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Vapor Degreasing
Vapor degreasing is a surface finishing process. It involves solvents in vapor form to cleanse the workpiece in preparation for further finishing operations. Process The acting principle behind the vapor degreaser process is that the solvents will Dissolution (chemistry), dissolve the contaminants on the workpiece and remove them by dripping off the part. A basin of solvent is set up with a Heat_exchanger#Spiral, heating coil to bring the solvent to Boiling point, boil. As the solvent evaporates it rises to the Fill line in the chamber, above which is air with a much lower density than the solvent. This contains the vaporized solvent in a closed space where the workpiece is placed. The solvent condenses on the more frigid workpiece and the now liquid solvent dissolves the greases on the part. With the impurities contained in the liquid beads, the solvent runs off the part. Some systems are designed to capture and reclaim this solvent, making the process much more economical. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Finishing
Surface finishing is a broad range of industrial processes that alter the surface of a manufactured item to achieve a certain property. Finishing processes may be employed to: improve product appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, the chemical resistance, the wear resistance, hardness, modify electrical conductivity, remove burrs and other surface flaws, and control the surface friction.. In limited cases some of these techniques can be used to restore original dimensions to salvage or repair an item. An unfinished surface is often called '' mill finish''. These processes can improve the durability, performance and even the appearance of the surface being finished. Surface finishing is often one of the final steps taken when working metal and is essential for guaranteeing that metal components meet the requirements of the necessary finish. Surface finishing processes can be categorized by how they affect the workpiece: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-propyl Bromide
1-Bromopropane (also known as ''n''-propyl bromide or nPB) is a bromoalkane with the chemical formula CH3CH2CH2Br. It is a colorless, flammable liquid that is used as a solvent. It has a characteristic hydrocarbon odor. Its industrial applications increased dramatically in the 21st century due to the phasing out of chlorofluorocarbons and chloroalkanes such as 1,1,1-trichloroethane under the Montreal Protocol. It was also used as a dry cleaning solvent as a substitute for perchloroethylene for a short time in the United States. 1-Bromopropane is highly neurotoxic and possibly carcinogenic to humans. Preparation Industrial routes to 1-bromopropane involve free-radical additions to the corresponding alkenes. In this way, the anti-Markovnikov product is obtained.David Ioffe, Arieh Kampf "Bromine, Organic Compounds" in Kirk-Othmer Encyclopedia of Chemical Technology 2002 by John Wiley & Sons. . Alternatively, ''n''propanol may be substitutively brominated. The latter reaction i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Bond
A chemical bond is the association of atoms or ions to form molecules, crystals, and other structures. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds, or some combination of these effects. Chemical bonds are described as having different strengths: there are "strong bonds" or "primary bonds" such as covalent, ionic and metallic bonds, and "weak bonds" or "secondary bonds" such as dipole–dipole interactions, the London dispersion force, and hydrogen bonding. Since opposite electric charges attract, the negatively charged electrons surrounding the nucleus and the positively charged protons within a nucleus attract each other. Electrons shared between two nuclei will be attracted to both of them. "Constructive quantum mechanical wavefunction interference" stabilizes the paired nuclei (see Theories of chemical bonding). Bonded nuclei maintain an optima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soldering
Soldering (; ) is a process of joining two metal surfaces together using a filler metal called solder. The soldering process involves heating the surfaces to be joined and melting the solder, which is then allowed to cool and solidify, creating a strong and durable joint. Soldering is commonly used in the electronics industry for the manufacture and repair of Printed circuit board, printed circuit boards (PCBs) and other electronic components. It is also used in plumbing and Metalworking, metalwork, as well as in the manufacture of jewelry and other decorative items. The solder used in the process can vary in composition, with different alloys used for different applications. Common solder alloys include tin-lead, tin-silver, and tin-copper, among others. Lead-free solder has also become more widely used in recent years due to health and environmental concerns associated with the use of lead. In addition to the type of solder used, the temperature and method of heating also p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welding
Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and #Solid-state welding, solid-state welding processes which bond without melting, such as pressure, cold welding, and diffusion bonding. Metal welding is distinct from lower temperature bonding techniques such as brazing and soldering, which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds. In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that can be stronger than the base material. Welding also requires a form of shield to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Painting
Painting is a Visual arts, visual art, which is characterized by the practice of applying paint, pigment, color or other medium to a solid surface (called "matrix" or "Support (art), support"). The medium is commonly applied to the base with a brush. Other implements, such as palette knives, sponges, airbrushes, the artist's fingers, or even a dripping technique that uses gravity may be used. One who produces paintings is called a painter. In art, the term "painting" describes both the act and the result of the action (the final work is called "a painting"). The support for paintings includes such surfaces as walls, paper, canvas, wood, glass, lacquer, pottery, leaf, copper and concrete, and the painting may incorporate other materials, in single or multiple form, including sand, clay, paper, cardboard, newspaper, plaster, gold leaf, and even entire objects. Painting is an important form of visual arts, visual art, bringing in elements such as drawing, Composition (visual art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be " miscible in all proportions" (or just "miscible"). The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations,J. de Swaan Arons and G. A. M. Diepen (1966): "Gas—Gas Equilibria". ''Journal of Chemical Physics'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petroleum
Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring unprocessed crude oil, as well as to petroleum products that consist of refining, refined crude oil. Petroleum is a fossil fuel formed over millions of years from anaerobic decay of organic materials from buried prehistoric life, prehistoric organisms, particularly planktons and algae, and 70% of the world's oil deposits were formed during the Mesozoic. Conventional reserves of petroleum are primarily recovered by oil drilling, drilling, which is done after a study of the relevant structural geology, sedimentary basin analysis, analysis of the sedimentary basin, and reservoir characterization, characterization of the petroleum reservoir. There are also unconventional (oil & gas) reservoir, unconventional reserves such as oil sands and oil sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Economical
An economic system, or economic order, is a system of production, resource allocation and distribution of goods and services within an economy. It includes the combination of the various institutions, agencies, entities, decision-making processes, and patterns of consumption that comprise the economic structure of a given community. An economic system is a type of social system. The mode of production is a related concept. All economic systems must confront and solve the four fundamental economic problems: * What kinds and quantities of goods shall be produced: This fundamental economic problem is anchored on the theory of pricing. The theory of pricing, in this context, has to do with the economic decision-making between the production of capital goods and consumer goods in the economy in the face of scarce resources. In this regard, the critical evaluation of the needs of the society based on population distribution in terms of age, sex, occupation, and geography is very pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvents
A solvent (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules, and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical syntheses and purification processes Some petrochemical solvents are highly toxic and emit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impurities
In chemistry and materials science, impurities are chemical substances inside a confined amount of liquid, gas, or solid. They differ from the chemical composition of the material or compound. Firstly, a pure chemical should appear in at least one chemical phase and can also be characterized by its phase diagram. Secondly, a pure chemical should prove to be homogeneous (i.e., a uniform substance that has the same composition throughout the material). The perfect pure chemical will pass all attempts to separate and purify it further. Thirdly, and here we focus on the common chemical definition, it should not contain any trace of any other kind of chemical species. In reality, there are no absolutely 100% pure chemical compounds, as there is always some small amount of contamination. The levels of impurities in a material are generally defined in relative terms. Standards have been established by various organizations that attempt to define the permitted levels of various impuriti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condenses
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or cloud condensation nuclei within the atmosphere. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition. Condensation is usually associated with water. Initiation Condensation is initiated by the formation of atomic/molecular clusters of that species within its gaseous volume—like rain drop or snow flake formation within clouds—or at the contact between such gaseous phase and a liquid or solid surface. In clouds, this can be catalyzed by water-nucleating proteins, produced by atmospheric microbes, which are capable of binding gaseous or liquid water molecules. Reversibility scenarios A few distinct rever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
