The effects of tool surface quality in micro-injection moulding

A new process chain for producing bulk metallic glass replication masters with micro- and nano-scale features

“…Figs 8a to 8f depict the SEM images of the polymer replicas produced with the five µIM process settings in Table 4 C. This is as expected because by increasing the mould temperature, the bulk temperature of the polymer can be kept sufficiently high to ensure the complete filling of the sub-micron surface structures (Griffiths et al, 2007;Tosello et al, 2010). A histo-distribution generated from the AFM measurements of the inspected samples is presented in Fig 9 and concurs with the SEM surface analysis results.…”

“…It is therefore usually necessary to optimise the µIM process using design of experiments (DOE) approaches. There are numerous parameters which can influence the process but the most statistically significant factors (Attia, Marson, & Alcock, 2009;Giboz et al, 2007;Griffiths, Dimov, Brousseau, & Hoyle, 2007;Sha, Dimov, Griffiths, & Packianather, 2006) include: melt temperature; mould temperature; injection speed; holding pressure and duration; mould surface roughness; runner and gate design and venting/ vacuum systems.…”

The Micro Injection Moulding Process for Polymeric Components Manufacturing

“…Quality responses are usually associated with the evaluation of the replication by complete filling of the mould cavity. The most widespread responses reported in literature include filling quality of micro sized channel [43], feature dimension [44,45], part mass [46], flow length [47], filling volume fraction [48], weld-line formation [49], demoulding forces [50], mould cavity pressure [51,52], and minimizing injection time, pressure and temperature distribution using a threedimensional simulation packages [53]. The different chosen responses of statistical studies can lead to different main results.…”

“…Griffiths et al [47] studied the factors affecting the flow behaviour in the interaction between the melt flow and the tool surface and PP, ABS and PC polymers were employed to perform moulding tests using cavities with the same geometry but different surface finish. It was found that there is a relationship between the tool surface finish and the level of turbulence in the melt flow.…”

Analysis for microstructure of micro-cantilevers arrays in micro-injection molding by using numerical simulations

“…Griffiths et al [1] studied the flow behavior of polymer melts in micro cavities by Moldflow Plastics Insight software and then validated against the experimental results of the study reported in reference [3]. They used two FEA models i.e.…”