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What is the liquid pump system?

When it comes to liquid color, we not only understand the material side when it comes to LiquiSol recommendations, we also can recommend the liquid system to best benefit your production facility.

With that in mind, the delivery system of liquid colorants can at times be confusing. Here is some basic information we think about when recommending liquid systems.

There are two types of delivery mechanisms to meter LiquiSol to the machine; either a peristaltic (roller pump) or a progressive cavity (shaft pump).

  • A peristaltic pump is generally recommended when you have shorter runs and frequent colors changes. Also, this mechanism uses a tube assembly as part of the delivery system.
  • A progressive cavity is typically recommended when you have long runs or a line dedicated to a specific color. With this, there is not tube set required as you use an internal rotating shaft that is controlled by the pump.

After you have determined the proper delivery mechanism, you then must consider the type of pump that is best for your operation. There are generally two types as well – volumetric and gravimetric.

  • Volumetric pumps are historically the standard in the industry.
    • There are two types of ways to calibrate a volumetric pump:
      • Sample collection: Place the pump on a calibration setting of 100 and count down to 0. When that is completed you weigh the sample and plug it into a formula that includes a variety of factors including LDR, part weight, etc. to determine proper calibration.
      • Mathematical calculation: This is a theoretical calculation based on known factors such as part weight, tube factor, LDR, and weight per gallon of the colorant to determine proper calibration.
    • The assumption with volumetric pumps is that all the variables will stay the same based on the initial evaluations and that nothing changes during the manufacturing process.
    • After calibration is complete, you introduce the delivery tube into the machine and the pump doses as the machine cycles.
  • Gravimetric pumps are a newer to use in liquid colorants.
    • This type of pump performs a self-calibration by analyzing all the variables and looks at weight loss between each cycle. (Depending on your system a cycle can range from seconds to minutes.)

That is just a quick overview highlighting some of the concepts regarding delivery mechanisms and pumps used in liquid systems. Plastics Color Corporation partners with our customers to utilize the best system for your operation.

Email us at Info@PlasticsColor.com

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