In this study an incompressible flow with non-Newtonian fluids in the reverse roll coating process was investigated.Non-Newtonian behavior of the coating fluid was accounted by using power law model with power index,n...In this study an incompressible flow with non-Newtonian fluids in the reverse roll coating process was investigated.Non-Newtonian behavior of the coating fluid was accounted by using power law model with power index,n,ranging from 0.8 to 1.2.Effect of roll speed ratio(V2/V1)of the panel roll to the applicator roll and gap distance on the coating film thickness were also investigated.Numerical results were in good agreement with those of experimental data within 15%-20%.Results indicated that the film thickness ratios are function of power-law index,roll speed ration and ratio of roll radius to gap distance.The equations for film thickness ratio were obtained from numerical results as shown below:■,where t1,t2 and t3 are inlet film,transferred film and leakage film thickness,respectively,n is power-law index,V1 and V2 are roll speed of applicator roll and panel roll,Rm is average radius of two rolls and H0 is gap distance.The correlations are accurate within 10%for 0.8≤n≤1.2,0.5≤V_(2)/V_(1)≤2,and 7.7×10^(−5)≤H_(0)/R_(m)≤1.54×10^(−4).展开更多
文摘In this study an incompressible flow with non-Newtonian fluids in the reverse roll coating process was investigated.Non-Newtonian behavior of the coating fluid was accounted by using power law model with power index,n,ranging from 0.8 to 1.2.Effect of roll speed ratio(V2/V1)of the panel roll to the applicator roll and gap distance on the coating film thickness were also investigated.Numerical results were in good agreement with those of experimental data within 15%-20%.Results indicated that the film thickness ratios are function of power-law index,roll speed ration and ratio of roll radius to gap distance.The equations for film thickness ratio were obtained from numerical results as shown below:■,where t1,t2 and t3 are inlet film,transferred film and leakage film thickness,respectively,n is power-law index,V1 and V2 are roll speed of applicator roll and panel roll,Rm is average radius of two rolls and H0 is gap distance.The correlations are accurate within 10%for 0.8≤n≤1.2,0.5≤V_(2)/V_(1)≤2,and 7.7×10^(−5)≤H_(0)/R_(m)≤1.54×10^(−4).
