scholarly journals Silicone rheological behavior modification for 3D printing: Evaluation of yield stress impact on printed object properties

2019 ◽  
Vol 28 ◽  
pp. 50-57 ◽  
Author(s):  
Edwin-Joffrey Courtial ◽  
Clément Perrinet ◽  
Arthur Colly ◽  
David Mariot ◽  
Jean-Marc Frances ◽  
...  
Keyword(s):  
3D Printing ◽  
Yield Stress ◽  
Behavior Modification ◽  
Rheological Behavior ◽  
Object Properties

Enhancing the Yield Stress in Liquid Polydimethylsiloxane to Allow Its 3D Printing: Hydrogels as Removable Fillers

2021 ◽  
Vol 306 (2) ◽  
pp. 2000553
Author(s):  
Clément Perrinet ◽  
Edwin‐Joffrey Courtial ◽  
Arthur Colly ◽  
Christophe Marquette ◽  
René Fulchiron
Keyword(s):  
3D Printing ◽  
Yield Stress

scholarly journals Rheological behavior of cereal straw suspensions

2021 ◽  
Author(s):  
Sandra Ukaigwe
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Rheological Behavior ◽  
Xanthan Gum ◽  
Mesh Size ◽  
General Purpose ◽  
Measuring Instrument ◽  
Fiber Concentration ◽  
Cereal Straw ◽  
Malt Barley

The rheological properties (yield stress and viscosity) of cereal straw suspensions are especially important in bioethanol production as they determine the mixing behaviour of the suspension during enzymatic hydrolysis. Yield stress measurements are generally difficult to perform in straw suspensions due to sedimentation, which commonly occur in the suspensions because of the difficulty encountered in loading the suspension into the measuring equipment. The process of placing the suspension in the measuring instrument causes a disturbance likely to induce the yielding of the suspension before the actual measurements are taken. Moreover cereal suspensions at high straw concentration (10-40 wt%) are soft solids and pourability is particularly difficult with solids. Rheological behavior of staw suspensions made from wheat, Oats and malt barley of fiber sizes 0.15 mm-4.20 mm (mesh sizes 20 to 100) and concentrations 5.0-15.0 wt% were studied. The suspensions were initially prepared by dispersing milled and sieved straws in distilled water at room temperature, followed by vortexing to aid the dispersion process; this was later modified to include a 30-minute de-aeration of the suspensions using vacuum and 2-minute mixing using a general purpose mixer at about 162 rpm. However, none these procedures produced a homogenous suspension. The viscosity of the dispersion medium was modified by the addition of Xanthan gum. This produced homogenous suspensions which remained suspended for about 20 minutes. The rheological properties of these suspensions were measured on a Bohlin rheometer in the controlled stress mode using a vane and cup measuring instrument, and the suspension yield stress determined by extrapolation and by regression of Herschel-Bulkley, Casson and Bingham models. Yield stress obtained from extrapolation ranged from 2-19 Pa, while model results ranged from 0.96- 8.15 Pa, for 5.0 wt% Oats straw suspensions with Xanthan gum strengths of 0.1-0.5 wt%. Extrapolation results for 7.5 wt% Oats staw suspensions with Xanthan gum strengths of 0.1-0.5 wt% ranged from 20-36 Pa while model results were in the range of 4.38-18.76 Pa. Wheat and malt barely straw suspensions evaluated using Herschel-Bulkley model at similiar Oats straw suspension conditions of 5.0 wt% fiber concentration with 0.3 wt% Xanthan gum strength produced statistically equivalent yields stress to Oats straw suspensions in the range of 2.31-4.04 Pa for fibers of mesh size 40-100. Cereal straw suspenions are non-Newtonian fluids with yield stresses that are highly straw concentration dependent.

Testing Procedures on Materials to Formulate the Ink for 3D Printing

2020 ◽  
Vol 2674 (2) ◽  
pp. 21-32 ◽  
Author(s):  
Malo Charrier ◽  
Claudiane Ouellet-Plamondon
Keyword(s):  
3D Printing ◽  
Yield Stress ◽  
Three Dimensional ◽  
Testing Procedure ◽  
Full Potential ◽  
Cement Pastes ◽  
Slump Test ◽  
Testing Procedures ◽  
Transportation Sector ◽  
Printing Ink

Three-dimensional (3D) printing has been used in various fields to tackle applications difficult for conventional manufacturing. To realize the full potential of this technology in the transportation sector, it is imperative to identify suitable tests and mixtures for printing “inks” made of mortar. In this study, several conventional and non-conventional tests on mortars and cement pastes were conducted. This work highlights the correlation between the results of slump test and the deformation test that indicates the comportment of the mixture under a stack of printed layers. Moreover, a strong connection between yield stress and mini-slump is observed, demonstrating a simplification of the testing procedure, and a link between the mortar and the cement paste is developed. In the printing ink design phase, this association enables the prediction of flowability. The yield stress and the final radius of the mini-slump tests were very well correlated for the admixture tested. The use of the mini-slump test simplifies the testing procedure and allows for quicker formulations of admixtures in the printing ink.

Sensory Evaluation and Rheological Behavior of Commercial Mayonnaise

2007 ◽  
Vol 3 (1) ◽  
Author(s):  
Dayane Izidoro ◽  
Maria-Rita Sierakowski ◽  
Nina Waszczynskyj ◽  
Charles W. I. Haminiuk ◽  
Agnes de Paula Scheer
Keyword(s):  
Shear Stress ◽  
Yield Stress ◽  
Sensory Evaluation ◽  
Rheological Behavior ◽  
Oil Content ◽  
Sensory Attributes ◽  
Rheological Parameters ◽  
Low Fat ◽  
Concentric Cylinder ◽  
Rheological Characterization

The effects of ingredients on the sensory evaluation and rheological behavior of two brands of mayonnaise were examined in this work. Mayonnaise samples were examined by Analytical Descriptive Test and Ranking Test of Preference. The rheological parameters were determined at 25°C using a concentric cylinder Brookfield rheometer with a spindle SC4-34. The results showed that standard mayonnaise as opposed to low-fat mayonnaise gained higher grades for most sensory attributes. All samples were found to exhibit non-Newtonian pseudoplastic behavior described by Herschel–Bulkley model. A decrease in the yield stress, viscosity and shear stress with the decrease in oil content was observed in all products, which confirm that the rheological characterization is capable of distinguishing rather well between mayonnaises made with different formulation.

Rheological behavior and particle alignment of cellulose nanocrystal and its composite hydrogels during 3D printing

2021 ◽  
Vol 253 ◽  
pp. 117217
Author(s):  
Tao Ma ◽  
Linxiang Lv ◽  
Chengzheng Ouyang ◽  
Xinna Hu ◽  
Xiaojun Liao ◽  
...  
Keyword(s):  
3D Printing ◽  
Rheological Behavior ◽  
Cellulose Nanocrystal ◽  
Composite Hydrogels ◽  
Particle Alignment

scholarly journals The Effect of Accelerator Dosage on Fresh Concrete Properties and on Interlayer Strength in Shotcrete 3D Printing

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 374 ◽  
Author(s):  
Inka Dressler ◽  
Niklas Freund ◽  
Dirk Lowke
Keyword(s):  
3D Printing ◽  
Yield Stress ◽  
Fresh Concrete ◽  
Testing Machine ◽  
Image Correlation ◽  
Early Age ◽  
Stress Evolution ◽  
Functional Interaction ◽  
Concrete Properties ◽  
Instantaneous Increase

Recently, the progress in 3D concrete printing has developed enormously. However, for the techniques available, there is still a severe lack of knowledge of the functional interaction of processing technology, concrete rheology and admixture usage. For shotcrete 3D printing technology, we present the effect of accelerator dosages (0%, 2%, 4% and 6%) on fresh concrete properties and on interlayer strength. Therefore, early yield stress development up to 90 min is measured with penetration resistance measurements. Deformation of layers under loading is investigated with digital image correlation and a mechanical testing machine. One point in time (10 min after deposition) is examined to quantify vertical buildability of elements depending on the accelerator dosage. Four different interlayer times (0, 2, 5 and 30 min), which occur for the production of small and large elements as well as due to delay during production, are investigated mechanically as well as quantitatively with computed tomography regarding the formation of cold joints. With increased accelerator dosage, an instantaneous increase in early age yield stress and yield stress evolution was observed. An increase in interlayer time leads to a reduced strength. This is mainly attributed to the observed reduced mechanical interlocking effect of the strands. Finally, a model to describe interlayer quality is presented. In the end, advantages as well as limitations of the findings are discussed.

scholarly journals Rheological behavior of cereal straw suspensions

2021 ◽  
Author(s):  
Sandra Ukaigwe
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Rheological Behavior ◽  
Xanthan Gum ◽  
Mesh Size ◽  
General Purpose ◽  
Measuring Instrument ◽  
Fiber Concentration ◽  
Cereal Straw ◽  
Malt Barley

The rheological properties (yield stress and viscosity) of cereal straw suspensions are especially important in bioethanol production as they determine the mixing behaviour of the suspension during enzymatic hydrolysis. Yield stress measurements are generally difficult to perform in straw suspensions due to sedimentation, which commonly occur in the suspensions because of the difficulty encountered in loading the suspension into the measuring equipment. The process of placing the suspension in the measuring instrument causes a disturbance likely to induce the yielding of the suspension before the actual measurements are taken. Moreover cereal suspensions at high straw concentration (10-40 wt%) are soft solids and pourability is particularly difficult with solids. Rheological behavior of staw suspensions made from wheat, Oats and malt barley of fiber sizes 0.15 mm-4.20 mm (mesh sizes 20 to 100) and concentrations 5.0-15.0 wt% were studied. The suspensions were initially prepared by dispersing milled and sieved straws in distilled water at room temperature, followed by vortexing to aid the dispersion process; this was later modified to include a 30-minute de-aeration of the suspensions using vacuum and 2-minute mixing using a general purpose mixer at about 162 rpm. However, none these procedures produced a homogenous suspension. The viscosity of the dispersion medium was modified by the addition of Xanthan gum. This produced homogenous suspensions which remained suspended for about 20 minutes. The rheological properties of these suspensions were measured on a Bohlin rheometer in the controlled stress mode using a vane and cup measuring instrument, and the suspension yield stress determined by extrapolation and by regression of Herschel-Bulkley, Casson and Bingham models. Yield stress obtained from extrapolation ranged from 2-19 Pa, while model results ranged from 0.96- 8.15 Pa, for 5.0 wt% Oats straw suspensions with Xanthan gum strengths of 0.1-0.5 wt%. Extrapolation results for 7.5 wt% Oats staw suspensions with Xanthan gum strengths of 0.1-0.5 wt% ranged from 20-36 Pa while model results were in the range of 4.38-18.76 Pa. Wheat and malt barely straw suspensions evaluated using Herschel-Bulkley model at similiar Oats straw suspension conditions of 5.0 wt% fiber concentration with 0.3 wt% Xanthan gum strength produced statistically equivalent yields stress to Oats straw suspensions in the range of 2.31-4.04 Pa for fibers of mesh size 40-100. Cereal straw suspenions are non-Newtonian fluids with yield stresses that are highly straw concentration dependent.

scholarly journals Assessing Mechanical and Rheological Properties of Potato Puree: Effect of Different Ingredient Combinations and Cooking Methods on the Feasibility of 3D Printing

Foods ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Iman Dankar ◽  
Amira Haddarah ◽  
Francesc Sepulcre ◽  
Montserrat Pujolà
Keyword(s):  
3D Printing ◽  
Rheological Properties ◽  
Yield Stress ◽  
Network Formation ◽  
High Yield ◽  
Cooking Methods ◽  
Starch Granules ◽  
Food Printing ◽  
3D Food Printing ◽  
Newtonian Behavior

The effects of agar, alginate, butter, olive oil, and carrots on the mechanical and rheological properties of potato puree prepared by two different cooking methods (microwave heating (MP) and boiling (BP)) were investigated and interpreted in terms of starch microstructural changes. Microscopic observations revealed more aggregated and densely concentrated starch granules in MP samples. This consequently led to a significant increase (p < 0.05) in mechanical and rheological properties up to five times more than BP samples. All samples exhibited shear thinning non-Newtonian behavior. Butter proved its ability to maintain stiff network formation with starch molecules forming lipid-starch complexes characterized by high retention properties and increased stability due to high thixotropic and yield stress values. The pseudo-plasticity combined with high self-supporting ability (high yield stress and mechanical values) comprised by MP samples allows them to better behave during advanced technological processes such as extrusion 3D food printing.

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