Investigation on Product and Process Fingerprints for Integrated Quality Assurance in Injection Molding of Microstructured Biochips

Injection molding has been increasing for decades its share in the production of polymer components, in comparison to other manufacturing processes, as it can assure a cost-efficient production while maintaining short cycle times. In any production line, the stability of the process and the quality of the produced components is ensured by frequently performed metrological controls, which require a significant amount of effort and resources. To avoid the expensive effect of an out of tolerance production, an alternative method to intensive metrology efforts to process stability and part quality monitoring is presented in this article. The proposed method is based on the extraction of process and product fingerprints from the process regulating signals and the replication quality of dedicated features positioned on the injection molded component, respectively. The features used for this purpose are placed on the runner of the moldings and are similar or equal to those actually in the part, in order to assess the quality of the produced plastic parts. For the purpose of studying the method’s viability, a study case based on the production of polymer microfluidic systems for bio-analytics medical applications was selected. A statistically designed experiment was utilized in order to assess the sensitivity of the polymer biochip’s micro features (μ-pillars) replication fidelity with respect to the experimental treatments. The main effects of the process parameters revealed that the effects of process variation were dependent on the position of the μ-pillars. Results showed that a number of process fingerprints follow the same trends as the replication fidelity of the on-part μ-pillars. Instead, only one of the two on-runner μ-pillar position measurands can effectively serve as product fingerprints. Thus, the method can be the foundation for the development of a fast part quality monitoring system with the potential to decrease the use of off-line, time-consuming detailed metrology for part and tool approval, provided that the fingerprints are specifically designed and selected.

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Investigation of Product and Process Fingerprints for Fast Quality Assurance in Injection Molding of Micro-Structured Components

Micromachines ◽

10.3390/mi9120661 ◽

2018 ◽

Vol 9 (12) ◽

pp. 661 ◽

Cited By ~ 2

Author(s):

Nikolaos Giannekas ◽

Per Kristiansen ◽

Yang Zhang ◽

Guido Tosello

Keyword(s):

Quality Control ◽

Injection Molding ◽

Quality Data ◽

Efficient Production ◽

Short Cycle ◽

Part Quality ◽

Molded Parts ◽

Micro Features ◽

Product And Process

Injection molding is increasingly gaining favor in the manufacturing of polymer components since it can ensure a cost-efficient production with short cycle times. To ensure the quality of the finished parts and the stability of the process, it is essential to perform frequent metrological inspections. In contrast to the short cycle time of injection molding itself, a metrological quality control can require a significant amount of time and the late detection of a problem may then result in increased wastage. This paper presents an alternative approach to process monitoring and the quality control of injection molded parts with the concept of “Product and Process Fingerprints” that use direct and indirect quality indicators extracted from part quality data in-mold and machine processed data. The proposed approach is based on the concept of product and process fingerprints in the form of calculated indices that are correlated to the quality of the molded parts. A statistically designed set of experiments was undertaken to map the experimental space and quantify the replication of micro-features depending on their position and on combinations of processing parameters with their main effects to discover to what extent the effects of process variation were dependent on feature shape, size, and position. The results show that a number of product and process fingerprints correlate well with the quality of the micro features of the manufactured part depending on their geometry and location and can be used as indirect indicators of part quality. The concept can, thus, support the creation of a rapid quality monitoring system that has the potential to decrease the use of off-line, time-consuming, and detailed metrology for part approval and can thus act as an early warning system during manufacturing.

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Process Control of Injection Molding Based on Multiscale Visualization Methodology - A Case Study

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.154-155.1839 ◽

2010 ◽

Vol 154-155 ◽

pp. 1839-1845

Author(s):

Jin Cheng ◽

Jian Rong Tan ◽

Jia Hong Yu

Keyword(s):

Injection Molding ◽

Optimal Process ◽

Part Quality ◽

Statistical Mathematics ◽

Injection Molded ◽

Plastic Parts ◽

Injection Molded Plastic ◽

Optimal Process Parameter

Multiscale visualization approaches are proposed to efficiently assist designers not familiar with statistical mathematics in determining the optimal process parameter schemes for achieving desired part quality in injection molding, based on which the parameters’ relative importance to part quality and their influence on either single quality index or comprehensive part quality can be visually described by the map of the sum of squared deviations, response surface diagram and distribution map of comprehensive part quality. The proposed visualization approaches are universal for analyzing the effects of process parameters on the quality of any injection-molded plastic parts although the mobile phone cover is utilized as an example in the presentation of our work.

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Micro-injection moulding: factors affecting the replication quality of micro features

4M 2006 - Second International Conference on Multi-Material Micro Manufacture ◽

10.1016/b978-008045263-0/50060-x ◽

2006 ◽

pp. 269-272 ◽

Cited By ~ 3

Author(s):

B. Sha ◽

S. Dimov ◽

C. Griffiths ◽

M.S. Packianather

Keyword(s):

Injection Moulding ◽

Factors Affecting ◽

Micro Injection Moulding ◽

Replication Quality ◽

Micro Features

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Characterization Methods of Nano-Patterned Surfaces Generated by Induction Heating Assisted Injection Molding

International Journal of Automation Technology ◽

10.20965/ijat.2015.p0349 ◽

2015 ◽

Vol 9 (4) ◽

pp. 349-355

Author(s):

Stefano Menotti ◽

◽

Giuliano Bissacco ◽

Hans Nørgaard Hansen ◽

Peter Torben Tang ◽

...

Keyword(s):

Injection Molding ◽

Induction Heating ◽

Process Condition ◽

Heating System ◽

Patterned Surfaces ◽

Quantitative Characterization ◽

Characterization Methods ◽

Replication Quality

An induction heating-assisted injection molding (IHAIM) process developed by the authors is used to replicate surfaces containing random nano-patterns. The injection molding setup is developed so that an induction heating system rapidly heats the cavity wall at rates of up to 10°C/s. In order to enable the optimization of the IHAIM process for nano-pattern replication, it is necessary to develop robust methods for quantitative characterization of the replicated nano-patterns. For this purpose, three different approaches for quantitative characterization of random nano-patterns are applied and compared. Results show that the use of IHAIM is an efficient way to improve replication quality. All three measurement methods are capable of detecting the trend of the replication quality of the surface changing the process condition.

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Filling-to-Packing Switchover Mode Based on Cavity Pressure for Injection Molding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.501.168 ◽

2012 ◽

Vol 501 ◽

pp. 168-173 ◽

Cited By ~ 1

Author(s):

Jian Wang

Keyword(s):

Injection Molding ◽

Crucial Role ◽

Mold Temperature ◽

The Other ◽

Injection Time ◽

Cavity Pressure ◽

Part Quality ◽

Molded Parts ◽

Screw Position

Filling-to-packing switchover control during injection molding plays a crucial role in ensuring the quality of the molded parts. In this study, a filling-to-packing switchover mode based on cavity pressure was presented, and it was compared with other two switchover modes by injection time and screw position. The objective of this study was to validate the accuracy of the switchover mode based on cavity pressure, and examine its consistency. Weight of the molded parts served as the main measure to probe the process capabilities. In this study, the change in mold temperature was monitored; variation of mold temperature affecting the process was examined. The results of the verification experiments revealed that the switchover mode based on cavity pressure could yield a better part quality and consistent part weight compared with the other two traditional switchover modes. It was proved that the switchover mode by cavity pressure can be used to improve the precision of the injection molding. However, a suitable switchover pressure must be used for achieving such high process capability, and the position to get the pressure signal and mold temperature should also be considered.

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DYNAMIC TEMPERATURE CONTROL INFLUENCE ON PRESSURE DURING INJECTION MOLDING OF PLASTIC PARTS TO IMPROVE PART QUALITY

International Journal for Quality Research ◽

10.24874/ijqr14.02-19 ◽

2020 ◽

Vol 14 (2) ◽

pp. 635-646

Author(s):

Luís Correia ◽

◽

Gilberto Santos ◽

António M. Brito ◽

Luís Faria ◽

...

Keyword(s):

Injection Molding ◽

Temperature Control ◽

Dynamic Temperature ◽

Part Quality ◽

Plastic Parts

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Experimental study on the replication quality of micro–nano cross-shaped structure arrays in injection molding

Microsystem Technologies ◽

10.1007/s00542-016-2819-1 ◽

2016 ◽

Vol 23 (4) ◽

pp. 983-989 ◽

Cited By ~ 11

Author(s):

Mingyong Zhou ◽

Bingyan Jiang ◽

Can Weng ◽

Lu Zhang

Keyword(s):

Experimental Study ◽

Injection Molding ◽

Replication Quality

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The Deformation Analysis and Optimization of the Injection Molded Parts Based on the Moldflow and Minitab Software

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.1180 ◽

2013 ◽

Vol 753-755 ◽

pp. 1180-1183 ◽

Cited By ~ 1

Author(s):

Na Li ◽

Hong Bin Liu ◽

Hai Tao Wu

Keyword(s):

Injection Molding ◽

Process Parameters ◽

Optimization Design ◽

Deformation Analysis ◽

Molded Parts ◽

Injection Molded ◽

The Common ◽

Plastic Parts ◽

Cae Technology

The deformation seriously affects the quality of the products, which is one of the common defects of plastic parts in the injection molding. Factorial design and CAE technology was used to study the product's warping rate influence in this paper. The minimum warping rate was obtained through the Minitab software and the optimized process parameters are verified with the Moldflow software. Experimental results show that the optimization design is effective and the warpage of the product is reduced.

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