DE102004007479A1 - Extruder for processing materials with different melt temperatures has separate processing units for each material before the different plasticized materials are combined in the extruder - Google Patents

Abstract

One material is plasticized in a first processing unit(2) of the extruder to form a first melt. A second and/or each additional material is plasticized in the first processing unit or in a further process unit(3) to form a second or further melts which are then combined with the first melt in the extruder to form a compound. Each material is processed in independent plasticizing zones(2',3') of each processing unit(2,3). Processing units are separated from each other by seals(4) so that material is prevented from flowing between them. The extruder has by-pass line(5,5') via which the first melt flows into the second and/or additional melts. An inlet(6) to the by-pass exists at the end of the plasticizing zone(2') for the first material. An outlet(7) of the by-pass lies at the end of the plasticizing zone(3') for the second or additional material. A pump, preferably a gear pump is located at the inlet and/or at the outlet of the by-pass. The extruder has a discharge system. An independent claim is included for a process for processing materials with different melting points as described to form products.

Description

The The invention relates to an apparatus and a method for processing of at least two materials having different melting temperatures to a product with an extruder, wherein at least one of Materials in the extruder in a first process unit to a first melt is plasticizable.

It are devices and methods of processing known in the two materials, eg. B. a rubber mixture and a thermoplastic Material - e.g. Polypropylene (PP) -, to a product, for example a compound. These Materials have different melting temperatures. The glass transition temperature of rubbers is usually below. The opposite is the melting temperature of thermoplastics usually at or above 170 ° C. Thermoplastics is here a collective name for different thermoplastic product families that are in the composition can differ from each other.

in the Compared to the rubber thermoplastic elastomers, for example TPE, in each case via specific Features and benefits, like that In some applications, rubber is replaced by TPE can. Due to their thermoplastic consistency, TPE materials can be used plasticize well and then in almost any desired Shape shape, taking care of this both the processing to a compound and the common procedures plastics processing, such as injection molding and blow molding, or extrusion suitable.

Apart from the separate processing of two materials such as rubber and TPE, the production of compounds, for example rubber compounds or TPE compounds, is also known. Such mixtures are often prepared discontinuously in so-called internal mixers. An advantageous continuous production of products from materials with different melting temperatures, such as rubber and thermoplastic, is from the DE 101 34 701 A1 known. The device disclosed therein comprises a short-screw extruder for melting or plasticizing the first material, here rubber, a twin-screw extruder for melting the second material, here thermoplastic, and a gear pump, which serves for introducing the one material with a predetermined throughput and temperature in the other material , Plastification is used in connection with rubber, since it is generally above the glass transition temperature at room temperature, that is, it is a supercooled melt. If the other material is in the form of a polymer such as thermoplastic, this is also melted. By means of from the DE 101 34 701 A1 known method is thus supplied to the twin-screw extruder melted rubber at a predeterminable temperature and predeterminable volume flow.

Become in another version Rubber and thermoplastic plasticized or melted together, This is how the thermoplastic melts and forms the second one Material a lubricating film. As a result, then the second material, for example Rubber as a polymer, not enough be melted or plasticized. Will turn in one another embodiment of the first Rubber added and later the thermoplastic, too little shear is present here to the Fast enough to melt thermoplastic in sufficient quality. Furthermore, it is problematic in this embodiment that the already plasticized rubber phase by the addition of the thermoplastic at Cool down room temperature again and leads to non-plasticized particles in the resulting product.

The For this purpose used devices or the method used is also to improve that it is a high machine Means and means to be used in terms of the production Device is expensive.

Of the Present invention is based on the object, a Device and a method for processing at least specify two materials for a product of the type mentioned above, at a cost Processing of products becomes.

According to the invention above task with regard to a device for processing from at least two materials to a product with the characteristics of claim 1. Thereafter, the device for processing at least two Materials for a product designed such that the second and / or any other material in the extruder in the first processing unit or in further process units to a second or further melt is plasticizable and in the extruder with the first melt to the Product is miscible.

Furthermore, the above object with regard to a method for processing at least two materials to a product having the features of claim 8 is achieved. Thereafter, a method for processing at least two Ma Materials to a product of the type mentioned in such a way that the second and / or each other material is plasticized in the extruder in the first process unit or other process units to a second or further melt and this is mixed in the extruder with the first melt to the product ,

In according to the invention has been recognized that a temporal and / or local Separation of the two materials with different melting temperatures should be made. In the molten or plasticized Phase could then the materials merged, preferably in a mixing unit, for example by a Section of the extruder may be formed, and preferably be dispensed by an output device from the extruder. In particular, thermoplastic and rubber form in such Approach a particularly good co-continuous phase. In can advantageously so uncrosslinked or crosslinked thermoplastic rubber blends - TPE-O or TPE-V - or the like. Accordingly, a separate reflow or plasticizing with only one extruder particularly advantageous. In a further advantageous manner could this is a twin-screw extruder.

In an advantageous embodiment of the extruder for preferably each material at least one process unit, in particular independent Plasticizing zones exhibit. This could be any process unit be matched to the material to be extruded and thus an optimal Processing and in particular plasticization of the respective material be achieved.

in the A particularly space-saving design could be the Process units by sealing devices from each other be that essentially no material from a process unit into another. It could thus an uncontrolled material transfer from a process unit on the other hand, at the direct interfaces of the process units be avoided substantially. The process units could hereby through specially adapted to the respective material snails be formed. In particular, could the process units are co-rotating twin screws. The different process units could thereby by a motor are driven. Could do this the process units within an extruder barrel in particular advantageously in succession and / or mechanically coupled be arranged. The process units could also be through two or more drive units to be driven to the process unit again particularly well matched to the respective material to be processed.

Regarding In a particularly preferred embodiment, the extruder could at least have a bypass over the first melt in the second and / or further melt can be introduced is. This bypass could be designed as a melt line, which depends on the first material and / or the length of the bypass in addition with a heating and / or cooling device could be provided. Thus could the melt temperature of the first melt is particularly good on one Level or regulated to other temperature values. additionally or alternatively could at a time separation of the plasticization of the bypass as Memory, in particular designed as a piston accumulator. In Such an embodiment could then first the first material to be plasticized and into the piston accumulator be initiated. Then, preferably in the same process unit, the second or further material can be plasticized. That first material could now from the piston accumulator into the plasticized second or further Material be introduced. The materials could in any case by a Mixing device or mixing unit to the product miscible and by means an output device can be output.

in the In the context of a particularly good plasticization and mixing of the Could be the materials Inlet of the bypass at the end of the plasticizing zone of the first material arranged be and / or the outlet of the bypass at the end of the plasticizing zone be arranged of the second or further material. In the Processing of multiple materials it would be conceivable that the materials cascading over serial bypasses be interconnected, d. H. that with three materials, the first melt over a first bypass introduced into the second melt and then mixed second melt over a second bypass is introduced into the third melt. Additionally or alternative would be it is possible that the different materials have their own bypasses from the end of their plasticizing zone to the end of the plasticizing zone of the last material, so that a mixing of the materials only after the plasticizing unit of the last material, preferably in a mixing unit. The mixing could be here be realized by a mixing unit, for example, as a mixing zone of an extruder screw or extruder twin screw is designed. But it is also any other type of mixing unit conceivable.

In view of a particularly good promotion of the material in the bypass, a pump, preferably a gear pump, could be arranged at the inlet and / or at the outlet of the bypass and / or in the bypass. But it could be any another type of device by means of which plasticized material can be conveyed arranged. In this case, the pressure and / or the volume flow, with which the melt is introduced into the further melt, could be regulated particularly well in a particularly advantageous manner. In a further embodiment, the gear pump could be followed by a screen, which filters out impurities from the melt. However, it is also possible for the first or further melt to be conveyed through the bypass solely via the pressure built up in the first process unit.

Regarding a particularly simple embodiment could be an output device be arranged, which designed for example as a spray head could be. By this spray head could then the product will be dispensed from the extruder. It could be also any other form of output devices, for example one slot die or the like, as the output device. The Type of output device depends on the use of the product.

The inventive method for processing at least two materials into one product could in particular for operating a device for processing at least two materials to a product according to the above serve. In the method is advantageous that a particularly good Mixing of at least two materials, such as molten Thermoplastic with plasticized rubber, is achieved and this Materials form a particularly good, so-called co-continuous phase.

It are now different ways to design the teaching of the present invention in an advantageous manner and further education. On the one hand to the subordinate claims, on the other hand to the following explanation a preferred embodiment the device according to the invention referring to the drawing. In conjunction with the explanation of the preferred embodiment With reference to the drawings are also generally preferred embodiments and further developments of the teaching explained. In the drawing shows

1 in a side view, partially and schematically, an embodiment of the inventive device for processing at least two materials to a product and

2 in a plan view, partially and schematically, the embodiment of the device according to the invention 1 ,

1 shows an embodiment of an inventive device for processing at least two materials to a product. The two materials are thermoplastic and rubber. Thus, an uncrosslinked thermoplastic elastomer blend TPE-O is produced. The device has an extruder 1 on, the extruder 1 an output device - not shown here - has. In this embodiment, the first material, in this case thermoplastic, is in the extruder 1 plasticized to a first melt.

In accordance with the invention, the second material, in this case rubber, in the extruder 1 plasticized to a second melt and it is in the extruder 1 the first melt, eg, the molten thermoplastic, and the second melt, eg, the plasticized rubber, to the product in a mixing unit of the extruder 1 mixed. The product is then removed from the extruder by means of the dispenser 1 output.

The embodiment of 1 has one process unit for each material 2 and 3 on, with the process units 2 and 3 are formed by a pair of twin screws, which are mechanically coupled and driven by a drive - not shown here. The process units 2 and 3 have plasticizing zones 2 ' and 3 ' on, in which the first and second material are plasticized. The process units 2 and 3 are through sealing devices 4 separated such that substantially no material from the process unit 2 in the process unit 3 transgresses. To transfer material from the first processing unit 2 in the second processing unit 3 indicates the extruder 1 a bypass 5 on that in 1 dash-dotted lines is shown. About this bypass 5 the molten thermoplastic is introduced into the second melt.

The inlet 6 of the bypass 5 is at the end of the plasticizing zone 2 ' arranged the first material. The outlet 7 of the bypass 5 is at the end of the plasticizing zone 3 ' of the second material. Thus, there is a melting of the thermoplastic, wherein the thermoplastic in the form of the melt via the bypass behind the plasticizing zone 3 ' of the second material, ie of the rubber.

In the embodiment described here is within the bypass 5 a gear pump - not shown here - arranged to promote the thermoplastic from the first process unit 2 to the second processing unit 3 to allow and minimize the pressure build-up of the feed unit before the seal, with which the plasticized thermoplastic introduced into the plasticized rubber becomes. In the further course, a thorough mixing of the two melts by the twin-screw extruder, before the product by means of the output device from the extruder 1 is issued.

2 shows a plan view of the inventive device of 1 , To avoid repetition, the comments on the comments 1 referenced, wherein like parts are provided with the same reference numerals. 2 shows that another parallel bypass 5 ' can be provided - here dash-dotted Darge presents - to achieve better mixing and promotion of the first melt.

Regarding further advantageous embodiments of the teaching of the invention is used to avoid repetition on the general part the description and the appended claims.

Finally, be expressly pointed out that the embodiment described above for discussion only the claimed teaching is, but not on the embodiment limits.

1

extruder

2

processing unit first material

2 '

plasticizing first material

3

processing unit second material

3 '

plasticizing second material

4

sealing device

5

bypass

5 '

bypass

6

inlet of the bypass

7

outlet of the bypass

Claims (8)

Device for processing at least two materials having different melting temperatures into a product with an extruder ( 1 ), wherein at least one of the materials in the extruder ( 1 ) in a first processing unit ( 2 ) is plastifiable to a first melt, characterized in that the second and / or each further material in the extruder ( 1 ) in the first processing unit ( 2 ) or in further process units ( 3 ) is plastifiable to a second or further melt and in the extruder ( 1 ) is miscible with the first melt to the product. Device according to claim 1, characterized in that the extruder ( 1 ) for preferably each material at least one processing unit ( 2 . 3 ) with in particular independent plasticizing zones ( 2 ' . 3 ' ) having. Apparatus according to claim 2, characterized in that the process units ( 2 . 3 ) by sealing devices ( 4 ) are separated from each other in such a way that substantially no material from a process unit ( 2 . 3 ) into another. Device according to one of claims 1 to 3, characterized in that the extruder ( 1 ) at least one bypass ( 5 . 5 ' ), via which the first melt in the second and / or further melt can be introduced. Device according to claim 2 or 3 and claim 4, characterized in that the inlet ( 6 ) of the bypass ( 5 ) at the end of the plasticizing zone ( 2 ' ) of the first material is arranged and / or the outlet ( 7 ) of the bypass ( 5 ) at the end of the plasticizing zone ( 3 ' ) of the second or further material is arranged. Device according to claim 4 or 5, characterized in that at the inlet ( 6 ) and / or at the outlet ( 7 ) of the bypass ( 5 . 5 ' ) and / or in the bypass ( 5 . 5 ' ) is arranged a pump, preferably a gear pump. Device according to one of claims 1 to 6, characterized that an output device is arranged. Method for processing at least two materials having different melting temperatures into a product, in particular for operating a device according to one of claims 1 to 7, with an extruder ( 1 ), wherein at least one of the materials in the extruder ( 1 ) in a first processing unit ( 2 ) is plasticized to a first melt, characterized in that the second and / or each further material in the extruder ( 1 ) in the first processing unit ( 2 ) or other process units ( 3 ) is plasticized to a second or further melt and this in the extruder ( 1 ) is mixed with the first melt to the product.