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Four sustainable materials including a recycled polypropylene blend, polybutylene adipate terephthalate, and two grades of polylactic acid are compared to a reference isotactic polypropylene. Tensile specimens were produced using a two-cavity, hot runner mold with fully automatic cycles per standard industrial practices to investigate the effect of melt temperature, injection velocity, cycle time, and screw speed on the mechanical properties. Multiple regression and principal component analyses were performed for each of the materials. Results indicated that all the materials were readily processed using a hot runner, and the mechanical properties exhibited minimal variation. To the extent that losses in mechanical properties were observed, the results indicated that the losses were correlated with thermal degradation as independently characterized by thermal gravimetric analysis. Such losses can be minimized by reducing melt temperature and cycle time, leading to a reduction of the environmental impact of injection molding processes.
David Kazmer; Davide Masato; Leonardo Piccolo; Kyle Puleo; Joshua Krantz; Varun Venoor; Austin Colon; Justin Limkaichong; Neil Dewar; Denis Babin; Cheryl Sayer. Multivariate Modeling of Mechanical Properties for Hot Runner Molded Bioplastics and a Recycled Polypropylene Blend. Sustainability 2021, 13, 8102 .
AMA StyleDavid Kazmer, Davide Masato, Leonardo Piccolo, Kyle Puleo, Joshua Krantz, Varun Venoor, Austin Colon, Justin Limkaichong, Neil Dewar, Denis Babin, Cheryl Sayer. Multivariate Modeling of Mechanical Properties for Hot Runner Molded Bioplastics and a Recycled Polypropylene Blend. Sustainability. 2021; 13 (14):8102.
Chicago/Turabian StyleDavid Kazmer; Davide Masato; Leonardo Piccolo; Kyle Puleo; Joshua Krantz; Varun Venoor; Austin Colon; Justin Limkaichong; Neil Dewar; Denis Babin; Cheryl Sayer. 2021. "Multivariate Modeling of Mechanical Properties for Hot Runner Molded Bioplastics and a Recycled Polypropylene Blend." Sustainability 13, no. 14: 8102.
Compressibility and viscosity of polymer feedstock are critical to their volumetric flow rate, weld strength, and dimensional accuracy in material extrusion additive manufacturing. In this work, the compressibility and viscosity of an acrylonitrile butadiene styrene (ABS) material is characterized with an instrumented hot end design. Experiments are first performed with a blocked nozzle to characterize the compressibility behavior. The results closely emulate the pressure-volume-temperature (PVT) behavior of a characterized generic ABS. Experiments are then performed with an open nozzle over a range of volumetric flow rates and temperatures. The static pressure data is fit to power-law, Ellis, and Cross viscosity models and the dynamic melt pressure data is then used to jointly fit material constitutive models for compressibility and viscosity. The results suggest that the joint fitting substantially improves the fidelity relative to the separately characterized viscosity and compressibility. The implemented methods support material extrusion process simulation and control including real-time identification of process faults such as (1) limited melting capacity of the hot end, (2) skipping (grinding) of the extruder drive gears, (3) low initial nozzle temperature, (4) varying flow rates associated with the intermeshing gear tooth velocity profile, and (5) delays and reduced melt pressures due to drool prior to extrusion. The ability to monitor the printing process for faults in real time, such as that presented in this work, is critical to born qualified parts. Additionally, these approaches can be used to screen new materials and identify optimal processing conditions that avoid these process faults.
David O. Kazmer; Austin R. Colon; Amy M. Peterson; Sun Kyoung Kim. Concurrent characterization of compressibility and viscosity in extrusion-based additive manufacturing of acrylonitrile butadiene styrene with fault diagnoses. Additive Manufacturing 2021, 46, 102106 .
AMA StyleDavid O. Kazmer, Austin R. Colon, Amy M. Peterson, Sun Kyoung Kim. Concurrent characterization of compressibility and viscosity in extrusion-based additive manufacturing of acrylonitrile butadiene styrene with fault diagnoses. Additive Manufacturing. 2021; 46 ():102106.
Chicago/Turabian StyleDavid O. Kazmer; Austin R. Colon; Amy M. Peterson; Sun Kyoung Kim. 2021. "Concurrent characterization of compressibility and viscosity in extrusion-based additive manufacturing of acrylonitrile butadiene styrene with fault diagnoses." Additive Manufacturing 46, no. : 102106.
The nozzle pressure was monitored in a fused filament fabrication process for the printing of high impact polystyrene. The contact pressure, defined as the pressure applied by the newly deposited layer onto the previous layer, is experimentally calculated as the difference between the pressure during printing and open discharge at the same volumetric flow rates. An analytical method for estimating the contact pressure, assuming one-dimensional steady isothermal flow, is derived for the Newtonian, power-law, and Cross model dependence of shear rates. A design of experiments was performed to characterize the contact pressure as a function of the road width, road height, and print speed. Statistical analysis of the results suggests that the contribution of the pressure driven flow is about twice that of the drag flow in determining contact pressure, which together describe about 60% of the variation in the observed contact pressure behavior. Modeling of the elastic and normal stresses at the nozzle orifice explains an additional 30% of the observed behavior, indicating that careful rheological modeling is required to successfully predict contact pressure.
Sun Kyoung Kim; David O. Kazmer; Austin R. Colon; Timothy J. Coogan; Amy M. Peterson. Non-Newtonian modeling of contact pressure in fused filament fabrication. Journal of Rheology 2021, 65, 27 -42.
AMA StyleSun Kyoung Kim, David O. Kazmer, Austin R. Colon, Timothy J. Coogan, Amy M. Peterson. Non-Newtonian modeling of contact pressure in fused filament fabrication. Journal of Rheology. 2021; 65 (1):27-42.
Chicago/Turabian StyleSun Kyoung Kim; David O. Kazmer; Austin R. Colon; Timothy J. Coogan; Amy M. Peterson. 2021. "Non-Newtonian modeling of contact pressure in fused filament fabrication." Journal of Rheology 65, no. 1: 27-42.
Polyamides (PAs) are repeatedly exposed to environments of varying humidity throughout their service life. Due to their hygroscopic nature, moisture diffusion can alter the polymer properties, sometimes irreversibly. It has been previously found that the effect of transport of water on the structure, morphology, and physical properties of polymers is not negligibly small. In certain semi-crystalline polyamides, the diffusion coefficient has been shown to be governed by the local chain dynamics (β relaxation). The final molecular weight of PAs achieved after melt processing is a result of the equilibrium between the forward and reverse polycondensation depending on the water concentration. With the growing demand for unreinforced and reinforced polyamides as well as polyamide fibers in high-performance applications, it is critical to understand the physics of the interaction between water molecules and polymer or composite systems. This article reviews the existing literature about polyamide-water interactions with a focus on the governing physical laws of moisture transport within the polyamide matrix, drying kinetics, and dynamics of water in the polymer system. The implications of moisture on the processing and properties of the polyamides class of materials are also discussed, suggesting the need for best practices in instrumentation and control.
Varun Venoor; Jay Hoon Park; David O Kazmer; Margaret J Sobkowicz. Understanding the Effect of Water in Polyamides: A Review. Polymer Reviews 2020, 61, 598 -645.
AMA StyleVarun Venoor, Jay Hoon Park, David O Kazmer, Margaret J Sobkowicz. Understanding the Effect of Water in Polyamides: A Review. Polymer Reviews. 2020; 61 (3):598-645.
Chicago/Turabian StyleVarun Venoor; Jay Hoon Park; David O Kazmer; Margaret J Sobkowicz. 2020. "Understanding the Effect of Water in Polyamides: A Review." Polymer Reviews 61, no. 3: 598-645.
Material extrusion is a popular process for both prototyping and digital manufacturing, yet it is lacking in terms of part strength, feature resolution, and production rate relative to alternative processes. Injection printing addresses these issues by combining material extrusion of the outer surfaces of the part at fine resolution with injection molding of larger interior cavities at high flow rates. Injection printing thus aims to utilize the full melting capacity of material extrusion printers to mitigate the curse of dimensionality that plagues additive manufacturing. Simple governing models for flow in the formed cavities as well as the stress and deflection of the shell walls are presented. To validate the performance of injection printing relative to material extrusion, impact specimens and tensile bars were printed of acrylonitrile butadiene styrene (ABS). The tensile and impact results of the samples were compared, and image analysis was performed on the post-test samples. It was found that injection printing increased print speeds by an average factor of 3.2 relative to conventional material extrusion using the same linear print velocities. With respect to properties, the stiffness, strength, and strain to failure of injection printed tensile bars (in-plane) were respectively increased by 21 %, 47 %, and 35 % compared to material extrusion. Properties of impact specimen and vertically printed tensile bars also showed promising gains albeit with constraints related to the printer’s melting capacity. Even still, injection printing is shown as a broadly applicable and readily accessible process for increasing part strength and production rate while enabling improved feature resolution without greatly extended print times.
David O. Kazmer; Austin Colon. Injection printing: additive molding via shell material extrusion and filling. Additive Manufacturing 2020, 36, 101469 .
AMA StyleDavid O. Kazmer, Austin Colon. Injection printing: additive molding via shell material extrusion and filling. Additive Manufacturing. 2020; 36 ():101469.
Chicago/Turabian StyleDavid O. Kazmer; Austin Colon. 2020. "Injection printing: additive molding via shell material extrusion and filling." Additive Manufacturing 36, no. : 101469.
The interlayer strengths of parts produced through material extrusion (also referred to as fused filament fabrication or FFF) suffer due to poor interlayer contact and insufficient diffusion. A model for predicting interlayer contact, based on pressure-driven flow, is combined with a model for polymer chain diffusion to predict the interlayer strength (aka, bond strength) of material extrusion parts. Interlayer contact is predicted based on in-line pressure measurements while diffusion is predicted based on in-line temperature and viscosity measurements, demonstrating that a combination of the appropriate in-line sensors and models can be used for real-time monitoring and process control. The interlayer strength model is successfully validated against strength measurements of parts made with high impact polystyrene, indicating that the strength of all parts suffers due to incomplete interlayer contact while only some parts suffered from incomplete diffusive healing. The melt pressure and in-line rheological measurements have proven extremely valuable for understanding the material extrusion process, optimizing quality, and monitoring consistency. Practical insights from the model are provided about how to select appropriate materials and processing conditions, and it concludes with a demonstration of using the in-line sensors and real-time modeling for defect detection.
Timothy J Coogan; David O Kazmer. Prediction of interlayer strength in material extrusion additive manufacturing. Additive Manufacturing 2020, 35, 101368 .
AMA StyleTimothy J Coogan, David O Kazmer. Prediction of interlayer strength in material extrusion additive manufacturing. Additive Manufacturing. 2020; 35 ():101368.
Chicago/Turabian StyleTimothy J Coogan; David O Kazmer. 2020. "Prediction of interlayer strength in material extrusion additive manufacturing." Additive Manufacturing 35, no. : 101368.
Extrusion screw designs and validation are presented for three multiple channel, fractal screws for comparison with common general purpose, and barrier screws using an instrumented single screw extruder with high impact polystyrene (HIPS) and low density polyethylene (LDPE) at varying screw speeds. The fractal screws are designed with multiple channels and pressure–volume–temperature relations to control shear heating with cooling by adiabatic decompression. The general‐purpose design had the highest throughput but did not provide sufficient mixing and so resulted in excessive variation in the melt temperature and pressure at screw speeds above 40 RPM. The barrier screw was a capable design with good performance for LDPE and HIPS with screw speeds from 20 to 60 RPM. However, it tended to provide excessive shear heating at higher screw speeds due to the large surface area of the barrier and mixing sections. The first fractal screw design was a multichannel variant of the general‐purpose design and exhibited good consistency but excessive heating due to the large bearing area between the flights and barrel. The second fractal screw design provided decompression in the feed zone and metering zone to improve throughput but was limited by a poor transition section design. The third fractal screw design remedied these deficiencies with an improved transition section and intermittent clearances for dispersive mixing. Its performance rivaled that of the barrier screw with respect to volumetric output and energy efficiency but provided better melt pressure consistency. Cold screw freezing experiments were performed for all five screws with 5% black, blue, and violet colorants serially added to neat HIPS. The cold screw pulls showed that the general purpose and barrier screws exhibited significant racing of the materials within their screw channels and, thus, broad residence time distributions. Examination of the material cross sections indicated persistent coiled sheet morphologies, which were best dispersed with the third fractal screw. POLYM. ENG. SCI., 2020. © 2020 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers.
David O. Kazmer; Clemens M. Grosskopf; David Rondeau; Varun Venoor. Design and Evaluation of General Purpose, Barrier, and Multichannel Plasticating Extrusion Screws. Polymer Engineering & Science 2020, 60, 752 -764.
AMA StyleDavid O. Kazmer, Clemens M. Grosskopf, David Rondeau, Varun Venoor. Design and Evaluation of General Purpose, Barrier, and Multichannel Plasticating Extrusion Screws. Polymer Engineering & Science. 2020; 60 (4):752-764.
Chicago/Turabian StyleDavid O. Kazmer; Clemens M. Grosskopf; David Rondeau; Varun Venoor. 2020. "Design and Evaluation of General Purpose, Barrier, and Multichannel Plasticating Extrusion Screws." Polymer Engineering & Science 60, no. 4: 752-764.
An in-line rheometer and data acquisition system are used to monitor the melt pressure, melt temperature, and environmental temperatures while producing parts via fused filament fabrication (FFF). Melt pressures are observed to increase when printing parts with small layer heights, which is attributed to the confined space created between the nozzle and the previous layer (i.e., an exit pressure). These exit pressures (referred to as contact pressure) and the resulting interlayer contact areas are analyzed for 2863 layers created at 21 different processing conditions. The measured contact pressure was found to directly influence the shape of the layers and the resulting interlayer contact. An intimate contact model based on contact pressure is combined with a wetting model to accurately predict the interlayer contact of FFF parts. This pressure-driven intimate contact model for FFF shows strong agreement with the observed interlayer contact. No theoretical model has previously existed for predicting interlayer contact, so this research provides a critical component for developing a comprehensive part strength model. Both the measurements and proposed model are sufficiently simple and accurate for real-time analysis of FFF quality, so the described in-line sensors provide valuable quality insights and are recommended for future researchers, printer manufacturers, and end-users.
Timothy J. Coogan; David O. Kazmer. Modeling of interlayer contact and contact pressure during fused filament fabrication. Journal of Rheology 2019, 63, 655 -672.
AMA StyleTimothy J. Coogan, David O. Kazmer. Modeling of interlayer contact and contact pressure during fused filament fabrication. Journal of Rheology. 2019; 63 (4):655-672.
Chicago/Turabian StyleTimothy J. Coogan; David O. Kazmer. 2019. "Modeling of interlayer contact and contact pressure during fused filament fabrication." Journal of Rheology 63, no. 4: 655-672.
An in-line rheometer has been incorporated into a fused deposition modeling printer for the first time by designing a modified nozzle with a custom pressure transducer and a thermocouple for measuring the processed melt temperature. Additionally, volumetric flow rates and shear rates were monitored by counting the stepper motor pulses as well as the pulses from a custom filament encoder to account for filament slippage and skipped motor steps. The incorporation of the sensors and the design and development of the in-line rheometer are described; and pressures, temperatures, and viscosities within the 3D printing nozzle are presented. The in-line rheometer was validated against traditional, off-line rotational rheology and capillary rheology measurements by analyzing two polymeric materials: polycarbonate and high-impact polystyrene. A variety of rheological corrections were considered for the in-line rheometer, including entrance effects, non-Newtonian corrections, shear heating, pressure effects, and temperature fluctuations/inaccuracies. Excellent agreement was obtained between the in-line and off-line rheometers after applying the most critical corrections, which were found to be entrance effects, non-Newtonian corrections, and temperature inaccuracies. After applying the appropriate corrections, the in-line rheometer provides an accurate viscosity measurement that can be used for real-time monitoring and process control.
Timothy J. Coogan; David O. Kazmer. In-line rheological monitoring of fused deposition modeling. Journal of Rheology 2019, 63, 141 -155.
AMA StyleTimothy J. Coogan, David O. Kazmer. In-line rheological monitoring of fused deposition modeling. Journal of Rheology. 2019; 63 (1):141-155.
Chicago/Turabian StyleTimothy J. Coogan; David O. Kazmer. 2019. "In-line rheological monitoring of fused deposition modeling." Journal of Rheology 63, no. 1: 141-155.
Variances in polymers processed by single-screw extrusion are investigated. While vortical flows are well known in the fluids community and fountain flows are well known to be caused by the frozen layers in injection molding, our empirical evidence and process modeling suggests the presence of vortical fountain flows in the melt channels of plasticating screws adjacent to a slower-moving solids bed. The empirical evidence includes screw freezing experiments with cross-sections of processed high-impact polystyrene (HIPS) blended with varying colorants. Non-isothermal, non-Newtonian process simulations indicate that the underlying causality is increased flow conductance in the melt pool caused by higher temperatures and shear rates in the recirculating melt pool. The results indicate the development of persistent, coiled sheet morphologies in both general purpose and barrier screw designs. The behavior differs significantly from prior melting and plastication models with the net effect of broader residence time distributions. The process models guide potential strategies for the remediation of the processing variances as well as potential opportunities to achieve improved dispersion as well as complex micro and nanostructures in polymer processing.
David O. Kazmer; Clemens M. Grosskopf; Varun Venoor. Vortical Fountain Flows in Plasticating Screws. Polymers 2018, 10, 823 .
AMA StyleDavid O. Kazmer, Clemens M. Grosskopf, Varun Venoor. Vortical Fountain Flows in Plasticating Screws. Polymers. 2018; 10 (8):823.
Chicago/Turabian StyleDavid O. Kazmer; Clemens M. Grosskopf; Varun Venoor. 2018. "Vortical Fountain Flows in Plasticating Screws." Polymers 10, no. 8: 823.
Multisensor data fusion can enable comprehensive representation of manufacturing processes, thereby contributing to improved part quality control. The effectiveness of data fusion depends on the nature of the input data. This paper investigates orthogonality as a measure for the effectiveness of data fusion, with the goal to maximize data correlation with part quality toward manufacturing process control. By decomposing sensor data into a lifted-dimensional space, contribution from each of the sensors for quantifying part quality is revealed by the corresponding projection vector. Performance evaluation using data measured from polymer injection molding confirmed the effectiveness of the developed technique.
Peng Wang; Zhaoyan Fan; David O. Kazmer; Robert X. Gao. Orthogonal Analysis of Multisensor Data Fusion for Improved Quality Control. Journal of Manufacturing Science and Engineering 2017, 139, 1 .
AMA StylePeng Wang, Zhaoyan Fan, David O. Kazmer, Robert X. Gao. Orthogonal Analysis of Multisensor Data Fusion for Improved Quality Control. Journal of Manufacturing Science and Engineering. 2017; 139 (10):1.
Chicago/Turabian StylePeng Wang; Zhaoyan Fan; David O. Kazmer; Robert X. Gao. 2017. "Orthogonal Analysis of Multisensor Data Fusion for Improved Quality Control." Journal of Manufacturing Science and Engineering 139, no. 10: 1.
Purpose The purpose of this paper is to present a diffusion-controlled healing model for predicting fused deposition modeling (FDM) bond strength between layers (z-axis strength). Design/methodology/approach Diffusion across layers of an FDM part was predicted based on a one-dimensional transient heat analysis of the interlayer interface using a temperature-dependent diffusion model determined from rheological data. Integrating the diffusion coefficient across the temperature history with respect to time provided the total diffusion used to predict the bond strength, which was compared to the measured bond strength of hollow acrylonitrile butadiene styr (ABS) boxes printed at various processing conditions. Findings The simulated bond strengths predicted the measured bond strengths with a coefficient of determination of 0.795. The total diffusion between FDM layers was shown to be a strong determinant of bond strength and can be similarly applied for other materials. Research limitations/implications Results and analysis from this paper should be used to accurately model and predict bond strength. Such models are useful for FDM part design and process control. Originality/value This paper is the first work that has predicted the amount of polymer diffusion that occurs across FDM layers during the printing process, using only rheological material properties and processing parameters.
Timothy J. Coogan; David O. Kazmer. Healing simulation for bond strength prediction of FDM. Rapid Prototyping Journal 2017, 23, 551 -561.
AMA StyleTimothy J. Coogan, David O. Kazmer. Healing simulation for bond strength prediction of FDM. Rapid Prototyping Journal. 2017; 23 (3):551-561.
Chicago/Turabian StyleTimothy J. Coogan; David O. Kazmer. 2017. "Healing simulation for bond strength prediction of FDM." Rapid Prototyping Journal 23, no. 3: 551-561.
Purpose The purpose of this paper is to investigate the factors governing bond strength in fused deposition modeling (FDM) compared to strength in the fiber direction. Design/methodology/approach Acrylonitrile butadiene styrene (ABS) boxes with the thickness of a single fiber were made at different platform and nozzle temperatures, print speeds, fiber widths and layer heights to produce multiple specimens for measuring the strength. Findings Specimens produced with the fibers oriented in the tensile direction had 95 per cent of the strength of the constitutive filament. Bond strengths ranged from 40 to 85 per cent of the filament strength dependent on the FDM processing conditions. Diffusion, wetting and intimate contact all separately affect bond strength. Practical implications This study provides processing recommendations for producing the strongest FDM parts. The needs for higher nozzle temperatures and more robust feed motors are described; these recommendations can be useful for companies producing FDM products as well as companies designing FDM printers. Originality/value This is the first study that discusses wetting and intimate contact separately in FDM, and the results suggest that a fundamental, non-empirical model for predicting FDM bond strength can be developed based on healing models. Additionally, the role of equilibration time at the start of extrusion as well as a motor torque limitation while trying to print at high speeds are described.
Timothy J. Coogan; David Owen Kazmer. Bond and part strength in fused deposition modeling. Rapid Prototyping Journal 2017, 23, 414 -422.
AMA StyleTimothy J. Coogan, David Owen Kazmer. Bond and part strength in fused deposition modeling. Rapid Prototyping Journal. 2017; 23 (2):414-422.
Chicago/Turabian StyleTimothy J. Coogan; David Owen Kazmer. 2017. "Bond and part strength in fused deposition modeling." Rapid Prototyping Journal 23, no. 2: 414-422.
A multivariate sensor is described for intelligent polymer processing that incorporates a piezoelectric ring to acquire melt pressure as well as a thermopile to acquire melt temperature and mold temperature. The mechatronic system analyzes the process states according to mechanistic relations to estimate the melt velocity and melt viscosity. Validation experiments are implemented to characterize the sensor's performance against an array of commercial sensors. Models of product quality with the described sensor far outperform those based on data from commercial sensors. While system identification of the transient thermopile voltage indicates an underdamped response that limited the model fidelity, the existing capability suggests a new standard for mold design that incorporates multivariate sensors into the runner system to provide a consistent set of physical states for process tuning irrespective of molding machine manufacturer and model.
David O. Kazmer; Guthrie W. Gordon; Gabriel A. Mendible; Stephen P. Johnston; Xinyao Tang; Zhaoyan Fan; Robert X. Gao. A Multivariate Sensor for Intelligent Polymer Processing. IEEE/ASME Transactions on Mechatronics 2014, 20, 1015 -1023.
AMA StyleDavid O. Kazmer, Guthrie W. Gordon, Gabriel A. Mendible, Stephen P. Johnston, Xinyao Tang, Zhaoyan Fan, Robert X. Gao. A Multivariate Sensor for Intelligent Polymer Processing. IEEE/ASME Transactions on Mechatronics. 2014; 20 (3):1015-1023.
Chicago/Turabian StyleDavid O. Kazmer; Guthrie W. Gordon; Gabriel A. Mendible; Stephen P. Johnston; Xinyao Tang; Zhaoyan Fan; Robert X. Gao. 2014. "A Multivariate Sensor for Intelligent Polymer Processing." IEEE/ASME Transactions on Mechatronics 20, no. 3: 1015-1023.
David O. Kazmer. System identification and modeling of viscoelastic behavior from capillary melt rheological data. Polymer Engineering & Science 2014, 54, 2824 -2838.
AMA StyleDavid O. Kazmer. System identification and modeling of viscoelastic behavior from capillary melt rheological data. Polymer Engineering & Science. 2014; 54 (12):2824-2838.
Chicago/Turabian StyleDavid O. Kazmer. 2014. "System identification and modeling of viscoelastic behavior from capillary melt rheological data." Polymer Engineering & Science 54, no. 12: 2824-2838.
Robert X. Gao; Xinyao Tang; Guthrie Gordon; David O. Kazmer. Online product quality monitoring through in-process measurement. CIRP Annals 2014, 63, 493 -496.
AMA StyleRobert X. Gao, Xinyao Tang, Guthrie Gordon, David O. Kazmer. Online product quality monitoring through in-process measurement. CIRP Annals. 2014; 63 (1):493-496.
Chicago/Turabian StyleRobert X. Gao; Xinyao Tang; Guthrie Gordon; David O. Kazmer. 2014. "Online product quality monitoring through in-process measurement." CIRP Annals 63, no. 1: 493-496.
Improving process observability is of high relevancy to improved manufacturing process control. This paper describes a novel measurement technique using acoustic waves for the transmission of multiple physical parameters from within the cavity of an injection mold to a receiver outside: temperature, pressure, velocity, and viscosity of polymer melt. Such a technique is a key to improved monitoring and control of plastic injection molding. A coded-acoustic wave modulation scheme enables multiparameter transmission through an acoustic transmitter with variable gains. This enables selective resonant frequencies that provide the carriers for the individual parameters to be transmitted, while suppressing noise induced in the modulation process. The presented acoustic wireless sensing method is applicable to a wide range of process monitoring scenarios.
Zhaoyan Fan; Robert X. Gao; Navid Asadizanjani; David O. Kazmer. Acoustic Wave-Based Data Transmission for Multivariate Sensing. IEEE Transactions on Instrumentation and Measurement 2013, 62, 3026 -3034.
AMA StyleZhaoyan Fan, Robert X. Gao, Navid Asadizanjani, David O. Kazmer. Acoustic Wave-Based Data Transmission for Multivariate Sensing. IEEE Transactions on Instrumentation and Measurement. 2013; 62 (11):3026-3034.
Chicago/Turabian StyleZhaoyan Fan; Robert X. Gao; Navid Asadizanjani; David O. Kazmer. 2013. "Acoustic Wave-Based Data Transmission for Multivariate Sensing." IEEE Transactions on Instrumentation and Measurement 62, no. 11: 3026-3034.
Robert X. Gao; David O. Kazmer. Multivariate sensing and wireless data communication for process monitoring in RF-shielded environment. CIRP Annals 2012, 61, 523 -526.
AMA StyleRobert X. Gao, David O. Kazmer. Multivariate sensing and wireless data communication for process monitoring in RF-shielded environment. CIRP Annals. 2012; 61 (1):523-526.
Chicago/Turabian StyleRobert X. Gao; David O. Kazmer. 2012. "Multivariate sensing and wireless data communication for process monitoring in RF-shielded environment." CIRP Annals 61, no. 1: 523-526.
A MATLAB programme has been developed for simulation of polymer blend self-assembly with nanoscaled features. The Cahn-Hilliard equation is implemented to calculate the free energy profile of the polymer blends. The Flory-Huggins type of energy is used to estimate the local free energy. This programme is capable to quantitatively simulate the phase separation of polymer blends. The effects of the substrate functionalisation, solvent evaporation and polymer materials properties are considered in the programme. Researchers can use the programme to estimate the model parameters from the real experimental processing parameters and the material properties. The simulation results can be evaluated quantitatively and compared with the experimental results with analysis tools provided with the programme.
Yingrui Shang; David Kazmer. A MATLAB programme for quantitative simulation of self-assembly of polymer blend films with nanoscaled features. International Journal of Computer Aided Engineering and Technology 2012, 4, 181 -192.
AMA StyleYingrui Shang, David Kazmer. A MATLAB programme for quantitative simulation of self-assembly of polymer blend films with nanoscaled features. International Journal of Computer Aided Engineering and Technology. 2012; 4 (2):181-192.
Chicago/Turabian StyleYingrui Shang; David Kazmer. 2012. "A MATLAB programme for quantitative simulation of self-assembly of polymer blend films with nanoscaled features." International Journal of Computer Aided Engineering and Technology 4, no. 2: 181-192.
The directed self-assembly of polymer-polymer-solvent ternary blends on heterogeneously functionalized substrate is investigated with a three dimensional numerical model. The numerical simulation results are quantitatively verified by the experimental results. The phase separation of PS-PMMA-DMF blends are spin coated on a substrate functionalized by ODT/2NHNH2 on Au surface. While many simulation parameters are set to the experimental conditions, other unmeasurable material constitutive model parameters are estimated from the real experiment observations. The effects of the spin speed, pattern periodicity, PS/PAA composition ratio, and the PAA molecular weight are investigated in both the experiments and numerical simulation. The simulation results are verified by comparison to the experimental results. During the verification process, numerical optimization methods are employed to determine the unmeasurable physical parameters. Quantitative methods are introduced for assessment of the results.
Yingrui Shang; Liang Fang; Ming Wei; Carol Barry; Joey Mead; David Kazmer. Verification of numerical simulation of the self-assembly of polymer-polymer-solvent ternary blends on a heterogeneously functionalized substrate. Polymer 2011, 52, 1447 -1457.
AMA StyleYingrui Shang, Liang Fang, Ming Wei, Carol Barry, Joey Mead, David Kazmer. Verification of numerical simulation of the self-assembly of polymer-polymer-solvent ternary blends on a heterogeneously functionalized substrate. Polymer. 2011; 52 (6):1447-1457.
Chicago/Turabian StyleYingrui Shang; Liang Fang; Ming Wei; Carol Barry; Joey Mead; David Kazmer. 2011. "Verification of numerical simulation of the self-assembly of polymer-polymer-solvent ternary blends on a heterogeneously functionalized substrate." Polymer 52, no. 6: 1447-1457.