High performance screw extruder

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High performance screw extruder

Technical Field

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The invention relates to a screw press for the treatment and manufacture of rubber and thermoplastic plastics according to the main subheading 1.

BACKGROUND OF THE INVENTION In the field of extrusion screw extrusion technology, it has long been known that the screw press can be formed by passing the metal pins into the space to be processed into the compressed material in the stirrer sections. For this reason, the press of the extruder is interrupted at the points where the pins penetrate. For example, DE-OS 22 35 70 or DE-OS 30 03 615 are known to the Applicant.

These screw presses are characterized by a good mixing and homogenizing action on the material to be processed and allowing it to increase the material throughput by a screw press at a unit of time at the same screw speed. These advantages have led to the fact that cylindrical screw presses with pins have become the most frequently used mixing and homogenizing screw presses in the last 15 years (not least by continuous improvement).

Independently of this, a stirring part for a screw press known as &amp; quot; transfermix &amp; quot; in DE-A 11 42 839 has been developed. This mixing part is essentially characterized in that both the screw of the press and the inner wall of the press sleeve are the longitudinal direction of the worm shell and the depth of engagement of the worm of the die and in the same manner then increases as the grooves of the sleeve are enlarged or decreasing again. Such a screw construction and the screw press bushing are rotatable mixing portions, a possible transport of the molded material from the grooves of the screw to the grooves of the sleeve, thereby stirring the molded substance well.

The transfer whisk press could require a certain share of the market in relation to the cylindrical screw worm, especially when the length of the press was to be small. However, the drawback of this stirrer structure is the high manufacturing cost.

Under Stay; / find

As the mixing technology of the screw press has not changed for the last 15 to 20 years, the invention has been the main task of creating a new generation of mixing and homogenizing screw presses based on known products.

By combining the two mixing technologies, a screw press with features of the main requirement could be formed, which has a significant advantage over the mixing and homogenizing screw presses according to the state of the art.

Thus, by means of a laboratory screw extruder having a cylindrical portion with pins and a transfer stirring portion, it has been found that the quality of stirring and at the same speed of the auger can be reduced, the worm press drive is less than 50%, and the throughput of the mass can be increased by 60- $ 100.

These excellent results further cause a 50% decrease in drive torque, which leads to a great reduction in the cost of drive. To do this, it is possible to combine the cylindrical mixing part with the pins and the transfer parts, to reduce the length of the stirring portion which is about 50% you need the same quality of mixing as opposed to a screw press that only works on the pin principle. An embodiment of the invention

The invention is explained on the basis of the example of the embodiment illustrated. This shows in a schematic view a longitudinally slit screw screwdriver with one screw 1.

Inside the housing 2 there is located a screw 6 which is driven by the drive unit about its axis. The housing 2 has at a point of convexity than the direction of movement, the filler hole 3 for the pressed mother liquor is mixed by leaving the screw press through the outlet 4. The screw 6 has a screw- the geometry required for the material to be plasticized in the press press by means of the filling opening 3 in a known manner.

In the direction of movement of this intake space 9, a cylindrical space with pins 7 is assumed to radially extend through the sleeve in two rows of pins 11 into the processing space 14 of the screw press. In this space 7, the screw threads 12 are known in a known manner interrupted in the plane of the pins to prevent collision with the pin pin,

In the direction of movement of the roller with the pins 7, a transverse mixing space 8 is provided, in which the angles between the grooves 12 of the screw 6 and the threads 13 of the housing 2 are greater than or equal to 105 °, and between each other there are no additional angles up to 90 °

The last part of the worm 6 is comprised of a pressure raising compartment 10 in which the geometry of the screw is selected so that in a known manner the crushing pressure is raised to the required tool pressure,

In addition to this embodiment, other realization possibilities for this high performance screw extruder are also conceivable. Thus, for example, the transverse space Q could also be placed against the direction of motion before the roller with the pins 7f while the above-mentioned vaporizer also brings better mixing and homogenizing results. In addition to this, it is noted that the space of the cylinder with pins meets its mixing and homogenization task with more than 2 rows of pins. Considering the cost-quality ratio of the mix, it is preferable to equip the roller compartments with 1-5 rows of pins.

Suggested. the length of the individual parts is equal to 10 screw worms (D) of about 3b for the intake area, 1.5-2 D for the roller with pegs, 2-2.5 b for the mixing space around the compaction space for the compression space.

Independently of these data, however, additional spaces may be accommodated before, behind or between the roller and the pins as an area of ​​degassing or kneading.