WO2015166431A1

WO2015166431A1 - Machine for continuously processing polymer material

Info

Publication number: WO2015166431A1
Application number: PCT/IB2015/053118
Authority: WO
Inventors: Giuseppe Ponzielli
Original assignee: Nexxus Channel SRL
Current assignee: Nexxus Channel SRL
Priority date: 2014-04-29
Filing date: 2015-04-29
Publication date: 2015-11-05
Anticipated expiration: 2016-10-29

Abstract

A machine for continuously processing polymer material has a rotor (3) which rotates about an axis of rotation (A1); a stator (4) sealed in sliding manner to the rotor (3); at least one annular processing channel (5) which extends heightwise (H) between the rotor (3) and the stator (4), and lengthwise between an inlet channel (6) for feeding polymer material to the annular processing channel (5), and an outlet channel (7) for expelling the polymer material from the annular processing channel (5); and a feed device (8) located inside the inlet channel (6) and designed to pre-treat the solid polymer material and to release the solid polymer material directly onto the outer face (9) of the rotor (3) inside the annular processing channel (5).

Description

MACHINE FOR CONTINUOUSLY PROCESSING POLYMER MATERIAL

TECHNICAL FIELD

The present invention concerns a polymer material continuous processing machine.

In particular, the present invention concerns a machine comprising a stator and a rotor which rotates about an axis of rotation and is coupled to the rotor, and an annular processing channel between the stator and the rotor for processing the polymer materials.

BACKGROUND ART

The patents US 5,200,204 (Douglas J. Horton) , US 4,012,477 (Beck), US 4, 813, 863 (Granville J. Hahn) , US 4, 501, 543 (Rutledge) , US 3,880,564 (Beck) show a type of machine comprising a cylindrical rotor, a stator having a seat for the rotor, and an annular processing channel formed due to the fact that the seat of the stator has a larger diameter than the diameter of the rotor, which is mounted in a rotating manner about an axis of rotation eccentric with respect to the seat or the seat has an elliptical shape.

Another type of machine for processing polymer materials is shown in the documents US 4, 194, 841 (Z. Tadmor) , US 4, 606, 646 (S. Metha) and WO2008071782 (G. Ponzielli) .

A drawback of the machines of known type consists in the difficulty of subjecting the solid polymer material, usually fed in the form of granules or flakes, to an effective cutting action in the annular channel. In fact, the solid polymer material tends to roll or slide in the annular processing channel, determining a reduction in the friction, which is the physical phenomenon that causes the melting. DISCLOSURE OF INVENTION

The object of the present invention is to produce a machine of the type identified above which is free from, or at least mitigates, the drawbacks of the known art.

According to the present invention, a machine is provided for continuous processing of polymer materials, the machine comprising a rotor which rotates about an axis of rotation; a stator sealed in sliding manner to the rotor; at least one annular processing channel, which extends heightwise between the rotor and the stator and lengthwise between an inlet channel for feeding the polymer material to the annular processing channel and an outlet channel for expelling the polymer material from the annular processing channel; and a feed device, which is located in the inlet channel, and is designed to compact the solid polymer material and release the compacted polymer material directly onto the outer face of the rotor inside the annular processing channel. By means of the present invention, the polymer material is forced into contact with the outer face of the rotor after being subjected to a compacting pre-treatment , thus rendering the cutting actions applied to the compacted polymer material more effective.

In particular, the feed device comprises a grooved roller tangent to the outer face of the rotor and designed to rotate and grip the solid polymer material against the outer face of the rotor.

In this way, the grooved roller receives in its grooves the polymer material and releases it onto the rotor.

In particular, the feed device comprises a scraper arranged contacting the grooved roller to detach the polymer material from the grooved roller. The scraper has a profile designed to engage the grooves of the grooved roller.

In this way, the polymer material is not circulated in the feed device but completely transferred to the rotor.

In particular, the feed device comprises a roller tangent to the grooved roller and designed to load and compact the solid polymer material in the grooves of the grooved roller. In particular, the feed device comprises a hopper partly defined by the grooved roller and by the roller.

In this way, the polymer material is fed between the grooved roller and the roller.

In particular, the feed device comprises a supporting structure which supports the grooved roller and the roller and defines, partly, the hopper. In particular, the polymer material continuous processing machine comprises a heating device designed to heat the feed device .

The compacting of the polymer material is facilitated by the heating.

According to one embodiment of the present invention, the polymer material continuous processing machine comprises a suction device for aspirating the vapours generated by the polymer material in the feed device.

The elimination of the vapours allows more effective compacting of the polymer material. BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will become clear from the following description of a non-limiting embodiment example, with reference to the figures of the accompanying drawings, in which:

- Figure 1 is a cross section view, with parts removed for clarity, of a polymer material continuous processing machine produced according to the present invention;

- Figure 2 is a perspective view, on an enlarged scale and with parts removed for clarity, of a detail of the machine of figure 1;

- Figure 3 is a perspective view, with parts in section and parts removed for clarity, of a detail of figure 2; and

- Figure 4 is a perspective view, with parts in section and parts removed for clarity, of two components of the detail of figure 3.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the figure, 1 indicates as a whole a polymer material continuous processing machine. For the purposes of the present description, by the term processing we mean melting the polymer material, and if necessary degassing the latter, infiltrating the polymer material between aggregated or agglomerated particles and/or fibres, dispersing the particles and/or fibres in the polymer material and dispersing one or more liquids in one or more different liquids. By the term polymer material we mean both thermoplastic polymer materials, for example the polyolefins LDPE, LLDPE, HDPE, PP etc., polystyrene, ABS, polyamide 6, 66, 11, 12 etc., Polyethylene Terephthalate , PBT, PEEK, PS, and thermosetting polymer materials such as phenolic resins, urea, melamine, epoxy resins, rubber and polyurethanes , in both liquid and solid form, according to the process requirements. The machine 1 comprises a frame 2; a rotor 3 mounted on the frame 2 in a rotating manner about an axis of rotation Al; and a stator 4 sealed in a sliding manner to the rotor 3; an annular processing channel 5 which extends by an angle of less than 360° between the rotor 3 and the stator 4; an inlet channel 6 for feeding the polymer material to the annular processing channel 5; an outlet channel 7 for expelling the polymer material from the annular processing channel 5; and a feed device 8, which is located in the inlet channel 6 and is designed to perform a pre-treatment of the solid polymer material and release the latter directly onto the rotor 3 in the annular processing channel 5.

With reference to figure 2, the rotor 3 has a cylindrical outer face 9 (with circular base) and comprising a smooth central portion, i.e. substantially without grooves or recesses and two lateral portions provided with helical grooves .

In the case illustrated in figure 1, the stator 4 is defined by a tubular element 10, which is housed in the frame 2 and has a housing seat for the rotor 3 defined by a cylindrical inner face 11 (cylinder with circular base) .

The outer face 9 of the rotor 3 and the inner face 11 of the tubular element 10 are concentric and facing each other and have respective radiuses of curvature such that the play between the rotor 3 and the stator 4 is minimised in the ambit of the tolerances that allow easy rotation of the rotor 3 with respect to the stator 4.

In the tubular element 10 a recess 12 is obtained, which extends in a circumferential direction along the face 11 by an angle of less than 360° between the inlet channel 6 and the outlet channel 7 and defines, together with the rotor 3, in particular the smooth central portion of the outer face 9 of the same, the annular processing channel 5. The recess 12 has a bottom face 13 and two lateral faces 14, only one of which is illustrated in figure 1. The distance measured in a radial direction between the outer face 9 of the rotor 3 and the bottom face 13 of the recess 12 corresponds to the height H, measured in a radial direction, of the annular processing channel 5 which, in the case illustrated, decreases progressively between the inlet channel 6 and the outlet channel 7. The width of the annular processing channel 5, i.e. the distance between the lateral walls 1, is constant.

The inlet channel 6 extends into the frame 2 and into the tubular element 10. The feed device 8 comprises a supporting structure 15 housed in the inlet channel 6; a grooved roller 16 and a roller 17; and a hopper 18 located above the grooved roller 16 and the roller 17. The hopper 18 is defined partly by the grooved roller 16 and the roller 17 and partly by the supporting structure 15. The grooved roller 16 is supported by the supporting structure 15 in a rotating manner about an axis of rotation A2, parallel to the axis of rotation Al, and is arranged substantially tangentially to the rotor 3 and at twelve o'clock relative to said rotor 3.

The roller 17 is supported by the supporting structure 15 in a rotating manner about an axis of rotation A3, parallel to the axes of rotation Al and A2, and is arranged substantially tangent to the grooved roller 16 at eleven o'clock relative to the grooved roller 16. The supporting structure 15 defines two seats 19 and 20 designed to provide precision housing for the grooved roller 16 and the roller 17 respectively with the exception of the area in which the hopper 18 converges. The supporting structure 15 comprises a main body 21; a sector 22; an insert 23; and a scraper 24, which are designed to provide form couplings between one another. The machine 1 comprises a suction device 25, which has the function of aspirating vapours from the polymer material in the inlet channel 6. The polymer material is heated along the inlet channel 6 and produces steam. The suction device 25 comprises a suction channel 26 which flows into the inlet channel 6 in an area between the roller 16, the roller 17, the sector 22 and the insert 23. With reference to figures 3 and 4, the scraper 24 has the function of detaching the polymer material from the roller 16 so that the roller 16 transfers all the polymer material to the rotor 3, which feeds the polymer material into the annular processing channel 5 (figure 1) .

The machine 1 comprises a heating device 27, which comprises heaters 28, sensors 29 and a control unit 30 to modulate the heat supplied according to the signals emitted by the sensors 29. In the case illustrated, the heaters 28 and the sensors 29 are housed in the frame 2, in the rotor 3 and in the supporting structure 15 of the feed device 8 so as to transfer heat to the polymer material both in the inlet channel 6 and in the annular processing channel 5. The machine 1 comprises a supplementary inlet channel 31 for feeding liquid polymer material into the annular processing channel 5 for the purpose of mixing the liquid polymer material with the solid polymer material fed by means of the feed device 8 or infiltrating the liquid polymer material with solid aggregates or agglomerates fed through said feed device 8. In this case the feed device 8 would be used as a doser.

In use, the rotor 3 is rotated clockwise in figure 1 by an actuator not illustrated in the attached figures and so as to feed the polymer material along the annular processing channel 5 between the inlet channel 6 and the outlet channel 7. The rollers 16 and 17 are fed anticlockwise and clockwise respectively by respective actuators not illustrated in the attached figures so as to ideally engage with each other and grip the polymer material in contact with the grooved roller 16 and the roller 17.

The solid polymer material in the form of flakes or granules is loaded in the hopper 18 in which it is heated and is in practice withdrawn by the combined action of the rollers 16 and 17. In fact, the polymer material is loaded into the grooves of the roller 16 with the contribution of the roller 16 and discharged onto the outer face 9 of the rotor 3 by means of the scraper 24. The vapours which are produced by the heating of the polymer material are aspirated by the suction device 25 and expelled from the machine 1.

The polymer material deposited on the rotor 3 is fed along the annular processing channel 5 which progressively decreases in height H, determining a pressure increase in the polymer material, melting of the latter, and a pumping effect on the polymer material, when it is in liquid form. The molten polymer material is then expelled in a liquid state through the outlet channel 7.

The feed device 8 performs pre-treatment of the polymer material which consists in compacting the polymer material in the grooves of the grooved roller 16. If necessary, to facilitate the compaction, the material is pre-heated in the feed device 8. The pre-heating causes the evaporation of any liquids present in the polymer material. Consequently, it is advisable to expel also the steam generated by means of the suction device 25.

Lastly, it is evident that variations to the embodiments of the present invention described can be made without departing from the protective scope of the attached claims.

For example the machine can comprise a suction channel with converging diverging sections, a plurality of parallel annular processing channels or a plurality of suction channels.

Claims

1) A machine for continuously processing polymer material, the machine comprising a rotor (3) which rotates about an axis of rotation (Al) ; a stator (4) sealed in sliding manner to the rotor (3) ; at least one annular processing channel (5) which extends heightwise (H) between the rotor (3) and the stator (4), and lengthwise between an inlet channel (6) for feeding polymer material to the annular processing channel (5), and an outlet channel (7) for expelling the polymer material from the annular processing channel (5); and a feed device (8) located inside the inlet channel (6) and designed to pre-treat the solid polymer material and to release the solid polymer material directly onto the outer face (9) of the rotor (3) inside the annular processing channel (5) .

2) A machine as claimed in Claim 1, wherein the feed device (8) comprises a grooved roller (16) tangent to the outer face (9) of the rotor (3) and designed to rotate and grip the solid polymer material against the outer face (9) of the rotor (3) .

3) A machine as claimed in Claim 2, wherein the feed device (8) comprises a scraper (24) positioned contacting the grooved roller (16) to scrape the polymer material off the grooved roller (16) .

4) A machine as claimed in Claim 3, wherein the scraper (24) has a profile designed to engage the grooves on the grooved roller.

5) A machine as claimed in one of Claims 2 to 4, wherein the feed device (8) comprises a roller (17) tangent to the grooved roller (16) and designed to load and compact the solid polymer material inside the grooves on the grooved roller (16) .

6) A machine as claimed in Claim 5, wherein the feed device (8) comprises a hopper (18) defined partly by the grooved roller (16) and the roller (17) .

7) A machine as claimed in Claim 6, wherein the feed device (8) comprises a supporting structure (15) which supports the grooved roller (16) and the roller (17), and partly defines the hopper (18) .

8) A machine as claimed in any one of the foregoing Claims, and comprising a heating device (27) for heating the feed device (8) .

9) A machine as claimed in any one of the foregoing Claims, and comprising a suction device (25) for aspirating the vapours generated by the polymer material in the feed device (8) .

10) A machine as claimed in any one of the foregoing Claims, wherein the annular processing channel (5) extends in an annular direction perpendicular to the axis of rotation (Al) .

11) A machine as claimed in any one of the foregoing

Claims, wherein the outer face (9) of the rotor (3) is cylindrical and substantially smooth. 12) A machine as claimed in any one of the foregoing Claims, wherein the stator (3) comprises a tubular member (10) surrounding and contacting the rotor (3) in sliding manner; the tubular member (10) having a recess (12) designed to define the annular processing channel (5) together with the outer face of the rotor (3) .

13) A machine as claimed in any one of the foregoing Claims, and comprising a supplementary inlet channel (31) for feeding liquid polymer material to the annular processing channel (5) .