• Boschard, Cédric
• Benayoun, Stéphane
• Brulez, Annecatherine
• Larochette, Mathieu

Abstract

International audience ; Abstract Injection manufacturing makes it possible to functionalize the surfaces of microtextured plastic parts without resorting to expensive post‐treatments. An instrumented mold was developed and microtextures were etched in the cavity with a femtosecond laser. A setting methodology only following in situ parameters, especially cavity pressurizing velocity was used to complete process control. The quality of the replication was quantified by the ratio, R , of microtexture part height replication over etched texture depth in the cavity. Different setting parameters such as injection velocity, V f , mold temperature, T Mo , and holding pressure, P HMax , were investigated on two different injection molding machine. A statistical analysis enabled a validation of the protocol while showing that the influence of the injection molding machine is nonsignificant. Furthermore, injection velocity appeared as a key parameter, it acts at the same time on the thermal aspect of the flow front, frozen‐layer fraction creation, but more importantly on the polymer's viscosity. An injection velocity threshold where above, mold temperature and holding pressure become secondary for better quality replication. This allowed as well to establish an empiric expression which makes it possible to calculate a pattern quality replication ratio, R , according to different parameters ( V f , T Mo , P HMax ).

Topics

• impedance spectroscopy
• surface
• polymer
• viscosity
• texture
• injection molding