Foaming Agent Content Research Articles

Effect of foaming on mechanical properties of microfibrillated cellulose-based porous solids

All-cellulose porous solids have been prepared by foaming watery suspensions of microfibrillated cellulose (MFC) and the foaming agent methyl cellulose (MC) followed by freeze-drying. Mechanical and structural characterization of foamed and unfoamed porous solids with and without MC was performed to evaluate the effect of the foaming agent and of the foaming process. In unfoamed systems, partial replacement of MFC by MC led to decreased mechanical stability and a stronger dependency of mechanical properties on density. The foaming process allowed to reach gas volume fractions of up to 52% through interfacial stabilization by MC and thus reduce specific volume of water before drying by half. The incorporated gas bubbles withstood the freezing and drying process as shown by scanning electron microscopy of freeze-dried samples. Final density and porosity were tailored by adjusting solid content in the suspension, foaming time or concentration of foaming agent. In uniaxial compression, foamed porous solids showed similar or even higher Young’s modulus and yield stress compared to unfoamed systems at same composition and density. In foamed porous solids with increased mechanical stability, X-ray μ-computed tomography revealed the occurrence of aligned tubes, which act as reinforcing substructure. Thus, foaming can be applied prior to freeze-drying to drastically reduce water content, while the mechanical performance is unaffected or even improved through restructuring.

Effect of processing temperature and foaming agent loading on properties of polylactic acid/kenaf fiber composite foam

The focus of this study was to investigate the effect of processing temperature and foaming agent loading on physical and mechanical properties of the foamed polylactic acid (PLA)/kenaf fiber (KF) composites. The foamed polymer composites made from PLA, KF and azodicarbonamide (ADC) were prepared via extrusion and compression molding. The temperature profile used for extrusion was set at 170, 185, 180, 175˚C (high temperature profile) and 165, 170, 175, 160˚C (low temperature profile). ADC loadings were varied at 0, 1, 3 and 5 phr. The density of the foamed composites exhibited a decreasing trend with the increasing of ADC loading. The morphology was analysed by Field Emission Scanning Electron Microscope (FESEM) and the results revealed the bigger size in the PLA/KF foamed composites extruded with high temperature. Tensile strength, strain @ break and Young modulus of the foamed composites decreased accordingly with respect of foaming agent content. The mechanical strength was positively affected when the lower extrusion temperature was used for extrusion.

Effect of surfactant concentration on foam texture and flow characteristics in porous media

Foam has been widely used for profile control, water plugging, and gas channeling control in enhanced oil recovery (EOR). Because of absorption, the surfactant concentration in foam decreases along the flow direction. In this study, the effects of surfactant concentration on the foam texture, foam seepage characteristics, and gas saturation were evaluated by core-flow experiments using a high-pressure visualization device. The results show that the surface tension of gas and liquid decreases, the flow resistance in core increases, and the foam takes a longer time to reach stability with the increase in concentration of foaming agent. The blocking capability of foam in porous media is closely related to foam texture. With the increase in surfactant concentration, the average diameter of bubbles in porous media decreases, and the bubbles are more uniform. Moreover, the diameter of bubbles is closer to the average pore diameter of core. Clearly, the diameter matching degree of the maximum distribution frequency of bubbles and the average pore diameter of core increase. Therefore, the blocking capability of foam becomes stronger. With the increase in surfactant concentration, the proportion of trapped gas in porous media increases, the gas saturation in core increases, and the flow resistance of foam increases. However, when the surfactant concentration reaches the critical value, the increasing amplitude of gas saturation decreases. Under an injected foam quality of 50%, the gas saturation is more than 80%. The research results can help to analyze the change along the channel of foam flow in formation and are of great significance to improve the effect of foam application.

HDPE/UHMWPE composite foams prepared by compression molding with optimized foaming capacity and mechanical properties

ABSTRACTHigh‐density polyethylene (HDPE) foams have attracted increasing interest because of their excellent toughness, chemical stability, and low cost. However, the low melt strength and narrow foaming window usually lead to poor foaming capacity and performances prepared by compression molding under high temperature for HDPE. Herein, ultra high‐molecular weight polyethylene (UHMWPE) is used to improve the melt strength, melting temperature, mechanical properties, and foaming capacity of HDPE. The HDPE/UHMWPE composite foams are fabricated by the single‐stage compression molding with dicumyl peroxide (DCP) as a crosslinking agent and azodicarbonamide (ADC) as a foaming agent. The effects of UHMWPE, DCP, and ADC on the cellular morphology, foaming density, and mechanical properties have also been investigated. The results show that UHMWPE can enhance the foaming capacity and physical properties of HDPE and make it feasible to prepare HDPE foams with a wide density range just by adjusting the content of foaming agent. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46768.

Fabrication of Porous Ceramics using Tailings Mud from Huzhou City as Raw Material

The comprehensive utilization of tailings mud has become a common concern of the society. The properties of tailings mud produced from Huzhou city were analyzed in this work. Moreover, porous ceramics with high strength were prepared by using the tailings mud as main raw material and adding a small amount of foaming agent. The results show that the foaming agent contents have a certain effect on the porosity and compressive strength of the porous ceramic samples. These results provided a certain theoretical basis for the comprehensive utilization of tailings mud and solve the pollution of tailings mud to the environment.

Effect of Control Technology on Properties of Quartz Porous Brick

A high-performance quartz sand insulation brick was prepared by using low grade quartz sand under different sintering process conditions. The optimum sintering process conditions were obtained by analyzing the relationship between microstructure and sintering process. Through the compounding, pulping, forming, drying and sintering processes, and the performance test of the porous brick, the following conclusions can be drawn, the comprehensive performance in all aspects, the porosity is similar, the preferred high compressive strength conditions, in order to get a best The bonding point, brick body sintering temperature of 1150 °C, porosity of 74.56%, compressive strength of 2.1 MPa of porous brick, and the pores are smooth, more uniform distribution. With the prolonging of the holding time, the porosity of the porous brick is reduced, and the performance is 1h, the porosity is 77.22% and the compressive strength is 2.05 MPa. When the raw material ratio is 60% quartz sand, 30wt% kaolin, calcium carbonate 9.6wt%, foaming agent 0.4wt%, water ratio 0.9 holding time at 1h sintering at 1150°C can get better porosity and compressive strength of the insulation brick. The porous material was sintered at 1150 °C, the content of foaming agent was 0.2wt%, the ratio of water to material was 0.9, and the compressive pressure and porosity were the better.

Preparation and Properties of YAG Porous Ceramics via the Casting Method

YAG has many excellent features and therefore has a wide range of applications. Preparation and properties of YAG porous ceramics via the casting method is investigated. Through analysis and discussion, the following conclusions can be obtained. With the increase of the content of foaming agent, in the foaming process of the slurry, bubbles generated by the foaming agent and water are gradually increased, the more pores are left in the body after casting, and when the blowing agent is too much, excessive bubbles are generated, which can lead to a very low strength of the green body and can not be formed and operated later. As the ratio of water to material increases, the porosity of the porous material increases. This is because when the blowing agent is constant, the amount of water required for foaming is constant, and the amount of foam generated is also constant. When the content of foaming agent and the ratio of water to material is both 1, the porosity and compressive strength is better.

Cutter-disc consumption during earth pressure balance tunnelling in mixed strata

The wear of excavation tools is considered to be one of the critical factors affecting the scheduling of shield tunnel construction. There is presently no effective countermeasure to prevent severe wear of excavation tools during tunnelling operations in complex geological formations. In addition, such wear is likely to lead to other problems, such as face instability and an unfavourable rate of tunnel advancement. The study reported in this paper analysed the various factors that affected the wear and performance of excavation tools during earth pressure balance machine tunnelling at the Ma-Lian section of line 9 of the Guangzhou metro, China. It was found that tunnelling in mixed ground conditions (upper soft and lower hard strata) led to severe wear of the cutter discs, resulting in additional costs and schedule delays. The foam expansion ratio, concentration of foaming agent and the foam injection ratio were measured to be 20, 2·5% and 40% respectively. Pre-grouting and effective soil conditioning were also found to prevent excessive wear of the cutter discs and surface collapse incidents caused by face instability.

Effect of Alkali Activator on Preparation, and Mechanical and Thermal Properties of Iron Mine Tailing-Based Lightweight Materials

Lightweight materials applied in construction field were prepared using waste iron mine tailings (WIMT) as raw materials, the commercial silicate cement (CSC) as cementing agent, NaOH as the alkali activator, and triethanolamine lauryl sulfate (TLS) as foaming agent via foam-gelcasting method. The effects of water/cement (W/C) mass ratio (0.6-1.0), addition of NaOH (0-0.15wt%) and foaming agent (0-0.3vol%) on the porosity, bulk density, and mechanical properties of the iron mine tailing-based lightweight materials were studied. The results showed that the mechanical properties of iron mine tailing-based lightweight materials were improved by adding NaOH, the as-prepared materials had a 7-day compressive strength of 5.18 MPa, porosity of 51.40%, bulk density of 1.73 g/cm3and thermal conductivity of 0.193 W・(m-1K-1) when the W/C ratio was 0.8, the mass ratio of WIMT/CSC/NaOH 1.85:1:0.15, and foaming agent content 0.3vol%.

Preparation and Properties of Split Microfiber Synthetic Leather

A split microfiber synthetic leather using split microfiber nonwoven as the base and waterborne polyurethane (WPU) coating as the polymer coating was prepared by a dry transfer-coating method. First, the nylon/polyester (N/P) split microfiber nonwoven was manufactured, and the structure and properties were investigated. FESEM analysis indicated fiber diameter size was between 2.2~5.5 μm, and performance attaributes met the demands of textiles-nonwovens for synthetic leather. Then the effect of coating-forming temperature, foaming agent concentration and foaming ratio on the structure and performance of WPU coatings were systematically studied. Finally, the structure and properties of the split microfiber synthetic leather were analyzed. The results showed that the split microfiber synthetic leather arranged in a three-layer configuration, and its air permeability, tensile strength, elongation at break, tear strength, peeling strength and creasy recovery angle were better than knitted synthetic leather and real leather.

Effect of track spacing on porosity of metallic foam fabricated by laser melting deposition of Ti6Al4V/TiH2 powder mixture

We fabricated porous metallic materials using laser melting deposition, wherein a mixture of a metal powder and a foaming agent is sprayed while a high-energy laser is irradiated on it to melt and deposit it, resulting in foaming action. To fabricate the porous materials, we used a powder of Ti6Al4V alloy. TiH2, a foaming agent, was employed to create pores within the deposited material. The track spacing was varied to examine its effect on the foaming characteristics and the porosity and pore size and distribution of the deposited material. We also investigated the effects of representative process parameters, including the laser power, foaming agent content, and powder feed rate. The results showed that, when the track spacing was smaller than the width of the deposited beads, pores were generated by the foaming agent. In the opposite case, however, open-cell pores were created between the tracks. This was because the fluidity of the molten metal varied with the track spacing, confirming that the porosity can be adjusted by changing the track spacing. Moreover, as the laser power was decreased or the powder feed rate increased, the porosity increased. Hence, the porosity is related to the cooling rate of the molten metal.

ВЛИЯНИЕ ПРИРОДЫ ПЕНООБРАЗОВАТЕЛЕЙ НА ФИЗИКО-ТЕХНИЧЕСКИЕ СВОЙСТВА ПЕН

The paper considers the influence of the nature of foaming agent on the properties of foams. Based on the analysis of the market of modern pore-forming additives, from the number of foaming agents the most widely used components, as well as novelties of the market, have been chosen. The technical characteristics of the foaming agents provided on the market are reviewed. The influence of foaming agent concentration, composition and base on the foam expansion, stability and density of foams is studied in the paper. The optimum ("working") concentrations of foaming additives are determined taking into account their stability. The stability of foams formed on the basis of working solutions in porous systems of various compositions is studied. Based on the complex of studies, the protein foaming agents are ranked according to the degree of their effectiveness, according to the data on the physical and technical properties of foams obtained on their basis.

Oil-Recovery-Parameter Optimization by Air—Foam Injection into a Low-Permeability Light-Oil Reservoir

The physical mechanism of air-foam flooding that was proposed earlier by other authors was studied using NB-95 foaming agent as an example. The parameters for air-foam injection in the T9 block of SY oilfield were simulated numerically optimized using the STARS module of the CMG reservoir simulation software. The experimental results demonstrate that the optimal injection-volume-to-production ratio for air-foam flooding in the T9 block is 0.8-1; gas-to-liquid ratio, 0.8-1; foaming agent concentration, 0.5-0.75%; and injection slug, 0.18-0.22 of the pore volume. Experimental physical simulation shows that air-foam flooding can enhance oil recovery by 25.85% and can be used to develop a theory of oil displacement by air-foam flooding.

Experimental Study on Optimization of Indoor Foaming Agent Concentration

Aiming at the selection of foaming agent in air foam flooding technology, in this paper,Ross-miles static experiment on the seven groups of surfactants at different concentrations of foam bubble height and half-life determination determines two important factors that affect the performance of a frothing agent:foaming volume and foam stability. It is also an important indicator of screening frothing agent in practical application. The experimental results show that the foaming volume and the stability of different foaming agents are different, the bubble volume of all blowing agents increased with increasing concentration, and the optimum concentration of most of the foaming agent solution is 0.5%. However, some foaming agents such as ZJ008 and KHD570A appeared foam hollow and fast defoaming at low concentration. They cannot be used as a practical frothing agent.

The Effects of Processing Parameters and AC Foaming Agent on the Mechanical Properties and Morphology of Foamed Wood-Polylactic Acid (PLA) Composites

Wood flour, PLA, and other additives were mixed evenly in a high speed mixing machine. The granules were prepared by melt blending and extrusion granulating with a twin-screw extruder, and test specimens were molded by a plate curing machine. By changing the heating temperature, the molding pressure, the holding pressure time, and azodicarbonamide (AC foaming agent) contents, the influences of four factors on the apparent density, the mechanical properties, and the morphology of the biodegradable foamed WPCs were investigated. The best processing parameters and the optimum AC foaming agent content were obtained. When heating temperature was 178 °C, heating time was 10 min, holding pressure time was 25 s, and molding pressure was 7 MPa, the test specimen was lighter in color, with a smooth surface and dense, uniform cross section. The mechanical properties (flexural strength and impact strength) of the foamed WPCs were relatively good. When adding 1% AC foaming agent, the foamed WPCs showed uniformly distributed microcellular structure, and the average pore diameter was about 67 µm. The density was reduced by 18.6%, and the flexural strength and impact strength were increased by 128.6% and 40%, respectively, compared with non-foamed WPCs.

Property experiments on the foam generator and its influencing factors during down-the-hole drilling

Abstract The present study developed a suitable foam dust-remove device for down-the-hole (DTH) drilling in open-pit mines and researched its foaming properties to solve the resulting serious dust pollution. We researched the foam dust removal mechanism and two-phase foaming principle to improve the disadvantages of traditional dust removal technology such as poor effects, big air consumption and water intake difficulties. We obtained the main factors that influence the foaming performance and optimum working point of the foam generator based on performance tests on the foam flow, foaming multiple, and half-life period of the foam generator. Based on the experimental results, the gas flow rate, liquid flow rate (gas–liquid ratio), foaming net, and foaming agent concentration were deemed the four main factors that affected the foaming performance of the foam generator. The following working conditions were operated: (1) foam net 1; (2) A 1.5% concentration of the formulation 2; (3) gas pressure of 0.7 MPa; (4) liquid flow rate of 18 L/min; (5) gas flow rate of 30 m3/h. Based on these conditions, the foam generator achieved its best performance with a foam flow rate of 515 L/min, foaming multiple of 22, and half-life of 65 min. The average dust removal rate throughout the field test was as high as 90% using foam dedusting in stope.

The Effect of Temperature and Concentration of Foaming Agent to the β-Carotene Content in Product Derived from Carrots

Carrot (Daucus carota L) is vegetable that contain body essetial vitamins, especially β-carotene. In this research, the essense of fresh carrots are taken and processed to carrot powder using foam mat drying method. This research aims to study the effect of temperature and concentration of foaming agent to the β-carotene content in product derived from carrots. The temperature variation that used in this research are 40°C, 50°C, 60°C and 70°C, while he variation of foaming agent (tween 80) are 0,01% (v/v); 0,1%(v/v); 0,2%(v/v) and 0,3%(v/v). The results shows that the maximum drying temperature is 50°C with β-carotene content 10.55 mg/kg and the maximum concentration of foaming agent (tween 80) is 0.2% (v/v) with β-carotene content 10.36 mg/kg.

Proportioning accuracy of foam concentrate testing in periodic control of foam fixed extinguishing systems

The proper concentration of foam concentrate in water solution is a key factor in the effectiveness of fire-fighting foams produced using all currently used foam systems. The standard method for measuring the concentration of foaming agent, used to control the operation of the foam systems, is conductivity method. In this study, the applicability of the refractive index of the solution and the conductivity method was tested. The research found that the conductivity method can be used to determine the actual concentrations of all types of foaming agents in the solutions made from tap water, or water of similar electrical conductivity, of approx. 0.5 ÷ 0.8 mS/cm. Conductivity meter must be equipped with temperature compensation system. Measurement uncertainty is estimated to be ± 0.1 vol. % under optimal conditions for this method. In the case of water with high electrical conductivity, also refractometric method gives good results. In the case of solutions made with tap water and foaming agents working concentrations of 3% and more acceptable uncertainty in the measurements provides portable digital refractometer without temperature stabilization. In other cases, obtaining sufficient accuracy requires sample temperature stabilization during the test.

Preparation of Porous Materials by Magnesium Phosphate Cement with High Permeability

High permeability and strength magnesium phosphate cement (MPC) with porosity, average pore size, and compressive strength varied from 63.2% to 74%, 138.7 μm to 284.7 μm and 2.3 MPa to 4.7 MPa, respectively, were successfully prepared by combining the physical foaming method and chemically entrained gas method at room temperature. The effects of borax content, chemical foaming agent content, zinc powder content and W/S ratio on the porosity, pore size distribution, compressive strength, and permeability of the MPC were investigated. The results indicate that the chemical foaming agent content tends to have little impact on the porosity and compressive strength, and the zinc powder content has the most significant influence on the average pore size of MPC. The air pores distribution and connectivity of MPC were mainly controlled by the borax content, W/S ratio, and chemical foaming agent content. Zinc powder played a destructive role in the pores formed by the early physical foaming and led to an increase in pore size and a large number of through pores, which increased the permeability of the materials.

Synthesis and Characterization of Porous Fly Ash‐Based Geopolymers Using Si as Foaming Agent

This paper concerns the synthesis of foamed geopolymers using fly ash and metallic Si as the binder and the porogent agent, respectively. The Taguchi approach was applied in order to study the effect of some significant synthesis parameters such as the Si foaming agent content (% w/w fly ash based), the alkali type (R : Na or K), and the alkalinity (R/Al molar ratio) of the activation solution on the compressive strength and apparent density of the foamed geopolymers. The final products were characterized by means of XRD, FTIR, and SEM, while optical microscopy was applied for the evaluation of the porosity. Lightweight geopolymers with a compressive strength of 2.08–14.88 ΜPa and an apparent density of 0.84–1.55 g/cm3 were prepared by introducing a Si content up to 0.2% w/w on fly ash basis.