JPH0249898B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The invention relates to a supply for core material which is provided with a connecting structure, a collecting block, a deformation unit and a wide slit nozzle, said connecting structure having a substantially rectangular channel cross-section. a channel, the supply channel leading to a coupling channel of the collecting block, which coupling channel widens towards the wide slit nozzle, and at least one coating in the transition region between the supply channel and the coupling channel. At least two plastic screw extruders, the introduction slits for the material communicating with each other, the slit cross section of this introduction slit in the region of the communication being variable by an adjustable control element extending over the width of the slits. This invention relates to a continuous extrusion device for multilayer plastic tape using a machine. The expression collecting block indicates that within the block several streams of thermoplastic plastic are collected and, as it were, combined in a connecting channel during layer formation. The overall layout and composition is as follows. That is, the layers of thermoplastic plastic are not mixed in a separate path up to the wide slit nozzle. In the deformation unit, the multilayer flow of thermoplastic plastic flowing into the connecting channel is first deformed into a shape corresponding to the plastic tape emerging from the wide slot nozzle. Plastic tape refers to plastic film or plastic board.

Prior Art In the known device as mentioned at the beginning (German Patent Application No. 1504190),
The coupling passage is between the two supply passages. The coupling channel passes into a wide slot nozzle, which extends over the length of the coupling channel and forms, as it were, the inlet of the deformation unit, to which the wide slot nozzle already described is connected. has been done. The two wide slit nozzles are oriented perpendicularly to each other. This has the disadvantage that, on the one hand, it is expensive in production technology and, on the other hand, the layer thickness of the plastic layer cannot be directly controlled. In particular, no adjustment elements are provided for the thermoplasticization partial flow or the separate coverings. However, this adjustment is important when making plastic tapes where the layer thicknesses can be easily determined in advance and where it is desired that the layers have the same thickness over the entire width of the plastic tape except for small tolerances. It is.

OBJECTS OF THE INVENTION It is an object of the invention that the layers have substantially the same thickness everywhere over the entire width of the plastic tape;
Moreover, the above-mentioned device is constructed so that it has the same thickness even when an extremely wide wide slit nozzle is used.

According to the invention, the present invention provides that the introduction slit for the coating material runs along the wide side of the rectangular channel cross section, and that a cylindrical hole is bored in contact with the introduction slit. has been
and a plurality of adjustment pins are attached to the hole in an exchangeable manner, and these adjustment pins have different external shapes around the circumference and are rotatable about an axis within the hole for the adjustment effect. It will be resolved.

The advantages obtained are as follows. Thus, in the device according to the invention, by adjusting the adjusting pin, the layer thickness of the plastic stream can first be adjusted, which plastic stream covers the plastic stream initially introduced into the connecting channel. Furthermore, in the finished plastic tape all the various layers have the same thickness, so that, for example, by means of an adjusting screw, the edge region can be made thicker than the central region, or vice versa. Adjustment screws are very easy to replace, so
It is particularly advantageous that the device according to the invention can be used for various extrusion operations. The above-mentioned procedures can be carried out in succession in multiple stages and on different sides of the coupling channel.

Description of examples Embodiments of the present invention will be described below with reference to the drawings.

The illustrated apparatus includes at least two
It is used for continuous extrusion of multilayer plastic tape by two plastic screw extruders. The device includes collection block 1, collection block 1
It includes a deforming unit 2 connected to the rear end of the deformation unit 2, and a wide slit nozzle 3 from which the multilayer plastic tape exits. These parts are shown schematically in FIG. The collecting block 1 has a connecting channel 4 to which a plastic screw extruder is connected. Via the deformation unit 2, the connecting channel 4 is connected to a wide slot nozzle 3.

As is clear from a comparison between FIGS. 1 and 2, the coupling passage 4 has a substantially rectangular passage cross section with rounded corners 5,
is connected on the one hand to a concentrically upstream supply channel 6 for core material for the first plastics screw extruder and on the other hand to the deforming unit 2. Downstream after the supply passage 6, in this embodiment, the supply passage 6 and the coupling passage 4 are connected.
In the exemplary embodiment, two coating material slots 7 are arranged in the transition region between the two, to which two further plastic screw extruders (not shown) are connected via channels 8. It is possible. These introduction slots 7 extend over the wide side of the rectangular coupling channel cross-section and communicate therewith. An adjusting pin 10 is rotatably arranged in a cylindrical hole 9 in the middle of the introduction slit 7. Depending on the position, this adjusting pin projects into the associated introduction slot 7 with varying widths or does not project at all. This is because, in order to adjust the thickness of the introduction slot 7, the circumference of the adjusting pin has different cross-sectional shapes. In that regard, different cross-sectional shapes 1
Please refer to FIG. 3, which shows numbers 1, 12, 13, and 14. In this embodiment, the introduction slot 7 extends over the wide side 15 of the rectangle and communicates here with the connection channel 4 . It is clear that the device generally has a plurality of adjustment pins 10, which adjustment pins are interchangeable. These adjusting pins have different cross-sectional shapes with respect to their circumference and can therefore be adapted to different operating conditions.

[Brief explanation of drawings]

1 is a side view, partially in section, of an apparatus according to the invention including a collecting block; FIG. 2 is a sectional view of the apparatus of FIG. 1 in the direction A--A; and FIG. FIG. 6 is a front view and four side views showing adjustment pins of the present invention. DESCRIPTION OF SYMBOLS 1... Collection block, 2... Deformation unit, 3... Wide slit nozzle, 4... Connection passage, 6... Supply passage for core material, 7... Introducing slit, 10... Adjustment pin.

Claims (1)

[Claims] 1. A connecting structure, a collecting block, a deformation unit and a wide slot nozzle are provided, said connecting structure having a supply channel for the core material with a substantially rectangular channel cross section, said supply channel forming a connection of the collecting block; adjoining a channel, the coupling channel widening towards the wide slot nozzle, and at least one introduction slot for the coating material communicating in the transition region between the supply channel and the coupling channel;
The slit cross section of this introduction slit in the region of the communication part is variable by means of an adjustable control element extending over the slit width, at least two
In an apparatus for continuous extrusion of multilayer plastic tapes using two plastic screw extruders, the introduction slit 7 for the coating material extends over the wide side of the rectangular channel cross-section, and a cylindrical A shaped hole 9 is drilled, and a plurality of adjustment pins 10 are exchangeably attached to the hole 9, which adjustment pins have different external shapes around the circumference and can be inserted into the hole for the adjustment effect. A continuous extrusion device for multilayer plastic tape, characterized in that it is rotatable around an axis.