Analysis of the influence of part thickness on the replication of micro-structured surfaces by injection molding

Masato, Davide; Sorgato, Marco; Lucchetta, Giovanni

doi:10.1016/j.matdes.2016.01.115

Cited by 84 publications

(70 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the rapid development of miniaturization and precision products, microinjection molding (MIM) is playing a vital role in the field of optical communication, computer data storage, automotive, aerospace, precision instrument, biomedicine, and engineering applications . Due to small size and volume, the rheological behavior of MIM parts is different from that of conventional injection‐molded parts .…”

Section: Introductionmentioning

confidence: 99%

Effect of injection speed on the mechanical properties of isotactic polypropylene micro injection molded parts based on a nanoindentation test

Wang

Zhang

Jiang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

Isotactic polypropylene micro parts were molded at different injection speeds by microinjection molding. The morphology and micro structure were characterized by a polarizing microscope, and the mechanical properties of differently structured layers were characterized by nanoindentation experiments. The influence of injection speed on the nanoindentation mechanical properties of each structural layer of the micro parts was analyzed. The results showed that the mechanical properties of different layers were different, the modulus and hardness of the position near the core layer were largest, and the modulus and hardness of the position near the skin were smallest. It is compelling that the modulus and hardness of each layer decreased first and then increased as the injection speed increased under a higher melt temperature (240 °C). Meanwhile, the opposite trend was observed at a lower melt temperature (220 °C). This phenomenon can be attributed to the competitive mechanism of the shear heat effect and the disorientation effect. In addition, injection speed had a greater influence on the nanoindentation mechanical properties in the perpendicular direction than in the flow direction. This work systematically explored the relationship between the microstructure and the local mechanical properties, which can provide new insights for microinjection molding design in the future. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47329.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of injection speed on the mechanical properties of isotactic polypropylene micro injection molded parts based on a nanoindentation test

Wang

Zhang

Jiang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…In the last decade, many research groups have focused their attention on the factors that affect the replication quality during the µIM process, in particular on process conditions and cavity geometry [1]. The results reported in the literature indicate that among the main factors, mould temperature (T m ) markedly affect the replication degree of micro features.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the influence of vacuum venting on mould surface temperature in micro injection moulding

Sorgato

Babenko

Lucchetta

et al. 2016

Int J Adv Manuf Technol

Self Cite

View full text Add to dashboard Cite

The application of vacuum venting for the removal of air from mould cavity has been introduced in injection moulding with the intent to enhance micro/nano features replication and definition. The technique is adopted to remove air pockets trapped in the micro-features, which are out of reach for conventional venting technologies and can create considerable resistance to the melt filling flow. Nonetheless, several studies have revealed a negative effect on replication that could possibly arise from the application of vacuum venting. Although the incomplete filling of micro-scale features has often been attributed to poor venting, the limited research examining the application of vacuum venting has produced mixed results. In this work, the effect of air evacuation was experimentally investigated, monitoring mould and polymer temperature evolution during the micro injection moulding process by means of a high speed infrared camera and a sapphire window, which forms part of the mould wall. The results show that air evacuation removes a mould surface heating effect caused by rapid compression of the air ahead of the flow front and subsequent conduction of that heat into the mould surface. Hence, with the increase of the surface-to-volume ratio in micro-cavities, air evacuation has a detrimental effect on the cavity filling with polymers that are sensitive to changes of the mould temperature.

show abstract

“…Focusing on in-flow sections, the H 1 dimensions (▲) are very close to the target values for both depth and width. Basically, proximity to the injection entry supports this result [14]. The H 2 results (▬) are the worst, since both depth and width are very far away from the target values.…”

Section: Resultsmentioning

confidence: 69%

Replicability of Ultrasonic Molding for Processing Thin-Wall Polystyrene Plates with a Microchannel

et al. 2018

View full text Add to dashboard Cite

Ultrasonic molding is a new technology for processing small and micro polymeric components with reasonable cost and energy savings when small and medium batch sizes are required. However, when microcomponents are manufactured, the replicability of different micro features has to be guaranteed. The aim is to investigate the capability of ultrasonic molding technology for processing thin-wall plates of polystyrene with a microchannel, analyzing the filling behavior, the optical transparency, and the dimensional accuracy of the thin plate. The replicability of the manufactured microchannel is studied according to dimension and shape. The results reveal that plunger velocity influences transparency and filling cavity, whereas the vibration amplitude has less effect in both cases. The thickness deviation achieved on the final part is below 7% and the replication of the microchannel is better in depth than width, obtaining an average deviation of 4% and 11%, respectively. This replication also depends on the orientation of the microchannels and the distance from the injection gate. The replicability and repeatability for processing thin-wall plates with microchannel in polystyrene polymer are proved in this paper.

show abstract

Analysis of the influence of part thickness on the replication of micro-structured surfaces by injection molding

Cited by 84 publications

References 13 publications

Effect of injection speed on the mechanical properties of isotactic polypropylene micro injection molded parts based on a nanoindentation test

Effect of injection speed on the mechanical properties of isotactic polypropylene micro injection molded parts based on a nanoindentation test

Investigation of the influence of vacuum venting on mould surface temperature in micro injection moulding

Replicability of Ultrasonic Molding for Processing Thin-Wall Polystyrene Plates with a Microchannel

Contact Info

Product

Resources

About