Below -10Â☌ however, that's when wax typically starts to precipitate (regardless of whether you add PPD or not) & things become seriously non-Newtonian. Take away the shear at 150Â☌ & it's KV is predictable using the classic double log relationship. HTHS is something of a special case because you're applying lots of shear. Only once the VII is 'in' can you let the oil cool to ambient.Īs I recall, VIIs, along with all other additive components behave predictability with temperature from about 0Â☌ upwards. However this might be explainable by the fact that.Ī) they cut the EPDM back in xylene (which is ultra low viscosity!), not base oil.ī) they don't actually state the 'active' (ie solid) concentration of the VII (I suspect it must be VERY dilute!)Ĭ) they blend the VII into base oil cold which is terrible practice! The rule with VIIs is always store hot, pump hot & blend hot. With this in mind, the numbers in the study look strange. The variation is 'dampened' by the fact that most commercial liquid VII are cut-back to a KV100 of around 1,000 cst (think thick but handleable).
It was one of the quick & dirty 'look-see' tests I did to anything & everything that came through the lab door.Īlthough there was some variation depending on SSI, dilution ratio, chemical type, straight or functionalised, etc, but typically 10% liquid VII will give you a KV100 bump of 5.5 cst & a KV40 lift of 40 cst. I think I must have tested every commercial liquid VII, ever produced at 10 wt% in Esso 150SN (Group I, KV100 about 5.5 cst).
0 kommentar(er)
