DE1942784B1 - Method for sheathing ribbon cables - Google Patents

Description

The invention relates to a method for encompassing, heating and melting the sheaths of ribbon cables with plastic by extruders for a certain time, so that the withdrawal speed, in which before the cooling section, in which the speed for the ribbon produced by lamination Plastic solidifies (second cooling section) at least cable is very low. In a practical case, a further cooling section (first cooling section) was before the take-off speed was 2.5 m per minute,
see is. The German patent specification 1047 276 describes

Through the book by Gerhard Schenkel, "Art - a method for automatic control of the thickness fabric extruder technology", Karl Hanser Verlag Munich, and the capacity of a plastic injection-molded 1963, chap. X, pp. 354 to 373, are method and th leader. According to this known method, arrangements for extruding sheaths should automatically interact with one another as a function of the continuously measured thickness and of wires, strands, lines and cables be _{T capacity.} In the above-cited book by Gerhard Kurig, the running speed of the conductor through Schenkel, it is stated on page 354 that the screw press and the heating current are adjusted for the preliminary diameter of the wires to be sheathed, for example for intermediate heating of the conductor. This misalignment is 0.4 and 180 mm. So far it has not yet been successfully used for sheathing, by extruding ribbon cables with more than a single conductor. The plastic should preferably be a foam with ten wires and wire diameters below 0.3 mm. This known method is to be established. Experience has shown that when extrusion with known methods is not used to influence the width of a ribbon cable, the required methods are suitable, because this regulation primarily does not adhere to the dimensions precisely enough 20 thickness and only very little influences the width,
can. When extruding, it is difficult to control- In German patent specification 1113 728 is under

Bare dimensional fluctuations of the ribbon cable, which mentions other things that ribbon cable produced thereby are far greater than the normal heat shrinkage that bare wires with insulating spray des Plastic and the material for the microelectronics are overmolded. The so produced exceed the required tolerances. The causes 25 ribbon cables, however, still have tolerances, see above and influencing variables for these dimensional fluctuations are that it can be assumed - that it is only with this band insufficiently known. In addition, one of the calibration cables is power cables, which are toIerung practically excluded from ribbon cables. satchel in the width of the ribbon cable and in the

A method of making ribbon cables spacing does not matter.

by extrusion is in German Auslegeschrift 30. The invention is based on the object of a 1075 695 described. In this known process for the production of ribbon cables, go into the insulation is used as a hollow tube around special ones with a large number of conductors and small ones to shape the parallel side by side by the injection molding tool wire diameters such that the running wires injected and then maintained by a conductor spacing with high dimensional accuracy Negative pressure in the space between the spray nozzle and 35 can be.

the hose applied to the ladder and between the The inventive method is thereby

welded them together. Since a good processability in that the temperature and / or the welding of thermoplastics, the use of length of the first cooling section and / or the stamp-printing requires the welding is not lOOpro- _ture of the second cooling section is controlled so / zentig, so that there will be between the conductors at 40 that the difference in temperature of the weld surface can form cavities. Such dj _e second cooling path entering ribbon cable and voids are undesirable because the second cooling path having determine moisture, dirt or solder is increased on the connection of the temperature in the participating width of the ribbon cable and can penetrate with ribbon cable. decreasing the width of the ribbon cable.

Another method for producing tape 45 The method according to the invention allows cables is described in US Pat. No. 3,082,292. Ribbon cables with a high number of conductors and very few wrote. This process was therefore designed to produce wire diameters. Wrapped in one because, as in the second paragraph of this patent, it is a trick with very little effort script is executed, great difficulties arise, possible the shrinkage of the cable after the if you can get more than two or three conductors under control by extruding 50 so precisely, Want to extrude coating. The one in the USA - that high dimensional tolerances, especially exact ones Patent specification 3 082292 described method conductor spacing can be maintained. That First, two plastic straps are made by extrusion method according to the invention is easier than that dieren made. In a welding device previously used lamination process, because as ejecting these tapes from both sides are attached to the wires 55 unrelated to the plastic process and so heated and tied together, only plastic granulate is required pressed so that the two plastic tapes will be together because the extruded ribbon cable directly weld. After cooling, the edge is ready to use - it no longer needs to be trimmed that of the welded strips should be of the same width - and because the production speed cut to size. 60 can be much larger than with the lamination process

In this known so-called lamination process.

The spaces in between will also drive

Filled with plastic, since the two plastic tapes are methods and devices according to the invention at high temperature and under high pressure to carry out this process described be squeezed together. However, the wires can be 65.

change their position by the action of pressure, so Fig. 1 shows an example of one according to the invention

that the electrical properties such as wave resistance method according to the ribbon cable produced; stand and capacity can fluctuate. In addition, Fig. 2 shows a complete device as it

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When carrying out the process according to the invention, the wires 10 then run from the left into the cross

driving is used; - Injection head 21 of an extruder press 22. the

F i g. 3 illustrates details of the extruder-extruder press is in FIG. 3 perspective press, as in the arrangement according to FIG. 2 is shown enlarged again so that the

is turned; 5 can better recognize the function of this machine. That

Fig.4 shows the width measuring arrangement of the plastic granulate, for example polyethylene, is

direction according to Figure 2 in detail; filled into a funnel 23. For preheating

Fig. 5 illustrates the shrinkage in width of the granules at the hopper 23

a ribbon cable during cooling, and. Fan 24 is provided, which via a pipe 25 air

F i g. 6 shows how the width of the ribbon cable is sucked in according to io and after heating in a heating device Process according to the invention can be influenced via a pipe 27 back to the feeder 26, funnel 23 releases. This preheated granulate

In FIG. 1 is an example of a ribbon cable that is fed into a screw press. The snail the method according to the invention manufactured kenpresse consists of a heated hollow cylinder was shown in cross section. The width of this 15 28, in which a screw 29 rotates, which is now Ribbon cable is 29.2 mm, the thickness 0.7 mm. The plastic material in the direction of the extrusion head 21 Diameter of a single wire is 0.3 min, transported there. The screw 29 is through a and in total are located in the ribbon cable next to the electric motor driven by which one in each other 60 wires. The signal conductors are with 1 order of the extruder only sees a cover cap, draws, on both sides of a signal conductor 20 by heating, compression and friction there is a ground conductor 2, which is created in the direction of the associated granules Shield signal conductors. During the extrusion of the tape extrusion head 21, it becomes more and more plastic kabeis there are grooves 3, the mass, on the surface. The spray head 21 used here is a form in the places where there is no wire so-called cross spray head, as is usually the case with is available. The plastic sheathing is used for the 25 sheathing of wires. In cross wires is in the present case polyethylene, it is spray head 21 is a channel 30; who can do the longings however, also other plastics, such as the form of the hollow cylinder 28 formed by concrete, in two channels 31, For example, polypropylene, copolymers of poly-32 split, both of which are deflected by 90 ° ethylene and, polypropylene, polyvinyl chloride, silicone and then from above and below against the parallel rubber or also fluorinated ethylene propylene, 30 guided wires 10 converge. At the use Find. confluence point of the two plastic streams

In Fig. 2 a device is shown with which the channels 31 and 32, the wires are sealed

Processes according to the invention are carried out encased in plastic material. At the right exit

can. The wires and later the ribbon cable run through the cross spray head 21, there is the nozzle 33,

from left to right through the in F i g. 2 shown 35 whose cross-sectional dimensions by the extent of the

Contraption. The wires 10 for the subsequent volume shrinkage of the tape (e.g. in width and height

cables are made of rollers 11, which at a drain-about 10%) is larger than the cross-section of the finished

frame 12 are attached, unwound. The same ribbon cable. A longitudinal shrinkage of the ribbon cable

Number of Rolleil is also still on is not possible because the wires prevent this,

the back of the discharge frame 12, these rollers 40 The screw conveying capacity, which is via the screw

are not visible in FIG. 2, however. Can be set to the main speed, is dimensioned in such a way that

position of a ribbon cable with 60 wires would have to be that the plastic material from the nozzle 33 with the

accordingly flows out of the same speed on each side of the drainage frame 12 at which the

30 rolls may be arranged, wires 10 are withdrawn for the sake of simplicity. When using

However, if a smaller number of rolls 11 were used, polyethylene, for example, is the plastic material

posed. In order to keep the wires 10 under tension when exiting the nozzle a temperature of

hold, the rollers 11 are preferably by about 200 ° C.

a shoe brake is constantly braked. Even with sudden- After exiting the nozzle 33 passes through By stopping the wires, the ribbon cable 34, which is still plastic, can sag and cause a first cooling effect Wires are avoided when between the 50 stretch 35 formed by the surrounding air Brakes and the rollers 11 coil springs is arranged. This cooling section ^ can, for. B. be 40 cm long, are, which the rolls against the unwinding direction Through an opening 36, the ribbon cable enters a, try to turn back. At 14 and 15 are um-. Cooling container 37, which is preferably a water castor "which is a pre-alignment of the cooling containers. The cooling container 37 includes two Effect wires 10. The wires then run on 55 cooling sections 38 and 39. Water becomes as it comes out a roller 16, which comes with the line running around the circumference, via an inlet pipe 40 into the Notches for guiding the wires is provided. Cooling section 39 introduced. The front edge of the The wires 10 then run over a comb-like cooling section 39 is designed as an overflow. That over-leadership 17 on another roller 18, the water flowing from the cooling section 39 also runs into the like the roller 16 with notches for guiding the cooling section 38. At the front edge of the cooling wires is provided. The wires 10 are by means of stretch 38 is also an overflow again. The above a rubber pressure roller 19 against the roller 18 ge this overflow collects in water presses. In the area between the roller 16 and the one basin 41 and can then via a drainage pipe Roll 18, the wires still have a larger drain 42 to be discharged. The ribbon cable 34 passes over stood apart as later in the ribbon cable; the 65 an opening 43 through busts above and below wires are sealed in a comb-like guide 20 half of the ribbon cable 34; in the a second cooling section 38 on the end distance existing in the ribbon cable. As explained later merged, ■ is, the temperature of the cooling section 38 is accurate

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set to target value. The temperature of this cooling section 38 is, for example, 80 ° C. in the present exemplary embodiment. This temperature is determined by means of a heating coil 44 is generated. To get one as possible to enable exact maintenance of this water temperature, The water is circulated by a circulator 45, which consists of an electric motor driven propeller is kept in motion. In the cooling section 38, the ribbon cable guided by means of two rollers 46. In the cooling section 39, three further rollers 47 are provided, of which the first is so high above the overflow that the ribbon cable over the overflow into the second Cooling section 39 can be introduced. As already mentioned above, the water in the cooling section 39 has Line temperature. This temperature is not critical. The ribbon cable is through an opening 48 which is lined with a foam pad to strip off the water adhering to the ribbon cable the cooling section 39 led out. ao

Behind the cooling container 37 a width measuring device 49 is provided, which here is a feeler roller measuring device Instead of a feeler roller measuring device, any other width measuring device can of course also be used. z. B, a working according to the pneumatic measuring principle can be used. The width measuring device 49 is shown in detail in FIG. The actual measuring device stands on a rack frame 50. The ribbon cable 34 runs between two rollers 51 and 52 through, The the two rollers 51 and 52 are resiliently mounted so that they can pass through the side edges of the ribbon cable 34 be deflected laterally. This lateral deflection is transmitted to a pin 53 and can can be displayed by means of a measuring instrument 54. The measuring instrument 54 shows the width of the Ribbon cable. In addition, a circuit 55 is provided that the mechanical deflection of the pen 53 converts into an electrical signal. This electrical signal appears on lines 56. The Conversion of the mechanical deflection of .Stiftes 53 into an electrical signal can be done in a variety of ways Way to be made. For example, a slide can be used with the pin 53 The rheostat can be shifted and thereby an electrical current can be changed. The pin 53 can also change a capacitor of a measuring bridge, the change in capacitance of which influences a signal. If necessary, these signals can be amplified. Devices for converting mechanical Shifts in electrical signals are for example in the book "Control Engineers Handbook" published by Truxal, McGraw Hill Company, Inc., 1958, in Chapter 17, "Signal Transducers."

A regulating device 57 is connected to the lines 56, which according to the method according to the invention regulates the heating voltage for the heating coil 43 so that with increasing width of the ribbon cable at the feeler roller measuring device 49, the temperature of the cooling section 38 is reduced and with decreasing Width at the feeler roller measuring device 49, the temperature of the cooling section 38 is increased. the The temperature of the cooling section 38 can also be set manually. This temperature setting of Hand takes place depending on the deflection of the pointer instrument 54 on the feeler roller measuring device. How the temperature of the cooling section 38 affects the width of the ribbon cable 34 produced, should later on the basis of FIG. 5 and 6 are explained in more detail.

In order to pull off the finished ribbon cable, a ribbon take-off device 58 is provided behind the feeler roller measuring device 49 and contains two tractors 59 and 60, which are rubber bands each running around two rollers. The two tractors 59 and 60 are driven by a non-visible electric motor. Finally, behind the tape take-off 58, a winding device 61 is provided which winds up the cable. The winding device 61 is driven by an electric motor (not shown) that can be braked to a standstill,

The shrinkage of the ribbon cable is illustrated in Figs. 5 shows the plan view of a Ribbon cable. To make the process of shrinking clear, the amounts of shrinkage are large exaggerated,

The dashed line 72 initially represents the outer edge of an extruded plastic tape without wires. The cooling and thus the shrinkage of this plastic tape is in the range the air cooling section 35 is relatively small. When entering the Wasserkühlstreeke 38 on line 70, this will be Plastic tape has cooled down to a relatively high degree, and a kink, the material, is formed on this line shrinks more, depending on the temperature of the cooling section 35, the plastic strip is in this area shrink to a greater or lesser extent. The total shrinkage of a plastic tape without longitudinal wires however, it is always the same regardless of whether the temperature in the cooling section 35 is high or low is. From the straight line 71 onwards, the plastic has solidified, neglecting the fact that it does not freeze goes over a larger area. There is also shrinkage behind straight line 71, however, this shrinkage is almost entirely due to the coefficient of thermal expansion.

The shrinkage is somewhat different from that of a plastic band (dashed border 72) a ribbon cable. The ribbon cable is represented by the solid line 73. You can see that the The shrinkage line of the ribbon cable at the transition 70 into the second cooling section does not have a kink, since the tensile stress of the wires prevents a sudden change in width in the plastic range, and that the strong shrinkage in the first cooling section over the wires the width already in the area behind the Nozzle reduced more than with a plastic band.

On the basis of the diagram in FIG. 6 is intended to explain in more detail how the shrinkage of a plastic tape with and without wires takes place and how the width of an extruded ribbon cable can be influenced by changing the temperature of the second cooling section 38. In the diagram of FIG. 6, the width B is shown on the abscissa during cooling compared to the distance Λ from the nozzle outlet. The three cooling areas, first cooling section 35, second cooling section 38 and third cooling section 39, are delimited from one another by vertical lines 100, 101 and 102. In the diagram in FIG. 6, the dashed curves should first be considered, which represent the decrease in width of an extruded plastic strip (without wires). The curve section 103 shows how the width of the extruded plastic tape in the

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first cooling section, the air cooling section 35, decreases. The freezing point 117 is further below the

At a cooling water temperature of the second cooling freezing point 109 than the freezing point 116 below the

stretch 38 from 80 ° C takes the width of the artificial freezing point 108. Since of the freezing points the

fabric tape according to the dashed curve 104 from. If curves of the plastic tape and ribbon cable run parallel with the same cooling water temperature of the second cooling section 5 chen cooling conditions result

38 colder, e.g. B. 50 ° C, then the decrease in width follows after complete cooling (on the straight line 102)

in the cooling section 38 of curve 105. On the ge different widths for the ribbon cables. The width

raden 100, the point where the plastic belts are in, the smaller the stronger in the second cooling

the cooling basin 23 enter, the latitude route 38 is cooled. This appearance that there is a kink. The curves 104 and 105 run approximately io in the case of plastic tapes;

proportional to the cooling. The points 108 and the invention to control the constant width of the

109 are the freezing points. Exploited from these places from ribbon cables. By setting the

If the plastic is temperature of the second cooling section 38 over its entire cross section, Ma-

fixed. Material differences in individual areas of the cross-section, temperature differences in the extrusion

however, the plastic solidifies earlier. 15 der, different conveying speeds and

According to the freezing points 108 and 109 , environmental influences such as room temperature, humidity

Shrinkage of the plastic can mainly be compensated for by speed etc.

the coefficient of thermal expansion and only to The effect of the temperature of the cooling section

a very small portion by the crystallization loading 38 to the end width of a ribbon cable can se

things. The degree of crystallization depends on the temperature as shown in FIG. 6 also very clear physically

the cooling section 38 dependent. Explain a post-crystallization. During the actual nozzle exit of the

tion can, however, long after the extruder has cooled down in the illustration in FIG.

(up to a week) take place. The heart of it that lies at 0 can be found in the area of the first

however, pre-called shrinkage is e.g. B. only cooling section in which the ribbon cable · is still very soft

about 2 ° / _{00 of} the transverse dimensions and is therefore 25 is to imagine a virtual nozzle. Let it be assumed

negligible. men, this virtual nozzle is just before the lowering

The straight line 101 identifies the transition to 100 on the right. On this vertical, the width has the cooling section 39. In the example, the temperature 114 or 115 of the ribbon cable should already be a noticeable 20 ° C. in this cooling section. The width of the difference, which is caused by the pressing together of the plastic band, now follows the dashed curve 30 wires as a result of the different shrinkage 106 when the temperature of the cooling basin 38 is 80 ° in the second cooling section 38. It carries heritage, and the dashed curve 107, when the aims therefore by this reaction an effect, as temperature is the cooling line 38 50 ⁰ C. Which he also converges through a real nozzle with changeable curves 106 and 107. The art cross-section could be evoked. In the fabric belt, with the same environmental and material conditions, the conditions, in particular the subrial influences, are of a uniform width, which is independent of the temperature of the second cooling section, of how the cooling takes place, i.e. here independent. depicted greatly exaggerated. In reality, it varies depending on whether the temperature of the cooling section 38 in a system according to the invention is 80 or 50 ° C. Water temperatures by only small amounts, both

The following is the decrease in width of a strip 40, for example, by 3 ° C. In an extruder system that

kabeis works according to the process according to the invention on cooling after the extrusion and

be sought. The course of the width of the ribbon for extruding polyethylene ribbon cables

kabeis is used in Fig. 6 with continuous lines with 60 veins and 29.2 mm end width, the

shown. The decrease in width of a ribbon cable Temperature of the regulated cooling section in the area

After the plastic has solidified, 45 ° C takes place in parallel, the temperature drops to 0.5 ° C

for reducing the width of the plastic tape. With one precisely regulated.

Temperature of 80 ° C in the second cooling section 38 can generally be said that the following is the width of a ribbon cable of curve 110 and the constriction of the cable in the area of the cooling section after entering the third cooling section 39 of 35 and thus also the Endab curve 111. Accordingly, the width a in 50 measurement of the cable the smaller is, the sharper dei the second cooling section 38, cooled to 50 ° C bend the cooling curve of a band without wires ribbon cable according to the glass transition temperature according to the curve at the same cooling conditions is above the inlet 112 and in the cooling section 39 after the curve 113 lead temperature. The sharpness of this kink can be reduced. The curve 110,111 is opposite to the curve 104, also in a way other than in the above example 106 and loading the curve 112,113 with respect to the curve 55 written - where the temperature of the second cooling 105,107 shifted downward. This displacement, in which the plastic solidifies and changes movement, results from the fact that the wires are influenced when they are removed. A change in the cooling in the cooling section 38, when compressed, the sharpness of the kink can also be achieved if this is done and this also changes the width of the still length of the first cooling section 35. This plastic ribbon cable in the area of the first cooling 60 will reduce the temperature of the ribbon cable at the entry stretch 35 . The course of the width in this changed in the second cooling section 38 . The tempe range is represented by curves 114 and 115 of the ribbon cable as it enters the second one. The width reduction is greater in proportion as the cooling section can also by changing the Temgrößer the cooling in the second cooling section 38, temperature of the first cooling section 35 (ζ., By compr. E. The sharper is the bend in the line 100th 65 Modified the air temperature or the air flow) The freezing points 116 and 117 for the ribbon cable are influenced. Finally, it is also possible, below the corresponding freezing points, to use these different parameters at the same time 108 and 109 for the plastic strips. change.

The invention is of course not only applicable to a cooling system that consists of an air and a water cooling section exists, rather any cooling system is usable, in which before the solidification point of the plastic is cooled at different cooling speeds.

Claims (6)

Claims: IO 1. Process for sheathing ribbon cables with plastic by extrusion, in which before the Cooling section in which the plastic solidifies (second cooling section), at least one further cooling section (first cooling section) is provided, characterized in that the temperature and / or the length of the first cooling section (35) and / or the temperature of the second cooling section (38) is / are controlled in such a way that the difference in the temperature of the in the second Cooling section (38) entering ribbon cable (34) and the temperature of the second cooling section (38) increases with increasing width of the ribbon cable (34) and with decreasing width of the ribbon cable (34) is reduced. 2. The method according to claim 1, characterized in that the width of the casing is determined behind the cooling lines. 3. Device for carrying out the method according to claim 1 or 2, characterized in that that a width measuring device (49) for the ribbon cable is arranged behind the cooling sections is that the output of the width measuring device (49) is connected to a control device (57) is the temperature of a heating device (44) for the first and / or second and / or sets the length of the first cooling section. 4. Apparatus according to claim 3, characterized in that a first cooling section (35) Air cooling section & with room temperature, behind it a regulated second cooling section (38) with heated Water and, behind it, a third cooling section (39) with water at normal temperature are. 5. Apparatus according to claim 3 or 4 for performing one of the methods according to claim 1 and 2, characterized in that the width measuring device (49) is a feeler roller measuring device is provided with an electrical output (56). 6. Apparatus according to claim 4, characterized in that in the second regulated, with Water-filled cooling section (38) has a circulating device (45), in particular one through a Electric motor driven propeller, is provided. For this purpose 2 sheets of drawings