scholarly journals Bitumen Foaming Optimisation Process on the Basis of Rheological Properties

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1854 ◽  
Author(s):  
Marek Iwański ◽  
Grzegorz Mazurek ◽  
Przemysław Buczyński
Keyword(s):  
Half Life ◽  
Expansion Ratio ◽  
Fractional Factorial ◽  
Effective Control ◽  
Maximum Expansion ◽  
Foaming Process ◽  
Original Apparatus ◽  
Foam Properties ◽  
Foamed Bitumen ◽  
Intended Use

This article discusses the results of bitumen foam properties optimisation with respect to three factors: air pressure, bitumen temperature and amount of water. The test materials were unmodified bitumen 50/70 and bitumen 50/70 modified with 2.5% synthetic wax. The experiment was designed according to the 3(3−1) fractional factorial design. The distribution of parameters of bitumen foam were measured with the authors’ original apparatus using a laser beam. This measurement method increased the accuracy of maximum expansion ratio (ER) and half-life (HL) estimation. Based on HL and ER results, it was found that the foaming process increased bitumen stiffness due to the dynamic ageing of the bitumen. The experimental design allows more effective control over the properties of foamed bitumen with respect to its intended use. The presence of synthetic wax extended the half-life of the bitumen foam.

Die opening-induced microstructure growth in extrusion foaming of thermoplastic sheets

2016 ◽  
Vol 36 (2) ◽  
pp. 129-138 ◽  
Author(s):  
Abhishek Gandhi ◽  
Naresh Bhatnagar
Keyword(s):  
Rotational Speed ◽  
Expansion Ratio ◽  
Pressure Drops ◽  
Maximum Expansion ◽  
Foaming Process ◽  
Extrusion Foaming ◽  
Critical Process Parameters ◽  
Die Temperature ◽  
Morphological Transformations ◽  
Thermodynamic Instability

Abstract In this study, the influence of die opening gap on foam attributes during a microcellular extrusion foaming process was investigated. Lower die openings developed higher pressure drops on the foams, as a result of which greater thermodynamic instability was stimulated and, consequently, higher cell density foams along with enhanced expansion ratios were achieved. Further investigations were performed to study the synergistic influence of altering die opening with critical process parameters, namely, screw rotational speed and die temperature, on the foam expansion ratio and morphological transformations. Higher screw rotational speed induced shear nucleation phenomenon, which further enhanced the foaming process significantly. Also, an optimum die temperature was observed, which developed maximum expansion ratio at the lowest die opening gap. This study intends to enhance the understanding of extrusion foam processing among academia as well as among industries.

Study on Modified Asphalt Foaming Characteristic Basing on Energy Analysis

2014 ◽  
Vol 1065-1069 ◽  
pp. 1842-1845
Author(s):  
Feng Cheng Wang ◽  
Xue Feng Nan
Keyword(s):  
Moisture Content ◽  
Half Life ◽  
Energy Analysis ◽  
Expansion Ratio ◽  
Stored Energy ◽  
Maximum Expansion ◽  
Modified Asphalt ◽  
Foamed Asphalt ◽  
Foam Index

Studying on the modified asphalt foaming characteristic, the energy indexes of the actual maximum expansion ratio and the foam index influencing on the modified asphalt foaming effect is analyzed reasonably by varying moisture content. The results show that the half-life of modified foamed asphalt decay sharply with the decrease of SBS content (modified asphalt viscosity),the moisture being mainly applied to modified asphalt foaming is proved with actual max expansion ratio index and evaporated vastly with the decrease of SBS content (modified asphalt viscosity), the modified foamed asphalt stored energy internally is reflected by the foam energy and corrected according to the viscosity.

Experimental Study on Foaming Characteristics of Foamed Asphalt

2013 ◽  
Vol 361-363 ◽  
pp. 1507-1510
Author(s):  
Li Li ◽  
Zhou Chao ◽  
Wang Nian ◽  
Wei Hua Qiao
Keyword(s):  
Experimental Study ◽  
Water Temperature ◽  
Water Content ◽  
Half Life ◽  
Expansion Ratio ◽  
Maximum Expansion ◽  
Foamed Asphalt

This paper presents study on foaming characteristics of two types asphalt with same Penetration-grade 70. Asphalt temperature (AT), water content (WC) and water temperature (WT) were selected for investigation their effects on the asphalt foamability. Maximum expansion ratio (ERMax) and half-life (HL) are important indicators of foamed asphalt. It is concluded that ERMax*HL reachs maximum at optimum foaming condition of foamed asphalt. The conclusion is used as criterion for optimizing foaming condition. The fact that the water temperature influences the ERMax and HL of foamed asphalt significantly was presented.

Feasibility of utilizing sweet potato solids in extrusion cooking / Extrusión de pulpa de batata

1997 ◽  
Vol 3 (3) ◽  
pp. 171-174 ◽  
Author(s):  
H.M. Khalil ◽  
B.R. Henry
Keyword(s):  
Moisture Content ◽  
Sweet Potato ◽  
Sugar Content ◽  
Expansion Ratio ◽  
Fractional Factorial ◽  
Snack Food ◽  
Screw Speed ◽  
High Sugar Content ◽  
Feed Moisture ◽  
Best Parameter

A fractional factorial design of four variables at two levels each was employed to assess the feasi bility and best parameter for extruding sweet potato solids (SPS) using a single screw extruder. It was determined that a high expansion ratio is a desired quality factor for this type of snack food, due to its contribution to textural perception. Preliminary trials on extrusion of sweet potato solids as the sole component in the feed resulted in brittle, dense, and burnt extrudate. The high sugar content (65% total sugar) of the sweet potato solids was cited as the cause of these attrib utes, consequently it was necessary to incorporate wheat flour into the feed to provide a starch matrix for expansion and to reduce sugar concentration. The controlled parameters were screw speed, barrel temperature, feed moisture content, and SPS level in the feed. Among all possible combinations of controlled parameters, the highest expansion ratio was obtained at a screw speed of 220 rpm, temperature profile of 110, 105, 115 and 105 °C, 13% feed moisture content, 50% sweet potato solids, and 0.5% leavening agent.

Life Augmentation of Turbine Exhaust System Compensators Through Integrated MADM Optimization Approach of Stress Based Fatigue Cycles

2021 ◽  
Author(s):  
Nitin D. Pagar ◽  
Amit R. Patil
Keyword(s):  
Exhaust System ◽  
Optimization Methods ◽  
Fractional Factorial ◽  
Design Parameters ◽  
Optimization Approach ◽  
Auxiliary Equipment ◽  
Maximum Expansion ◽  
Optimal Configurations ◽  
Selection Of ◽  
Turbine Exhaust

Abstract Exhaust expansion joints, also known as compensators, are found in a variety of applications such as gas turbine exhaust pipes, generators, marine propulsion systems, OEM engines, power units, and auxiliary equipment. The motion compensators employed must have accomplished the maximum expansion-contraction cycle life while imposing the least amount of stress. Discrepancies in the selecting of bellows expansion joint design parameters are corrected by evaluating stress-based fatigue life, which is challenging owing to the complicated form of convolutions. Meridional and circumferential convolution stress equations that influencing fatigue cycles are evaluated and verified with FEA. Fractional factorial Taguchi L25 matrix is used for finding the optimal configurations. The discrete design parameters for the selection of the suitable configuration of the compensators are analysed with the help of the MADM decision making techniques. The multi-response optimization methods GRA, AHP, and TOPSIS are used to determine the parametric selection on a priority basis. It is seen that weighing distribution among the responses plays an important role in these methods and GRA method integrated with principal components shows best optimal configurations. Multiple regression technique applied to these methods also shows that PCA-GRA gives better alternate solutions for the designer unlike the AHP and TOPSIS method. However, higher ranked Taguchi run obtained in these methods may enhance the suitable selection of different design configurations. Obtained PCA-GRG values by Taguchi, Regression and DOE are well matched and verified for the all alternate solutions. Further, it also shows that stress based fatigue cycles obtained in this analysis for the L25 run indicates the range varying from 1.13 × 104 cycles to 9.08 × 105 cycles, which is within 106 cycles. This work will assist the design engineer for selecting the discrete parameters of stiff compensators utilized in power plant thermal appliances.

FOAMING AND MOISTURE CROSSLINKING OF VINYL TRIETHOXY SILANE GRAFTED ETHYLENE–PROPYLENE–DIENE TERPOLYMER

2022 ◽  
Author(s):  
Zhengwei Lin ◽  
Qinghong Zhang ◽  
Gongliang Wang ◽  
Jie Mao ◽  
Martin Hoch ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Side Reaction ◽  
High Energy ◽  
Expansion Ratio ◽  
Ethylene Propylene ◽  
Foaming Process ◽  
The Matrix ◽  
High Energy Absorption ◽  
Ethylene Propylene Diene Terpolymer

ABSTRACT Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.

Effect of rare earth nucleating agent on supercritical CO2 foaming behavior of block copolymerized polypropylene

2021 ◽  
pp. 026248932110536
Author(s):  
Yun Zhang ◽  
Yadong He ◽  
Chunling Xin ◽  
Yanbin Su
Keyword(s):  
Rare Earth ◽  
Saturation Temperature ◽  
Nucleating Agent ◽  
Expansion Ratio ◽  
Good Effect ◽  
Cell Diameter ◽  
Average Cell ◽  
Foaming Process ◽  
Foaming Temperature ◽  
Crystal Content

The rare earth nucleating agent was used to modify block copolymerized polypropylene (PPB) in foaming process. The results show that the crystallization of PPB and the melting temperature of β-crystal increased gradually with increased β-crystal nucleating agent content. The total crystallinity decreased with amount of addition increasing, and the relative content of β-crystal increased first and then decreased. When β-crystal nucleating agent content was 0.4 wt%, the relative β-crystal content reached the maximum value of 95.27%, and the final crystal grain refinement significantly. The addition of rare earth β-crystal nucleating agent has a good effect on improving the uniformity of foam cells. Under the same content of β-crystal nucleating agent and pressure, the average cell diameter and expansion ratio increased with the saturation temperature increasing. After the foaming temperature reaches 155°C, the expansion ratio began to decrease, which was also consistent with the changed trend of relative β-crystal content. At the same content of temperature and relative β-crystal, as the foaming pressure increased, the cell diameter decreased gradually, and the expansion ratio increased first, and then decreased.

Effect of pH and Dodecylamine Concentration on the Properties of Dodecylamine Two-Phase foam

2020 ◽  
Vol 42 (4) ◽  
pp. 495-495
Author(s):  
Weimin Xie Weimin Xie ◽  
Dongsheng He Dongsheng He ◽  
Shuang Liu Shuang Liu ◽  
Fei Chen Fei Chen ◽  
Hongqiang Li Hongqiang Li
Keyword(s):  
Change Process ◽  
Half Life ◽  
Foam Stability ◽  
Solution Chemistry ◽  
Two Phase ◽  
Diffusion Capacity ◽  
New Device ◽  
Foaming Property ◽  
Effects Of Ph ◽  
Foam Properties

Over-stabilized foam has always been a problem that plagues the dodecylamine (DDA) flotation system. In this study, a new device, “automatic foam analyzer”, was successfully used to characterize the behavior of foam in DDA solution. The effects of pH and DDA dosage on the foam properties were investigated from four aspects: bubble diffusion capacity, Bikerman coefficient, half-life period and solution conductivity, and the mechanism of pH and DDA concentration on foam properties was analyzed by solution chemistry and surface tension of DDA, then the change process of foam structure was deduced. The results showed that the foaming property and stability of DDA bubbles were the best at pH=8. Simultaneously, with the increase of DDA dosage, the foaming property of bubbles was enhanced, the half-life was prolonged, and the foam stability was also improved.

Shape Characteristics and Condensation Heat Transfer of Supersonic Steam Jet in Subcooled Water

2017 ◽  
Author(s):  
Wang Fangnian ◽  
Qin Huan ◽  
Chen Yaodong ◽  
Bai Ning ◽  
Xing Mian ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Expansion Ratio ◽  
Penetration Length ◽  
Shape Identification ◽  
Maximum Expansion ◽  
Heat Transfer Correlations ◽  
The Look ◽  
Experimental Values ◽  
Regime Map ◽  
Shape Characteristics

The shape characteristics and direct contact condensation (DCC) heat transfer of submerged supersonic steam jet were investigated. One of the shape identification methods is the DCC shape regime map as a function of nozzle exit pressure, mass flux and pool water temperature, another one is the Look Up Table. Then based on the theoretical analysis, the new basic expressions of supersonic steam jet dimensionless penetration length, maximum expansion ratio, and heat transfer correlations were given, which were in terms of Ma number and Ja number. The correlations were nonlinearly fitted and validated well against the experimental data form open literatures. The discrepancies of penetration length and maximum expansion ratio between predicted and experimental values were within ±25% and ±12% respectively. Supersonic steam jet DCC heat transfer is feasible to be calculated via the identification of steam jet shape and selection of the corresponding shape and heat transfer correlations.

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