Study on the replication quality of micro-structures in the injection molding process with dynamical tool tempering systems

Abstract

The injection molding of micro-structures is a promising mass-production method for a broad range of materials. However, the replication quality of these structures depends significantly on the heat flow during the filling stage. In this paper, the filling and heat transfer of v-groove and random structures below 5 lm is investigated with the help of an AFM (atomic force microscope) and thermo couples. A numerical model is developed to predict the filling of surface structures during the filling and packing stage. The model implies the use of simple fully developed flow models taking the power-law material model into account. This permits investigation into which ways several processing parameters affect the polymer flow in the surface structures. The mold wall temperature, which has significant effects on the polymer flow, is varied by using a variothermal mold temperature control system to validate the model proposed.

Effect of micro injection molding parameters on cavity pressure and temperature assisted by Taguchi method

“…In terms of defects among the parts, peak cavity pressure was able to de-tect defective parts based on the measured peak cavity pressure value. The finding from the current investigation demonstrates significant potential for cavity pressure to be utilized as an indicator of part quality as well as a process monitoring tool for the microinjection molding process [15][16][17][18][19]. Moreover, effect of injection molding parameters of injection molded polymer materials on the cavity pressure is less been reported.…”

Replication of micro and nano-features on iPP by injection molding with fast cavity surface temperature evolution

“…The systems proposed to control mold temperature evolution were often tested also to enhance the replication of micro and nano-features on polymeric molded parts and the findings confirmed that the increase of mold surface temperature can enhance the replication accuracy of micro and nanometric parts (Matschuk and Larsen, 2013). Some authors adopted variothermal systems to improve the replication-ability of the amorphous polymers during the injection molding process (Kalima et al, 2007;Kuhn et al, 2010;Zhou et al, 2017). They generally concluded that the replication is…”

“…replicate micro and nano-features on polymeric components allows to control the surface properties of the objects. For instance, the modification of tribological properties is of particular interest in the cases in which coatings are not allowed (Lee et al, 2004) such as in medical technology, where the local wetting of the surface could influence the effectiveness (Kuhn et al, 2010) of the devices.…”

A statistical analysis of nanocavities replication applied to injection moulding

“…• Walls: No shear rate wall is used. Reason is that using no-slip boundary condition the simulation leads to unphysical results due to the contact line discontinuity of the Navier-Stokes equation, what is already reported in the literature (Gal [12]) and specifically for flows at the nanometre scale (Eijkel [7]). Apart from the theory, Kuhn [13] publishes AFM sections of different short shots at different mold temperatures of molded v-grooves and it is clearly seen that the contact line went into the grooves, hence, slipping through the wall.…”