scholarly journals Development of rapid set mortar for additive manufacturing

2021 ◽  
Vol 1205 (1) ◽  
pp. 012010
Author(s):  
B Nespor ◽  
M Bohac ◽  
M Nejedlik
Keyword(s):  
Additive Manufacturing ◽  
Surface Defects ◽  
Blended Cement ◽  
Rheological Behaviour ◽  
Print Quality ◽  
Rheological Characterization ◽  
Cement Mortars ◽  
Slaked Lime ◽  
Shape Retention

Abstract The study presents the development results of blended cement mortars for additive manufacturing. The goal was to achieve a balanced rheological behaviour of the fresh mixture through optimal granulometry, suitable grain shape and the choice of micro-admixtures. The article closely describes the granulometric and rheological characterization of the proposed ternary and quaternary blended mortar mixtures with various SCM’s. The print quality and shape stability of the promising mortars and the researched 3DP mixes were evaluated during incremental layering for comparison. The performed experiments confirmed that the mixtures containing blast furnace slag, quartz powder and metakaolin are more plastic and allow faster layering in height. The slaked lime-enriched mixture has excellent plasticity and is able to resist deformation during overlaying, the printed layers are without surface defects. The small addition of polypropylene fibre (0.08 wt.%) improves the plasticity and shape retention ability.

Physicochemical and Electro-Rheological Characterization of Kaolinite / CMS / Silicone Oil Fluid

2010 ◽  
Vol 446 ◽  
pp. 33-41
Author(s):  
Thomas Reiss ◽  
Saoussen Laribi ◽  
Jean-Marie Fleureau ◽  
Jean Francois Tassin
Keyword(s):  
Electric Field ◽  
Yield Stress ◽  
Applied Electric Field ◽  
Silicone Oil ◽  
Rheological Behaviour ◽  
Rheological Characterization ◽  
Clay Particles ◽  
Observed Behaviour ◽  
Composite Nature

The aim of this study is to elaborate electro-rheological fluids based on kaolinite. the scientific characterization made it possible the identification of the composite nature and the checking of the intercalation of the polymer among the clay particles The rheological behaviour of the fluid depends on the electric field. A yield stress of the suspensions is observed, which increases with the applied electric field. An interpretation based on the different modes of association between the clay particles is proposed to account qualitatively for the observed behaviour.

scholarly journals Processing of Sr2+ Containing Poly L-Lactic Acid-Based Hybrid Composites for Additive Manufacturing of Bone Scaffolds

2020 ◽  
Vol 7 ◽  
Author(s):  
Priscila Melo ◽  
Raasti Naseem ◽  
Ilaria Corvaglia ◽  
Giorgia Montalbano ◽  
Carlotta Pontremoli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Additive Manufacturing ◽  
Hybrid Composites ◽  
Homogeneous Distribution ◽  
Fused Filament Fabrication ◽  
Rheological Characterization ◽  
Biodegradable Composite ◽  
Manufacturing Technologies

Biodegradable composite materials represent one of the major areas of investigation for bone tissue engineering due to their tuneable compositional and mechanical properties, which can potentially mimic those of bone and potentially avoid the removal of implants, mitigating the risks for the patient and reducing the overall clinical costs. In addition, the introduction of additive manufacturing technologies enables a strict control over the final morphological features of the scaffolds. In this scenario, the optimisation of 3D printable resorbable composites, made of biocompatible polymers and osteoinductive inorganic phases, offers the potential to produce a chemically and structurally biomimetic implant, which will resorb over time. The present work focuses on the development and process optimisation of two hybrid composite filaments, to be used as feedstock for the fused filament fabrication 3D printing process. A Poly L-lactic acid matrix was blended with either rod-like nano-hydroxyapatite (nano-HA) or nanoparticles of mesoporous bioactive glasses, both partially substituted with strontium (Sr2+), due to the well-known pro-osteogenic effect of this ion. Both inorganic phases were incorporated into Poly L-lactic acid using an innovative combination of processes, obtaining a homogeneous distribution throughout the polymer whilst preserving their ability to release Sr2+. The filament mechanical properties were not hindered after the incorporation of the inorganic phases, resulting in tensile strengths and moduli within the range of cancellous bone, 50 ± 10 MPa and 3 ± 1 GPa. Finally, the rheological characterization of the hybrid composites indicated a shear thinning behaviour, ideal for the processing with fused filament fabrication, proving the potential of these materials to be processed into 3D structures aiming bone regeneration.

scholarly journals Rheological Characterization of Biomaterials Directs Additive Manufacturing of Strontium‐Substituted Bioactive Glass/Polycaprolactone Microfibers

2019 ◽  
Vol 40 (11) ◽  
pp. 1900019 ◽  
Author(s):  
Naomi C. Paxton ◽  
Jiongyu Ren ◽  
Madison J. Ainsworth ◽  
Anu K. Solanki ◽  
Julian R. Jones ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Bioactive Glass ◽  
Rheological Characterization

scholarly journals Honey Adulterated with Glucose Syrup: Rheological Modeling

2021 ◽  
Vol 65 (2) ◽  
pp. 217-227
Author(s):  
Vincent O. Anidiobu
Keyword(s):  
Rheological Behaviour ◽  
High Price ◽  
High Demand ◽  
Rheological Characterization ◽  
Ambient Temperatures ◽  
Glucose Syrup ◽  
Rheological Modeling ◽  
Acceptable Measure ◽  
Better Than

Abstract Honey's reputation for its various both nutritional and medicinal benefits and pleasant taste ensures a sustained high demand for the product all over the world. However, honey supply is quite limited and seldom meets the demand, and consequently the product commands a relatively high price and is exposed to adulteration and imitation. Honey was adulterated with glucose syrup weight of 10%, 50%, 70% and 90%, and each sample was analysed. Pure honey at ambient temperatures exhibits peculiar non-Newtonian rheological behaviour. Adulteration with glucose syrup (a Newtonian fluid) drags its viscosity towards Newtonian flow behaviour. Malcolm Cross and Ostwald-de Waele Power-Law models were used to fit the rheological data, and the former fitted better than the latter. The behaviour indices in both models increased with increasing adulteration of honey with glucose syrup. Chromatographic characterizations of honey which provides an acceptable measure of honey quality corroborated the conclusions derived from the rheological characterization of this study.

Materials for Anticorrosive Protection of Cellular Bodies of Rotatory Air Preheaters from Energentic Installations. Modification and Rheological Characterization of Some Epoxy Resins

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Adriana Bantas ◽  
Lelian Cioroianu ◽  
Gabriela Cioroianu ◽  
Minodora Leca ◽  
Alexandra Pica ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Epoxy Resins ◽  
Rheological Behaviour ◽  
Specific Weight ◽  
Heat Conducting ◽  
Metal Powders ◽  
Rheological Characterization ◽  
Film Forming ◽  
Fluid Behaviour

Celualar bodies from the cold region of the heat exchange surface of rotatory air preheaters from energetic installations are strongly affected by sulphuric corrosion and, can be protected using heat conducting and thermally resistant coatings. Epoxy resins, mofied firstly with tall and soy fatty acids to increase their elasticity and then reacted with acrylic acid and styrene to increase chemical, heat and corrosion resistance, adherence and elasticity, correspond to the qualities required for the film-forming material. The thermal conductivity of coating can be increased by introducing finely dispersed metal powders. Rheological measurement emphasizes that the resins esterified with both kinds of fatty acids have relatively low viscosities, ranging between 3500 and 8600 mPa.s, and ideal plastic fluid behaviour; the higher the epoxy equivalent of the resin the lower the viscosity of the esters. Treatment of resins (previoisly esterifies with tall fatty acids) with the two monomers increases the viscosity and modifies the rheological behaviour, transforming it into a pseudoplastic one. The increase of viscosity is huge for the resin having lower epoxy equivalent and its behaviour becomes thixotropic. Given the high specific weight of metal powders , it is expected that this last modified resin gives the most stable film-forming disperse systems with metal powders.

Rheological characterization of tack and viscoelasticity of compositions of crepe coating used in the Yankee dryer

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 641-649
Author(s):  
JOSHUA OMAMBALA ◽  
CARL MCINTYRE
Keyword(s):  
Normal Force ◽  
Weight Ratio ◽  
Good Combination ◽  
Rheological Characterization ◽  
Nonlinear Viscoelastic ◽  
Coating Composition ◽  
Linear And Nonlinear ◽  
Work Done ◽  
Tissue Production

The vast majority of tissue production uses creping to achieve the required set of properties on the base sheet. The Yankee coating helps to develop the desired crepe that in turn determines properties such as bulk and softness. The adhesion of the sheet to the Yankee surface is a very important characteristic to consider in achieving the desired crepe. The coating mix usually consists of the adhesive, modifier, and release. A good combination of these components is essential to achieving the desired properties of the tissue or towel, which often are determined by trials on the machine that can be time consuming and lead to costly rejects. In this paper, five compositions of an industrial Yankee coating adhesive, modifier, and release were examined rheologically. The weight ratio of the adhesive was kept constant at 30% in all five compositions and the modifier and release ratios were varied. The normal force and work done by the different compositions have been shown at various temperatures simulating that of the Yankee surface, and the oscillatory test was carried out to explain the linear and nonlinear viscoelastic characteristic of the optimal coating composition.

Lignin-Containing Photoactive Resins for 3D Printing by Stereolithography

2018 ◽  
Author(s):  
Jordan T. Sutton ◽  
Kalavathy Rajan ◽  
David P. Harper ◽  
Stephen Chmely
Keyword(s):  
Additive Manufacturing ◽  
New Products ◽  
High Surface ◽  
Fold Increase ◽  
Print Quality ◽  
Renewable Materials ◽  
Lignin Concentration ◽  
Environmentally Sustainable ◽  
Manufacturing Applications ◽  
Modified Lignin

Generating compatible and competitive materials that are environmentally sustainable and economically viable is paramount for the success of additive manufacturing using renewable materials. We report the successful application of renewable, modified lignin-containing photopolymer resins in a commercial stereolithography system. Resins were fabricated within operable ranges for viscosity and cure properties, using up to 15% modified lignin by weight with the potential for higher amounts. A four-fold increase in ductility in cured parts with higher lignin concentration is noted as compared to commercial SLA resins. Excellent print quality was seen in modified lignin resins, with good layer fusion, high surface definition, and visual clarity. These materials can be used to generate new products for additive manufacturing applications and help fill vacant material property spaces, where ductility, sustainability, and application costs are critical.

Lignin-Containing Photoactive Resins for 3D Printing by Stereolithography

2018 ◽  
Author(s):  
Jordan T. Sutton ◽  
Kalavathy Rajan ◽  
David P. Harper ◽  
Stephen Chmely
Keyword(s):  
Additive Manufacturing ◽  
New Products ◽  
High Surface ◽  
Fold Increase ◽  
Print Quality ◽  
Renewable Materials ◽  
Lignin Concentration ◽  
Environmentally Sustainable ◽  
Manufacturing Applications ◽  
Modified Lignin

Generating compatible and competitive materials that are environmentally sustainable and economically viable is paramount for the success of additive manufacturing using renewable materials. We report the successful application of renewable, modified lignin-containing photopolymer resins in a commercial stereolithography system. Resins were fabricated within operable ranges for viscosity and cure properties, using up to 15% modified lignin by weight with the potential for higher amounts. A four-fold increase in ductility in cured parts with higher lignin concentration is noted as compared to commercial SLA resins. Excellent print quality was seen in modified lignin resins, with good layer fusion, high surface definition, and visual clarity. These materials can be used to generate new products for additive manufacturing applications and help fill vacant material property spaces, where ductility, sustainability, and application costs are critical.

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