WO2020120873A1

WO2020120873A1 - System for butt-joining rubber strips to supply an extruder

Info

Publication number: WO2020120873A1
Application number: PCT/FR2019/052883
Authority: WO
Inventors: Eddy Ferjoux; Nicolas LECHEVALIER; Gilles MIOCHE
Original assignee: Compagnie Generale Des Etablissements Michelin
Priority date: 2018-12-14
Filing date: 2019-12-02
Publication date: 2020-06-18

Abstract

The invention relates to a system (10) for butt-joining two or more rubber strips (B1, B2) selected according to a predetermined rubber mixing recipe to supply at least one extruder with a strip complexed with rubbery material (B 12) from the butt-joined rubber strips. The system includes at least one conveyor which transports the rubber strips from an inlet (12) of the system to an outlet (14) of the butt-joining system; a frame (18) which operationally supports the conveyor to allow the continuous transport of the rubber strips as well as the simultaneous butt-joining of the rubber strips supplied to the system; and a roller system (20) which performs the butt-joining of the rubber strips without a drill. The invention also relates to a method for butt-joining the rubber strips produced by the system of the invention.

Description

Title: Joining system of rubber bands to feed an extruder Technical Area

The invention relates to a feeding system which feeds an extruder from several rubber bands. More particularly, the invention relates to a feed system for an extruder which continuously gum butts avoiding the feed holes.

Prior art

In the manufacture of tires, it is required that the tire has various performance (e.g. reduced rolling resistance, better wear resistance, comparable grip in wet and dry conditions, estimated mileage, etc.). Tires are therefore composed of different types of rubber mixtures having properties essential to the functioning of the tire itself. To ensure that a marketable tire exhibits expected performance, a rubber blend can be selected from a variety of rubber blends, each having different ingredients mixed in different amounts and derived from a variety of production sequences.

Rubber blends are often delivered to extruders in the form of zig zag or wig-wag strips. Two or more different rubber blends are often manually introduced into a feed portion of an extruder (as used herein, the term "extruder" refers to a variety of known extruders, including, without limitation screw extruders , torpedo extruders and other equivalent extruders). The optimal functioning of the extruders depends on the continuity of the composition of the rubbery material and on the continuity of the feeding operation to which the composition is subjected. An example of an automated system for feeding extruders is disclosed by US Patent 9,919,468.

Although multiple types of rubber mixtures are envisaged in the tire production processes, there is an optimized layout of the equipment which makes it possible to feed extruders in an automated manner. The need for a uniform supply must be respected while keeping the operation essentially automatic and without degrading the homogeneity of the resulting rubber bands. In addition, the possibility of creating rubber loops (and therefore creating a buffer stock) makes it possible to join the products without prolonged stop of the conveyors. So the invention disclosed discloses a system which performs the assembly, in a controlled and uniform manner, of two or more rubber bands without perforation thereof.

Summary of the invention

The invention relates to a system for joining two or more rubber bands selected according to a predetermined rubber mixing recipe for feeding at least one extruder with a complexed band of rubbery material from the butted rubber bands. The system comprises at least one conveyor which carries out the transport of the rubber bands from an inlet of the system to an outlet of the abutment system, and a frame which supports the conveyor operatively to allow the continuous transport of the rubber bands and to also allow the simultaneous joining of the rubber bands fed to the system. The system also comprises a roller system which performs the joining of the rubber bands without drilling, the roller system comprising at least one upper roller and one lower roller, each roller with a center through which an axis of rotation of the roller s 'and extends each roller with a cylindrical body of predetermined diameter which extends perpendicularly and which rotates about its axis of rotation relative to the frame which supports the roller system, the two rollers being arranged so that the two axes of rotations remain in the same plane with the axes parallel to each other, and the upper roller with a toothed surface along which a contact length is established between a first supplied rubber band and the toothed surface when the first rubber band passes through the roller system, the toothed surface comprising several consecutive teeth arranged along a common axis defined with respect to two opposite ends of the cylindrical body of the upper roller.

In some embodiments of the system, the lower roller includes a smoothed surface along which a contact length is established between a second supplied rubber strip and the smoothed surface when the second rubber strip is passed through the delivery system. rollers, the smoothed surface comprising a circumferential surface which has a bearing surface between two opposite ends of the cylindrical body of the lower roller.

In some embodiments of the system, the lower roller includes a complementary toothed surface along which a contact length is established between the second fed rubber band and the toothed surface of the lower roller when the second rubber band is passed through. through the roller system, the complementary toothed surface comprising several consecutive teeth arranged along a common axis defined with respect to the opposite ends of the cylindrical body of the lower roller in a complementary manner with respect to the teeth of the upper roller.

In some embodiments of the system, the two rollers maintain an adjustable spacing between the toothed surface of the upper roller and a surface of the lower roller. In certain embodiments of the system, the conveyor comprises an entry mat which carries out the entry of the rubber bands at the entry of the system and an exit mat which carries out the transport of the butted rubber bands from the exit of the system to one or more installations downstream of the system.

In some embodiments of the system, the system further includes a power inlet to which the rubber bands are supplied to the system relative to the frame which supports 1 power inlet.

The invention also relates to a method for joining rubber bands produced by the disclosed system. The process comprising the following steps:

the step of providing at least a first rubber band and a second rubber band, each rubber band with the material properties chosen according to a selected rubber mixture recipe;

the step of rotating the upper and lower rollers in opposite directions; the stage of starting the conveyor;

the step of feeding the two rubber bands on the conveyor at the entrance to the system;

the step of joining the two rubber bands to form the complexed band, this step comprising the step of simultaneously passing the two rubber bands between the upper roller and the lower roller so as to maintain uniform contact between a surface opposite of the first rubber band and an opposite surface of the second rubber band without drilling from each other; and

the step of removing the complexed strip from the roller system.

In some embodiments of the method, the joining step comprises joining the end of the first rubber band with the start of the second rubber band without interrupting the conveyor and so that a junction is made between the end of the first rubber band and the start of the second rubber band does not pierce either the first rubber band or the second rubber band.

In some embodiments of the method, the method further includes the step of adjusting a spacing between the upper roller and the lower roller.

In some embodiments of the method, the method further comprises the step of detection of a thickness of the complexed strip leaving the roller system.

Other aspects of the invention will become apparent from the following detailed description.

Brief description of the drawings

The nature and the various advantages of the invention will become more evident on reading the detailed description which follows, together with the appended drawings, in which the same reference numbers designate identical parts everywhere, and in which:

FIG. 1 represents a perspective view of a system for joining the rubber bands of the invention.

FIG. 2 represents a perspective view of an embodiment of a roller system of the abutment system of FIG. 1.

FIG. 3 represents a side view of the roller system of FIG. 2.

Figure 3 A shows a cross-sectional view of the roller assembly of Figure 3 along line A- A.

FIG. 4 represents a schematic view of the roller system of FIGS. 2 to 3A during a cycle of a process for joining the rubber bands.

FIG. 5 represents a perspective view of another embodiment of the roller system of the butting system of FIG. 1.

FIG. 6 represents a top view of the roller system of FIG. 5.

Figure 6 A shows a cross-sectional view of the roller assembly of Figure 3 along the line A’-A ’.

FIG. 7 represents a schematic view of the roller system of FIGS. 5 to 6A during a cycle of a process for joining the rubber bands.

Figures 8, 8 A and 8B show cross-sectional views of the butted rubber bands.

Figure 8C shows a cross-sectional view of a tooth representative of a roller of the roller system.

detailed description

Referring now to the figures, in which the same numbers identify identical elements, FIG. 1 represents an embodiment of a butting system (or "system") 10 which feeds at least one extruder (not shown) with two or more strips of rubber material. The extruder can be chosen from known screw extruders which are found commercially. The system 10 may include an installation of a tire production system. The bands are made of different rubber materials according to a predetermined rubber mixing recipe. Each rubber band can be made from a known rubber composition, including a diene rubber, that is to say from any elastomer derived at least in part from diene monomer. This diene elastomer can be selected from polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), butadiene copolymers, isoprene copolymers and mixtures of these elastomers, such copolymers being chosen from butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR), and isoprene-butadiene-styrene copolymers (SBIR).

A rubber composition selected for a rubber band may contain one or more diene elastomers as well as one or more additives commonly used in rubber dies for the manufacture of tires. Such fillers include, without limitation, carbon black, silica, coupling agents, antiaging agents, antioxidants, plasticizers, extension oils, plasticizing resins having a high glass transition temperature (greater than 30 ° C), agents improving the treatment capacity of unprocessed compositions, tackifying resins, anti-reversion agents, methylene acceptors and donors, reinforcing resins, known adhesion promoter systems of the metal salt type and a crosslinking or vulcanization system. By preparing a mixture of two or more rubber bands, a person skilled in the art knows how to adjust the formulation of the rubber composition so as to derive the properties desired for a specific tire. Each rubber strip is created in the form of a continuous element of profiled product (i.e. a generally elongated rubber element of predetermined width and thickness, which is intended for use in tires and tires. tire products such as interior linings, sidewalls, carcasses, treads, etc.). The rubber bands are supplied on one or more known pallets (not shown) and / or supplied to the system 10 by one or more manual or automated means (for example, one or more robot effectors) (not shown).

The system 10 comprises at least one conveyor which carries out the rubber bands from an inlet 12 of the system to an outlet 14 of the system. By way of example, a representative conveyor is provided which includes an inlet belt 12a which carries out the entry of the rubber bands into the system 10 and an outlet belt 14a which carries out the transport of the butted rubber bands from the system to a or several downstream installations (for example, one or more extruders and / or other mixers). Entrance carpet 12a and carpet outlet 14a may comprise a single belt or several belts in continuous movement by known rollers 16. It is understood that other equivalent conveyors can be used (for example, one or more belt or roller conveyors or their known equivalents).

Referring again to FIG. 1, a frame 18 supports the belts 12a, 14a in an operational manner to allow the continuous transport of the rubber bands and to also allow the simultaneous joining of the rubber bands fed to the system 10. Together with the belts 12a, 14a, the frame 18 supports a system of rollers 20 which carries out the joining of the selected rubber bands. The frame 18 can also support an optional feed inlet 50 to which the rubber bands are supplied to the system 10. In the embodiments of the system comprising the feed inlet 22, the rubber bands are guided towards the roller system 20 by the input belt 12a.

Referring still to Figure 1, and further to Figures 2 to 4, in one embodiment of the invention, the roller system 20 includes an upper roller 22 and a lower roller 24. It is understood that roller system with rollers 22, 24 is given by way of example and that the roller system 20 is adaptable for use in existing finger jointing systems.

The upper roller 22 comprises a cylindrical body 22a of predetermined diameter which is chosen according to the properties of the rubber bands (including, without limitation, their thicknesses and their material properties). The upper roller 22 has a toothed surface 22b along which a contact length is established between a supplied rubber band and the toothed surface when the rubber band passes through the roller system 20. The toothed surface 22b comprises several teeth 22b 'fixed between two opposite ends 22a' and 22a ”of the cylindrical body 22a. The teeth 22b ’are consecutively arranged along a common axis defined with respect to the opposite ends 22a’, 22a ”. The contact length of the toothed surface 22b can be adjusted according to a width of the rubber band. This configuration can take the form of a chain sprocket which has the advantage of making indentations in a surface of a rubber band without tearing off the rubber band.

The lower roller 24 comprises a cylindrical body 24b of predetermined diameter which is chosen according to the properties of the rubber bands (including, without limitation, their thicknesses and their material properties). The lower roller 24 has a smoothed surface 24b along which a contact length is established between a rubber band fed and the surface smoothed when the rubber band passes through the roller system 20. The smoothed surface 24b comprises a circumferential surface which has a bearing surface between two opposite ends 24a 'and 24a ”of the cylindrical body 24a.

The contact length of the smoothed surface 24b can be adjusted according to a width of the rubber band. The contact length of the smoothed surface 24b can also be adjusted as a function of the contact length of the toothed surface 22b of the upper roller 22. Each roller 22, 24 has a center through which an axis of rotation of the roller. Each roller 22, 24 extends perpendicularly and rotates about its axis of rotation relative to the frame 18 which supports the system of rollers 20. The rollers 22, 24 are arranged so that the two axes of rotation remain in the same plane with axes parallel to each other. The placement of the rollers 22, 24 relative to the frame 18 is adjustable according to the properties of the rubber plies to be butted.

The upper roller 22 and the lower roller 24 maintain a predetermined spacing E20 between the toothed surface 22b of the upper roller 22 and the smoothed surface 24b of the lower roller 24. This spacing can be adjusted according to the material properties and the thicknesses of the rubber bands. to abut during a cycle of a method of joining the system 10. An adjustment device 30 is represented in FIG. 1 which comprises a known means for making this adjustment of the spacing (for example, by means of a linear actuation, which can be performed by a cylinder-piston unit or by another known actuator).

During a process of joining the rubber bands carried out by the system 10, one or more drive motors (represented in FIG. 1 by the motor 40) rotate the two rollers 22, 24 in opposite directions (the direction of rotation of each roller being indicated by the arrows A in FIG. 4). Each roller 22, 24 can be driven by a corresponding programmable drive motor which controls a speed of rotation for each roller (which can be, for example, a speed of a moving rubber band). Alternatively, a common drive system (for example, a gear or belt or the like) can control the rotation of the two rollers. During a jointing cycle of the rubber bands, the respective speed of each roller guarantees the generally constant thickness of a butted rubber band leaving the roller system 20, while facilitating alignment and adhesion rubber bands fed to system 10.

With further reference to FIGS. 1 to 4, and particularly to FIG. 4, an example of a cycle of a joining process of the invention is described using the system 10 with the rollers 22, 24. By initiating a cycle of the process of joining the rubber bands, the joining process comprises a step of supplying at least a first rubber band B1 and a second rubber band B2. It is understood that the two bands B1, B2 are used by way of example and that two or more rubber bands can be introduced into the system 10 during this step. The properties of the two rubber bands B1, B2 are different and they are chosen according to a selected rubber mixture recipe. It is understood that the rubber bands can be supplied on corresponding pallets (or by other equivalent means) which identify the material properties of each rubber band (for example, by RFID code, by bar code, by auto means -learning and / or by other known equivalent means). The joining process also comprises a step of rotating the rollers 22, 24 (see the arrows in FIG. 4). This step may include the implementation step

routing of the entry conveyor 12a and / or the exit conveyor 14a. In all the embodiments of the system 10, the speed of rotation of each roller can be variable during the cycle.

The joining process also comprises a step of feeding the two rubber bands B1, B2 onto the entry belt 12a already in transit (see arrow B in FIG. 1). In the embodiments of the system 10 comprising a feed inlet 50, the feed inlet allows the introduction of the rubber bands on the entry belt 12a to the roller system 20. The first rubber band Bl includes a bearing surface B la which will be introduced into the roller system 20 so that the toothed surface 22b of the upper roller 22 engages the bearing surface B la during the process of joining the two rubber bands. The second rubber strip B2 includes a support surface B2a which will be introduced into the roller system 20 so that the smoothed surface 24b of the lower roller 24 engages the support surface B2a during the process of joining the two strips rubber. Each rubber strip Bl, B2 includes a corresponding opposite surface Blb, B2b which will be introduced into the roller system so that the two opposite surfaces face each other during this feeding step.

Each rubber strip B 1, B2 comprises a respective predetermined thickness defined between a bearing surface Bla, B2a and an opposite surface Blb, B2b corresponding to it. The joining process also comprises a step of joining the two rubber bands B1, B2. This step includes the step of simultaneously passing the two rubber bands B1, B2 towards the spacing E20 between the toothed surface 22b of the upper roller 22 and the smoothed surface 24b of the lower roller 24. During the butting step strips of rubber Bl, B2, the upper roller 22 holds the first strip of rubber B1 along a tangential contact line, with the bearing surface Bla of the first strip of rubber engaged by the teeth 22b 'without drilling the first rubber band. During the step of joining the rubber bands Bl, B2, the lower roller 24 maintains the second rubber band B2 along a tangential contact line, with the bearing surface B2a of the second rubber band. rubber engaged by the smoothed surface 24b. During the step of joining the rubber bands Bl, B2, the opposite surfaces Blb, B2b of the two respective rubber bands are maintained along a contact line so that the two rubber bands can engage along opposite surfaces without drilling from each other.

During the joining step, the system 10 performs, without interrupting the conveyor, joining the end of the first rubber strip Bl with the start of the second rubber strip B2. It is understood that the joining can be carried out for the rubber bands of a common pallet and / or for the rubber bands of successive pallets. A junction made between the end of a first rubber band and the start of a second rubber band does not pierce either the first band or the second band. Thus the butt joint obtained allows the use of a long length of rubber band (for example, two or more pallets) in a downstream process without operator intervention.

The rubber bands now butted together form a complexed band B 12 which includes all the material properties of the two rubber bands. During the joining step, each roller 22, 24 is rotated so as to maintain uniform contact between the opposite surface Blb of the first rubber strip Bl and the opposite surface B2b of the second rubber strip B2. Thus, the pressure is applied uniformly in a controllable manner to eliminate unwanted holes in the complexed strip B12.

The bonding process further comprises a step of removing the complexed strip from the roller system 20. Once the rubber bands Bl, B2 are assembled and abutted as complexed product, the roller system 20 directs the strip complexed B 12 to the output belt 14a (already in transit) for treatment at a downstream installation which performs a mixing step (for example, a mixing installation comprising at least one extruder) (see arrow C in FIG. 1 ).

Referring to Figures 5 to 7, where the same numbers identify the same elements, another embodiment of the roller system 20 is shown which is usable in the system 10 of Figure 1. In this embodiment, the roller system 20 includes an upper roller 22 as described above. The roller system 20 also comprises a lower roller 24 'which has a complementary toothed surface 24b' along which a contact length is established between a fed rubber band and the toothed surface of the lower roller during the passage of the band of rubber through the roller system 20. The complementary toothed surface 24b 'of the lower roller 24b' comprises several teeth 24b ”fixed between two opposite ends 24V, 24'a” of a cylindrical body. The teeth 24b ”are consecutively arranged along a common axis defined with respect to the opposite ends 24'a ', 24'a” in a complementary manner with respect to the teeth 22b' of the upper roller 22. This configuration of the lower roller can take a shape of a chain sprocket as described above with respect to the upper roller 22.

Referring to FIG. 7, a cycle of a joining process using this embodiment of the invention is carried out in the same way as described above with respect to the embodiment of FIGS. 2 to 4 (the directions of rotation of the two rollers 22, 24 'are indicated by the arrows D in FIG. 7). Each bearing surface B 1a, B2a of a respective rubber band B1, B2 is engaged by a respective toothed surface 22b, 24b ’to form the complexed band B12. The pressure is still applied uniformly in a controllable manner to eliminate unwanted holes in the complexed strip B 12.

In all of the embodiments of the abutment method of the invention, the abutment method may further comprise a step of adjusting the spacing E20 (either between the toothed surface 22b of the upper roller 22 and the smoothed surface 24b of the lower roller 24, ie between the toothed surface 22b of the upper roller 22 and the complementary toothed surface 24b 'of the lower roller 24'). During this step, the spacing between the rollers can be variable during the cycle of a butting process.

Referring to Figures 8, 8A and 8B, each series of teeth 22b ', 24b ”may have a predetermined cross-section geometry. In the illustrated embodiments shown, complexed bands of various geometries are produced from the rubber bands butted by the system 10. Such selected geometries include a V-shaped configuration (see FIG. 8), a shaped configuration of U (see Figure 8A) and an arched configuration (see Figure 8B). It is understood, however, that other geometries could be substituted for it. In one embodiment of the invention, a tooth is deleted locally regardless of the geometry selected (see FIG. 8C by way of example). The removal of a tooth allows a rubber band to pass without gumming without stopping the process in progress. The system 10 can also include at least one sensor (not shown) which performs a step of detecting a thickness of the complexed strip B 12 leaving the roller system and of determining a detected value of the thickness relative to a reference thickness of the thickness (for example, by determining compliance with one or more specifications for the complexed strip B12). The sensor can be placed just upstream of the rollers of the roller system 20 so as to detect the thickness of each rubber band entering the roller system. The sensor can therefore indicate whether an adjustment of the spacing E20 is necessary to ensure a complexed strip thickness

generally constant before feeding the complexed strip to an extruder (or other installation) downstream.

The system 10 can be one of several systems which together form at least part of a tire production system, one or more of which can be controlled by one or more programmable control units. A cycle of an abutting process of the invention can be done by PLC control and can include pre-programming of management information. For example, a profile can be associated with the complexed strip which is provided by the system 10, including the material properties of the complexed strip leaving the system.

For all achievements, a monitoring system could be put in place. At least part of the monitoring system can be provided in a portable device such as a mobile network device (for example, a mobile phone, a laptop, one or more portable devices connected to the network (including "reality" devices augmented "and / or" virtual reality ", portable clothing connected to the network and / or any combination and / or all equivalent).

In embodiments of the invention, the system 10 can receive voice commands or other audio data representing, for example, an approach or a stop of rotation of the rollers of the roller system 20. The request can include a request for the current state of a butting process cycle. A generated response can be represented audibly, visually, tactile (for example, using a haptic interface) and / or virtual or augmented.

In one embodiment, the method may include a step of training the system 10 (or training a system which incorporates the system 10) to recognize values representative of a complexed strip leaving the system 10 (by example, of a thickness value) and to make a comparison with targeted values. This step may include the step of training the system to recognize non-equivalence between the compared values. Each stage of training includes a classification generated by means of self-learning. This classification can include, without limitation, the parameters of the materials of the rubber bands selected according to the chosen mixing recipe. The invention preserves optimum productivity while retaining the various properties of rubber. At the same time, the invention avoids the holes associated with existing solutions. Thus, a single system is provided which is adaptable to process a variety of mixtures without changing equipment in a tire production system The terms "at least one" and "one or more" are used to way

interchangeable. The ranges that are presented as "between a and b" include the values "a" and "b".

Although particular embodiments of the disclosed apparatus have been illustrated and described, it will be understood that various changes, additions and modifications can be made without departing from the spirit or scope of this disclosure. Therefore, no limitation should be imposed on the scope of the invention described with the exception of those set out in the appended claims.

Claims

1. System (10) for joining two or more rubber bands (B1, B2) selected according to a predetermined rubber mixing recipe to supply at least one extruder with a complexed band of material

rubbery (B 12) from butted rubber bands, in which the system comprises:

at least one conveyor which carries out the rubber bands from an inlet (12) of the system to an outlet (14) of the abutment system;

a frame (18) which supports the conveyor in an operational manner to allow the continuous transport of the rubber bands and to also allow the simultaneous joining of the rubber bands fed to the system; and

a roller system (20) which joins the rubber bands without drilling, the roller system comprising at least one upper roller (22) and one lower roller (24, 24 '), each roller with a center through which an axis of rotation of the roller extends and each roller with a cylindrical body of predetermined diameter which extends perpendicularly and which rotates about its axis of rotation relative to the frame (18) which supports the system of rollers ( 20), the two rollers (22, 24) being arranged so that the two axes of rotation remain in the same plane with the axes parallel to each other, and the upper roller (22) with a surface toothed (22b) along which a contact length is established between a first supplied rubber strip (Bl) and the toothed surface when the first rubber strip (Bl) passes through the roller system (20), the toothed surface (22b) comprising several teeth (22b ') consecutively arranged along a common axis defined with respect to two opposite ends (22a ’, 22a”) of the cylindrical body (22a) of the upper roller.

2. The system (10) of claim 1, wherein the lower roller (24) comprises a smoothed surface (24b) along which a contact length is established between a second fed rubber strip (B2) and the smoothed surface when the second rubber band passes through the roller system (20), the smoothed surface 24b comprising a circumferential surface which has a bearing surface between two opposite ends (24a ', 24a ”) of the cylindrical body (24a ) from the lower roller.

3. The system (10) of claim 1, wherein the lower roller (24 ') comprises a complementary toothed surface (24b') along which a length contact is established between the second supplied rubber band (B2) and the toothed surface of the lower roller when the second rubber band passes through the roller system (20), the complementary toothed surface (24b ') comprising several teeth (24b ”) consecutively arranged along a common axis defined with respect to the opposite ends (24 V, 24'a”) of the cylindrical body of the lower roller (24 ') in a complementary manner with respect to the teeth (22b') of the upper roller (22).

4. System (10) of any one of claims 1 to 3, wherein the two rollers maintaining an adjustable distance (E20) between the toothed surface (22b) of the upper roller (22) and a surface (24b, 24b ' ) from the lower roller (24, 24 ').

5. System (10) of any one of claims 1 to 4, in which the conveyor comprises an entry mat (12a) which carries out the entry of the rubber bands at the entry (12) of the system and a outlet belt (14a) which carries out the abutting rubber bands from the outlet (14) of the system to one or more installations downstream of the system.

The system (10) of any of claims 1 to 5, further comprising a feed inlet (50) to which the rubber bands are supplied to the system relative to the frame (18) which supports the inlet supply (50).

7. A method of joining rubber bands produced by a system (10) of any one of claims 1 to 6, the method comprising the following steps:

the step of providing at least a first rubber strip (B1) and a second rubber strip (B2), each rubber strip with the material properties chosen according to a selected rubber mixture recipe; the step of rotating the upper and lower rollers in opposite directions;

the stage of the conveyor routing;

the step of feeding the two rubber bands (B1, B2) on the conveyor at the inlet (12) of the system (10);

the step of joining the two rubber bands (B1, B2) to form the complexed band (B12), this step comprising the step of the simultaneous passage of the two rubber bands (Bl, B2) between the upper roller and the lower roller so as to maintain uniform contact between an opposite surface (Blb) of the first rubber strip (Bl) and an opposite surface (B2b) of the second rubber band (B2) without drilling from one another; and

the step of removing the complexed strip from the roller system (20).

8. The method of claim 7, wherein the joining step comprises joining the end of the first rubber band (B1) with the start of the second rubber band (B2) without interrupting the conveyor and so that a junction made between the end of the first rubber band and the start of the second rubber band does not pierce either the first rubber band or the second rubber band.

9. The method of claim 7 or claim 8, further comprising the step of adjusting a spacing (E20) between the upper roller and the lower roller.

10. The method of any one of claims 7 to 9, further comprising the step of driving the system 10 to recognize values representative of a complexed strip (B12) leaving the system (10).