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Hiding Power
The hiding power is an ability of a paint to hide the surface that the paint was applied to. Numerically, it is defined as an area of surface coated by a volume of paint ( spreading rate) at which the " complete hiding" of the underlying surface occurs. Causes Whenever light is shone onto a paint-coated surface, it is partially reflected and absorbed by the coating. Once the light reaches the underlying surface (''substrate''), it is again reflected and absorbed by the substrate, the process happens once more as the reflected light travels back through the paint layer. Depending on the paint properties, the information about the substrate might be visible (or not) in the light that emerges back from the coating. Hiding power is the property of the paint material that inhibits this visibility, manifesting in the opacity of a ''layer'' of paint. The term ''hiding'' is generic and applied to designate either hiding power or opacity. If the coating of paint is highly absorptive, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hiding Power
The hiding power is an ability of a paint to hide the surface that the paint was applied to. Numerically, it is defined as an area of surface coated by a volume of paint ( spreading rate) at which the " complete hiding" of the underlying surface occurs. Causes Whenever light is shone onto a paint-coated surface, it is partially reflected and absorbed by the coating. Once the light reaches the underlying surface (''substrate''), it is again reflected and absorbed by the substrate, the process happens once more as the reflected light travels back through the paint layer. Depending on the paint properties, the information about the substrate might be visible (or not) in the light that emerges back from the coating. Hiding power is the property of the paint material that inhibits this visibility, manifesting in the opacity of a ''layer'' of paint. The term ''hiding'' is generic and applied to designate either hiding power or opacity. If the coating of paint is highly absorptive, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiative Transfer
Radiative transfer is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering processes. The equation of radiative transfer describes these interactions mathematically. Equations of radiative transfer have application in a wide variety of subjects including optics, astrophysics, atmospheric science, and remote sensing. Analytic solutions to the radiative transfer equation (RTE) exist for simple cases but for more realistic media, with complex multiple scattering effects, numerical methods are required. The present article is largely focused on the condition of radiative equilibrium. Definitions The fundamental quantity that describes a field of radiation is called spectral radiance in radiometric terms (in other fields it is often called specific intensity). For a very small area element in the radiation field, there can be electromagnetic radiat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extender (ink)
An extender, also known as a filler, in printing ink technology is a white transparent, or semi-transparent, component whose purpose is to reduce the cost of the ink, by increasing the area covered by a given weight of pigment. They generally have little colouring power. Composition and Properties Extenders are typically white inorganic solids. Their transparency in inks is frequently due to their refractive indices In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ... being similar to the ink, as opposed to opaque pigments, which are generally substantially higher. Use Extenders primarily serve to reduce the cost of the ink, but can also impart useful properties to it. They can reduce the colour strength of the ink without adding any white colour to it, which is useful if the pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractive Indices
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or refraction, refracted, when entering a material. This is described by Snell's law of refraction, , where ''θ''1 and ''θ''2 are the angle of incidence (optics), angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices ''n''1 and ''n''2. The refractive indices also determine the amount of light that is reflectivity, reflected when reaching the interface, as well as the critical angle for total internal reflection, their intensity (Fresnel's equations) and Brewster's angle. The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is , and simil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binder (paint)
A binder or binding agent is any material or substance that holds or draws other materials together to form a cohesive whole mechanically, chemically, by adhesion or cohesion. In a more narrow sense, binders are liquid or dough-like substances that harden by a chemical or physical process and bind fibres, filler powder and other particles added into it. Examples include glue, adhesive and thickening. Examples of mechanical binders are bond stones in masonry and tie beams in timber framing. Classification Binders are loosely classified as organic ( bitums, animal and plant glues, polymers) and inorganic (lime, cement, gypsum, liquid glass, etc.). These can be either metallic or ceramic as well as polymeric depending on the nature of the main material. For example, in the compound WC-Co (Tungsten Carbide used in cutting tools) Co constitutes the binding agent for the WC particles. Based on their chemical resistance, binders are classified by the field of use: non-hydraulic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compounds. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli. Economic impact In 2006, around 7.4 million tons of inorganic, organic, and special pigments were marketed worldwide. Estimated at around US$14.86 billion in 2018 and will rise at over 4.9% CAGR from 2019 to 2026. The global demand for pigments was roughly US$20.5 billion in 2009. According to an April 2018 report by ''Bloomberg Businessweek'', the estimated value of the pigment industry globally is $30 billion. The value of titanium dioxide – used to enhance the white brightness of many products – was placed at $13.2 billion per year, while the color Ferrari red is valued at $300 million each year. Physical principles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Perception
Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum reflected by objects in the environment. This is different from visual acuity, which refers to how clearly a person sees (for example "20/20 vision"). A person can have problems with visual perceptual processing even if they have 20/20 vision. The resulting perception is also known as vision, sight, or eyesight (adjectives ''visual'', ''optical'', and ''ocular'', respectively). The various physiological components involved in vision are referred to collectively as the visual system, and are the focus of much research in linguistics, psychology, cognitive science, neuroscience, and molecular biology, collectively referred to as vision science. Visual system In humans and a number of other mammals, light enters the eye through the cornea and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (matter)
In the physical sciences, an interface is the boundary between two spatial regions occupied by different matter, or by matter in different physical states. The interface between matter and air, or matter and vacuum, is called a surface, and studied in surface science. In thermal equilibrium, the regions in contact are called phases, and the interface is called a phase boundary. An example for an interface out of equilibrium is the grain boundary in polycrystalline matter. The importance of the interface depends on the type of system: the bigger the quotient area/volume, the greater the effect the interface will have. Consequently, interfaces are very important in systems with large interface area-to-volume ratios, such as colloids. Interfaces can be flat or curved. For example, oil droplets in a salad dressing are spherical but the interface between water and air in a glass of water is mostly flat. Surface tension is the physical property which rules interface processes involvin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Wavelength
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths). In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity, propagation direction, frequency or wavelength spectrum and polarization. Its speed in a vacuum, 299 792 458 metres a second (m/s), is one of the fundamental constants of nature. Like all types of electromagnetic radiation, visible light propagates by massless elementary particles called photons that represents the quanta of electromagnetic field, and can be analyzed as both waves and partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drawdown Chart
Drawdown charts are rectangular pieces of non-fluorescent paper which are used to test a variety of coating properties. These properties include opacity, spreading rate, penetration, and flow & leveling behavior. This non-fluorescent material has to be especially rugged in order to maintain its structure and give reliable readings, as the coatings tested are often corrosive or abrasive. These charts are necessary in the testing of any coating as they give reliable and accurate readings for any type of coating before the coating is applied to the intended material. Drawdown bars Drawdown bars are used in collaboration with drawdown charts. The bars are generally made of stainless steel or aluminum and touch the chart at each end, while the center is slightly raised to a desired height in order to obtain the desired film thickness. As with the charts, the bars have to be especially resistant to corrosion Corrosion is a natural process that converts a refined metal into a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflectometry
Reflectometry uses the reflection of waves at surfaces and interfaces to detect or characterize objects. There are many different forms of reflectometry. They can be classified in several ways: by the used radiation (electromagnetic, ultrasound, particle beams), by the geometry of wave propagation (unguided versus wave guides or cables), by the involved length scales (wavelength and penetration depth versus size of the investigated object), by the method of measurement (continuous versus pulsed, polarization resolved, ...), and by the application domain. Used radiation Electromagnetic radiation of widely varying wavelength is used in many different forms of reflectometry: * Radar and Lidar: Reflections of electromagnetic pulses are used to detect the presence and to measure the location and speed of objects like aircraft, missiles, ships, cars. * Characterization of Semiconductor and Dielectric Thin Films: Analysis of reflectance data utilizing the Forouhi Bloomer dispersion e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kubelka–Munk Theory
The Kubelka-Munk theory, devised by Paul Kubelka and Franz Munk, is a fundamental approach to modeling the appearance of paint films. As published in 1931, the theory addresses "the question of how the color of a substrate is changed by the application of a coat of paint of specified composition and thickness, and especially the thickness of paint needed to obscure the substrate". In their article, "fundamental differential equations" are developed using a two-stream approximation for light diffusing through a coating whose absorption and remission ( back-scattering) coefficients are known. The total remission from a coating surface is the summation of: 1) the reflectance of the coating surface; 2) the remission from the interior of the coating; and 3) the remission from the surface of the substrate. The intensity considered in the later two parts is modified by the absorption of the coating material. The concept is based on the simplified picture of two diffuse light fluxes moving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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