scholarly journals System Performance and Process Capability in Additive Manufacturing: Quality Control for Polymer Jetting

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1292
Author(s):  
Razvan Udroiu ◽  
Ion Cristian Braga
Keyword(s):  
Additive Manufacturing ◽  
Mass Production ◽  
Production Management ◽  
Process Capability ◽  
High Volume ◽  
Thin Layers ◽  
Tolerance Interval ◽  
Statistical Process ◽  
Radial Dimension ◽  
Short Time

Polymer-based additive manufacturing (AM) gathers a great deal of interest with regard to standardization and implementation in mass production. A new methodology for the system and process capabilities analysis in additive manufacturing, using statistical quality tools for production management, is proposed. A large sample of small specimens of circular shape was manufactured of photopolymer resins using polymer jetting (PolyJet) technology. Two critical geometrical features of the specimen were investigated. The variability of the measurement system was determined by Gage repeatability and reproducibility (Gage R&R) methodology. Machine and process capabilities were performed in relation to the defined tolerance limits and the results were analyzed based on the requirements from the statistical process control. The results showed that the EDEN 350 system capability and PolyJet process capability enables obtaining capability indices over 1.67 within the capable tolerance interval of 0.22 mm. Furthermore, PolyJet technology depositing thin layers of resins droplets of 0.016 mm allows for manufacturing in a short time of a high volume of parts for mass production with a tolerance matching the ISO 286 IT9 grade for radial dimension and IT10 grade for linear dimensions on the Z-axis, respectively. Using microscopy analysis some results were explained and validated from the capability study.

A Low Volume Production Process Capability Analysis

2009 ◽  
Vol 16-19 ◽  
pp. 1038-1042
Author(s):  
Mark A. Harris ◽  
Diane J. Mynors ◽  
Chang J. Wang
Keyword(s):  
Data Gathering ◽  
Process Capability ◽  
High Volume ◽  
Machining Process ◽  
Statistical Process ◽  
Process Modification ◽  
Capability Indices ◽  
Capability Analysis ◽  
Before And After ◽  
Low Volume

Statistical Process Control (SPC) and Process Capability Indices (PCI) are used extensively within manufacturing and service environments. This paper reports the results of a statistical quality improvement programme when applied to a low volume, high gauge frequency machining process. The resultant capability indices (Cp and Cpk) are calculated from acquired data both before and after process modification, and are discussed in relation to the specific process. Box Cox data transformations are utilised in order to centralise data and the applicability of the capability improvements are determined. Historically SPC and capability analysis are performed on high volume processes with data being gathered on a sample basis. This investigation applies the high volume theory to a low volume 100% data gathering process. The validity of capability analysis of this nature is discussed due to long cycle times and large gauge inspection frequency.

scholarly journals Personalized Mass Production by Hybridization of Additive Manufacturing and Injection Molding

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 309
Author(s):  
Praveen Kannan Rajamani ◽  
Tatyana Ageyeva ◽  
József Gábor Kovács
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Mass Production ◽  
Bonding Strength ◽  
High Surface ◽  
High Volume ◽  
Fused Filament Fabrication ◽  
Injection Molded ◽  
The Creation ◽  
Manufacturing Techniques

The new trend in the composites industry, as dictated by Industry 4.0, is the personalization of mass production to match every customer’s individual needs. Such synergy can be achieved when several traditional manufacturing techniques are combined within the production of a single part. One of the most promising combinations is additive manufacturing (AM) with injection molding. AM offers higher production freedom in comparison with traditional techniques. As a result, even very sophisticated geometries can be manufactured by AM at a reasonable price. The bottleneck of AM is the production rate, which is several orders of magnitude slower than that of traditional plastic mass production technologies. On the other hand, injection molding is a manufacturing technique for high-volume production with little possibility of customization. The customization of injection-molded parts is usually very expensive and time-consuming. In this research, we offered a solution for the individualization of mass production, which includes 3D printing a baseplate with the subsequent overmolding of a rib element on it. We examined the bonding between the additive-manufactured component and the injection-molded component. As bonding strength between the coupled elements is significantly lower than the strength of the material, we proposed five strategies to improve bonding strength. The strategies are optimizing the printing parameters to obtain high surface roughness, creating an infill density in fused filament fabrication (FFF) parts, creating local infill density, creating microstructures, and incorporating fibers into the bonding area. We observed that the two most effective methods to increase bonding strength are the creation of local infill density and the creation of a microstructure at the contact area of FFF-printed and injection-molded elements. This increase was attributed to the porous structures that both methods created. The melt during injection molding flowed into these pores and formed micro-mechanical interlocking.

System framework of adopting additive manufacturing in mass production line

2021 ◽  
pp. 1-24
Author(s):  
Zhuming Bi ◽  
Guoping Wang ◽  
Joel Thompson ◽  
David Ruiz ◽  
John Rosswurm ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mass Production ◽  
Production Line ◽  
System Framework

scholarly journals Spreadability Testing of Powder for Additive Manufacturing

2021 ◽  
Vol 166 (1) ◽  
pp. 9-13
Author(s):  
Christopher Neil Hulme-Smith ◽  
Vignesh Hari ◽  
Pelle Mellin
Keyword(s):  
Additive Manufacturing ◽  
Layer Thickness ◽  
Measurement Procedure ◽  
Quantitative Information ◽  
Thin Layers ◽  
Spreading Speed ◽  
Powder Bed ◽  
Critical Step ◽  
Robust Image

AbstractThe spreading of powders into thin layers is a critical step in powder bed additive manufacturing, but there is no accepted technique to test it. There is not even a metric that can be used to describe spreading behaviour. A robust, image-based measurement procedure has been developed and can be implemented at modest cost and with minimal training. The analysis is automated to derive quantitative information about the characteristics of the spread layer. The technique has been demonstrated for three powders to quantify their spreading behaviour as a function of layer thickness and spreading speed.

Mass-Production Management

1974 ◽  
Vol 25 (2) ◽  
pp. 330-330
Author(s):  
F. de P. Hanika
Keyword(s):  
Mass Production ◽  
Production Management

Process Capability of Aerosol-Jet Additive Processes for Long-Runs Up to 10-Hours

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Pradeep Lall ◽  
Amrit Abrol ◽  
Nakul Kothari ◽  
Benjamin Leever ◽  
Scott Miller
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Process Capability ◽  
High Volume ◽  
Process Efficiency ◽  
Shear Load ◽  
Additive Processes ◽  
Sintering Time ◽  
Load To Failure ◽  
Aerosol Jet Printing

Abstract Traditionally, printed circuit assemblies have been fabricated through a combination of imaging and plating-based subtractive processes involving the use of photo-exposure followed by baths for plating and etching in order to form the necessary circuitry on rigid and flexible laminates. The emergence of a number of additive technologies presents an opportunity for the development of processes for manufacturing of flexible substrates by utilizing mainstream additive processes. Aerosol-jet printing is capable of printing lines and spaces below 10 μm in width. The aerosol-jet system also supports a wide variety of materials, including nanoparticle inks, screen-printing pastes, conductive polymers, insulators, adhesives, and biological matter. The adoption of additive manufacturing for high-volume commercial fabrication requires an understanding of the print consistency and electrical mechanical properties. Little literature that addresses the effect of varying sintering time and temperature on the shear strength and resistivity of the printed lines exists. In this study, the effect of process parameters on the resultant line consistency and mechanical and electrical properties has been studied. Print process parameters studied include sheath rate, mass flow rate, nozzle size, substrate temperature, and chiller temperature. Properties include resistance and shear load to failure of the printed electrical line as a function of varying sintering time and temperature. The aerosol-jet machine has been used to print interconnects. Printed samples have been exposed to different sintering times and temperatures. The resistance and shear load to failure of the printed lines have been measured. The underlying physics of the resultant trend was then investigated using elemental analysis and scanning electron microscopy. The effect of line consistency drift over prolonged runtimes has been measured for up to 10 h of runtime. The printing process efficiency has been gaged as a function of the process capability index (Cpk) and process capability ratio (Cp). Printed samples were studied offline utilizing optical profilometry in order to analyze the consistency within the line width, height, and resistance, and shear load to study the variance in electrical and mechanical properties over time.

scholarly journals Development of the correction procedure for High Volume Instrument elongation measurement

2019 ◽  
Vol 89 (19-20) ◽  
pp. 4095-4103 ◽  
Author(s):  
Kolby M McCormick ◽  
João Paulo Saraiva Morais ◽  
Eric Hequet ◽  
Brendan Kelly
Keyword(s):  
Independent Set ◽  
Main Tool ◽  
High Volume ◽  
Correction Method ◽  
Correction Procedure ◽  
Fiber Elongation ◽  
Direct Role ◽  
Acquisition Speed ◽  
New Varieties ◽  
Short Time

Cotton spinning mills need high-quality fibers to maintain their manufacturing efficiency. Machinery throughput is increasing and it could translate into more processes with higher breaking stress. Consequently, more fibers are susceptible to breaking or damage. To face this problem, breeders must develop new varieties whose fibers can better withstand this mechanical stress. The main tool utilized in cotton breeding programs is the High Volume Instrument (HVI), which reports in a short time measurements such as micronaire, length, color, and strength. This instrument can also determine fiber elongation, but there is no current correction method for it. Both elongation and strength factor into the work-to-break of fibers, which plays a direct role in fiber breakage and spinning performance. The objective of this work was to develop cotton elongation standards, devise a correction procedure for HVI lines, evaluate measurement stability, and validate these results with a set of independent samples. Two commercial bales, one with low and one with high HVI elongation, were identified as potential elongation standards. The potential standards were produced and evaluated. After validation, they were used to correct HVI lines against Stelometer (STrength-ELOngation-METER) measurements. An independent set of samples was tested on corrected HVIs to confirm the effectiveness of the elongation corrected measurements. The HVI data were at least as good as the Stelometer data, with increased data acquisition speed and precision. This research can help cotton breeders to improve fiber elongation and strength at the same time, resulting in better fibers for yarn spinning.

scholarly journals The Effect of Stepped Austempering on Phase Composition and Mechanical Properties of Nanostructured X37CrMoV5-1 Steel

2015 ◽  
Vol 60 (1) ◽  
pp. 517-521
Author(s):  
S. Marciniak ◽  
E. Skołek ◽  
W. Świątnicki
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
Isothermal Annealing ◽  
Volume Fraction ◽  
Bainitic Ferrite ◽  
High Volume ◽  
Thin Layers ◽  
Strength Parameters ◽  
One Step ◽  
Step Heat Treatment

AbstractThis paper presents the results of studies of X37CrMoV5-1 steel subjected to quenching processes with a one-step and a two-step isothermal annealing. The TEM observation revealed that steel after one-step treatment led is composed of carbide-free bainite with nanometric thickness of ferrite plates and of high volume fraction of retained austenite in form of thin layers or large blocks. In order to improve the strength parameters an attempt was made to reduce the austenite content by use of quenching with the two-step isothermal annealing. The temperature and time of each step were designed on the basis of dilatometric measurements. It was shown, that the two-step heat treatment led to increase of the bainitic ferrite content and resulted in improvement of steel's strength with no loss of steel ductility.

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