The method of filling color dosing systems using a Venturi loader is a familiar one. The method which is based on air pressure principles is common to most dosing systems. However, what is Venturi emptying? LIAD has developed a unique Venturi emptying mechanism for the ColorSave 1000 dosing units Gravimetric and Volumetric.
To change colors in a dosing unit, the unit must first be emptied and then refilled with a different color. Emptying a dosing unit is usually done manually, through an emptying hatch located at the base of the feeder. Furthermore, emptying some feeders requires the removal of the entire feeder from the throat it’s attached to.
The throat of the machine, the entry point of raw materials, is not readily accessible, especially in mid to large size injection molding machines and extruders. An operator must climb on the machine, requiring acrobatic skills. As for safety, this operation is a dangerous one as the operator risk injury.
Emptying without climbing up
LIAD’s innovation resulted in the development of the Venturi Emptying Mechanism, which is located at the base of the feeder, found where the emptying hatch is usually is. Similarly
to the Venturi Filling Mechanism, the Venturi Emptying mechanism works through an air pressure principle, extracting the colorant without the need for an operator to have physical access to the feeder. When an operator needs to empty the colorant from the feeder, it is achieved automatically through the touch screen.
The emptying mechanism includes a piston that opens during the emptying process, and at the same time air pressure draws out the colorant. When the Venturi emptying mechanism is activated, the feeder’s screw turns backwards to release grains of colorant from the screw area, improving the cleaning process. Furthermore, it’s possible to add an air nozzle connected to the throat opposite the feeder, which releases a jet of air directed towards the feeder’s screw for more efficient cleaning. Residual colorant is emptied into a container located near the operator, so the change of color is done on the operator’s level.