Properties Of Powders Research Articles

Optimization of green spherical agglomeration process based on response surface methodology for preparation of high-performance spherical particles

Spherical agglomeration (SA) is a processing technique that enhances the physical properties of particles, reduces the number of unit operations in pharmaceutical manufacturing, and improves process efficiency. However, one of the limitations of SA is its high nonlinearity, which makes scalability a challenge. This prospective study was designed to realize the optimization of SA process parameters of aspirin, the world’s first and most widely used nonsteroidal anti-inflammatory drug, by developing a green SA model through response surface methodology. First, Plackett-Burman experiments were conducted to identify the key operating variables affecting SA, and Sustainability Index (STI) was defined to evaluate the effects of these operating variables on the SA and the energy input to the environment during the post-processing process. Furthermore, the effects of three independent variables on mean size, yield, and STI were investigated based on Box-Behnken design. A second-order regression equation with response values was developed to optimize the above three objectives. As a result, the spherical products were obtained with excellent powder properties, including anti-caking property, filtration property, and tableting performance compared to the raw materials. This work provides an experimental and modelling basis for the further application of this environmentally-friendly SA technology.

Comparison of cell morphology and mechanical properties of wheat straw powder/HDPE parts molded by supercritical fluid foamed injection with and without gas counter pressure technology

AbstractComposites were fabricated using maleic anhydride‐grafted high‐density polyethylene as the matrix material and wheat straw as the filler. Differential scanning calorimetry and rheological properties of these composites were investigated to determine the processing parameters for supercritical fluid (SCF) microcellular injection with and without gas counter pressure (GCP) technology. The impacts of different proportions and dimensions of wheat straw, along with process parameters related to GCP, were determined on both the cellular structure and mechanical characteristics of foamed injection molded components. Experimental results revealed that an increase in the ratio of wheat straw and a reduction in its size led to enhancements in both storage modulus and complex viscosity of the composites, while also improving their cell structure when foamed with SCF. By adjusting GCP process parameters, it was possible to regulate both cell morphology and mechanical properties of foamed injection molded parts. Higher GCP or longer GCP holding time resulted in increased skin thickness and tensile strength but decreased notched Izod impact strength.Highlights Built relations between GCP technology parameters and cell morphologies. Compared the influence of wheat straw powder and GCP parameters quantitatively. Explored the correlation between cellular morphology and mechanical properties. The regulatory mechanism of cell morphology, size ratio, and distribution. GCP effectively modulates cell morphologies and mechanical properties.

Combined thermal and particle shape effects on powder spreading in additive manufacturing via discrete element simulations

The thermal and mechanical behaviors of powders are crucial for additive manufacturing. In powder bed fusion, capturing temperature profiles and packing structures before melting is challenging due to diverse heat transfer pathways and powder properties. This study tackles this challenge with a discrete element model simulating non-spherical particles with thermal properties during powder spreading. Thermal conduction and radiation are integrated into a multisphere particle formulation to model heat transfer among irregular-shaped powders with temperature-dependent elastic properties. The model is utilized to simulate the spreading of pre-heated PA12 powder over a hot substrate representing the part under manufacturing. Variances in temperature profiles are observed in the spreading cases based on particle shapes, spreading speed, and temperature-dependent elastic modulus. Particle temperature beneath the spreading blade is influenced by the kinematics of the particle heap and temperature-dependent properties.

Kinetic Studies and Adsorption of Fluoride from Drinking Water using Tamarind Shell as Adsorbent

The excessive intake of fluoride in drinking water is a serious health concern in most of the states in India and in the world. The regular consumption of drinking water containing fluoride leads to a disease called as fluorosis. The Present work of this paper explores the removal of fluoride from synthesized aqueous solution of fluoride using Tamarind fruit shell powder. The Adsorption of fluoride by Tamarind fruit shell is cost effective method and gives high efficiency than other adsorbents. In the present study, The pretreatment for moisture removal from the tamarind shell powder given also we have shown the Kinetics and comparative study to find highest fluoride removal efficiency. In the Kinetic study, the the controlling parameters for adsorption like pH, Adsorbent concentration, Contact time relation on the removal efficiency is studied. The data obtained is fitted in the Langmuir and Freundlich Adsorption Isotherms. The work shows the selective adsorbing property of tamarind shell powder for fluoride removal. The comparison of removal efficiency of fluoride by using tamarind shell powder with wheat straw is done

Feasible production of highly homogeneous nano-scaled WC powders: An industrial practice via raw material pretreatment and direct reduction-carbonization

A method for industrial production of nano-scaled WC powders has been proposed. In this work, WO2.9 is subject to pre-reduction, followed by jet-milling treatment. The precursor is then mixed with carbon black by ball milling, and directly reduced-carbonized to nano-scaled WC powders. The WC powders prepared at different carbonization temperatures were made into alloys and micro drills, revealing the influence of powder properties on the microstructure and properties of the alloys through comparative analysis. The results indicate that when WO2.9 powder is reduced at 700 °C for 1h and then jet-milled at a rotational speed of the grading wheel of 3500 rpm, the aggregates in the powder can be effectively broken, and the precursor powders with fine particle size and near-single phase can be obtained. In this way, the equipment exhibits relatively high productivity. By comparing the microstructure and properties of the alloy prepared from raw materials at different carbonization temperatures, it can be seen that if the carbonization temperature is too high, the average particle size of the powder increases and agglomeration appears in the microstructure. An increase in the average particle size of the powder will lead to an increase in the average grain size of the prepared alloys, thereby reducing the hardness and the wear resistance during service. In addition, the agglomerated particles in the powders can easily lead to abnormal WC grain growth in the microstructure of the prepared alloys, which reduces the bending strength.

Electronic Structure and Surface Chemistry of BaZrS3 Perovskite Powder and Sputtered Thin Film.

Chalcogenide perovskites exhibit optoelectronic properties that position them as potential materials in the field of photovoltaics. We report a detailed investigation into the electronic structure and chemical properties of polycrystalline BaZrS3 perovskite powder by X-ray photoelectron spectroscopy, complemented by an analysis of its long- and short-range geometric structures using X-ray diffraction and X-ray absorption spectroscopy. The results obtained for the powdered BaZrS3 are compared to similar measurements on a sputtered polycrystalline BaZrS3 thin film prepared through rapid thermal processing. While bulk characterization confirms the good quality of the powder, depth-profiling achieved by photoelectron spectroscopy utilizing Al Kα (1.487 keV) and Ga Kα (9.25 keV) radiations shows that, regardless of the fabrication method, the oxidation effects extend beyond 10 nm from the sample surface, with zirconium oxides specifically distributing deeper than the oxidized sulfur species. A hard X-ray photoelectron spectroscopy study on the powder and thin film detects signals with minimal contamination contributions and allows for the determination of the valence band maximum position with respect to the Fermi level. Based on these measurements, we establish a correlation between the experimental valence band spectra and the theoretical density of states derived from density functional theory calculations, thereby discerning the orbital constituents involved. Our analysis provides an improved understanding of the electronic structure of BaZrS3 developed through different synthesis protocols by linking it to material geometry, surface chemistry, and the nature of doping. This methodology can thus be adapted for describing electronic structures of chalcogenide perovskite semiconductors in general, a knowledge that is significant for interface engineering and, consequently, for device integration.

Evaluating the impact of stirrer design on powder behaviour in capsule filling using dyed lactose as tracer

Ensuring temporal and spatial uniformity in the chamber of a capsule filling machine with vacuum drum is crucial for consistent dosing to in-row capsules. A stirrer must induce axial mixing to maintain a homogeneous powder bed and prevent accumulation in specific regions, primarily caused by the feeding system above the chamber. To achieve satisfactory filling, the performance of different stirrers was analysed using a tracer particle strategy. This contribution introduces a lactose dyeing process, preventing agglomerate formation and yielding minimal differences in powder properties. Four lactose grades, exhibiting diverse particle sizes and flow behaviours, were dyed with methylene blue. A comprehensive analysis of lactose properties, such as particle size, density, and flow behaviour, confirms minimal alterations post-dyeing. Tracers obtained through this process reveal that a spike-type stirrer induces more axial mixing compared to a wire-type stirrer. The dyed lactose tracers effectively contribute to understanding and optimising the capsule filling process.

Physical and Functional Properties of Powders Obtained during Spray Drying of Cyani flos Extracts.

Edible flowers are a potential source of bioactive ingredients and are also an area of scientific research. Particularly noteworthy are Cyani flos, which have a wide range of uses in herbal medicine. The below study aimed to investigate the influence of selected soluble fiber fractions on the selected properties of physical and biochemical powders obtained during spray drying a water extract of Cyani flos. The drying efficiency for the obtained powders was over 60%. The obtained powders were characterized by low moisture content (≤4.99%) and water activity (≤0.22). The increase in the addition of pectin by the amount of 2-8% in the wall material resulted in a decrease in hygroscopicity, water solubility, and protection of flavonoids and anthocyanins both before and after digestion in the tested powders in comparison to the sample with only inulin as a carrier. Additionally, it was noted that all samples were characterized by high bioaccessibility when determining antioxidant properties and xanthine oxidase inhibition.

Evaluation of hot-air drying conditions of ora-pro-nobis leaves: Effects on bioactive compounds and powder properties

This study aimed to evaluate the effect of hot-air drying conditions on the bioactive composition, antioxidant capacity, and technological properties of ora-pro-nobis (OPN) leaves. Drying time decreased from 300 min to 75 min, with increasing air temperature from 60 to 120 °C. There was an increase in total phenolic (1.2 to 2.4 times) and total flavonoid (1.2 to 2.1 times) contents when drying conditions were changed from 60 °C for 300 min to 100 °C for 105 min. The highest antioxidant activities were observed in samples dried at 100 or 110 °C, with positive correlations with kaempferol, catechin, trans-cinnamic acid, and hydroxybenzoic acid contents. Thus, drying at 100 °C for 105 min was considered the moist suitable condition for OPN leaves, because higher temperatures caused greater changes in color, technological properties, and powder microstructures.

Effects of Ultrasound-Assisted Soy Lecithin Addition on Rehydration Behavior and Physical Properties of Egg White Protein Powder.

This study investigated the effects of ultrasound-assisted soybean lecithin (SL) on the rehydration behavior and physical properties of egg white protein powder (EWPP) and its ability to enhance the efficacy of EWPP instant solubility. The results of rehydration, including wettability and dispersibility, indicated that ultrasound (200 W)-assisted SL (5 g/L) addition had the shortest wetting time and dispersion time, which were 307.14 ± 7.00 s and 20.95 ± 2.27 s, respectively. In terms of powder properties, the EWPP with added SL had lower lightness, moisture content and bulk density. In addition, the increase in average particle size, net negative charge, free sulfhydryl group content and surface hydrophobicity indicated that ultrasound treatment facilitated the protein structures unfolding and promoted the formation of SL-EWP complexes. Overall, our study provided a new perspective for the food industry regarding using ultrasound technology to produce instant EWPP with higher biological activity and more complete nutritional value.

Durability properties of slag-waste glass binary geopolymer

This paper reports the durability properties of slag-glass powder (GP) geopolymer mortars at different GP contents and compares them with Portland cement mortars (PCM). The slag-GP mixes are activated with 6 M NaOH solution at 0.35 liquid-to-solid ratio. The performance of 28-day cured specimens under high-temperature exposures, wetting-drying and freezing-thawing cycles, water slaking, surface abrasion, and alkali-silica reactions (ASR) are examined. Scanning electron microscopic analysis is carried out to identify the microstructural changes in the material. The study outcomes indicate that an appropriate GP content (10%) enhances the performance of slag-GP binary geopolymers and improves its durability. However, ASR expansion is found to be increased marginally. The geopolymer specimens achieved higher strength and durability than PCM due to a dense and compact microstructure with significant gel formations.

Effect of Preparation and Drying Techniques on the Physicochemical, Functional and Nutritional Properties of products from Beetroot (Beta Vulgaris L.) varieties

Beetroot (Beta vulgaris L.) is rich in biologically active compounds. This study aimed to assess how different methods of preparation and drying affect the physical, chemical, functional, and nutritional properties of iron-rich beetroot powder. Two beetroot varieties, Detroit Dark Red (DetR) and Crimson Globe (CrimG), were processed using three drying techniques: sun drying (SD), oven drying (OD), and freeze drying (FD), with both boiled and fresh beetroots. The properties evaluated in the study included water activity, color, total phenolics and flavonoids, oxalate content, and mineral content. The results showed significant (p<0.05) differences in these properties between the dried and fresh samples. Notably, drying increased calcium, zinc, and phosphorus levels while decreasing the iron content. Boiling followed by sun drying was the best method for retaining iron, particularly for the CrimG variety. The study suggests that drying can help preserve or even enhance the physicochemical properties and micronutrient content, especially iron while reducing phytochemical levels affecting iron absorption. These findings are important for developing iron-rich beetroot products to improve dietary iron intake, especially for adolescent children.

Independently regulating the electric and magnetic properties of flaky FeSiAl powder based composites for high-performance microwave absorber

Independently regulating the electric and magnetic properties of flaky FeSiAl powder based composites for high-performance microwave absorber

Size enlargement by semibatch reactive crystallization with varying reactant addition methods and reaction kinetics: The study of dicumarol

Fine crystals of active pharmaceutical ingredient (API) with sizes of 0.1–10 μm are undesirable as they may cause difficulty in downstream operations, including filtration, washing, and drying, as well as issues in storage, formulation, and transportation. Dicumarol, synthesized via the condensation reaction of 4-hydroxycoumarin with formaldehyde, was used as a model drug in the present study. Due to the extreme insolubility in water, dicumarol crystals would rapidly precipitate, resulting in sizes less than 5 μm during the course of reactive crystallization. Therefore, our aims are to increase the crystal size of dicumarol in reactive crystallization, and to improve powder properties. Dimethylacetamide (DMAc) was identified as a suitable solvent for substituting water due to the higher dicumarol solubility, allowing a wider operating window to lower nucleation rates, and thereby, produce large-sized dicumarol crystals. The crystal size of dicumarol was enlarged by adjusting the addition mode of formaldehyde during semibatch reactive crystallization. Fast nucleation could thus be avoided. The reaction solution was sampled for the evolution of crystal habit observed by optical microscopy, and its kinetic process was thoroughly studied. Dicumarol crystals were enlarged to about 200 μm with an 85.2 % yield, with the improved powder properties: Carr’s index at 16.4±1.6 % and angle of repose at 37.0±0.5°. Fourier-transform infrared spectroscopy and powder X-ray diffraction confirmed the chemical and crystal properties of the final dicumarol products.

A Review on the Production and Characteristics of Cheese Powders.

Cheese powder is a product resulting from the removal of moisture from cheese. At first, cheese emulsion is prepared by dissolving cheese(s) with water and calcium sequestering salts followed by drying. The desirable characteristics of cheese powder are high solubility, no lumps, storage stability, and imparting a typical cheesy flavor to the final product. Many current studies on cheese powder are focused on reducing calcium-sequestering salts (CSSs) to reduce the sodium content of cheese powder. This review discusses the production processes and physio-chemical properties of cheese emulsions and powders, aiming to enhance current understanding and identifying potential research gaps. Furthermore, strategies for producing cheese powder without CSSs, including pH adjustment, homogenization, and addition of dairy components such as buttermilk powder and sodium caseinate, are elaborated upon. Processing variables such as heating conditions during the preparation of cheese emulsion may vary with the type and age of the cheese used and product formulation. These conditions also effect the characteristics of cheese powders. On the other hand, producing a stable cheese emulsion without CSSs is challenging due to impaired emulsification of fat. The combined use of buttermilk powder and sodium caseinate among various alternatives has shown promising results in producing cheese powder without CSSs. However, future research on replacing CSSs should focus on combining two or more strategies together to produce cheese powder without CSSs. The combination of pH adjustment and dairy ingredients and the use of novel processing technologies with different ingredients are interesting alternatives.

The effect of LaSi2 content on the powder characteristics and coating structure of ZrB2-SiC

To investigate the effect of LaSi2 content on the properties of ZrB2-SiC composite powder and coatings, different amounts of LaSi2 were added to the ZrB2-SiC system. The composite powders were prepared using the induction plasma spheroidization process, and the coatings were fabricated using atmospheric plasma spraying. Results showed that LaSi2 significantly improves the density of both the powder and the coatings. As LaSi2 content increase to 15 vol%, the density of the powders increases to 2.75 g/cm3 and the porosity of the coatings decreases to 6.92 %. Our results suggest that LaSi2 can fully melt in the plasma jet field and act as a sealing phase to heal pores, thereby improving the performance of both the powders and subsequently, the coatings.

Effect of Paprika Powder on the Antioxidant Capacity of Emulsion-Type Sausages.

Antioxidant activity of freeze-dried paprika powder and storage properties of emulsion-type pork sausages containing diverse concentrations of this powder (0%, 1%, 2%, and 3%) were analyzed. Antioxidant activities of red and yellow paprika powders were analyzed by evaluating their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), total phenol content (TPC), and total flavonoid content (TFC). The yellow paprika powder exhibited remarkably higher DPPH radical scavenging activity, FRAP values, and TPC than the red paprika powder (p<0.05), while TFC showed no remarkable difference between them (p>0.05). Storage properties of sausages containing the yellow paprika powder were analyzed by evaluating their water holding capacity, cooking yield, and thiobarbituric acid reactive substance (TBARS), and volatile basic nitrogen (VBN) values. The 3% yellow paprika powder group showed remarkably higher water-holding capacity and cooking yield compared to the 0% group (p<0.05). TBARS values were remarkably lower in the 2% and 3% yellow paprika powder groups than in the 0% group at all weeks (p<0.05). VBN value was remarkably lower in the 3% yellow paprika powder group than in the 0% group at all weeks (p<0.05). Overall, addition of 3% yellow paprika powder improved the storage properties of emulsion-type sausages.

A Comparative Evaluation of Powder Characteristics of Recycled Material from Bronze Grinding Chips for Additive Manufacturing.

In the manufacturing process of ship propellers, large quantities of grinding chips are generated. These grinding chips result from the finishing of the blade surfaces after the primary casting process of the propeller. The aim of this study was to investigate and compare different preparation processes used to produce chip powders with sufficient powder quality for the additive manufacturing process of directed energy deposition. The preparation of the samples was performed through different sieving, milling and re-melting processes. For the characterization of the prepared samples, powder analysis according to relevant industry standards was carried out. It was found that the re-melting processes result in superior powder quality for additive manufacturing in terms of particle size, morphology, and flowability. For some characteristics, the powder exhibits even better properties than those of commercial powders. Furthermore, the powder properties of the milled samples demonstrate a promising potential for use in additive manufacturing.

Study on properties of re-dispersible latex powder and polypropylene fiber-reinforced lightweight foam concrete

Foam concrete has a broad application prospect due to its lightweight, convenient construction and other characteristics. However, the low strength and tensile toughness limit the application range of foam concrete. In this study, re-dispersible latex powder and polypropylene fiber were used to improve the mechanical properties of foam concrete. The effects of re-dispersible latex powder and polypropylene fiber on the compressive and tensile properties of foam concrete were studied. The results showed that compared with ordinary foam concrete, the combination of re-dispersible latex powder and polypropylene fiber increased the energy absorption capacity, ductility index and tension compression ratio of foam concrete by 13.4 %, 5024.6 % and 190.7 %, respectively. The bio-membrane formed by the hydration of re-dispersible latex powder improves the internal pore structure, which can cooperate with polypropylene fiber to optimize the crack growth behavior and ductility of foam concrete, thereby improving the compression and tensile properties of foam concrete.

Impact of Spray Drying on the Properties of Grape Pomace Extract Powder

Incorporating anthocyanins, valuable natural pigments, into a powder can improve their stability, but exposure to high temperatures during processing can cause them to degrade. The purpose of this study was to investigate how the inlet air temperature during spray drying affects the physical and chemical characteristics as well as the flowability of a grape pomace anthocyanin powder obtained through ultrasound-assisted extraction using acidified water as the solvent. An anthocyanin solution containing 13% (w/v) maltodextrin was subjected to spray drying at temperatures ranging from 120 to 170 °C. Tukey’s test was applied to compare the means of the samples. The samples dried at temperatures between 130 and 170 °C were adequate, with a moisture content &lt; 5% and a water activity &lt; 0.3, indicating that the powder was stable. The highest anthocyanin retention (91.94 ± 1.59%) and process yield (50.00 ± 3.06%) were achieved at 140 °C, while higher temperatures resulted in anthocyanin degradation. Furthermore, the powder exhibited poor flowability, indicating cohesive behavior (Hausner ratio &gt; 42.29% and Carr index &gt; 1.73), which is an industrial parameter rarely considered in spray-drying studies. The acidification process was found to promote high anthocyanin retention following high-temperature processing. However, powders obtained from food matrices with low pH and high sugar content may exhibit increased cohesion due to interaction forces. These findings highlight the potential of utilizing grape pomace and green solvents to produce bioactive-rich powders for industrial applications.