Search Results for fused dry-resin coatings

A coating can be defined as a substance spread over a surface to provide protection or to serve decorative purposes. This article discusses two industrial coating components, namely, nonvolatile components such as the resin or binder, pigments, and any additives that may be incorporated into the formulation; and volatile components such as solvents, or water in emulsions and their composition. It provides general information on volatile organic compounds. The article describes the film-forming mechanisms of various coating types, namely, lacquers, chemically converting coatings, latex coatings, alkyds and other resins, which cure by oxidation, moisture-curing polyurethanes and inorganic zinc primers, and powder coatings. The article concludes with a discussion on the functions of the primer, intermediate coat, and topcoat in coating systems.

This article provides a brief review of the classification and characteristics of cast irons. It describes the processes used to clean iron castings, including mechanical cleaning and finishing and nonmechanical cleaning. The article discusses surface treatments used to extend casting life when resistance to corrosion, wear, and erosion is required. The common methods include electroplating, electroless plating, hardfacing, weld cladding, surface hardening, porcelain enameling, and organic coatings.

This article discusses coating products available for use in the aerospace industry that are compliant with regulations requiring reductions in emissions from organic solvents. The coating products addressed include primers, topcoats, and chemical milling maskants. It describes their characteristics and limitations compared to conventional noncompliant materials. The article addresses the methods and products commonly used achieve regulatory compliance: waterborne coatings, exempt-solvent-based coatings, high-solids coatings, powder coating, and electro-deposition.

Painting is a generic term for the application of a thin organic coating to the surface of a material for decorative, protective, or functional purposes. This article provides a detailed account of the types and selection factors of paints and the various application methods, including conventional air atomized, airless, and electrostatic spray; roller coating; dip coating; flow coating; curtain coating; tumble coating; electrocoating; and powder coating. Surface preparation methods and prepaint treatments for coating systems are also discussed. The article includes information on quality control procedures, causes of paint film defects, cost calculation, and safety and environmental precautions. The composition and characteristics of organic coatings, coating system selection factors, the types of paints for structural steel, and the applications of paint on structural steel are also reviewed.

Advanced thermoplastic composites possess impact resistance, fracture toughness, and elevated temperature endurance properties due to their melt-fusible nature. This article presents the material options available for thermoplastic composites such as pseudothermoplastics, post-impregnated thermoplastics, and true thermoplastics. It describes the processing methods of thermoplastic composites, including weaving, seaming, autoclaving, preconsolidation, roll consolidation, roll forming/pultruding, thermoforming, press forming, hydroforming, and diaphragm forming. The article provides information on different types of joints, namely, fastened, adhesive bonded, dual polymer bonded, co-consolidated, and welded joints. It explains the joining methods of thermoplastic composites, such as press forming, diaphragm forming, autoclaving, ultrasonic welding, resistance welding, and induction welding.

This article describes the protective coatings technology used in naval aircrafts. It reviews the future needs and trends of the protective coatings technology based on advancing technology, environmental concerns, and operational requirements. The article discusses the standard finishing systems for aircrafts: the surface pretreatment system, primer, topcoat, advanced-performance topcoat, self-priming topcoat, and specialty coatings. It presents safe compliant solutions to environmental problems associated with the protective coatings technology. These solutions include the use of environmental regulations and hazardous materials, nonchromated pretreatments, waterborne technology, high-solids technology, and touch-up paints. The article also deals with the use of electrodeposition coatings, powder coatings, adhesive films, paint application equipment, and non-chromated sealants in the protective coatings technology.

Successful adhesive bonding of organic-matrix composites is dependent on the nature of the adherend surfaces. This article emphasizes the critical importance of proper surface preparation in both thermoset and thermoplastic composites. It provides information on surface preparation for thermoset composite adherends along with a standard technique (water-break test) for verifying the adequacy of surface preparation for metal bonding. In addition, the article provides examples of good and bad adhesive bonds and describes some important process variables that are considered and controlled in bonding process for thermoset adhesives. The article concludes with a discussion on three different approaches for bonding thermoplastic composite composite panels together.

Rotational molding is a simple but unique process that has the capability of producing small to large hollow items with very uniform wall thicknesses. Providing an overview of the operating principles of rotational molding, this article discusses the key selection factors, including function and property requirements for resins and additives; size, shape, design, and cost of molded parts; equipment type and size; and the type of mold to be used. Commonly used molds include cast aluminum, fabricated sheet metal, nickel deposit, machined aluminum, silicone, fiberglass, and prototype molds.

This article discusses classification of foundry processes based on the molding medium, such as sand molds, ceramic molds, and metallic molds. Sand molds can be briefly classified into two types: bonded sand molds, and unbonded sand molds. Bonded sand molds include green sand molds, dry sand molds, resin-bonded sand molds, and sodium silicate bonded sand. The article describes the casting processes that use these molds, including the no-bake process, cold box process, hot box process, the CO2 process, lost foam casting process and vacuum molding process. The casting processes that use ceramic molds include investment casting, and plaster casting. Metallic molds are used in permanent mold casting, die casting, semisolid casting, and centrifugal casting.

This article reviews the pattern materials used in investment casting, which can be loosely grouped into waxes and plastics. The patternmaking process, pattern tooling, and pattern and cluster assembly are described. The article also describes the manufacture of ceramic shell molds and cores, detailing the binders and other materials used, as well as the formulation and control of slurries. Methods for pattern removal, mold firing, melting, casting, postcasting treatment, and inspection are explained. After presenting design recommendations for investment castings, the article concludes with information on applications and special versions of the investment casting process.

This article provides a detailed discussion on the principal classes and curatives of epoxy resins used in the coatings industry. The principal classes are bisphenol A epoxy, bisphenol F epoxy, epoxy phenol novolac, cycloaliphatic epoxies, epoxy acrylate, brominated bisphenol-A-based epoxy, phosphorus-containing epoxy, fluorinated epoxies, epoxy esters, epoxy phosphate esters, and waterborne epoxy. The principal curatives are amines, amine adducts, cyanoethylated amines, ketimines, polyoxyalkylene amines, cycloaliphatic amines, aromatic amines, polyamides, amido amines, and dicyandiamides. Other curatives include polyester co-polymers, phenolic co-polymers, melamine and urea formaldehyde co-polymer resins, phosphate flame retardants, ultraviolet and electron beam curing of epoxy resins, Mannich bases, Mannich-based adducts, and anhydrides. The article concludes by discussing the concerns regarding the use of epoxy coatings.

Traditional ceramics, one of two general classes, are commonly used in high-volume manufacturing to make building materials, household products, and various industrial goods. Although there is a tendency to equate traditional ceramics with low technology, sophisticated processes and advanced manufacturing techniques are often used where these materials are employed. This article examines several traditional ceramics, including structural clay, whiteware, glazes, enamels, portland cements, and concrete. It also provides a detailed account of fabrication methods, properties, and applications. As an example, common applications for structural clay include facing materials, load-bearing units, pavers, and ceramic tiles.

Polyvinylidene fluoride (PVDF)-based coatings are typically used in outdoor applications that require exceptionally high performance and excellent long-term exterior durability with little maintenance. This article provides a background of three fluoropolymers most commonly used for coatings, namely, PVDF, polyvinyl fluoride, and polytetrafluoroethylene. It focuses on general properties, polymerization, resin types, coating formulation, technology of organic coatings, coating properties, and health and related safety considerations of PVDF. The article describes the application and typical end uses of PVDF-based coatings and the opportunities for improvement in PVDF-based coatings as with all organic coatings.

This article is a compilation of definitions for terms related to engineering materials, including plastics, elastomers, polymer-matrix composites, adhesives and sealants, ceramics, ceramic-matrix composites, glasses, and carbon-carbon composites.

Synthetic diamond and cubic boron nitride are among a class of superhard materials from the boron-carbon-nitrogen-silicon family of elements. This article focuses on the two materials, the forms in which they are produced, and their respective properties. Synthetic diamond and cubic boron nitride compounds are available in the form of grit and sintered polycrystalline blanks of various size, shape, and composition. The article explains how superabrasive grains made from these materials can be used in lapping, polishing, and grinding applications, and how diamond and boron nitride blanks can be mounted to suitable substrates to form ultrahard cutting edges and tools.

Functional fusion-bonded epoxy (FBE) coatings are used as external pipe coatings, base layer for three-layer pipe-coating systems, internal pipe linings, and corrosion coatings for concrete reinforcing steel (rebar). This article provides information on the chemistries of FBE, and discusses the application procedures for internal and external FBE pipe coating. The procedures involve pipe inspection, surface preparation, heating, powder application, curing, cooling, coating inspection, and repairing. It describes the problems and solutions for FBE external pipe coatings, girth weld FBE application, FBE custom coatings, internal FBE pipe linings, and FBE rebar coatings.

Metal is removed from the workpiece by the mechanical action of irregularly shaped abrasive grains in all grinding operations. This article discusses three primary components of grinding wheels, namely, abrasive (the cutting tool), bond (the tool holder), and porosity or air for chip clearance and/or the introduction of coolant. It describes the compositions and applications of coated abrasives and types of grinding fluids, such as petroleum-base and mineral-base cutting oils, water-soluble oils, synthetic fluids, semisynthetic fluids, and water plus additives. The article concludes with information on different types of grinding processes, namely, rough grinding, precision grinding, surface grinding, cylindrical grinding, centerless grinding, internal grinding, and tool grinding.

Coating of cast irons is done to improve appearance and resistance to degradation due to corrosion, erosion, and wear. This article describes inorganic coating methods commonly applied to cast irons. The coating methods include plating, hot dip coating, conversion coating, diffusion coating, cladding, porcelain enameling, and thermal spray. Organic coatings have a wide variety of properties, but their primary use is for corrosion resistance combined with a pleasing colored appearance. The article discusses the various types of organic coatings applied to cast irons. Practically any degree of smoothness or roughness and requirement for color and gloss can be filled by organic coatings. The article describes abrasive blast cleaning, abrasive waterjet cleaning and finishing, vibratory finishing, barrel finishing, and shot peening for processing iron castings.

This article introduces thermal spray coatings and describes the various types of coating processes and coating devices, including the flame spray, electric-arc spray, plasma spray, transferred plasma arc, high-velocity oxyfuel, and detonation gun. It provides information on the surface preparation methods and finishing treatments of coated parts. The article also explains the tests to evaluate the coating quality and the effects of coating structures and mechanical properties on coated parts. It concludes with a discussion on the uses of thermal spray coatings.