Liquid Color Sources/Delivery
In the past, liquid color has been often thought of as difficult to handle prior to processing, it is still widely used in various industries due to its unique properties. Recently introduced methods for delivery of the colorant to processors, have brought higher levels of convenience, cleanliness and eco-consciousness.
Traditional Delivery Methods:
Traditional delivery methods for color concentrate are typical liquid vessels including poly barrels and smaller quantities in 5 gallon containers. When delivered in this manner, the user provides a pump for pulling the colorant from the supply drum and metering it into the process. Metering can include at-the-throat units that fit below the standard material supply hopper and work in conjunction with the molding cycles of the processing machine. In these applications, the liquid pump control is coordinated with molding machine operation to feed colorant for a specific duration at a specific time in the machine cycle for proper let-down. The liquid color may also be fed to a multi-component automatic blender to be combined with other materials into a common blend.
A peristaltic, or roller pump, is the standard positive displacement pump used for pumping liquid colorants. The colorant is drawn from the storage container into a flexible tube fitted inside a circular pump casing. A rotor with a number of "rollers" rotates and compresses the flexible tube. The part of tube under compression closes (or "occludes") forcing the colorant to move through the tube at the time and rate selected on the metering or blending controller.
When using traditional delivery methods, the user is responsible for connecting their pump to the delivery vessel and then, when the vessel is empty, retrieving the siphoning tube in the cleanest possible way. Preventing spills, dribbles, contamination and fully emptying the supply drum are issues traditionally associated with liquid coloring.
New Liquid Color Delivery and Cleanliness:
New methods for the delivery and pumping of liquid color have reignited this thought-to-be-messy coloring method. The concept is based upon maximizing the user’s efficiency and cleanliness by placing a pumping system into a proprietary drum which is initially delivered by the liquid colorant manufacturer and then replaced as needed. The unique diaphragm pumping system maximizes the draining of each barrel by the use of a pump made specifically for that barrel (or other vessel).
With each delivery, the user is provided with another liquid pump, built right into the delivery vessel (drum). If metering at the throat, the user is equipped with a mating control (which stays on site) so each new drum may be simply connected to the control, and turned on for reliable, consistent liquid metering with no need to ever actually touch or otherwise deal with the colorant. The proprietary control is easily set for the metering let-down ratio, or the pump/metering system may be connected to a batch blender as an additional ingredient for the blend.
The system not only delivers liquid color in a convenient and clean way, but is also eco-friendly, by eliminating the waste associated with empty color delivery containers. Each container (with its on-board pump) is recycled back to the supplier for re-use.