Surely when we go to buy AIO liquid cooling we think about safety, possible leaks or evaporation. Although this is perfectly understandable, the reality is that AIOs currently have a degree of quality beyond any doubt. One of the points where they have improved the most has been in their tubes, which now use much more advanced materials. What types do manufacturers currently mount?
The problem with manufacturers is that they want to keep any improvements as a general rule secret. If there is no patent involved, they are very reluctant to publish their news, and in the world of AIO tubes the patents are not exactly theirs.
Therefore, in the technical specifications almost no brand gives details of this, but luckily we are here to unravel everything they want to hide.
Materials from which AIO tubes are made
At first it may seem that there is a huge amount of materials and that is why there is so much secrecy, but the problem is simpler and at the same time more complex, and we explain ourselves.
Currently, all manufacturers choose to use only two materials in their tubes: fluorinated propylene-ethylene or FEP and an isoprene polymer which is normally a type of rubber. The difficulty and where the R&D of this section is destined is not the tube itself, but in its internal or external coating and here is the whole problem.
No company specifies these coatings, but we do know with certainty that they all come from a petroleum derivative that has already been processed and optimized for the liquid they must preserve.
Fluorinated Ethylene Propylene or FEP
FEP is a hexafluoropropylene and tetrafluoroethylene copolymer that is extremely injection moldable. It melts at 260 ºC and as a rule it is very transparent and resistant, even in sunlight.
The advantage it has in AIOs is that it is practically insoluble to any glycol or solvent and also maintains its flexibility without deforming, so as a tube it is very suitable for certain manufacturers who are going to use very extreme liquids.
In addition, it has a very high coefficient of dynamic friction, so it is very smooth and with very few imperfections, where it is also a dielectric material in itself. Finally, we must talk about its capillarity, a very important aspect in AIOs, where it is very low.
Isoprene Polymers: rubbers
They come from latex, those used in the AIO liquid cooling industry are not of natural origin, but are synthetic, since other compounds are needed to give them greater virtues.
This type of rubber is commonly referred to as synthetic polyisoprene and is capable of withstanding from -20 degrees to 80 ºC . Like good rubber, it is extremely flexible, withstands great compression set, has good electrical, wear, impact and abrasion resistance, but does not like sunlight.
It also supports water, ketones and alcohols very well, making it ideal for this sector. Finally, it should be noted that its capillarity is low, but not as good as that of FEP, since to achieve its flexibility the chains of atoms are very long and allow some capillarity.
For this reason, manufacturers usually include a series of covers or layers that allow a better watertight seal.
Sleeved, a distraction with no greater functionality than aesthetics
The majority of current AIOs do not leave the tube visible to the user, but instead cover it by means of various sleeved techniques with heat shrink covers . This does not provide any real advantage to the tube, but as a rule either subtracts (depending on the cover) or does not bother and provides a more premium aesthetic touch.
This sleeve is what the user touches when he reaches for the tube itself, leaving the actual material under it. In the past this was not done and the tube was touched, which was also sealed to prevent leaks.
But currently this is difficult to see in modern AIOs (not impossible, some maintain it), mainly because the aesthetic improvement is appreciable and secondly because it is cheap for the manufacturer.