 11 is adjusted during the subsequent color or mixture change so that the rest of the color mixture just extruded is pressed out through the bore 12 . At the same time, the new color mixture is moved into the additional extruder 6 at an increased speed of rotation of the screw 7 until the new color mixture emerges from the bore 12 properly. The locking member 11 is actuated again so that the bore 12 is closed and at the same time the transition to the spray head 10 is released. At the same time, the screw speed of the additional extruder is set back to normal. During these measures, the main extruder continues to run at the same or a reduced speed. The mixture that emerged from the bore 12 during the color change can be collected and fed into the main extruder during the following production phase.

FIG. 3 shows a further improvement in the identification of electrical wires with the aim of an efficient production process . Subtracted from inventories that are not shown, the conductor 14 runs into the main extruder 15 . The insulating mixture 16 , which is of the same color for all wires, is transported in a known manner via the annular feed channel 17 to the spray head 18 and is shaped there for insulation 19 via the conductor 14 . To identify such cores, the main extruder 15 has a further bore 20 through which the colored insulating mixture is optionally supplied by the additional extruders 21 or 22 .

In the exemplary embodiment shown, the color mixture is just introduced into the main extruder 15 by the additional extruder 21 and applied over the insulating mixture 16 by the so-called displacement tool 23 . Then both materials are molded together so that a further thin characteristic insulation 24 is arranged over the monochrome insulation 19 .

Depending on the wire length to be produced, a new color mixture is provided in the additional extruder 22 and introduced into the channel 26 shortly before the locking member 25 is switched over and carried out through the bore 27 . The controlled switching of the blocking member 25 is then carried out briefly so that the channel 26 is assigned to the auxiliary extruder 21 , so that residual mixture material still present there is conveyed to the outside through the bore 27 , while at the same time the additional extruder 22 supplies the new color mixture provided through the bore 20 feeds the main extruder 15 .

Fast color changes can be achieved here in particular be, because of the existing in the additional extruders small masses in relation to the same colored Mass in the main extruder is the inevitable committee only very small.

Claims (10)

1. A method for the color coding of plastic or rubber-insulated wires of electrical cables and wires, in which the marking is carried out by extrusion of a colored insulation mixture, characterized in that on the first insulating layer, which is colored the same way for all the wires, a respectively identifying colored second insulating layer in the form of a extruded thin closed sheath and both insulating layers are formed together, the time of the start and end of extrusion of the characteristic insulation layer depending on the respective cable or line length and / or the time of providing the characteristic insulation mixture is controllable. 2. The method according to claim 1, characterized in that that for solid color insulation and the characteristic insulating mixture of the same basic materials be used. 3. The method according to claim 1, characterized in that the characteristic insulation mixture is a higher than the same colored insulation Has insulation and / or extrusion quality.   4. The method according to claim 1 or one of the following, characterized in that the wall thickness of the characteristic layer 0.01 to 0.10 mm, preferably 0.03 to 0.06 mm. 5. Device for performing the method according to Claim 1 or one of the following, characterized by at least one the characteristic Insulating compound leading and the extruder head for the insulation of the same color, which also feeds Extruder with controllable locking element on Extruder outlet. 6. The device according to claim 5, characterized characterized in that the locking member an in closed state of the outlet opening for the characteristic insulating mixture. 7. The device according to claim 5 or 6, characterized characterized in that for the transition of the characteristic insulating mixture in the extruder for the same colored insulation provided Feed channel can be closed from the outside. 8. The device according to claim 5 or one of the following with two extruders for distinctive Insulating mixtures, characterized in that both extruders to the same feed channel are connected, one being two Locking element assigned to extruder outputs at the same time feeding one characteristic insulating mixture in the extruder for the same colored insulation mix and the discharge a residual quantity of the second characteristic Insulation mixture allowed outside.   9. The device according to claim 8, characterized characterized in that the locking member is a rotary valve is. 10. The device according to claim 5 or one of the following, characterized in that for Apply the characteristic insulating mixture so-called displacement tool is used.