Jet Mill Research Articles

NUMERICAL AND EXPERIMENTAL STUDY OF MIXTURE GRINDING OF MATERIALS WITH DIFFERENT STRENGTHS

At joint grinding of components with different strength the particles of more strong material are of larger size than the particles of less strong material. The size classification of such mixture allows enriching the objective component in the end product. The scientifically grounded choice of technological conditions for effective separation of a mixture of materials of different strength is an actual problem for chemical and other industries. The computational research was done using the conception of chemical processes modeling based on the discrete analogues of the Boltzmann equation. A special program for experimentations and experimental data treatment obtained at a lab-scale fluidized bed jet mill was developed. A model to describe the grinding kinetics for each component of a mixture was developed. It allows estimating the efficiency of enrichment of the end product by the objective component. A method to solve the equations of the selective model of grinding and the computer algorithm for its realization was developed as well. The experimental data on grinding of binary mixture of components at their different content in the fluidized bed jet mill hold-up were obtained. These data were used to identify the model with respect to the parameters that characterized the grindability of each component. The model adequacy was checked using the data on joint grinding of mixtures with different content of components. These data were not used for the model identification. Comparison of calculated and experimental data showed the model adequacy and possibility of its usage to estimate the efficiency of components separation. The investigation allowed generalizing the conceptions of chemical processes modeling based on the discrete analogues of the Boltzmann equation to the case of selective grinding of a mixture of components with different strength. The computational analysis showed that the model allowed describing the process with acceptable for engineering practice accuracy, practical estimating the possibility of components enrichment and defining the optimal technological conditions for their separation.Forcitation:Zhukov V.P., Osipov D.А., Otwinowski H., Urbaniak D. Numerical and experimental study of mixture grinding of materials with different strengths. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 6. P. 109-115.

Stability of Pharmaceutical Cocrystal During Milling: A Case Study of 1:1 Caffeine–Glutaric Acid

Despite the rising interest in pharmaceutical cocrystals in the past decade, there is a lack of research on the solid processing of cocrystals downstream to crystallization. Mechanical stress induced by unit operations such as milling could affect the integrity of the material. The purpose of this study is to investigate the effect of milling on pharmaceutical cocrystals and to compare the performance of ball mill and jet mill, using caffeine–glutaric acid (1:1) cocrystal as the model compound. Our results show that ball milling induced polymorphic transformation from the stable Form II to the metastable Form I, whereas Form II remained intact after jet milling. Jet milling was found to be effective in reducing particle size, but ball milling was unable to reduce the particle size beyond a certain limit even with increasing milling intensity. The heating effect during ball milling was proposed as a possible explanation for the difference in the performance of the two types of mill. The local increase in t...

Micronization and nanosizing of particles for an enhanced quality of food: A review

ABSTRACTSize reduction to micron to nanosize range is rapidly developing technology applied to foods in the recent decades. This article reviews the particle size reducing technologies for solid particulate and liquid materials. For solid particulate materials, the jet milling, ball milling and colloid milling are mainly used. For liquid materials, primarily the high pressure homogenization, ultrasonic homogenization and microfluidization technologies are used. Due to the reduction in particle size, micron- and nanotechnology significantly enhance the physico-chemical and functional characteristics of food materials, resulting in the improvement of food quality.

The Functional Properties of Chokeberry and Kale Powders Obtained by an Innovative Method of Fluidised-Bed Jet Milling with Drying Compared to Freeze Drying

Abstract The study evaluated the functional properties of chokeberry and kale powders obtained by the fluidised-bed jet milling with drying (FJMD) method compared to the freeze-drying (FD) method. The powders obtained by the FJMD method were characterised by low water activity (<0.3), vitamins C content of 320.2 mg/100 g d.m. for kale powder, total content of polyphenols of 1864.2 mg/100 g d.m. for chokeberry powder, antioxidant activity of 37.0 and 27.6 mmol Trolox/g d.m for chokeberry and kale powders respectively and sensory quality similar to raw material. The high content of vitamin C in the kale powder indicates the desirability of its greater use as a natural source of this vitamin. The properties of FJMD powders were similar to the functional properties of the FD powders, which indicate that the FJMD method can be very competitive as compared to FD method.

ДВИЖЕНИЕ ДВУХФАЗНОГО ПОТОКА В РАЗГОННОЙ ТРУБКЕ СТРУЙНОЙ МЕЛЬНИЦЫ

ДВИЖЕНИЕ ДВУХФАЗНОГО ПОТОКА В РАЗГОННОЙ ТРУБКЕ СТРУЙНОЙ МЕЛЬНИЦЫ

Protein isolation from jet milled rye flours differing in particle size

A commercial rye flour (R) was solubilised by mixing at different ratios with three solvents, namely ΝaOH solutions, HCl solution and deionised water. The highest protein extracted content (74.27%) was reported for a flour: 0.02M NaOH solution ratio of 1:14. After solubilisation at the defined optimum condition, precipitation was performed at different pH values (3–7). The best performance on the basis of protein recovery was found at pH 5.5. The optimum conditions for both solubilization and precipitation of rye flour proteins were applied to rye flours (R1, R1A and R1B) differing in their particle size. Flours R1A and R1B resulted from pulverizing flour R1 by a jet mill at a feed rate of 3.35 and 1.17kg/h, respectively. In contradiction to the expected in terms of smaller particle size, greater protein recovery percentage was achieved for both R1 and R1B flours. As the formation of aggregates seem possible, the duration of the isolation procedure as well as the duration and the speed of the centrifugation seem to be important for the explanation of our findings.

Particle size distribution control and related properties improvements of tungsten powders by fluidized bed jet milling

Fine grinding process of different particle size tungsten powders was carried out by fluidized bed jet milling. The results showed that the jet milling treatment caused deagglomeration of tungsten powders, which led to particles sufficient dispersion and narrow particle size distribution. Grinding gas pressure of 0.70Mpa made the particles achieve high speed which promoted the particles collision contributing to particle dispersion and shape modification. For tungsten powder with particle size of 3μmFSSS, a higher packing density with 5.54g/cm3 was obtained, compared with the 3.71g/cm3 of the original powder. For tungsten powder with particle size of 1μmFSSS, the big agglomerates disappeared and the particle size distribution become narrower, while small aggregates about 2–3μm still exist after the jet milling process. For tungsten powder with particle size of 5μm and 10μmFSSS, different medium diameter particle size and narrow particle size distribution of monodisperse tungsten powders can be produced by the optimized jet milling parameters. More important, the effective dispersion, favorable shape modification and precise classification have been achieved in the simple process.

МИКРОСТРУКТУРА ПРОДУКТОВ ГИДРАТАЦИИ ВЯЖУЩИХ КОМПОЗИЦИЙ, ПОЛУЧЕННЫХ В ВИХРЕВОЙ СТРУЙНОЙ МЕЛЬНИЦЕ

Zagorodnuk L.H., Sumy D.A., Golden S.V., Kaneva E.V.
 MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL
 By electron microscopy to study the microstructure of the cement stone made from Portland cement and activated binders of the compositions in the vortex jet mill. It was found that the open pores of the cement and cementitious compositions prepared using perlite fillers, always filled with tumors, at different stages of collective growth. The microstructure of cementitious compositions has a dense structure by rationally selected composition, effective use of mineral filler - perlite waste, creating additional support for the formation of the internal microstructure of the composite, mechanical activation raw mixture, allowing to obtain composites with desired properties.

The role of particle size of glyburide crystals in improving its oral absorption.

Currently, nanosizing is becoming increasingly prevalent as an efficient way for the improvement of oral drug absorption. This study mainly focuses on two points, namely the crystal properties, and the in vitro and in vivo characterizations of drug crystals during the nanosizing process. We used glyburide, an oral type 2 diabetes (T2D) medication, as our model drug. We sought to reduce the crystalline size of this drug and evaluate its absorption properties by comparing it with the original coarse drug because of previous reports about its gastrointestinal absorption insufficiency. Glyburide crystals, ranging from 237.6 to 4473nm were prepared successfully by jet milling and media milling. The particle sizes and the crystal morphology were analyzed by characterization of the solid states, equilibrium solubility, and dissolution behavior. Additionally, pharmacokinetic study was performed in SD rats. The solid state results indicated a loss in crystallinity, amide-imidic acid interconversion, and partial amorphization during nanosizing. Further, in in vitro tests, nanocrystal formulations remarkably increased the solubility and dissolution of the drug (compared to microcrystals). In the in vivo test, reducing the particle size from 601.3 to 312.5nm showed no improvement on the C max and AUC (0-36h) values, while a profound slowing of the drug elimination occurred with reduction of particle size. Further reduction from 312.5 to 237.6nm lead to a significant increase (p<0.001) of the AUC (0-36h) from 6857.8±369.3ngmL-1h to 12,928.3±1591.4ngmL-1h, respectively, in rats. Our present study confirmed that nanosizing has a tremendous impact on promoting the oral absorption of glyburide.

Air Jet Mill 공법과 PMMA의 단분산성이 프레스드 파우더의 밀착성 및 발림성 향상에 대한 연구

베이스메이크업 중의 하나인 프레스드 파우더는 주요 품질 속성으로 밀착성과 발림성이다. 일반적으로 메이크업 화장료에서 밀착성을 향상시키면 반대속성인 발림성이 저하되기 때문에 밀착성과 발림성을 동시에 충족시키는데 한계가 있었다. 본 연구에서는 두 가지 주요 속성을 만족시키기 위해서 air jet mill 공정을 시도하였고, lauroyl lysine (LL)과 sodium cocoyl glutamate (SCG)의 혼합물로 습식 코팅 처리한 sericite를 적용하여 밀착성을 향상시켰다. 또한, 분산성이 단분산성을 이루고 있는 polymethyl methacrylate (PMMA)와 diphenyl dimethicone/ vinyl diphenyl dimethicone/ silsesquioxane crosspolymer (DDVDDSC)를 적용하여 발림성을 향상시켜 서로 양립하기 어려운 두 가지 품질 속성을 모두 만족시켰다. air jet mill 공정은 제약, 식품 산업에서 주로 적용되고 있으며 화장품 분야에서는 파우더 소재 가공을 위해 사용되고 있는 공법이다. 본 연구에서는 air jet mill 공정을 제조 공정단계에서 접목시켜 최적의 입경인 <TEX>$6.8{\mu}m$</TEX>의 화장료를 완성할 수 있었다. 그리고, EDS 매핑으로 Ti 원소가 화장료에서 전체적으로 고르게 분포하고 있음을 확인하였고, SEM 분석을 통하여 판상 입자의 모서리 부분이 둥글게 가공처리 됨을 확인하였다. 이는 화장 도구를 이용하여 화장료를 취하여 피부에 도포할 때, 발림성이 향상되는 효과를 줄 수 있다고 판단된다. 피부 친화성이 우수한 LL과 저자극이면서 코코넛에서 유래한 SCG를 습식 코팅하여 sericite의 밀착성을 더욱 향상시켰다. 그리고, PMMA의 분산성과 형태가 발림성에 미치는 영향을 평가하기 위해서 SEM을 분석하였다. 유사한 형태를 갖는 구형 및 진구형에서도 분포도가 균일하고 단분산상일 때 발림성 효과가 더욱 증가하는 것으로 나타났다. PMMA의 단분산성과 입경에 따른 발림성을 동마찰계수 측정으로 확인하였고, 최적의 함량을 결정하였다. 그리고, 실리콘 러버 파우더 종류에 따른 발림성과 경도, 낙하안정성 등을 확인하여 DDVDDSC를 결정하였다. 최종적으로 PMMA의 단분산성과 실리콘 러버 파우더가 발림성에 영향을 끼치는 것을 알 수 있었다. 이와 같은 화장료는 적정한 경도를 갖으면서도 낙하안정성이 우수하며, 경시에 따른 안정성도 우수하였다. 본 연구 결과를 통해 본 논문에서 제시하는 프레스드 파우더의 밀착성과 발림성을 향상시킬 수 있는 한 가지 방법으로 활용될 수 있을 것이라 판단된다. The key quality attributes of the pressed powder, one of base makeup products, are skin-affinity and spreadability. In general, there was a limit to meet skin-affinity and spreadability simultaneously, which are opposite attributes each other. In this study, air jet mill process was tried to satisfy two main properties. Skin-affinity was improved by a wet coating of sericite with a mixture of lauroyl lysine (LL) and sodium cocoyl glutamate (SCG). The application of mono-dispersed polymethyl methacrylate (PMMA) and diphenyl dimethicone/vinyl diphenyl dimethicone/silsesquioxane crosspolymer (DDVDDSC) improved both qualities. Air jet mill process has been mainly applied in the pharmaceutical and food industries, and is a method used for processing powder materials in cosmetic field. In this study, we were able to complete makeup cosmetics with an optimum particle size <TEX>$6.8{\mu}m$</TEX> by combining the air jet mill process at the manufacturing stage. It was confirmed that the Ti element was uniformly distributed throughout the cosmetics by EDS mapping, and that the corners of the tabular grains were rounded by SEM analysis. It is considered that this can provide an effect of improving the spreadability when the cosmetic is applied to the skin by using a makeup tool. LL with excellent skin compatibility and SCG derived from coconut with little skin irritation were wet coated to further enhance the adhesion of sericite. SEM images were analyzed to evaluate effect of the dispersion and uniformity of PMMA on spreadability. With the spherical shapes of similar size, it was found that the spreading effect was further increased when the distribution was homogeneously mono-dispersed. The dispersion and spreadability of PMMA were confirmed by measuring the kinetic friction and optimal content was determined. The silicone rubber powder, DDVDDSC, was confirmed by evaluating the hardness, spreading value, and drop test. Finally, it was found that the dispersion of PMMA and silicone rubber powder affected spreadability. Such makeup cosmetics have excellent stability in drop test while having appropriate hardness, and good stability over time. Taken together, it is concluded that air jet mill process can be utilized as a method to improve skin-affinity and spreadability of the pressed powder.

Production of CuSn10 bronze powder from machining chips using jet milling

In this study, an experimental target plate jet mill was designed and used to produce CuSn10 bronze powder from its machining chips. Taguchi method with an L9 orthogonal array was used as experimental design to determine the optimum conditions for the pulverization of the machining chips via jet milling. The effect of process variables including nozzle to target distance, impact angle, and air pressure were investigated. The optimum conditions were found to be 8 cm for nozzle to target distance, a 90° angle between nozzle and target, and an air pressure of 7 bar. Repeated impact cycles lead to the production of finer and more rounded particles, although the rate of size reduction was reduced. The jet-milled powder did not contain any contamination, and the amount of the surface oxide of the jet-milled powder was even lower than that of the initial machining chips. Investigation of the fragmentation of particles revealed that the initial machining cracks were the main sites for breakage during pulverization. In addition, the delta phase in the microstructure of the bronze alloy plays an important role in the propagation of pre-existing cracks as well as creating new cracks.

Effectiveness of Jet Milling for Producing Superfine Powders from Blast-Furnace Slag

The paper examines the effect of ball (drum) grinding and jet milling on the particle size distribution and specific surface area of the powders produced from blast-furnace slag. The effectiveness of jet milling, providing relatively equal powder particles (more than 85% of the fractions is 0–10 μm in size), is shown. Decrease in the average particle size leads to greater specific surface area of the powder and to a sharp increase in activity (strength of the samples prepared with use of blastfurnace slag). Hydraulic activity σ ≥ 30 MPa can be reached by the powder produced from slag with an average particle size to 12 μm and specific surface area S = 0.6–0.8 m2/g, which increases the sample strength. The strength of cemented compositions based on blast-furnace slag can be improved to 40–43 MPa by adding 15–20% Portland cement to the starting mixture.

Optimum parameters for the production of porous ceramic materials

In this research, the effects of parameters such as sintering temperature, forming method, milling type and the content of alunite within kaolin were investigated for the production of porous ceramic material. For this purpose, kaolin samples with three different alunite contents, taken from the Balikesir-Sindirgi region of Turkey, were used. During the research, ball and jet mills were utilized to determine the effect of mill type onto the strength and porosity values of the porous body. Optimum milling times for the two mills were determined during this stage. Moreover, the effect of forming method onto the strength and porosity values of the porous bodies was investigated. For these tests, dry pressing and slip casting methods were employed. The samples formed were then sintered at a temperature range of 900 to 1300 °C. Consequently, the most optimum conditions for the production of the highest porosity ceramic material were determined.

Acceleration of dispersing calcium carbonate particle in aqueous media using jet milling method

Suspending particles in a liquid phase is a key to producing various functional nano products. We prepared calcium carbonate (CaCO3) particles in aqueous suspension using two methods, ultrasonication and jet milling, and characterized them using various techniques. Suspensions of CaCO3 particles in aqueous media were prepared with different industrial surfactants: polyethylene glycol p-(1,1,3,3,-tetramethylbutyl)-phenyl ether (Triton X-100), polyoxyethylene(23) lauryl ether (Brij35), polyoxyethylene alkylether (Softanol70), and sodium dodecyl sulfate (SDS). According to dynamic light scattering and asymmetric flow field-flow fractionation assessments, the dispersed CaCO3 particles are clearly small when Triton X-100 or Softanol 70 is used as the surfactant regardless of whether ultrasonication or jet milling was used as the dispersion method, although the size distribution of the particles varies depending on the dispersion method. The observed zeta potentials of the CaCO3 particles in various surfactant solutions support the finding that Triton X-100 and Softanol70 are good dispersants for CaCO3 particles in aqueous media because of their larger electrostatic repulsion interaction. Pulsed field gradient nuclear magnetic resonance (PFG-NMR) indicated that jet milling accelerates interaction/adsorption between CaCO3 particles and surfactant molecules, so it disperses the aggregated/agglomerated CaCO3 particles more effectively than ultrasonication. In addition, interestingly, we found that Softanol70 worked well as a dispersant for CaCO3 particles in aqueous media for both ultrasonication and jet milling, as indicated by the PFG-NMR assessment.

МИКРОСТРУКТУРА ПРОДУКТОВ ГИДРАТАЦИИ ВЯЖУЩИХ КОМПОЗИЦИЙ, ПОЛУЧЕННЫХ В ВИХРЕВОЙ СТРУЙНОЙ МЕЛЬНИЦЕ

Zagorodnuk L.H., Sumy D.A., Golden S.V., Kaneva E.V.&#x0D; MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL&#x0D; By electron microscopy to study the microstructure of the cement stone made from Portland cement and activated binders of the compositions in the vortex jet mill. It was found that the open pores of the cement and cementitious compositions prepared using perlite fillers, always filled with tumors, at different stages of collective growth. The microstructure of cementitious compositions has a dense structure by rationally selected composition, effective use of mineral filler - perlite waste, creating additional support for the formation of the internal microstructure of the composite, mechanical activation raw mixture, allowing to obtain composites with desired properties.

Improving Carob Flour Performance for Making Gluten-Free Breads by Particle Size Fractionation and Jet Milling

Many different raw materials have been proposed for producing nutritious gluten-free breads, but rarely, there is a parallel analysis of the effect of physical treatment on those ingredients. The aim of this study was to incorporate carob flour fractions of varying particle size on rice gluten-free breads prepared with carob/rice (15:85) flour blends. Carob flour particle size was controlled by fractionation or jet milling application. Quality features of gluten-free breads containing carob flour and commercially available gluten-free breads were compared. Carob flour addition led to breads with improved colour parameters, crumb structure, retarded firming and lower moisture loss compared to rice bread. Further improvement in specific volume, crumb hardness, protein and ash content and estimated glycaemic index (eGI) could be obtained by a careful selection of the particle size distribution of the carob flour. Carob breads prepared either with the coarsest or the finest fraction prepared using jet milling led to end products with the highest specific volume (≈2.2 g/cm3) and the lowest crumb hardness (≈5.5 N), although they had lower specific volume and harder crumbs than breads from commercial blends (≈3–4 g/cm3, 0.6–3.8 N). Nevertheless, rice-based bread made with the finest carob flour was superior considering its slower firming, protein content and lower eGI. The incorporation of carob flour obtained by jet milling in rice-based gluten-free breads led to end products with quality characteristics and sensory acceptance resembling commercial breads and high nutritional value.

Study on the Performance of an Air-Jet Mill by varying operating Parameters

In the present work, performance of an Air-Jet Mill was studied. Although jet mill has several advantages but it is still an energy intensive process as only 2% - 5% of the energy supplied is used to create new surfaces. In the present work some trial runs are performed by varying the operating parameters of the jetmill. Product quality is the factor which determines whether determines whether a specific grinding technique is appropriate. The roduct of a jet mill is a fine powder with a well defined and narrow particle size distribution. The RPM and blower alue conditions were varied and the results were tabulated. The optimum conditions for the desired quality and production rate of the jet mill in the plant are determined.

Numeric Evaluation of Kinematic and Dynamic Characteristics of Mineral Treatment in Disintegrator

The numerical modeling provides a holistic picture of mechanical treatment and activation of substances in a disintegrator. The authors calculate kinematic and dynamic characteristics of elastic and inelastic collisions in terms of halite, quartz and sulfur particles and disintegrator fingers. The recommendations on selecting optimal treatment conditions for natural minerals and waste material in order to dissociate mineral concretions and for selective activation of minerals are given. The research findings can partly be used for other types of percussion disintegrating devices, in particular, jet mills.

ジェットミル粉砕プロセスにおける粒子径分布のリアルタイムモニター

The optimum parameters for grindings by a jet mill is determined by many experiments, changing parameters, such as the feeding speed, the inlet pressure, and measure the particle size distribution of the corrected powder. This process takes long time and work load. To reduce this optimization time, in-line monitoring of the particle size distribution for the jet mill process was investigated. We could successfully monitor the particle size distribution of the ground particles, just after the jet mill process, using an in-line laser diffraction measurement system. A proportional relationship was observed between the supplying speed of the material, and the Volume based median diameter, Dv50 of the ground powder. When we changed the feed rate step by step, we could see the Dv50 value was changed with those steps.

Towards quality by design in pharmaceutical manufacturing: modelling and control of air jet mills

Milling is an important step in pharmaceutical manufacturing as it not only determines the final formulation of the drug product, but also influences the bioavailability and dissolution rate of the active pharmaceutical ingredient (API). In this respect, the air jet mill (AJM) is most commonly used in the pharmaceutical industry as it is a non-contaminating and non-degrading self-classifying process capable of delivering narrow particle size distributions (PSD). Keeping the principles of Quality by Design in mind, the Critical Process Parameters (CPPs) of the AJM have been identified to be the pressures at the grinding nozzles, and the feed rate which affect the PSD, surface charge and the morphology of the product (i.e. the Critical Material Attributes (CMAs)). For the purpose of this research, the PSD is considered to be the only relevant CMA. A population balance based model is proposed to simulate the dynamics milling operation by utilizing the concept of breakage functions. This model agrees qualitatively with experimental observations of the air jet mill unit present at Janssen Pharmaceutica but further steps for model validation need to be carried out.