No abstract

F lu id Co a tin g fro m a P o ly m e r S o lu tio nAla in de Ryck † a n d Da vid Qu ér é* , ‡ E Ä cole d es M in es d 'Albi, rou te d e T eillet, 81013 Albi CT Ced ex 09, Fran ce, an d L aboratoire d e Ph ysiqu e d e la M atière Con d en sée, UR A 792 d u CN R S , Collège d e Fran ce, 75231 Paris Ced ex 05, Fran ceNew exper im en t s on coa t in g of a wir e wit h a qu eou s poly(et h ylen e oxide) solu t ion s a r e r epor t ed. If t h ese exper im en t s a r e com pa r ed wit h coa t in g wit h a pu r e liqu id of t h e sa m e ph ysica l ch a r a ct er ist ics, a st r on g t h icken in g of t h e liqu id la yer is obser ved. Th is effect is descr ibed by con sider in g t h e n or m a l st r esses, wh ich a llows u s t o obt a in a n a n a lyt ica l expr ession for t h e coa t ed t h ickn ess in good a gr eem en t wit h t h e da t a .

Fibres can be coated by passing them through a solution. At low velocity, the thickness of the entrained film is given by the Landau law. For liquids of low viscosity, we discuss the high-speed withdrawal regimes which are of technological interest. We focus on inertial effects and geometrical limitations. New experimental data are presented and discussed by using dimensional arguments. Finally, a classification is proposed.