DE102014200438A1 - Device for granulating plastics - Google Patents

Abstract

The invention relates to a device for granulating plastics with a granulator (2) which has at least one substantially axially directed outlet nozzle (14) arranged in a knife plate (13), from which plastic melt can be pressed, wherein in its flow direction behind the outlet nozzle ( 14) a rotating cutting device (9 to 11) with a plurality of blades (11) is arranged, which are moved past the blade plate (13), so that the exiting plastic melt is cut off and can solidify in the water to granules. The knives (11) is associated with a positioning device (6 to 8, 17, 18) with several piston-cylinder units (17), which is fed by a common hydraulic piston (6) and an adjustment of the blade (11) in the axial direction on the blade plate ( 13) causes.

Description

The invention relates to a device for granulating plastics with a granulator having at least one preferably axially directed arranged in a blade plate outlet nozzle, from the plastic melt can be pressed, wherein in the flow direction behind the outlet nozzle, a rotating cutter is arranged with a plurality of knives, the the knife plate are moved past, so that the exiting plastic melt is cut off and can solidify in water to the granules.

For underwater pelletizing, plastified plastic is usually pressed through holes which are usually arranged annularly in a knife plate. On the exit side of the holes rotating blades are moved past the blade plate, so that the exiting plastic melt is cut off and can solidify in the water to granules.

From the CH 411 317 is a Granuliereinrichtung known in which a rotating screw presses the product to be granulated in the axial direction through a nozzle plate which is equipped with a rotating knife which cuts the exiting through the nozzle opening strands into granules.

The invention is based on the object to form a device for granulating plastics of the type mentioned in such a way that it is ensured in a simple manner that the rotating blades are adjustable so that they always have an optimal cutting performance in cooperation with the fixed blade plate ,

The object is achieved in that the knives an adjusting device is associated with a plurality of piston-cylinder units, which are fed by a common hydraulic piston and causes an adjustment of the blade in the axial direction of the blade plate.

This provides a simple and inexpensive adjusting device for the knives, which can be employed all in the same way and at the same time.

It has proven to be advantageous if the common hydraulic piston is driven by an air pressure or pneumatic piston.

It is thereby achieved that for generating the actual contact pressure due to the low elasticity hydraulic means, for. As oil or even less compressible liquid can be used, so that there is a high consistency in the employment of the knife. However, the pneumatic piston allows a simple way to generate the required pressure.

So that the pneumatic piston does not have to be constantly under pressure, a backstop can be assigned to the pneumatic piston. The backstop prevents the pneumatic piston, even if it is depressurized, from being moved back

Advantageously, the knives can be fastened by means of knife holders to the piston-cylinder units. The attachment can be direct or indirect.

The invention is explained in more detail with reference to embodiments shown in the drawing. Show it:

1 a granulating device for use of the invention,

2 a cutter head of the granulator according to the invention shown partially cut off 1 .

3 a granulator for use in the Granuliereinrichtung invention according to 1 in a perspective sectional view,

4 a sectional perspective view of the cutter head with inventive adjusting device of the knife and

5 a drive device shown in section for the adjusting according to 3 ,

In the 1 is a Granuliereinrichtung 1 with a granulator 2 represented by a coupling 3 and a gearbox 4 with a drive motor 5 connected is. One on the gearbox 4 mounted common hydraulic piston 6 , whose operation will be explained in more detail below, is a backstop 7 having air pressure or pneumatic piston 8th operated.

The 2 shows a cutting device of in 1 Granulator device shown 1 with a rotating cutter head according to the invention 9 , on which by means of knife holders 10 several knives 11 are attached. These knives 11 should be at an in 3 shown within a granulator housing 12 arranged knife plate 13 abut and glide along the surface. The knife plate 13 has several holes or outlet nozzles 14 on, which are arranged in a ring or circular and aligned in the axial direction. About an annular circumferential groove 15 become these outlet nozzles 14 of at least one melt feed 16 fed with a plastic melt, so that These can escape and the knives 11 the plastic melt can cut off or cut off, with the knife 11 close to the knife plate 12 must be present. These cut off portions of the plastic melt can fall, for example, to cool in water and solidify there to granules.

In the 4 is the knife head 9 with inventive Anstellvorrichtung the knife 11 cut shown in more detail. Each of the knives 11 is a piston 17 assigned as a small piston-cylinder unit, through which the on the cutterhead 9 arranged knife holder 10 with the knives 11 further out of the knife head 9 can be moved out, leaving each knife 11 in the required degree to the blade plate 13 such that it is from the outlet nozzles 14 cut off streaming plastic melt safely and clean and the granules thus produced in a water tank (not shown) can solidify.

The 5 shows a sectional view of a drive device for the adjusting according to 4 , The hydraulic adjusting pistons 17 be by means of the common hydraulic piston 6 applied with the desired pressure, so that the knives 11 with their required contact pressure against the blade plate 13 Press that results in an optimal cutting action.

The common hydraulic piston 6 is by the pneumatic piston 8th operated, which builds up the desired pressure. It provides a backstop 7 for being the pestle 18 not from the common hydraulic piston 6 can be pushed back when the pressure of the pneumatic piston 8th wears off or the pneumatic piston 8th is switched off. This requires the pneumatic piston 8th only to be operated intermittently when the contact pressure of the knife 11 to the knife plate 13 falls below a required minimum value.

The adjusting device according to the invention has small piston-cylinder units that come from the common hydraulic piston 6 be fed. Oil is used because of its low elasticity. To build up the common oil pressure, the hydraulic piston 6 from the pneumatic piston 8th driven and pressurized. Thus the pneumatic piston 8th do not work constantly and must be under pressure, the pneumatic piston 8th a backstop 7 on. The backstop 7 prevents the pneumatic piston 8th Even if it is depressurized, it can be moved back.

This requires the pneumatic piston 8th to any wear on the knives 11 and the knife plate 13 be compensated, only impulsually, for example, at fixed intervals and / or in dependence on the knife gap distance, the wear or the like. Be supplied with compressed air. This will be the common hydraulic piston 6 again moved forward and moves the individual oil pressure piston or Anstellkolben 17 the knife 11 in the direction of the knife plate 13 , After switching off the air pressure, the backstop ensures 7 for the slightly advanced common hydraulic piston 6 remains in this position.

This can compensate for the wear of the knife 11 be carried out at regular intervals or wear-dependent, without constantly air pressure on the pneumatic piston 8th or air pressure piston is applied.

LIST OF REFERENCE NUMBERS

1

granulating

2

granulator

3

clutch

4

transmission

5

drive motor

6

common hydraulic piston

7

Backstop

8th

Air pistons

9

cutter head

10

knife holder

11

knife

12

granulator

13

blade plate

14

vents

15

groove

16

melt supply

17

Anstellkolben

18

tappet

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• CH 411317 [0003]

Claims (5)

Device for granulating plastics with a granulator ( 2 ), at least one in a knife plate ( 13 ) arranged outlet nozzle ( 14 ), can be pressed out of the plastic melt, wherein in the flow direction behind the outlet nozzle ( 14 ) a rotating cutting device ( 9 to 11 ) with several knives ( 11 ) is arranged, which at the knife plate ( 13 ) are moved past, so that the exiting plastic melt can be cut off and solidified in water to granules, characterized in that the knives ( 11 ) a setting device ( 6 to 8th . 17 . 18 ) is assigned, that the adjusting device ( 6 to 8th . 17 . 18 ) Piston-cylinder units ( 17 ), wherein at least one respective piston-cylinder unit ( 17 ) is in operative connection with a knife that the piston-cylinder units ( 17 ) from a common hydraulic piston ( 6 ) and that the knives ( 11 ) by means of the piston-cylinder units ( 17 ) and the hydraulic piston ( 6 ) with respect to the knife plate ( 13 ) are adjustable. Device for granulating plastics according to claim 1, characterized in that the common hydraulic piston ( 6 ) with an air pressure or pneumatic piston ( 8th ) is in operative connection. Apparatus for granulating plastics according to claim 1 or 2, characterized in that find hydraulic oil or even less compressible liquids application. Device for granulating plastics according to one of claims 1 to 3, characterized in that the pneumatic piston ( 8th ) a backstop ( 7 ) assigned. Device for granulating plastics according to one of Claims 1 to 4, characterized in that the knives ( 11 ) by means of knife holders ( 10 ) on the piston-cylinder units ( 17 ) are attached directly or indirectly.

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