Product Fingerprints for the Evaluation of Tool/Polymer Replication Quality in Injection Molding at the Micro/Nano Scale

2021 ◽  
Author(s):  
Dario Loaldi ◽  
Francesco Regi ◽  
Dongya Li ◽  
Nikolaos Giannekas ◽  
Matteo Calaon ◽  
...  
Keyword(s):  
Injection Molding ◽  
Nano Scale ◽  
Replication Quality

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

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.

Comparison of Tooling Materials in Injection Molding of Microscale Features

2009 ◽  
Author(s):  
Sung-Hwan Yoon ◽  
Prabhu Palanisamy ◽  
Purushotham Padmanabha ◽  
Joey L. Mead ◽  
Carol M. F. Barry
Keyword(s):  
Aspect Ratio ◽  
Injection Molding ◽  
Optical Profilometry ◽  
Free Surfaces ◽  
Polymer Hybrid ◽  
Aspect Ratios ◽  
Replication Quality ◽  
Repeated Use ◽  
Metal Polymer ◽  
Scanning Electron

Although high aspect ratio micro and nanoscale polymer features have been replicated in a range of polymers using injection molding, researchers have also used tooling inserts with a range of sizes, aspect ratios, and tooling materials. In this work, microscale features with molded in polymethylmethacrylates using three types of tooling with similar features. The tooling materials included silicon wafers with an antistiction coating, gold-coated nickel inserts, and a metal-polymer hybrid tooling. Tooling was evaluated based on the ease of melt filling and part ejection; the replication quality as characterized using optical profilometry, confocal microscopy, and scanning electron microscopy; and the damage to the tooling after repeated use. With lower aspect ratio features, the tooling type did not significantly affect replication, but for higher aspect ratio features the hybrid tooling provided far better replication than the silicon tooling. This difference was attributed to retardation of heat transfer in the features of the hybrid tooling. All three tooling materials exhibited polymer-free surfaces after injection molding.

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

2018 ◽  
Vol 2 (4) ◽  
pp. 79
Author(s):  
Nikolaos Giannekas ◽  
Yang Zhang ◽  
Guido Tosello
Keyword(s):  
Injection Molding ◽  
Quality Monitoring ◽  
Efficient Production ◽  
Replication Fidelity ◽  
Part Quality ◽  
Replication Quality ◽  
Micro Features ◽  
Product And Process ◽  
Plastic Parts

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.

Effect of Micro-Injection Molding Processing Conditions on the Replication and Consistency of a Dense Network of High Aspect Ratio Microstructures

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
John W. Rodgers ◽  
Meghan E. Casey ◽  
Sabrina S. Jedlicka ◽  
John P. Coulter
Keyword(s):  
Injection Molding ◽  
Flow Rate ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Molding Process ◽  
Micro Injection Molding ◽  
Fluid Behavior ◽  
Replication Quality ◽  
Average Standard Error ◽  
Experimental Trials

When molding macroscale polymer parts with a high density of microfeatures (>1 × 106/cm2), a concern that presents itself is the ability to achieve uniform replication across the entire domain. In the given study, micro-injection molding was used to manufacture microfeatured polymer substrates containing over 10 × 106 microfeatures per cm2. Polystyrene (PS) plates containing microtopography were molded using different processing parameters to study the effect of flow rate and mold temperature on replication quality and uniformity. Flow rate was found to significantly affect replication at mold temperatures above the glass transition temperature (Tg) of PS while having no significant effect on filling at mold temperatures below Tg. Moreover, replication was dependent on distance from the main cavity entrance, with increased flow rate facilitating higher replication differentials and higher replication near the gate. Simulation of the molding process was used to corroborate experimental trials. A deeper understanding of polymer fluid behavior associated with micro-injection molding is vital to reliably manufacture parts containing consistent microtopography (Note: Values are expressed in average ± standard error).

Micro Metal Injection Molding Using Hybrid Micro/Nano Powders

2007 ◽  
Vol 534-536 ◽  
pp. 381-384 ◽  
Author(s):  
Kazuaki Nishiyabu ◽  
Kenichi Kakishita ◽  
Shigeo Tanaka
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Injection Molding ◽  
Binder Content ◽  
Metal Injection Molding ◽  
Molding Machine ◽  
Melt Viscosity ◽  
Nano Scale ◽  
Microstructure Density ◽  
Trial Efficiency

This study aims to investigate the effects of hybrid micro/nano powders in a micro metal injection molding (μ-MIM) process. A novel type of mixing-injection molding machine was used to produce tiny specimens (<1mm in size) with high trial efficiency using a small amount of feedstock (<0.05cm3 in volume). Small dumbbell specimens were produced using various feedstocks prepared by changing binder content and fraction of nano-scale Cu powder (130nm in particle size). The effects of adding the fraction of nano-scale Cu powder on the melt viscosity of the feedstock, microstructure, density and tensile strength of sintered parts were discussed.

Injection Molding Nano and Micro Pillar Arrays

2006 ◽  
Vol 326-328 ◽  
pp. 449-452
Author(s):  
Young Eun Yoo ◽  
Young Ho Seo ◽  
Seong Kon Kim ◽  
Tai Jin Je ◽  
Doo Sun Choi
Keyword(s):  
Injection Molding ◽  
Quartz Plate ◽  
The Other ◽  
Plastic Substrate ◽  
Nano Scale ◽  
Pillar Arrays ◽  
Injection Molded ◽  
Thin Plastic

An injection molding technology is developed to replicate pillars in micro/nano scale on the thin plastic substrate. Two types of pillar are to be replicated and one is square type of 10um x 10um, the other is circular type whose diameter is in range of 100 nm ~ 300 nm. For both types of the pillars, the height is about 250 nm. A pattern master is first fabricated on the photo resist(PR) layer spin coated to about 250nm of thickness on chrome/quartz plate by patterning e-beam writing and then developing the PR. The patterns on the PR master are transferred by nickel electro-plating to fabricate rigid nickel stamper. Using this nickel stamper, a substrate with nano pillars on its surface is injection molded by optimizing the conditions to fabricate DNA separating chip.

scholarly journals Molecular Dynamics Study on the Deformation Behaviors of Nanostructures in the Demolding Process of Micro-Injection Molding

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 470 ◽  
Author(s):  
Can Weng ◽  
Jin Yang ◽  
Dongjiao Yang ◽  
Bingyan Jiang
Keyword(s):  
Molecular Dynamics ◽  
Injection Molding ◽  
Mold Insert ◽  
Adhesion Energy ◽  
Molded Parts ◽  
Replication Quality ◽  
Deformation Behaviors ◽  
Dynamics Simulations ◽  
Polymer Nanostructure

Polymer parts with nanostructures have broad applications, possessing excellent optical, electrochemical, biological, and other functions. Injection molding technology is one of the main methods for mass production of polymer parts with various shapes and sizes. The demolding process is vital to the replication quality of molded parts with nanostructures. For this study, molecular dynamics simulations of polypropylene (PP), polymethyl methacrylate (PMMA), and cycloolefin copolymer (COC) were conducted for the demolding process. The average velocity, density distribution, adhesion energy, and demolding resistance were introduced to analyze the deformation behaviors of polymer nanostructure from a nickel nano-cavity with an aspect ratio of 2:1. The shoulders of nanostructures were firstly separated from the nickel mold insert in the simulation. Under the external demolding force of 0.07 nN, PP and PMMA could be successfully demolded with some deformations, while COC could not be completely demolded due to the greater adhesion energy between COC and Ni. It was found that the maximum adhesion energy occurred in the separation process between the shoulder of the nanostructure and Ni and the huge adhesion energy was the main cause of demolding defects. The velocity difference of the whole polymer layer and polymer nanostructure was further analyzed to explain the nanostructure deformation. In order to improve the quality of demolding, the external force applied on polymers should be properly increased.

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