DE2110179C - Device for plasticizing and homogenizing viscous masses - Google Patents

Description

The invention relates to a device for plasticizing and homogenizing tough Masses, especially of plastics and rubber, in which the processing of the material between a rotating roller and a roller partially enclosing, relative to her rounding shell takes place on its inner surface facing the roller j multiply, one behind the other in the direction of material movement _ j-r-shaped mixing grooves that run through

as shear channels or columns are connected.

There are a number of processes and machines for plasticizing plastics and rubber and known for shaping them into sheet-like structures, that is to say foils or plates.

In extruders, the material in the cylinder is plasticized with the help of the rotating screw then pulled apart in a slot die and pressed into the desired width and thickness. There are considerable difficulties in doing so.

a steady flow of material from the end of the screw to the very far To achieve outlet openings, which leads to unequal residence time of the material in the heat, to viscosity changes and leads to quality differences across the width of the film or web produced.

Relatively sensitive material, especially PVC,

is processed on multi-roll calenders. However, these calenders are very expensive and require one high space requirements. There are also known roll extruders in which there is only one roll in one cylindrical housing rotates and the mass to be plasticized through under pressure build-up and shear the one through the roller and the housing; ^ formed annular gap is conveyed through it. From N.;, ■ · V d here, however the long narrow flow paths. 1 · .not to a Overheating of the material at the same time insufficient Mix thoroughly.

There are still devices with a rotating roller and one or more wedge-shaped gaps Known shells employed for this purpose, which plasticize the raw material and spread it into a fur (German patent specification 1256401, German patent specification 1 191 547). A device according to the German Offenlegungsschrift 1 912 779 enables it is to feed raw material across the entire width of the roller and for less than one revolution of the roller tangential to the roller surface by several arranged one behind the other in the direction of rotation of the roller Single wedge gaps or mixing grooves worked into a shell with relatively narrow exit wedge gaps to promote. A similar device is described in German Auslegeschrift 1,629,288.

All of these wedge gap arrangements have some essential disadvantages, which result from the incomplete and uneven guiding and working through of the material. In the "first gap e; - = r such a device, the material is inserted between the rotating roller and the wedge gap shell. The material is pressed against the roller, if it is drawn into the narrow part of the gap, a shear zone is formed between the rotating roller and the stationary shell wall A part of the material adheres to the roller; this material is therefore transc-located with rollers _{- s ch λ "-ndiskeii.} The close-to-shell: " _ä <: r ~ adheres to the shell, so it is in the F. . _{; O £} j _he will definitely be with just Ia ^. . . .

Along the shell, .1. aiu. «, when the material passes through the next gap and so on, there is no change. _r this stratification;

: i the roller and '■ -.hn: the shell - :: vjn part in the ■ · ■ part! every ke- ■ -r lingers the middle jfi on the spot. ! '' cn in the flow

and thus

the material close to the roller! remains
is fo through all columns you.-.-: -.
roped material becomes cmc; ·.
Umiat'fs'.römung, which in the <*:
The gap is running around, engaging H;
rial in circulation in the WescntluK to e <; accidentally by Inhom.-j;. · mung through the narrow gap; m ·· is transported further.

The consequence of this training ::;. cir.er two-layer flow is a very large width of the verueizeit distribution: the particles hitting the roller are essentially transported at the speed of the wind, occur in practice ^; > Usual roller circumferential speed. ;! so after a few seconds from processing ^ / une; So they are very short-term and not worked through enough. The particles close to the shell, which are also in the in dei. Wedge gaps of circumferential flow are drawn in, circulate there for a very long time, in the circumferential direction with spaced-apart mixing grooves arranged one behind the other in the circumferential direction, mixing grooves arranged one behind the other run axially or obliquely to the roller axis, and in the mixing grooves separating from one another, adjacent to the roller webs essentially in Narrow shear channels leading in the tangential direction, which connect the mixing grooves with one another in the circumferential direction, are arranged offset from one another from groove to groove and together with the mixing grooves form a network of alternately more or less tangential and then again more or less axially extending material guide channels. To introduce the raw material, a

j- wedge-shaped a-if the roller feeding insertion surface

"h'Aindigkeit at the 15 at the beginning of the bowl, which is at the
Approach the roller then in single, to each other
divides parallel channels.

The mixing grooves can e; nfuui in the axial direction incorporated into the shell. So according to a wciieie- inventive idea the mixing and conveying rods also zigzag be incorporated in the axial direction in the shell, each successive in Walzendrehrichiu-ig Grooves are offset by half a zigzag division: -j so that \ on <i.At the end of a shallow shear gap de: Mas> estrom to the right and left diagonally forwards / ur in the direction of rotation is promoted to at the front articulation point again a tangential shear channel / uge-3c leads to become.

In some cases it is useful to use the mixing grooves only work obliquely in one direction, i.e. thread-like, into the shell. These grooves run shortly before the end of the shell into the shell surface.

The mixing grooves are preferably semicircular or substantially rectangular in cross-section Channels, with a carefully rounded shape in the depth of the groove and with more sharp edges Edge at the transition to the shell surface. the

differences have the result:

in the order of 5 to 10 minutes until they are replaced again, d. H. brought close to the roller and wider angle between the groove flank and the shell surface be guided. This substantial dwell time is preferably 90 or less.

The number of nuien arn shell circumference can can be chosen arbitrarily, preferably between 5 and 15. The cross-sectional area of the grooves can remain the same or preferably become smaller when viewed in the direction of travel of the roller.

The shear channels incorporated into the mixing grooves have depths of about 2 to 0.2 mm on; these depths preferably take in

a layering of the material, as there is a thin, very fast-moving layer forms over a layer that passes through much more slowly, with the risk of fanning out the layers as well as different coloring;

ei "! possibly too long dwell time \ m _{$ 0} circumferential direction.

Core of the circulating flow, which leads to thermal degradation and in the case of sensitive substances

increased cost of the raw material with the addition of increased amounts of stabilizers; higher loss when changing material, as the old material continues to run for a long time; Insufficient mixing effect of the material near the roller.

Another embodiment of the invention looks at the end? the shell in front of a retaining lip through which the ivieieriai in a \ ui £ ug »wciä £ radia! directed Nozzle in and then out of the as a film or plate

Production of individual breakthroughs

To the

Nozzle is pressed out.

Strands can also only be provided individually through the shell.

If the shell comprises significantly more than a quarter of the roller circumference, it makes sense to use it. The object of the invention is to produce the two parts, with both shell halves described and other disadvantages of the known devices pivoted about a common axis, soft with work on a roller, so that for the purpose of cleaning a comfortably overcome, that is, opening the shells in an improved device is possible, with the combination of the type mentioned a homogeneous, but completely uniform and without local flaps of the same Overheating of the 05 closed inner surface results,
to achieve arbettetes material. To ensure that the material is fed into the feed

According to the invention, this object is achieved in that the dia in the inside diameter of the To make the gap easier, it is advisable to have a powered one there To arrange Einzueswalze. Thereby w! Rd on

Schalcnanfang a scraper is provided, which continues directly. At the end of the shell there is a nozzle holder 8 for resting against the feed roller and nozzle lips 9 and 10 which can be adjusted for the raw material. Which redirects completely into the gap. Nozzle lip 10 carries the Abstrci-

To further improve the quality of the manufacturer.

Provided product can be a closed space 5 channels 24 in roller 1 and shell 2 are used be formed over the roller and shell, which guide the heating medium.

can be evacuated, and in soft the raw material

material is introduced through the appropriate vacuum-tight lock surface and the unprocessed webs or through the upstream extruder. The shell is about 0.01 mm _f it is just that big. The advantages achieved with the Frfindune consist in the fact that there is no frictional wear between the roller and then that it is now possible to get the entire through-shell, but tight enough to keep the predominant material evenly and gently the part of the unem previous shear channel to be processed.

ingenious columns as well as the uniform The mode of operation of the device is as follows:

By means of the axial movement in the raw material 12 is exposed over the entire width of the misfeed, so a very large roller 1 is placed on this, laterally limited by narrow contraction of the roller 1 in this uniform processing is a very homogeneous so the feed gap 13 between the roller and import F ndproduct with the same properties -be; ά <? surface 4 of the shell is drawn in and in this gap the width and thickness of an M3itrialbahn streams pressed out into individual parallel conveying channels in the shear channels 5 at the exit of the arrangement. During the intensive mixing, a switching passage through the channels 5 is reliably avoided as, according to the height of the shear channel and the forced and not accidental delivery speed of the roller into the material, the material freezes brought through the mixing and shear zones, which increases the temperature and ensures a perfect exchange of material in these areas in the breaking up of larger granulates or agglomerates for a short time. The danger of being angled leads. The processed material then ends up in TolziMicn. too long dwell with the mixing groove 6, the rear side 14 of which acts as a scraper risk of burning, the heated material is scraped off the roller are now through the employment of the Scherila- now in the axial direction relative to the V / alze then the shear channels against the roller, so either further transposed. In this case, a comparative cutting surface takes place parallel to the roller surface, with the temperature reduction and homogeneous mixing occurring only in a pure drag flow, or slightly in all parts. After a certain axial trans-wedge shape employed, which is considerably higher h \ diod> - port, the material is caused by the continuing in namisthe prints. The possibility of the axially offset shear channel 7 for the next adjustment of relatively low processing pressures creates a groove with renewed application of shear and facilitates the simple construction of very wide machines for thermal energy. At the end of the shell, the production of> rather wide foils or plates is carried out. the plastified material from the Ablreifkante 11 Auslreifkante 11 AusuiigsbeispKle of the invention are shown in the gap between the nozzle lips 9 and 10 ra drawings and are in the following pushed dial to the roller I and finally described as Foiiahcr. Fs shows lie or plate 15 struck.

Fig. 1 shows a cross section through an embodiment · * - 45 Fig. 2 shows the flow process of the material in

hot example. the recesses in the shell 2 that form a network

F1 s 2 a plan view of the inside of the same in a plan view of the inside. Through

Bowl. Arrows is the course of the flow! It knows the material

F 1 E- 5 made an enlarged section of the loaned. It clearly shows the compulsory funding

Sheep cross section. 50 dening of the material 12 by the system of en-

F1 g. 4 a variant of the groove course with zigzag. Tangential in the circumferential direction

jagged grooves. Then splitting into two opposite

F i g. 5 shows a variant of the groove course with set directed axial mixing and delivery flows in

grooves running obliquely on one side. the grooves 6. and then again the discharge into the

Fig. I shows a cross section through an execution 55 Scherkzaalen7. the opposite of the shear channels5 in ^!

rungsbeispicl of the device. One with liquid. are offset in the axial direction. i

Steam or electricity heated and with adjustable F i g. 3 shows an enlarged section from i

Circumferential ^ .- speed driven roller 1 is on the cross section of the shell according to Fig. I. It is I

a part of the heated one and made clear here that all material, both that temperature-controlled shell 2 surrounded. In the infeed 60 material 16 lying directly on the roller, such as area of the shell are lateral delimitation plates, including the material 17 that grazes along the shell th 3 arranged. The shell itself has the mixing and conveying part in the intake section of the squeegee 14 first of all a single groove 6 set at an angle to the roller is stripped off, and under a circular mixing surface 4. transitioning into individual parallel movements axially, i.e. perpendicular to the image plane, Channels 5. which open into the mixing groove 6. To which 65 is promoted.

The cutting edge is offset from the cutting edge. 4 shows the plan view of the inside of a

n / A! 7. In the same way, the grooves and the shell in between are set with a variant of the groove course Shear channels up to the end of the shell stalu that the Mischnuteno not axparallel, but

are incorporated into the shell in a zigzag shape, with the next following groove is axially offset by half a zigzag division. The material 12 is fed through the shear channels 5 to the groove 6 and there divided into two conveying flows 18 and 19, which run obliquely in the direction of the roller.

F i g. 5 shows another possible variant of the design of the mixing grooves. There will only be Mixing grooves 20 to 23 running obliquely to the roller in one direction are arranged. The raw material 12 is fed here directly into the grooves 20 to 23, from these through the continuing shear channels 7

as in the execution according to the F i g. 1 to 3 with the introduction of Schcrencrgie v. The grooves run into the surface of the shell just before the end of the shell

S shell out.

With the invention is a simple device for plasticizing and homogenizing viscous masses, especially in connection with production created by foils or plates, the one

ίο very even and gentle processing and so that the production of very uniform products is possible.

1 sheet of drawings

309635/400

Claims (10)

Patent claims: 1. Device for plasticizing and homogenizing viscous masses, in particular plastics and rubber, in which the processing of the material takes place between a rotating roller and a shell that partially encloses the roller and is stationary relative to it, which on its inner surface facing the roller has several, Contains mixing grooves arranged one behind the other in the direction of material movement, which are connected by shear channels or gaps, characterized in that the mixing grooves arranged in the circumferential direction at a distance behind one another extend axially or obliquely to the roll axis in the shell corresponding in its inner diameter to the roll outer diameter. U ₁ Id in the webs separating the mixing grooves from one another and resting on the roller, narrow shear channels leading essentially in the tangential direction, which connect the mixing grooves with one another in the circumferential direction, are offset from one another from groove to groove and, together with the mixing grooves, form a network of alternately more or Form material guide channels running less tangentially and then again more or less axially. 2. Apparatus according to claim 1, characterized in that ar ¹ inlet of the shell a wedge-shaped feeding surface is provided on the roller, d ^; When sewing on to the shell, it divides into individual, mutually parallel, essentially tangential channels. 3. Apparatus according to claim 1 and 2, characterized in that the mixing grooves (6) in are incorporated in the axial direction in the shell (2). 4. Apparatus according to claim 1 and 2, characterized in that the mixing grooves (6) run zigzag in the axial direction in the shell and each successive in the circumferential direction Grooves are axially offset from one another by half a zigzag division. 5. Device according to claims 1 and 2, characterized in that the mixing grooves only machined into the shell at an angle in one direction are. 6. Device according to claims 1 to 5, characterized in that the mixing grooves (6) than semicircular in cross-section or substantially rectangular channels with carefully rounded shape in the depth of the groove and with a sharp edge at the transition to the surface and the angle α between the groove flank and the shell surface is not greater than Is 90 °. 7. Apparatus according to claim 6, characterized in that the cross-sectional area of the Mixing grooves (6) become smaller in the running direction of the roller. 8. Device according to claims i to 7, characterized in that the in the webs between the grooves (6) incorporated shear channels decreasing in the circumferential direction. Depths of about 2 to 0.2 mm. 9. Device according to claims 1 to 8, characterized in that at the end of the shell (2) one presses out the material in the radial direction Nozzle is connected. 10. Device according to claims 1 to 9, characterized in that the shell (2) from consists of two halves that are pivotably mounted about a common axis and in the. in the amount folded State a .''completely closed or joint-free inner contour.