Plasticizers or dispersants are additives that increase the plasticity/fluidity of plastic, especially polyvinyl chloride (PVC) tubing in computer liquid cooling. Unfortunately, the majority of plasticizing agents break down over time and under heat, thus leaching the fine powder particles which deposit on all surfaces.
Tubing that contains plasticizer is usually the culprit for many system failures as a result of clogging the microchannel fins in the water block or buildups on the water pump impeller shaft that ultimately overload the motor.
Top photo shows a cut section of plasticizer leaching affected PVC tubing. Photo oin the bottom shows (green) dyed strains of plasticizer powder 'gunk' (source: overclock.net)
In the past, these "buildup" or "gunking" issues have been mistakenly attributed to premixed coolants (and their glycol base) instead of tubing. Plasticizing powder, dyed by the color of the premixed coolant, was leading users to the false conclusion that the coolant itself was the issue.
Cleaning the liquid cooling equipment affected by this occurrence is, unfortunately, time-consuming. EK recommends taking apart all cooling equipment and cleaning it by following our Cleaning Guide. Warm soapy water and Q-tips (for cleaning hard-to-reach spots) are a must. The affected tubing should be discarded, and a fresh tube must be installed.
- Use plasticizer-free tubing in your water cooling loop. EK ZMT (Zero Maintenance Tubing) is an EPDM rubber-type tubing, has no added plasticizer, and is thus safe to use. The rubber ensures a great bend radius!
- In case you are not sure if certain tubing contains a plasticizer, it is best not to use it! As of 2013, all tubing manufactured and sold by EK is safe to use.