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Thixotropy can be regarded as the loss of viscosity in a paint or other material that is brought about by mechanical agitation, and where the viscosity continues to decrease provided that this disturbance is continued for a period of time. Conversely, when the mechanical force is removed, the material then increases in viscosity and this recovery toward the initial structure continues to take place over a period of time. Sometimes the time dependency of the viscosity is vanishingly small so that the material is then properly referred to as pseudoplastic. In most of the literature, however, it is not usually possible to differentiate between thixotropy and true pseudoplasticity and therefore both kinds of structure are included in this review as they each are destroyed by mechanical agitation and recover when this is discontinued.

Salts of aluminium and calcium such as stearates, octoates and naphthenates, are used to impart structure to oleoresinous paints. Alternatively, aluminium alcohoiates can be used as reactive intermediates which form salts by reaction with the medium. The use of these materials is generally restricted to flat or semi‐gloss paints and storage instability is sometimes encountered. A chlorinated rubber paint which contains titanium, kaolin, talc, a chloroparaffin plasticiser, and a solvent blend of hexyl acetate and xylene, is rendered thixotropic using a 1% level of aluminium stearate addition. The product is suitable for applying as thick corrosion‐resistant coatings to metals.

The thixotropy of lubricating grease thickened with lithium 12-hydroxystearate with mineral base oil was investigated. The thixotropy has a significant influence on the flow resistance and pressure drop in the structural components of lubrication systems, which is of major importance as today the latter are being centralized and automated. The paper aims to discuss these issues.

Rheometer studies on thixotropy were carried out and the grease microstructure was visualized using atomic force microscopy (AFM). Total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used to study the physicochemical interactions which indicate the disintegration and recovery of the grease microstructure.

A qualitative assessment of the physicochemical interactions between lithium soap floccules was made and a theory of the self-ordering effect of lithium 12-hydroxystearate associated molecules during shearing and their aggregation and flocculation during relaxation has been proposed.

Because of the complexity of the disintegration and recovery of the lubricating grease thickener microstructure, there is still limited physical understanding of the mechanism of this process. Therefore, the present research was undertaken to identify the phenomena involved.

This study aims on a broad review of Concrete's Rheological Properties. The Concrete is a commonly used engineering material because of its exquisite mechanical interpretation, but the addition of constituent amounts has significant effects on the concrete’s fresh properties. The workability of the concrete mixture is a short-term property, but it is anticipated to affect the concrete’s long-term property.

In this review, the concrete and workability definition; concrete’s rheology models like Bingham model, thixotropy model, H-B model and modified Bingham model; obtained rheological parameters of concrete; the effect of constituent’s rheological properties, which includes cement and aggregates; and the concrete’s rheological properties such as consistency, mobility, compatibility, workability and stability were studied in detail.

Also, this review study has detailed the constituents and concrete’s rheological properties effects. Moreover, it exhibits the relationship between yield stress and plastic viscosity in concrete’s rheological behavior. Hence, several methods have been reviewed, and performance has been noted. In that, the abrasion resistance concrete has attained the maximum compressive strength of 73.6 Mpa; the thixotropy approach has gained the lowest plastic viscosity at 22 Pa.s; and the model coaxial cylinder has recorded the lowest stress rate at 8 Pa.

This paper especially describes the possible strategies to constrain improper prediction of concrete’s rheological properties that make the workability and rheological behavior prediction simpler and more accurate. From this, future guidelines can afford for prediction of concrete rheological behavior by implementing novel enhancing numerical techniques and exploring the finest process to evaluate the workability.

Unsatisfactory level of construction materials quality has been a persistent problem for companies in construction. This study aims to describe the application of the Six Sigma methodology for improving the tensile strength in a Chinese reinforcement material manufacturing company.

Six Sigma-based framework of define-measure-analyse-improve-control (DMAIC) methodology is adopted in this case study. During different stages, quality problems and critical factors are identified to improve the low performance of tensile strength and thixotropy of the impregnating resin.

The results provide solid evidence that how Six Sigma can be successfully applied in reinforcement material manufacturing. Results showed that vacuum degree, reaction temperature and stirring rate are significant factors on tensile strength. Control plans for continuous improvements are suggested and implemented. Our study found that managerial assurance activities such as verification were less developed than equipment-related control activities. Besides, data management required further elaboration on integrated data and information systematically, thereby to enable the company to make informed decisions and to support continuous improvement.

This study contributes to show a potential area in which Six Sigma DMAIC approach can promote to improve the tensile strength of impregnating resin. This case can prompt managers of the company to apply Six Sigma method to address complicated problems in other reinforcement material processes. Companies of construction and their suppliers can refer to this study when improving their manufacturing process.

The purpose of the paper is to develop a methodology to characterize the rheological behaviour of macroscopic non-Brownian suspensions, like solder paste, based on microstructural evolution.

A structure-based kinetics model, whose parameters are derived analytically based on assumptions valid for any macroscopic suspension, is developed to describe the rheological behaviour of a given fluid. The values of the parameters are then determined based on experiments conducted at a constant shear rate. The parameter values, obtained from the model, are then adjusted using an optimization algorithm using the mean deviation from experiments as the cost function to replicate the measured rheology. A commercially available solder paste is used as the test fluid for the proposed method.

The initial parameter values obtained through the analytical model indicates a structural breakdown that is much slower than observations. But optimizing the parameter values, especially the ones associated with the structural breakdown, replicates the thixotropic behaviour of the solder paste reasonably well, but it fails to capture the structure build-up during the three interval thixotropy test.

The structural kinetics model tends to under-predict the structure build-up rate.

This study details a more realistic prediction of the rheological behaviour of macroscopic suspensions like solder paste, thermal interface materials and other functional materials. The proposed model can be used to characterize different solder pastes and other functional fluids based on the structure build-up and breakdown rates. The model can also be used as the viscosity definitions in numerical simulations instead of simpler models like Carreau–Yasuda and cross-viscosity models.

The rheological description of the solder paste is critical in determining its validity for a given application. The methodology described in the paper provides a better description of thixotropy without relying on the existing rheological measurements or the behaviour predicted by a standard power-law model. The proposed model can also provide transient viscosity predictions when shear rates vary in time.

The aim of this paper is to characterize the rheological properties of the flux media exposed to different levels of solicitation and to determine its influence on the rheology of the solder paste. The data obtained experimentally are fundamental for the development of numerical models that allow the simulation of the printing process of printed circuit boards (PCB).

Rheological tests were performed using the Malvern rheometer Bohlin CVO. These experiments consist of the analysis of the viscosity, yield stress, thixotropy, elastic and viscous properties through oscillatory tests and the capacity to recover using a creep-recovery experiment. The results obtained from this rheological analysis are compared with the rheological properties of the solder paste F620.

The results have shown that the flux is viscoelastic in nature and shear thinning. The viscosity does not decrease with increasing solicitations, except in the case where the flow is withdrawn directly from the bottle. Even if the solder paste shows a thixotropic behavior, this is not the case of the flux, meaning that this property is given by the metal particles. Furthermore, the oscillatory tests proved that the flux presents a dominant solid-like behavior, higher than the solder paste, meaning that the cohesive/tacky behavior of the solder paste is given by the flux.

To complement this work, printing tests are required.

This work demonstrates the importance of the rheological characterization of the flux in order to understand its influence in the solder paste performance during the stencil printing process.

The rheological properties of coating suspensions containing a blend of clay and CaCO3 as a pigment have been evaluated at 22°C, using a rheometer with shear rates from 0.5 to 100rpm. The state of dispersion of the pigment, the structure viscosity of the suspension as a result of pigment‐pigment or pigment‐binder interactions, and its behaviour by changing the solid content and ionic strength, were limited from the examination of the flow curves. The flow parameters for each suspension were calculated. The results showed that changes in solid content and ionic strength by the addition of divalent simple electrolyte (CaCl2) and pH level have a more profound effect on the flow parameters than that obtained by the addition of monovalent simple electrolyte (NaCl) or polyelectrolyte soluble polymers (CMC) with different degrees of substitution. The type of acid used to adjust the pH of the suspension also has a great influence on the flow parameters.

Behind every successful technology is a great body of scientific knowledge. The paint industry managed to get along pretty well from the time of the Egyptians until World War I, a span of approximately 5,000 years, without much scientific insight. Indeed, the empirical approach to paint formulation could hardly be criticised. When one visits museums of Egyptology today, one sees coatings formulated three to five thousand years ago which are bright coloured and which still have good adhesion and film integrity. But coating mummy cases in a very dry climate is considerably less demanding than coating missiles which find themselves in a hostile environment. Although paint for mummy cases, houses, and barns and even the first assembly‐line‐produced automobiles could be made without much scientific understanding, it is fair to say that coatings for the exacting demands of modern technology could never have evolved without an understanding of the scientific principles on which the modern coatings industry is based. The scientific basis for the modern coatings industry is found in an understanding of polymer chemistry, an understanding of the chemistry of solvents, a knowledge of the chemistry of pigments, and a large body of physical chemistry relating to solubility, rheology, adhesion, cohesion, and many other important phenomena.

Viscosity, thixotropy, flow, spreading, and settling are some of the terms that come to mind when rheology is mentioned. Numerous papers in the literature discuss these points relative to coatings.