Viscosity dhalaalka ee koollada kuleylka leh waa mid ka mid ah tilmaamayaasha caadiga ah, muhiimaddeeduna waxay si toos ah u saamaysaa doorashadaxabag dhalaalaysa kululfarsamada dhismaha. Isticmaalka kululeeyaha-kululku waa inuu isticmaalo qalabka kuleyliyaha si uu ugu beddelo koollada adag ee dhalaalaysa xaalad aalquid. Warshadaha kala duwan, isticmaalka kala duwan, waxay leeyihiin hanti jidheed oo kala duwan, qalabka xabagta iyo hababka cabbirka.
Hababka kala duwan ee cabbirka ayaa go'aamiya viscosity dhalaalka ee kala duwan ee koollada kululeeyaha ay tahay inay lahaato. Hababka caadiga ah ee isticmaalka xabagta waxaa ka mid ah buufin, dhibco, buufin, duubid, iyo xoqid. Guud ahaan, meltviscosity loo baahan yahay waa mid hoose ilaa sare. . Viscosity-ka dhalaalidda xabagta kulul lama xiriirto adhessionka iyo awoodda isku xirnaanta. Looma tixgelin karo in viscosity dhalaalku uu sarreeyo, mawjaduhuna uu wanaagsan yahay, waana inay la xidhiidhaan dareereheeda.