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Spreading Rate (paint)
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, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Radiative Transfer
Radiative transfer (also called radiation transport) 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, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refrac ... 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Refractive Indices
In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the 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 and 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 and . 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 equations) and Brewster's angle. The refractive index, n, 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 similarly the wavelength in that me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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. More narrowly, 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 (gyps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pigment
A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage in their use. Dyes are often organic compounds whereas pigments are often inorganic compound, inorganic. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli. Economic impact In 2006, around 7.4 million tons of inorganic chemistry, inorganic, organic chemistry, organic, and special pigments were marketed worldwide. 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 yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Visual Perception
Visual perception is the ability to detect light and use it to form an image of the surrounding Biophysical environment, environment. Photodetection without image formation is classified as ''light sensing''. In most vertebrates, visual perception can be enabled by photopic vision (daytime vision) or scotopic vision (night vision), with most vertebrates having both. Visual perception detects light (photons) in the visible spectrum reflected by objects in the environment or emitted by light sources. The light, visible range of light is defined by what is readily perceptible to humans, though the visual perception of non-humans often extends beyond the visual spectrum. 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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Light Wavelength
Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively '' optical radiation''. 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 vacuum, , is one of the fundamental constants of nature. All electromagnetic radiation exhibits some properties of both particles and waves. Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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] [Amazon] |
Reflectometry
Reflectometry is a general term for the use of the reflection of waves or pulses at surfaces and interfaces to detect or characterize objects, sometimes to detect anomalies as in fault detection and medical diagnosis. 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 in relation to size of the investigated object), by the method of measurement (continuous versus pulsed, polarization resolved, ...), and by the application domain. Radiation sources *Electromagnetic radiation of widely varying wavelength is used in many different forms of reflectometry: ** Radar: Reflections of radiofrequency pulses are used to detect the presence and to measure the location and speed of objects such as aircraft, missiles, ships, vehicles. ** Lidar: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Kubelka–Munk Theory
In optics, the Kubelka–Munk theory devised by Paul Kubelka and Franz Munk, is a fundamental approach to modelling 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". The mathematical relationship involves just two paint-dependent constants. In their article, 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: # the reflectance of the coating surface; # the remission from the interior of the coating; and # the remission from the surface of the substrate. The intensity considered in the latter two parts is modified by the absorption of the coating material. The c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
