| 摘要 |
PURPOSE:To attain the enhancement of productivity and the reduction in cost, by increasing a resin having a colorant added thereto at the time of cleaning corresponding to the increase amount of a resin and reducing the same corresponding to the supply amount of the resin at the time of molding operation. CONSTITUTION:When the colorant B in a cylinder 1 is cleaned by performing free shot, a nozzle head 6 becomes free and, therefore, the resistance to the filling of a resin 3 is reduced and the resin 3 is supplied to the cylinder 1 from a hopper 2 at a speed faster than that at the time of molding operation. Because of this, the content of the colorant B in the resin discharged from the cylinder 1 is reduced and, therefore, the colorant B supplied to the hopper 2 is added corresponding to the increase amount of the resin 3 to be preliminarily increased. As a result, the cylinder 1 is filled with the resin 3 with proper colorant content at the point of time when the mixing of the colorant B with the resin 3 discharged from the cylinder 1 is not observed and, therefore, if a screw 5 is retracted and molding operation is performed, a product having proper hiding power is obtained and the loss of the resin 3 or the colorant B is suppressed to a min. degree to perform efficient molding. |
