Optimising process conditions for multiple quality criteria in micro-injection moulding

AbstractThis paper discusses micromanufacturing process quality proxies called “process fingerprints” in micro-injection moulding for establishing in-line quality assurance and machine learning models for Industry 4.0 applications. Process fingerprints that we present in this study are purely physical proxies of the product quality and need tangible rationale regarding their selection criteria such as sensitivity, cost-effectiveness, and robustness. Proposed methods and selection reasons for process fingerprints are also justified by analysing the temporally collected data with respect to the microreplication efficiency. Extracted process fingerprints were also used in a multiple linear regression scenario where they bring actionable insights for creating traceable and cost-effective supervised machine learning models in challenging micro-injection moulding environments. Multiple linear regression model demonstrated %84 accuracy in predicting the quality of the process, which is significant as far as the extreme process conditions and product features are concerned.

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Part mass and shrinkage in micro injection moulding: Statistical based optimisation using multiple quality criteria

Polymer Testing ◽

10.1016/j.polymertesting.2013.06.009 ◽

2013 ◽

Vol 32 (6) ◽

pp. 1079-1087 ◽

Cited By ~ 10

Author(s):

Daniele Annicchiarico ◽

Usama M. Attia ◽

Jeffrey R. Alcock

Keyword(s):

Injection Moulding ◽

Quality Criteria ◽

Micro Injection Moulding

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Simulation of the micro-injection moulding process: effect of the thermo-rheological status on the morphology

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408911415940 ◽

2011 ◽

Vol 225 (4) ◽

pp. 224-238 ◽

Cited By ~ 6

Author(s):

T Nguyen-Chung ◽

C Löser ◽

G Jüttner ◽

T Pham ◽

M Obadal ◽

...

Keyword(s):

Injection Moulding ◽

Process Conditions ◽

Transfer Coefficients ◽

Moulding Process ◽

Micro Injection Moulding ◽

Mould Filling ◽

Injection Moulding Process ◽

Moulding Machine ◽

Simulation Results ◽

Micro Cavity

The software package Moldflow Plastics Insights was used to simulate the filling of a micro-cavity by considering precise material data and accurate boundary conditions. Experiments were carried out on an accurately controlled micro-injection moulding machine (formicaPlast) for providing important parameters to verify the simulation results and improve the accuracy of the simulation. Based on the relationship between the cavity pressure and the mould-filling ratio, the heat transfer coefficients can be appropriately determined for different process conditions. Finally, the transient thermo-rheological results were analysed with regard to their influence on the morphology of semi-crystalline (PP) micro-injection moulded parts, which not only give rise to the mechanisms of the morphological formation but also verify the quality of the simulation results.

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Micro Injection Moulding Process and Product Characterization

Volume 7: 5th International Conference on Micro- and Nanosystems; 8th International Conference on Design and Design Education; 21st Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2011-48301 ◽

2011 ◽

Author(s):

Rossella Surace ◽

Gianluca Trotta ◽

Alessandro Bongiorno ◽

Vincenzo Bellantone ◽

Claudia Pagano ◽

...

Keyword(s):

Tensile Strength ◽

Injection Moulding ◽

Process Conditions ◽

Scale Production ◽

Mould Temperature ◽

Melt Temperature ◽

Injection Speed ◽

Moulding Process ◽

Micro Injection Moulding ◽

Injection Moulding Process

Due to its high efficiency for the large scale production of polymeric parts, micro injection moulding is one of the key technologies of the new millennium. Although a lot of researches have been conducted to identify the most effective processing conditions for micro injection moulding, the comprehension of the influence of all parameters on the quality, the properties and the reliability of the moulded parts is still an issue. In this context, this study aims to evaluate the effects of the micro injection moulding process conditions on the tensile properties of micro parts, investigating the influence of three main process parameters: the injection speed, the mould temperature and the melt temperature. A full factorial plan has been applied to study the contributions of these parameters and a second study has been performed to understand the synergic interaction between the two temperatures on the tensile strength. Due to its high level of potential crystallinity, a typical semi-crystalline thermoplastic resin was used in the experiments. The results of the analysis showed a great influence of the mould temperature (Tmould) on the ultimate tensile strength and of the melt temperature (Tmelt) on the deformation at the point of breaking; whereas the injection speed was significant on the overall mechanical performance. A new studied factor (Tmelt-Tmould) could affect the resulting molecular structure and consequently the mechanical behaviour, but itself is not sufficient to thoroughly explain the observed behaviour. Moreover, the visual inspection of the deformation mechanism at break shows three distinctive trends demonstrating the great variability of the mechanical properties of micro-injected specimens due to process conditions.

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Correlation of Processing, Inner Structure, and Part Properties of Injection Moulded Thin-Wall Parts on Example of Polyamide 66

International Journal of Polymer Science ◽

10.1155/2014/718926 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Dietmar Drummer ◽

Steve Meister

Keyword(s):

Cooling Rate ◽

Injection Moulding ◽

Degree Of Crystallinity ◽

Process Conditions ◽

Thin Wall ◽

Polyamide 66 ◽

Slow Cooling ◽

Cooling Conditions ◽

Internal Structures ◽

Wall Injection

In micro- and thin-wall injection moulding the process conditions affect the developed internal structures and thus the resulting part properties. This paper investigates exemplarily on polyamide 66 the interactions of different cooling conditions on the morphological and crystalline structures. The investigations reveal that a slow cooling rate of the melt results in a homogeneous morphology and a higher degree of crystallinity and also a favoured crystalline structure. Consequently, the dielectric behaviour and light transmitting part properties are affected.

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