Apparatus for making a sheet of material comprising vegetable and/or alkaloid substances
An apparatus for making a sheet of material including vegetable and/or alkaloid substances including a roller rolling mill system including a plurality of rollers rotatable around respective rotation axes defining a rolling mill path provided with pressure lines adapted to substantially press the material so as to provide the latter with a sheet-like shape, and a scraping system configured to engage by contact the working surface of a transfer roller along a contact line so as to detach the material. Specifically, the scraping system including a closed-loop endless scraping band movable at the contact line parallel to the rotation axis of the transfer roller via an actuating assembly.
1. An apparatus for making a sheet of material comprising vegetable and/or alkaloid substances, the apparatus including:
a roller rolling mill system comprising a plurality of rollers rotatable about respective rotation axes parallel to each other,
the rollers being operatively adapted to receive the material adhering to respective working surfaces, and
the rollers being further arranged in succession one adjacent and substantially tangent to the other defining a rolling mill path having a rolling mill direction, wherein a rotation direction of a roller is opposite to the rotation direction of the adjacent roller,
along the rolling mill path being provided between two adjacent rollers respective pressure lines substantially adapted to press the material so as to provide the latter with a sheet-like shape,
a scraping system configured to engage by contact the working surface of a transfer roller of the plurality of rollers along a contact line so as to detach the material having the sheet-like shape from the transfer roller,
wherein
the scraping system comprises a closed-loop endless scraping band operatively adapted to engage the working surface of the transfer roller along the contact line by means of a scraping edge,
the endless scraping band being movable at the contact line parallel to the rotation axis of the transfer roller by means of an actuating assembly.
2. The apparatus according to claim 1 , wherein the contact line is arranged at an engagement height lower than or equal to an axis height of the rotation axis of the transfer roller.
3. The apparatus according to claim 2 , wherein the contact line is arranged so that a vertical plane on which lies the rotation axis of the transfer roller is interposed between the contact line and the ending pressure line between the transfer roller and the previous adjacent roller of the plurality of rollers.
4. The apparatus according to claim 1 , wherein the actuating assembly is configured to move the endless scraping band at the contact line at a speed less than 1.5 m/min, or at a speed of 0.01 to 0.5 m/min.
5. The apparatus according to claim 1 , wherein at the contact line the endless scraping band defines with respect to the tangent plane to the working surface of the transfer roller an engagement angle of 0.1 to 30 degrees.
6. The apparatus according to claim 1 , wherein the endless scraping band comprises a first face and a second face parallel and spaced from each other by a thickness, the first face and the second face being connected to each other by the scraping edge,
the scraping edge comprising a first edge portion and a second edge portion consecutive to each other so as to define a scraping vertex, wherein the second face defines the second edge portion,
the first edge portion and the second edge portion defining at the scraping vertex a vertex angle of 5 to 45 degrees, and
the second edge portion operatively facing towards the working surface of the transfer roller at the contact line.
7. The apparatus according to claim 1 , wherein the actuating assembly comprises at least a first pulley and a second pulley adapted to actuate the endless scraping band so that the scraping edge lies on a working plane, wherein
when the rotation direction of the transfer roller is opposite to the rotation direction of a first feeding roller distal with respect the rolling mill direction of the plurality of rollers, the working plane is parallel to a lying plane or defines with the latter an angle of 0.1 to 45 degrees, or
when the rotation direction of the transfer roller is equal to the rotation direction of the first feeding roller distal with respect the rolling mill direction of the plurality of rollers, the working plane defines with the lying plane an angle of 45 to 90 degrees.
8. The apparatus according to claim 1 , wherein the scraping system comprises a cleaning device configured to remove foreign bodies adhering to the endless scraping band and/or to the scraping edge.
9. The apparatus according to claim 1 , wherein the scraping system comprises a sharpening device configured to restore the scraping edge of the endless scraping band.
10. The apparatus according to claim 1 , wherein the scraping system comprises a support device configured to slidably receive along a direction parallel to the rotation axis of the transfer roller the endless scraping band so as to keep the latter in a contact relationship with the working surface of the transfer roller at the contact line through the scraping edge having a given pressure and/or tilt.
11. The apparatus according to claim 1 , comprising conveyor means configured to receive and move the material having the sheet-like shape when detached from the working surface of the transfer roller,
the conveyor means being adapted to receive the material at a receiving height lower than an engagement height of the contact line, wherein
the conveyor means and the transfer roller are at least partially in an overlapping relationship with each other when viewed in a plan view.