What is Progressive Cavity Displacement Dispensing?

Progressive Cavity Displacement Dispense Technology revolutionizes how you dispense and how you perceive dispensing.

PCD is a continuously volumetric dispense pump based on the Progressive Cavity principle. Progressive Cavity Displacement technology is an innovation in dispensing for a wide range of fluids, from low viscosity coatings to high viscosity greases. The many advantages of Progressive Cavity Displacement technology will simplify your dispense process and improve reliability and quality in the long run.

  1. Pump will not drip or drool even when under 80 psi of pressure.
  2. Dispense as much or as little as you need – volumetrically.
  3. Experience outstanding repeatability over the full range of fluid pot life.
  4. Level of fluid in a syringe will not affect the volumetric repeatability or capability of the pump.

You will no longer need to make manual adjustments during a process to compensate for pump variability. Productivity improves because operators no longer need to spend time fine tuning or performing rework for insufficient or inadequate fluid.

The two primary parts of Progressive Cavity Displacement continuously volumetric dispense technology are the rotor and stator. The rotor “threads” into the stator, and a “fluid engine” is generated between the two. The rotor is a stainless steel, single helix device with a complex geometry designed to push fluid through the double helix stator. In the fluid engine, two out-of-phase fluid chambers are deposited to the substrate. When the rotor rotates, fluid is fed from chamber A, chamber A + B, or Chamber B. At any time in the dispense process the volume of fluid is the same.

Progressive Cavity Rotor Stator
continuous volume cavities with constant volume
Continous volume cavitiesb with constant volume exist at all points in the dispensing motion.
PCD pump mounted on automated fluid dispense equipment

Progressive Cavity Displacement dispense technology enhances dispense processes that require fluids ranging from very low viscosity, such as water, to thick pastes up to 80,000 cps. Semi-abrasive fluids can be handled by the PCD Volumetric Pump because it pushes fillers through the pump rather than grinding them.

  • Underfill
  • LED encapsulation
  • Flux
  • Grease
  • Conformal coatings
  • Silicones
  • And many more

Why Progressive Cavity Displacement Dispensing is Superior

One issue with dispense technologies such as time-pressure and other dispense methods reliant on air to consistently feed fluid through the dispense mechanism is that the volume of fluid changes with the level of fluid in the syringe if no other dispense parameters are changed. Variables such as friction between the stopper and the side of the fluid reservoir and the weight of fluid in the fluid column (reservoir) affect the process. This is not the case with PCD technology. The fluid reservoir, whether it is a 10 cc syringe, a 70 cc syringe, a 20 oz. cartridge, or a large pail ram, is continually pressurized to feed fluid to the internal fluid reservoir. As long as fluid is present in the internal reservoir, the rotor and stator pull fluid into the volumetric cavities. Progressive Cavity Displacement technology is not affected by a change in fluid reservoir pressure of a few psi or the level of fluid in the syringe.

volumetric repeatabilty results chart
Volumetric repeatability results over multiple days without pump calibration.

Progressive Cavity Displacement Technology is available on all GPD MAX Series, DS Series, and benchtop systems. To enhance your existing robot capabilities, we offer an integration kit with a fully programmable controller that will immediately improve your current dispense results.