Concurrent characterization of compressibility and viscosity in extrusion-based additive manufacturing of acrylonitrile butadiene styrene with fault diagnoses

Kazmer, David O.; Colon, Austin R.; Peterson, Amy M.; Kim, Sun Kyoung

doi:10.1016/j.addma.2021.102106

Cited by 15 publications

(9 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We hypothesize that the lower-than-predicted tear energies at T ext = 250 °C are due, at least in part, to the fact that thermography on a surfaces does not capture real-time faults and variations in dimensions or temperatures. As we recently reported, real-time differences between input extrudate temperatures and flow rates can be substantial due to physical considerations including limitations in hot end thermal capacity, drool, and the intermeshing of drive gears 22 . Differences in temperature and flow rate will affect the quality and dimensions of a weld.…”

Section: Resultsmentioning

confidence: 94%

“…For one, high fidelity modeling is computationally intensive, while lower fidelity models may require simplifications that lead to large inaccuracies. Secondly, the information that we can use as input data is limited to what we can measure, such as temperature (either from thermography 3 or thermocouples 21 – 23 ) and pressure (e.g., melt pressure 21 , 22 ). Finally, existing modeling methods can predict which conditions will lead to relatively higher or lower strengths/fracture energies, but do not provide information about the minimum conditions necessary to achieve bulk properties.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Predicting mechanical properties of material extrusion additive manufacturing-fabricated structures with limited information

Peterson

Kazmer

2022

Sci Rep

Self Cite

View full text Add to dashboard Cite

Mechanical properties of additively manufactured structures fabricated using material extrusion additive manufacturing are predicted through combining thermal modeling with entanglement theory and molecular dynamics approaches. A one-dimensional model of heat transfer in a single road width wall is created and validated against both thermography and mechanical testing results. Various model modifications are investigated to determine which heat transfer considerations are important to predicting properties. This approach was able to predict tear energies on reasonable scales with minimal information about the polymer. Such an approach is likely to be applicable to a wide range of amorphous and low crystallinity thermoplastics.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Predicting mechanical properties of material extrusion additive manufacturing-fabricated structures with limited information

Peterson

Kazmer

2022

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, leaking from one of the ports was observed, which would lower actual volumetric flow rates and explain the below target road widths. Additionally, in a similar hot end, Kazmer et al found that flow rates above 5 mm 3 /s exceed the hot end melt capacity, leading to lower extrudate temperatures and higher melt viscosities 35 . At high target volumetric flow rates, achieved volumetric flow rates may be lower than the target due to limitations in the hot end melt capacity and increased fluid pressure.…”

Section: Resultsmentioning

confidence: 99%

Interrelationships between process parameters, cross‐sectional geometry, fracture behavior, and mechanical properties in material extrusion additive manufacturing

Adisa,

Colon,

Kazmer

et al. 2023

Polymer Engineering & Sci

Self Cite

View full text Add to dashboard Cite

Additive manufacturing offers reduced lead time between design and manufacturing. Fused filament fabrication, the most common form of material extrusion additive manufacturing, enables the production of custom‐made parts with complex geometry. Despite the numerous advantages of additive manufacturing, reliability, reproducibility, and achievement of isotropic bulk properties in part remains challenging. We investigated the tensile behavior of a model polycarbonate system to explore what leads to different tensile properties, including sources of ductile versus brittle fracture. We utilized a one factor at a time (OFAT) design of experiments (DOE), printed single road‐width boxes, and performed tensile tests on specimens from these boxes. Additionally, we characterized the cross‐sections of parts printed under different conditions and their subsequent fracture behavior. The results demonstrate that isotropic bulk properties are achievable by printing at high speeds, and provide mechanisms to explain why.Highlights Printing at high speeds leads to improved mechanical properties. Printed samples undergo a mix of ductile and brittle failure. Jagged fracture path is associated with superior adhesion. High layer times lead to worse interfacial bonding.

show abstract

“…That being said, the custom hot end design shows better performance than a typical hot end design (see supplementary materials Section S.11). Hot end performance is critical because it affects the systems energy efficiency (Kazmer et al , 2023) and the material properties (Kazmer et al , 2021; Kim et al , 2021), which affect the final part’s properties.…”

Section: Discussionmentioning

confidence: 99%

Steady melting in material extrusion additive manufacturing

Colon,

Kazmer,

Peterson

et al. 2023

RPJ

Self Cite

View full text Add to dashboard Cite

Purpose A main cause of defects within material extrusion (MatEx) additive manufacturing is the nonisothermal condition in the hot end, which causes inconsistent extrusion and polymer welding. This paper aims to validate a custom hot end design intended to heat the thermoplastic to form a melt prior to the nozzle and to reduce variability in melt temperature. A full 3D temperature verification methodology for hot ends is also presented. Design/methodology/approach Infrared (IR) thermography of steady-state extrusion for varying volumetric flow rates, hot end temperature setpoints and nozzle orifice diameters provides data for model validation. A finite-element model is used to predict the temperature of the extrudate. Model tuning demonstrates the effects of different model assumptions on the simulated melt temperature. Findings The experimental results show that the measured temperature and variance are functions of volumetric flow rate, temperature setpoint and the nozzle orifice diameter. Convection to the surrounding air is a primary heat transfer mechanism. The custom hot end brings the melt to its setpoint temperature prior to entering the nozzle. Originality/value This work provides a full set of steady-state IR thermography data for various parameter settings. It also provides insight into the performance of a custom hot end designed to improve the robustness of melting in MatEx. Finally, it proposes a strategy for modeling such systems that incorporates the metal components and the air around the system.

show abstract

Concurrent characterization of compressibility and viscosity in extrusion-based additive manufacturing of acrylonitrile butadiene styrene with fault diagnoses

Cited by 15 publications

References 25 publications

Predicting mechanical properties of material extrusion additive manufacturing-fabricated structures with limited information

Predicting mechanical properties of material extrusion additive manufacturing-fabricated structures with limited information

Interrelationships between process parameters, cross‐sectional geometry, fracture behavior, and mechanical properties in material extrusion additive manufacturing

Steady melting in material extrusion additive manufacturing

Contact Info

Product

Resources

About