Process and plant for producing tyres

Patent metadata

Field	Value
Publication number	US-9365006-B2
Application number	US-201414243606-A
Country	US
Kind code	B2
Filing date	Apr 2, 2014
Priority date	Dec 23, 2008
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A compound plant for processing elastomeric compounds for tires with both a high quality and a high throughput includes at least one batch mixing device in combination with at least one multi-shaft continuous mixing device having a high number of shafts. For example, the multi-shaft continuous mixing device could be a ring extruder having a plurality of co-rotating screws disposed to form a ring. In operation, a first elastomeric compound is discharged from the at least one batch mixing device and processed with the at least one multi-shaft continuous mixing device to obtain a second elastomeric compound.

First claim

The invention claimed is:

1. A plant for manufacturing a tyre, comprising:
a compounding plant capable of being adapted to produce at least one crosslinkable elastomeric compound;
at least one manufacturing machine capable of being adapted for preparing a green tyre using a plurality of structural elements;
at least one device capable of being adapted for preparing at least one structural element of said plurality of structural elements, wherein said at least one structural element comprises said at least one crosslinkable elastomeric compound; and
at least one vulcanization press capable of being adapted to moulding and crosslinking said green tyre to obtain a finished tyre,
wherein the compounding plant comprises:
a mixing apparatus comprising at least one batch mixing device, said mixing apparatus capable of being adapted to produce a first elastomeric compound; and
at least one multi-shaft continuous mixing device, said multi-shaft continuous mixing device being a ring extruder and comprising an inner core, an outer housing defining with said inner core an annular chamber, and at least six rotating screws, wherein said ring extruder comprises at least one gas outlet opening provided in said outer housing, said multi-shaft continuous mixing device capable of being adapted to receive said first elastomeric compound and to produce a second elastomeric compound; and
a vacuum device configured to apply a vacuum to said at least one gas outlet opening during mixing of said first elastomeric compound in said ring extruder.

2. The plant according to claim 1 , wherein said at least one batch mixing device is selected from internal mixers and open mixers.

3. The plant according to claim 1 , wherein said at least one multi-shaft continuous mixing device comprises at least six co-rotating screws.

4. The plant according to claim 1 , wherein said at least one multi-shaft continuous mixing device comprises at least twelve rotating screws.

5. The plant according to claim 1 , wherein said rotating screws have a diameter of at least 30 mm.

6. The plant according to claim 5 , wherein said rotating screws have a diameter of at least 60 mm.

7. The plant according to claim 1 , wherein said at least six screws are at least partially intermeshed.

8. The plant according to claim 1 , wherein said mixing apparatus includes at least one open mixer.

9. The plant according to claim 1 , wherein said mixing apparatus comprises at least one internal mixer and at least one open mixer, said open mixer capable of being placed downstream of said at least one internal mixer.

10. The plant according to claim 1 , further comprising at least one conveying extruder between said mixing apparatus and said at least one multi-shaft continuous mixing device.

11. The plant according to claim 10 , wherein said at least one conveying extruder comprises:
a housing comprising at least one feed opening and a discharge opening; and
at least one conveying element rotatably mounted in said housing.

12. The plant according to claim 1 , comprising a further batch mixing device downstream of said multi-shaft continuous mixing apparatus, the further batch mixing device capable of being adapted to perform a further mixing of said second elastomeric compound.

13. The plant according to claim 1 , wherein an output of said at least one multi-shaft continuous mixing device is equipped with a roller die or with a fixed die.

14. The plant according to claim 1 , wherein an output of said at least one multi-shaft continuous mixing device is an open head.

15. The plant according to claim 1 , wherein said compounding plant comprises at least two multi-shaft continuous mixing devices.

16. The plant according to claim 1 , wherein said mixing device is configured to operate at a rotor speed of about 20 rpm to about 60 rpm.

17. The plant according to claim 1 , wherein said mixing device is configured to operate at a rotor speed of about 30 rpm to about 50 rpm.

18. The plant according to claim 1 , wherein said mixing device is configured to operate using a fill factor of the mixing chamber that is not higher than about 80%.

19. The plant according to claim 1 , wherein said mixing device is configured to operate using a fill factor of the mixing chamber from about 55% to about 70%.

20. The plant according to claim 1 , wherein said mixing device is configured to operate at a screw rotation speed of about 10 rpm to about 600 rpm.

21. The plant according to claim 1 , wherein said mixing device is configured to operate at a screw rotation speed of about 40 rpm to about 400 rpm.

22. The plant according to claim 1 , wherein said mixing device is configured to produce an average throughput of at least 500 kg/h.

Assignees

• Testi Stefano
• Bottomley Alan
• Longoni Alessio
• Pirelli

Inventors

• Testi Stefano
• Bottomley Alan
• Longoni Alessio

Classifications

• B29C48/405

  Intermeshing co-rotating screws · CPC title

• B29C48/40

  using two or more parallel screws {or at least two parallel non-intermeshing screws}, e.g. twin screw extruders · CPC title

• B29C48/43

  Ring extruders · CPC title

• B29B7/183

  having a casing closely surrounding the rotors, e.g. of Banbury type (with single shaft B29B7/125) · CPC title

• B29B7/485

  with three or more shafts provided with screws · CPC title