| 摘要 |
PURPOSE:To mass-produce plastic pellets inexpensively using small-sized simple and lightweight equipments, by molding pellet preform rods through a primary crushing roll thereby rendering the plastic material brittle, and breaking the pellet preforms through a secondary crushing roll made up of a combination of a grooved roll and smooth roll. CONSTITUTION:A platelike plastic 1 that has been prepressed is fed via feeding rolls 2 to a primary crushing roll 3. The crushing roll 3 consisting of a smooth roll 5 and a grooved roll 4 having shallow grooves 6 formed in the surface in parallel with the axis. The plastic 1 is broken by each smooth surface 7 between the grooves 6. The primary broken items, that is, the pellet preform rods 8 are thin rods having a shape approximately corresponding to the grooves 6. The length of them is determined by the width of the rolls 4, 5, and the crosssectional shape thereof will be in conformity with the profile of the grooves 6. preferably, the shape of the grooves 6 is V-shaped and is relatively wide. A secondary crushing roll 10 consists of a combination of a grooved roll 11 and a smooth roll 12. As the pellet preform rods 8 have already been made brittle substantially, they are easily broken into pellets 14, which are conveyed on a conveyor 9. |
