Lub viscosity Performance index qhia qhov degree uas viscosity ntawm tag nrho cov kua hloov nrog kub. Qhov siab dua qhov viscosity index yog, qhov tsawg dua cov kua viscosity cuam tshuam los ntawm qhov kub thiab txias, thiab qhov tsawg dua qhov viscosity yog kub.
Raws li qhov sib txawv viscosity Performance index, lubricating roj tuaj yeem muab faib ua peb qib: 35-80 yog nruab nrab viscosity Performance index lubricating roj; 80-110 yog hais txog lubricating roj nrog siab viscosity Performance index; Saum toj no 110 yog super siab viscosity index lubricating roj. Lub cav roj nrog viscosity Performance index ntawm 100-170 yog ib tug high-qib multistage lubricating roj. Nws muaj kev hloov pauv ntawm viscosity kub nkhaus thiab zoo viscosity kub khoom. Thaum qhov kub thiab txias, solubility ntawm macromolecular organic compound molecules nyob rau hauv cov roj ntawm cov viscosity index improvers yog me me, thiab cov molecules curl mus rau hauv compact me me pawg, yog li cov viscosity ntawm cov roj nce me ntsis; Thaum kub kub, nws solubility nyob rau hauv cov roj nce, thiab cov curly linear molecules nthuav thiab elongate, yog li ua rau lub viscosity zoo heev, ua rau txo viscosity ntawm lub hauv paus roj vim kub nce. Yog li ntawd, qhov siab dua qhov viscosity index, qhov me me qhov viscosity hloov nrog kub.