Roll forming machine refers to the operation of calendering raw materials by rotating rolls with a smooth or processed surface and a certain shape to obtain a certain shape product. In the food processing process, many materials need to undergo rolling operations, such as pressing in the production of biscuits, noodles in the production of confectionery, pressing and forming in the production of noodles and instant noodles.
Different products have different technological requirements for the rolling operation. In the production of biscuits, the purpose of rolling is to form a dough with uniform thickness, smooth surface, fine texture, and moderate cohesion and plasticity. In the process of candy processing, the purpose of rolling is to make the massecuite into a candy bar with a certain shape and specification and to eliminate the bubbles in the candy bar to facilitate operation, and the formed candy mass is quantitatively accurate.
During the rolling process of the roll forming machine, the inside of the material layer presents different flow states due to different pressure directions. In the initial stage of rolling in the front section of the roll work zone, due to the small radial pressure and friction of the roll on the material layer, the surface speed of the material layer is close to the surface speed of the roll, while the internal flow is opposite to the surface of the material layer. It is even greater than the forward movement speed value of the material surface. After entering the vicinity of the rolling pitch, the pressure of the roll increases sharply, the pressure inside the material layer is close to the pressure at the surface, and the relative movement of the surface and the inside of the material layer decreases, and the overall movement speed increases. At the moment after passing the rolling pitch, due to the pressure of the roll, the material inside begins to flow forward relative to the surface layer. The forward movement speed of the center part of the material layer is higher than the surface speed of the roll, and the radial pressure of the roll drops rapidly.