Liquid Binder Research Articles

Engineering of Piroxicam Agglomerates by Additives Using Wet Agglomeration Technique

Background: Wet agglomeration is a method wherein the crystals of dispersion are held together in aggregates by small amount of a liquid acting as an intercrystal binder. In present study, in order to study the possible modification of agglomerate structure, low concentrations of additives (0.1-1%) were added to binder liquid. Methods: Piroxicam agglomerates were produced by wet agglomeration method by three solvent systems including a good solvent (dimethylformamide or acetone), antisolvent (water) and a binder liquid (ethylacetate or isopropylacetate). Span 80, talc, ethylcellulose and Eudragit RS in different concentrations were used as additives. The agglomerates were evaluated for production yield of agglomerates, size, friability and drug release properties. Results: The results showed that formation of agglomerates was possible in presence of span and talc. However, no agglomerates could be obtained with polymers tested (ethylcellulose and Eudragit RS). Talc increased agglomerate size, whereas the obtained agglomerates were more susceptible to breakup. However, using span as opposed to talc resulted in agglomerates with higher strength but smaller particle size. The dissolution tests showed that both additives adversely affected the dissolution rate of piroxicam from the agglomerates. Conclusion: Result of this study suggested that additives even in small amounts played a major role in agglomerate properties.

Soy-substituted liquid phenol formaldehyde binders for flakeboard

The degree to which liquid phenol formaldehyde resin for flakeboard applications can be replaced by soy flour was studied through a design of experiment approach. Up to ten percent substitution could be achieved while substantially maintaining board properties. Higher levels of substitution increased the viscosity of the resin droplet, which reduced resin spread and various strength properties. The loss of strength was most apparent for dense boards where the spreading limitation reduced the relative bonded area.

Development of a supercritical fluid CO2 granulator: Effect of mixing and composition

Conventional wet granulation is commonly used in the pharmaceutical industry for size enlargement, where small primary particles are binded together using agitation and a liquid binder. However, after the wet mass is produced, it needs to dry the granules for long periods of time causing high-energy inputs. This report presents a novel supercritical fluid CO2 granulator (SFG) to produce granule batches with low particle size distribution (PSD), while using less drying time and minimizing the additional drying steps. This study focused on understanding the effect of mixing (e.g., flow rate, location of inlet flow, agitation) and composition (e.g., binder and solvent type water vs. ethanol) in the SFG process. Sieves were used to measure the PSD, and scanning electron microscopy (SEM) was performed to observe the granules' shape. The PSD and the shape of the granules were used to evaluate the efficiency of the SFG process. The excipients used included anhydrous lactose and monohydrate lactose, while acetaminophen was used as the active pharmaceutical ingredient (API). The results show that the SFG process could effectively be used as an alternative to the conventional wet granulation process (Patent Pending # 62/398,645). The study also discusses how changes in the mixing and composition conditions affect the resulting granule size, distribution, and shape.

Grain growth and hardness of TiC-based cermets: Experimental investigation and thermodynamic calculations

In the present work, the influence of Mo and W additions and sintering time on the microstructure, grain growth and hardness of TiC-based cermets was systematically investigated by means of experimental determination and thermodynamic calculations. Under the guidance of the calculated carbon window, the TiC-based cermets with different Mo and W contents have been designed and sintered at 1430°C in Ar atmosphere for 0h, 1h, 2h and 5h. The microstructure of cermets was observed by using scanning electron microscopy (SEM), while the volume fraction and average grain size of ceramic phase were measured by using ImageJ software. The volume fraction of ceramic phase decreases with the addition of Mo and W, which indicates the promoting effect of Mo and W on the carbide dissolution. The grain growth kinetics followed the cubic law, which was controlled by the diffusion of dissolved atoms through liquid binder phase (i.e. Ostwald ripening mechanism). The addition of Mo and W in TiC-based cermets can lead to a slow grain growth process during liquid-phase sintering. In addition, the Vicker hardness measurement was performed for the cermets, and the hardness was influenced by several factors, such as volume fraction and composition of binder phase, average grain size of ceramic phase and bonding strength of interface.

Statistical analysis and comparison of a continuous high shear granulator with a twin screw granulator: Effect of process parameters on critical granule attributes and granulation mechanisms

This study is concerned with identifying the design space of two different continuous granulators and their respective granulation mechanisms. Performance of a continuous high shear granulator and a twin screw granulator with paracetamol formulations were examined by face-centered cubic design, which focused on investigating key performance metrics, namely, granule size, porosity, flowability and particle morphology of granules as a function of essential input process parameters (liquid content, throughput and rotation speed). Liquid and residence time distribution tests were also performed to gain insights into the liquid-powder mixing and flow behavior. The results indicated that continuous high shear granulation was more sensitive to process variation and produced spherical granules with monomodal size distribution and distinct internal structure and strength variation. Twin screw granulation with such a particular screw configuration showed narrower design space and granules were featured with multimodal size distribution, irregular shape, less detectible porosity difference and tighter range of strength. Granulation mechanisms explored on the basis of nucleation and growth regime maps revealed that for most cases liquid binder was uniformly distributed with fast droplet penetration into the powder bed and that granule consolidation and coalescence mainly took place in the nucleation, steady growth and rapid growth regimes.

An Experimental Investigation on Seeded Granulation of Detergent Powders

Granulation is commonly used as an enlargement process of particles produce granules with desirable characteristics and functionality. Granulation process transforms fine powders into free-flowing, dust-free granules with the presence of liquid binder at certain operating conditions. The main focus of this research is on seeded granulation of detergent powders, a new phenomenon of granulation in which a layer of fine powders surround the coarse particle. This is already proven for calcium carbonate (Rahmanian et al., 2011). Here, detergent granules were produced in a 5 L high shear Cyclomix granulator using different fine/coarse powder ratio (1/3, 1, 3) and different binder ratio of 10 %, 20 % and 30 %. The granules were then characterized for their particle size distribution, strength and structure. It was found that a high percentage (70 wt. %) of granules in the desired size range between 125 - 1,000 µm were produced using the powder ratio of 1/3 and a binder content of 10 %. Low mean crushing strength (3.0 N) with a narrow distribution was obtained using this condition. Structure characterization of the detergent granules produced in the granulator shows that consistent seeded granule structures are produced under the optimum process and formulation conditions of 1/3 powder ratio with 10 % binder.

Evaluation of the effect of some additives on the efficiency of binder liquid in wet agglomeration of crystals

Objective: Wet agglomeration is a process wherein dispersed particles are held together in an aggregated form by the presence of a small quantity of solvent which acts as binder liquid. In this work, the efficiency of binder liquid was tested in the presence of various additives.Methods: Solid state of carbamazepine (CBZ) agglomerates was characterized by DSC and FT-IR. The obtained agglomerates were also investigated in terms of yield, size distribution, friability, and drug release.Results: CBZ agglomerates formed only in the presence of talc, span, and croscarmellose sodium (CCS), whereas ethyl cellulose and eudragit RS100 failed to make CBZ agglomerates. The presence of talc decreased the agglomerate size and produced CBZ agglomerates with a poor strength. However, span and CCS led to larger agglomerates with superior strength. In contrast to CCS samples, span and talc altered the dissolution rate of CBZ. FT-IR results showed that there is an interaction between CCS and drug.Conclusion: This study suggests that care must be taken when additives are used to manufacture agglomerates as the type of additives even in low concentrations can have a big impact on the efficiency of the binder liquid in forming agglomerates thereby affecting the quality of agglomerates.

Rheological properties of carbon composition within temperature rang 120-170 ºC

Carbon production is widely used in chemical and metallurgic industries. Particularly, electrode mass is used in forming of permanent self baking electrode (Sodenberg`s electrode) in electrical and thermal furnaces of ferrous and non-ferrous metallurgy. Elements of electric furnaces constructions, for instance, electrolysis units, are made of carbon blocks. Manufacturing of such class of products includes multistage technological process and during each stage monolithic product is formed out of powder filler and liquid binder. The given materials have unique physical properties: high thermal conductivity, thermal stress resistance, chemical inertia. That is the reason why it is so widely used in industry. Different methods of measurement of rheological properties of carbon composites were discussed, particularly, it concerns non-Newton liquids, such as Bingham liquid. The method and developed investigation equipment enables us to measure viscosity within wide temperature range. The method is based on locating the spherical body in viscous environment under definite isothermal temperature. It`s possible to measure effective dynamic viscosity up to 107 Pа∙s within temperature range up to 800 oС. Estimated error of experimental research does not exceed 10–15%. Having made the research, thermal dependence on effective factor of dynamic viscosity within temperature range 120–170 oС was found out. It concerns carbon composite materials where coke is used as a binder and thermally processed carbon material are used as a filler

Wettability of tungsten carbide by liquid binders in WC–Co cemented carbides: Is it complete for all carbon contents?

The wettability of tungsten carbide by liquid binders with various carbon contents and infiltration of WC–WC grain boundaries in cemented carbide by such binders were examined. The wettability of tungsten carbide by the liquid Co-based binder is complete at low carbon contents and becomes incomplete when increasing the carbon content. The wettability of WC by the Co-based binder alloy saturated with carbon is relatively poor with a wetting angle of about 15°. The well-known phenomenon of Co migration from carbide regions with high carbon contents into regions with low carbon contents is presumably caused mainly by the variance in capillary forces related to the different wettability rates of WC by liquid binders with various carbon contents. The Co-based binders with various carbon contents are found to have different behaviors with respect to infiltrating WC–WC grain boundaries in cemented carbides during sintering. WC–WC interfaces in a cemented carbide sample with a high carbon content do not comprise nm-thick Co interlayers. In contrast to that, the majority of the WC–WC interfaces in a cemented carbide sample with a low carbon content comprise continuous Co interlayers of the order of at least several nanometers in thickness.

Silicified microcrystalline cellulose based pellets and their physicochemical properties

ABSTRACTSilicified microcrystalline cellulose (SMCC), Prosolv SMCC 50 was used as spheronization aid to manufacture pellets by extrusion and spheronization. Different ratios of SMCC to lactose were used to manufacture pellets using appropriate levels of water as liquid binder. Avicel PH101 based pellets were also manufactured for comparison of their physical properties. The ratio of liquid binder to spheronization aid was critical to produce pellets of desired size and shape. Extrudates composed of 20% aid could withstand only smaller spheronization force in order to be shaped into pellets. The successful products fulfilled the quality of pellets such as narrow size distribution and spherical in shape. The highest surface tensile strength was observed in pellets with equal ratio of lactose to SMCC while pellets having 20% aid disintegrated rapidly within 15 min. Furthermore, Prosolv SMCC 50 based pellets possessed a stronger surface tensile strength when compared with Avicel PH101 based pellets. In conclusion, Prosolv SMCC 50 has showed to be a good spheronization aid for extrusion and spheronization when used in the range of 20 to 80% content. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43829.

A novel use of friability testing for characterising ribbon milling behaviour

Dry granulation using roll compaction (DGRC) has been increasingly adopted in the pharmaceutical industry due to its unique advantage of not requiring liquid binder and a subsequent drying process. However the DGRC process presents also some challenges, in particular, a high fine fraction generated during the milling stage significantly limits its application. Although the fines produced can be recycled in practice, it may lead to poor content uniformity of the final product. At present there is a lack of mechanistic understanding of milling of roll compacted ribbons. For instance, it is not clear how fines are generated, what are the dominant mechanisms and controlling attributes and whether any measurement technique can be used to characterise ribbon milling behaviour. Therefore, the aim of this paper was to assess whether ribbon milling behaviour can be assessed using some characterisation methods. For this purpose, friability was evaluated for ribbons made of microcrystalline cellulose (MCC) powders using a friability tester that was originally developed for characterising the tendency of pharmaceutical tablets to generate small pieces while being abraded. Granules were also produced by milling of the ribbons and their size distributions were measured. The correlation between the fine fraction of the granules with ribbon friability was then explored. It was found that there was a strong correlation between ribbon friability and the fine fraction of granules generated during milling. This implies that friability tests can be performed to characterise ribbon milling behaviour, and ribbon friability provides a good indication of the fraction of fines generated during ribbon milling.

The effect of high temperature on the design of blast furnace slag and coarse fly ash-based geopolymer mortar

Abstract In this study, geopolymer mortars were prepared by replacing blast furnace slag (BFS) based mixtures with coarse fly ash (FA) in different proportions. The aim of this study was to build a geopolymer mortar design for high temperatures using constant NaOH molarity (M) and constant curing temperature. In addition to 14 M NaOH solution and BFS as the binder material at a 60 °C curing temperature, double binder mixture ratios were prepared adding 25%, 50% and 75% FA. Geopolymer mortars with a liquid binder (L/B) ratio of 1 were subjected to oven curing for 5, 24, 48, 168 h. After physical and mechanical tests, the samples with the highest compressive strength were determined and six different mixtures with an L/B ratio in the range from 1 to 0.5 were prepared in order to increase the compressive strength of the samples in question. The physical and mechanical tests were repeated for the new samples. After the tests, the mortar sample with the highest compressive strength and its high temperature behavior was determined. For this purpose, the mortar sample with the highest compressive strength was subjected to temperatures of 200, 400, 600, 800 and 1000 °C, and changes in the physical and mechanical properties was analyzed. As a result of the experiments, the highest flexural strength value (3.6 MPa) was obtained from the mortar samples with a 25% BFS content subjected to curing for 5 h. The highest compressive strength values (27.3 MPa) were obtained from the mortar samples with a 100% BFS content subjected to curing for 48 h. In terms of compressive strength, the optimization of the L/B ratio resulted in a 28% increase (0.7) and this way, 35.1 MPa was achieved. Following the high temperature tests, 400 °C and 600 °C were determined as critical temperatures for changes in mechanical properties and changes in physical properties, respectively. However, the geopolymer mortars lost around 58% of strength at 1000 °C which is the final temperature.

Effect of glycerol concentrations on the mechanical properties of additive manufactured porous calcium polyphosphate structures for bone substitute applications

Event Abstract Back to Event Effect of glycerol concentrations on the mechanical properties of additive manufactured porous calcium polyphosphate structures for bone substitute applications Esmat Sheydaeian1, Mihaela Vlasea1, Ami Woo1, Robert Pilliar2, Youxin Hu3 and Ehsan Toyserkani1 1 University of Waterloo, Mechanical and Mechatronics Engineering, Canada 2 University of Toronto, Institute of Biomaterials and Biomedical Engineering, Canada 3 University of Toronto, Faculty of Dentistry, Canada Introduction: In this study, the focus is on the development of a new liquid binder to be used with calcium polyphosphate (CPP)[1] [University of Toronto, Toronto, ON, Canada] powders in additive manufacturing (AM) of biocompatible and bioresorbable bone substitutes[1]. From the different number of the solutions which have been proposed for this system in literature, ZbTM 58 [3D Systems, Rock Hill, USA] liquid binder has been previously employed in studies on CPP substitutes[2]-[6], with some limitations. The purpose of the new liquid binder is to be used as an alternative to the commercially available counterpart in manufacturing bioceramic bone substitutes. Materials and Methods: Nine different water-based solutions were prepared to achieve this goal by alternating the percent of glycerol (GLY) [EMD Chemicals, NJ, USA] (10, 12.5 and 15wt%) as the binding agent, and ethylene glycol diacetate (EGD) [Sigma-Aldrich, MO, USA] (0, 0.75 and 1.5wt%) acting as a flow enhancer. To narrow done the number of solutions to the best candidates, an image processing algorithm was performed, which indicated the better print quality for solutions with 1.5wt% of EGD. Therefore three solutions with 1.5wt% of EGD and 10, 12.5 and 15wt% of GLY have been selected for manufacturing the CPP samples. ZPrinter310-Plus system [3D Systems, Rock Hill, USA] was used for additive manufacturing of samples. In order to complete this process, a combination of CPP (90wt%) with polyvinyl alcohol (PVA) [Alfa Aesar, Ward Hill, MA] (10wt%) was loaded on the system with the proper solution in each trial. Results and Discussion: The properties of samples in both the green and sintered phase were studied by different analyses such as porosity measurement, compressive strength, shrinkage analysis, and structural characterization using SEM. Among these specimens, the one manufactured by binder solution consisting of 12.5wt% of GLY and 1.5wt% EGD dissolved in distilled water, suggests the highest value for mechanical strength after sintering (34.6 ± 5.8 MPa) which is similar with previous study results obtained by employing the commercially available binder solutions (33.9 ± 6.3 MPa)[7]. Furthermore, this category of samples also had good sinter neck formation and an appropriate bulk porosity of 32.1 ± 2.6 %. Conclusion: A new water-based solution has been developed to be used for binder jetting additive manufacturing of the CPP bioceramic bone substitutes. This newly developed binder opens up the possibility of use for AM of components using other types of powder materials.

Co drifts between cemented carbides having various WC grain sizes

Functionally graded cemented carbides obtained on the basis of capillarity phenomena can be very important for numerous applications and are expected to substitute conventional WC–Co cemented carbides. Drifts of liquid Co-based binders in couples of model WC–Co alloys with different WC mean grain sizes sintered together were examined. Noticeable Co drifts occur from coarse-grain into fine-grain regions of the model alloys due to different capillary forces. The Co drifts become more pronounced when the difference between WC mean grains sizes of the coarse-grain region and fine-grain region increases.

Моделирование процесса многоуровневой фильтрации жидкого связующего в тканевом композите при RTM-методе изготовления

Моделирование процесса многоуровневой фильтрации жидкого связующего в тканевом композите при RTM-методе изготовления

Layer-by-layer fully printed Zn-MnO2 batteries with improved internal resistance and cycle life

This research created direct layer-by-layer printed zinc-based secondary batteries with an ionic liquid-based gel polymer electrolyte to power micro- and meso-scale devices. The use of a gel polymer electrolyte composed of [BMIM][Otf] ionic liquid, ZnOtf salt, and PVDF-HFP polymer binder enabled direct layer-by-layer printing of functional cells. The effects of additive printing methods on cell discharge capacity, cycle life, and internal resistance are discussed. Fully printed cells have demonstrated average discharge capacities of 0.548 mAh/cm2, energy densities of 8.20 mWh/cm3, and specific energies of 2.46 mWh/g with some cells achieving over 1000 cycles without catastrophic failure. Layer-by-layer printed devices exhibited decreased DC internal resistance and longer cycle life over previous mechanically assembled cells.

실리카 에어로젤을 이용한 단열·내화재 개발에 관한 연구

Abstract In this study, silica aerogel-glass wool composites were developed for improvement of thermal conductivityand overcoming the water adsorption of glass wool boards. Silica aerogel-glass wool composites were prepared by glass wool and silica aerogel with liquid binder. Mixtures with binder were composed of CMC (carboxymethyl cellulose) and silica aerogel for glass wool board. Silica aerogel-glass wool composite boards were had 0.065 g/ ㎤ density by impregnation silica aerogel where from origin glass wool board at 0.048 g/ ㎤ density. Thermal conductivityof silica aerogel-glass wool composites were 0.0315 W/mK (up to 7.4% thermal resistance) and fire penetration timecame to 362 seconds (up to 2.7 times stronger than origin glass wool board). In addition, hydrophobic aerogel characteristics prevented the adsorption of water onto silica aerogel-glass wool composite boards that was good for lightweight. Keywords : Board, glass wool, insulation, silica aerogel, thermal conductivity *

Characterization of intermetallic bonded TiC composites prepared by mechanically induced self-sustained reaction

The microstructure and mechanical properties of Ni3Al bonded TiC composites prepared by mechanically induced self-sustained reaction (MSR) were investigated. Ultrafine TiC–Ni3Al composite powders with various binder contents were synthesized by high energy ball milling of Ti–C–Ni–Al powder mixtures. Some porous blocks, which consisted of spherical TiC grains and Ni3Al binder, were also formed in each system after MSR. A core-rim structure present in the grains of the sintered TiC–Ni3Al composites was observed by Scanning Transmission Electron Microscopy (STEM). TiC particles dissolved selectively and then precipitated along with a stable crystal plane and gradually evolved into a faceted octahedron in the 3D space, which led to the formation of sharp-edged ceramic grains. High Resolution Transmission Electron Microscopy (HRTEM) analysis showed a 1–2nm width transition zone and a low-angle misorientation between the ceramic phase and the binder phase. The TiC particles that precipitated from Ni3Al during MSR were easily wetted by the liquid Ni3Al binder, which gave rise to the superior mechanical properties of the TiC–Ni3Al composites.

The Influence of Sintering Temperature of Reactive Sintered (Ti, Mo)C-Ni Cermets

Titanium-molybdenum carbide nickel cermets ((Ti, Mo)C-Ni) were produced using high energy milling and reactive sintering process. Compared to conventional TiC-NiMo cermet sintering the parameters for reactive sintered cermets vary since additional processes are present such as carbide synthesis. Therefore, it is essential to acquire information about the suitable sintering regime for reactive sintered cermets. One of the key parameters is the final sintering temperature when the liquid binder Ni forms the final matrix and vacancies inside the material are removed. The influence of the final sintering temperature is analyzed by scanning electron microscopy. Mechanical properties of the material are characterized by transverse rupture strength, hardness and fracture toughness. DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7179

Formulation and characterization of self emulsifing pellets of carvedilol

The purpose of present study was aimed at developing self emulsifying drug delivery system in liquid and then in pellet form that would result in improved solubility, dissolution and permeability of the poorly water soluble drug carvedilol. Pellets were prepared using extrusion-spheronization technique incorporating liquid SEDDS (carvedilol, capmul MCM EP, cremophore EL, tween 20, propylene glycol), adsorbents ( and crospovidone), microcrystalline cellulose and binder (povidone K-30). Ternary phase diagram was constructed to identify different oil-surfactant-cosurfactant mixtures according to the proportion of each point in it. The optimal CAR-SEDDS pellets showed a quicker redispersion with a droplet size of the reconstituted microemulsion being 160.47 nm, which was almost unchanged after solidification. SEM analysis confirmed good spherical appearance of solid pellets; DSC and XRD analysis confirmed that there was no crystalline carvedilol in the pellets. Pellets were then capable of transferring lipophilic compounds into the aqueous phase and significantly enhancing its release with respect to pure drug.