Polymer Rheology

Influence of thermocapillary flow in a liquid film jet

“…The conclusion of the present paper suggests a more enlargement of the cross-section. The Barus e ect or Die Swell e ect on the change of cross-section in a polymer jet is explained usually by the rheological property of the polymer melts [9,10]. The results of present paper show that, the Die Swell e ect may also be explained by the thermocapillary e ect in the liquid jet of a Newtonian uid.…”

“…The Barus e ect has been usually explained by the rheology property of the uid, and the di erence of normal stresses may enlarge the cross-section of the melt jet [9,10]. The conclusion of the present paper shows that, the in uence of thermocapillary ow of a Newtonian uid has contribution to the enlargement of the cross-section.…”

Numerical modeling of multilayer film coextrusion with experimental validation

“…Within the temperature range shown, G 00 > G 0 for all three resins. At the core processing temperature of 280 C, tan d is equal to 7.1, 21.9, and 3.1 for B, A, and C, respectively, where tan d5G 00 =G 0 [9]. This implies that viscous effects dominate over elastic ones for the three polymers used in this study and therefore elastic effects are not considered.…”

“…1 are produced when different polymers are extruded, producing separate polymer melt streams. These streams then come together for the first time in either an injector (or feed) block linked to a die or a multimanifold die [1,4,5,[8][9][10][11][12][13][14][15]. A thin, unified melt curtain sheet exits the die, which is then rapidly cooled by a casting drum before being stretched in both the machine and transverse directions, producing a biaxially oriented final film [5].…”

“…It is stated in [23] that under standard conditions, encapsulation occurs after 100D, where D is the pipe diameter. Differences in the elasticity of the melt layers can also affect the coextruded structure and lead to elastic-based layer deformation and encapsulation [1,8,9,14,22,23,32,33]. In elastic encapsulation, the more elastic fluid tends to push into the less elastic one [14,30].…”