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Search Publications by: Kalman Migler (Fed)

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Displaying 1 - 25 of 108

Temperature Dependence of Kinetic Friction: A Handle for Plastics Sorting?

February 26, 2024
Author(s)
Chad R. Snyder, Kalman Migler
Sortation is a crucial step in mechanical recycling of post-consumer plastics (PCR) whereby properties such as density or spectral signature are used to separate plastics. However it is difficult to sort polyolefin flakes at high throughput by these

Crystallization Kinetics in an Immiscible Polyolefin Blend

December 12, 2022
Author(s)
Derek Huang, Anthony Kotula, Chad R. Snyder, Kalman Migler
Motivated by the problem of brittle mechanical behavior in recycled blends of high density polyethylene (HDPE) and isotactic polypropylene (iPP), we employ optical microscopy, rheo-Raman, and differential scanning calorimetry (DSC) to measure the

Coating Kinetics of Fluoropolymer Process Aids for Sharkskin Elimination: The Role of Domain Size

October 12, 2021
Author(s)
D Bigio, Mathurin G. Meillon, S B. Kharchenko, David C. Morgan, Hui Zhou, S Oriani, C Macosko, Kalman D. Migler
We study the ability of fluoropolymer based polymer processing aids (PPA) to eliminate surface melt fracture (sharkskin) during extrusion of polyethylene in relation to blend morphology (PPA droplet size) and processing conditions (shear rate). Under the

Estimations of the effective Young's modulus of specimens prepared by fused filament fabrication

April 5, 2021
Author(s)
Lichen Fang, Yishu Yan, Ojaswi Agarwal, Jonathan Seppala, Kalman D. Migler, Thao D. Nguyen, Kevin Hemker, Sung Hoon Kang
The elastic response of homogeneous isotropic materials is most commonly represented by their Young's modulus (E), but geometric variability associated with additive manufacturing results in materials that are neither homogeneous nor isotropic. Here we

AMB2018-03: Benchmark Physical Property Measurements for Material Extrusion Additive Manufacturing of Polycarbonate

October 29, 2020
Author(s)
Daniel P. Cole, Frank Gardea, Todd C. Henry, Jonathan Seppala, Edward Garboczi, Kalman D. Migler, Christopher M. Shumeyko, Jeffery R. Westrich, Sara Orski, Jeffery L. Gair
Material extrusion (MatEx) is finding increasing applications in additive manufacturing of thermoplastics due to the ease of use and the ability to process disparate polymers. Since part strength is anisotropic and frequently deviates negatively with

Percolation implications in the rheology of crystallization

October 26, 2020
Author(s)
Anthony P. Kotula, Kalman D. Migler
The rheology of polymer crystallization is an old problem that often defies explanation due to the complex interrelationships between crystallization and flow properties. Although separate measurements of rheology and crystallinity can give some

Outcomes and Conclusions from the 2018 AM-Bench Measurements, Challenge Problems, Modeling Submissions, and Conference

February 13, 2020
Author(s)
Lyle E. Levine, Brandon M. Lane, Jarred C. Heigel, Kalman D. Migler, Mark R. Stoudt, Thien Q. Phan, Richard E. Ricker, Maria Strantza, Michael R. Hill, Fan Zhang, Jonathan E. Seppala, Edward J. Garboczi, Erich D. Bain, Daniel Cole, Andrew J. Allen, Jason C. Fox, Carelyn E. Campbell
The Additive Manufacturing Benchmark Test Series (AM-Bench) was established to provide rigorous measurement test data for validating additive manufacturing (AM) simulations for a broad range of AM technologies and material systems. AM-Bench includes

Mechanisms of spontaneous chain formation and subsequent microstructural evolution in shear- driven strongly confined drop monolayers

May 18, 2019
Author(s)
Sagnik Singha, Abhilash R. Malipeddi, Mauricio Zurita-Gotor, Kausik Sarkar, Kevin Shen, Michael Loewenberg, Kalman D. Migler, Jerzy Blawzdziewicz
It was experimentally demonstrated by Migler and his collaborators [Phys. Rev. Lett. 2001, 86, 1023; Langmuir 2003, 19, 8667] that a strongly confined drop monolayer sheared between two parallel plates can spontaneously develop a flow-oriented drop-chain

Flow-induced crystallization during materials extrusion additive manufacturing

September 10, 2018
Author(s)
Lily Northcutt, Sara Orski, Kalman D. Migler, Anthony Kotula
Material extrusion additive manufacturing processes force molten polymer through a printer nozzle at high (> 100 s-1) wall shear rates prior to cooling and crystallization. These high shear rates can lead to flow-induced crystallization in common polymer

Weld formation during material extrusion additive manufacturing

August 11, 2017
Author(s)
Jonathan E. Seppala, Seung Hoon Han, Kaitlyn E. Hillgartner, Chelsea S. Davis, Kalman D. Migler
Material extrusion (ME) is a layer-by-layer additive manufacturing process that is now used in personal and commercial production where prototyping and customization are required. However, parts produced from ME frequently exhibit poor mechanical

Raman Identification of Multiple Melting Peaks of Polyethylene

August 1, 2017
Author(s)
Ying Jin, Anthony P. Kotula, Chad R. Snyder, Angela R. Hight Walker, Kalman D. Migler, Young J. Lee
Multiple melting peaks of high-density polyethylene produced by complex thermal pre-treatment are investigated with variable temperature Raman spectroscopy and differential scanning calorimetry (DSC). We examine the origin of the observed multiple melting

The rheo-Raman microscope: Simultaneous chemical, conformational, mechanical, and microstructural measures of soft materials

October 4, 2016
Author(s)
Anthony P. Kotula, Matthew Meyer, Francesca De Vito, Jan Plog, Angela R. Hight Walker, Kalman D. Migler
We describe the design and demonstrate performance of an instrument capable of simultaneous Raman spectroscopy, rheology, and optical microscopy of materials. The instrument couples a Raman microscope with a rotational rheometer through an optically