The layer is a cover applied to the surface of an object, commonly referred to as substrate . The purpose of coating application may be decorative, functional, or both. The coating itself may be a complete coating, which completely covers the substrate, or covers only the substrate portions. Examples of all these types of coatings are product labels on many bottles - one has a whole functional layer (adhesive) and the other side has one or more decorative coatings in the appropriate pattern (printing) forming words and images.
Paints and lacquers are coatings that mostly have multiple uses protecting the substrate and become decorative, although some paint artists are only for decoration, and paint on large industrial pipes may be just for the function of preventing corrosion.
Functional coatings can be applied to change the surface properties of the substrate, such as adhesion, wettability, corrosion resistance, or wear resistance. In other cases, e.g. fabrication of semiconductor devices (where the substrate is a wafer), the coating adds an entirely new property, such as magnetic response or electrical conductivity, and forms an essential part of the finished product.
The main consideration for most coating processes is that coatings should be applied to controlled thickness, and a number of different processes are being used to achieve this control, ranging from simple brushes to painting the walls, to some highly expensive machine applications of coatings in the electronics industry. A further consideration for 'non-all-over' coatings is that controls are needed where coatings should be applied. A number of non-all-over coating process is the printing process.
Many industrial coating processes involve the application of thin films from functional materials to substrates, such as paper, fabric, film, foil, or stock sheets. If the substrate starts and ends, the process will end up in a roll, this process can be called "roll-to-roll" or "web-based" coating. The coil of the substrate, when it is wrapped around the coating machine, is usually called web .
Coatings can be applied as liquids, gases or solids.
Video Coating
Coating function
- Adhesives - adhesive tape, pressure sensitive label, ironing cloth
- Change adhesion properties
- Non-stick PTFE coated-cooking pot
- Launch a coating, e.g. liner coated silicone coatings for many self-adhesive products
- the primer encourages the next coating to adhere well (sometimes also has anti-corrosive properties)
- Optical coating
- Reflective coating for mirrors
- Anti-reflective coatings for example, on glasses
- UV absorbent coatings to protect the eyes or increase the age of the substrate
- Colored as used in some colored lighting, stained glass, or sunglasses
- Catalytic eg. self-cleaning glass
- Light-sensitive as previously used to create photographic movies
- Protective layer
- Most coatings or surface paints to some extent protect the substrate eg.
- Sealing and waterproofing wood
- Seal concrete surface
- Sealer and floor paint that make up the film
- Polymer/floor resin seamlessly
- Wall layer/round containment
- Coating of concrete and moisture concrete walls
- Roof coating
- Membrane concrete bridge deck
- Sealing and waterproofing of masonry
- Preserving machinery, equipment, and structures
- Maintaining coating/paint for metals, alloys and concrete
- Chemical resistant coatings
- wear resistance
- Anti-Friction, Wear, and Scuffing Resistance Coatings for Rolling-element pads
- Anti-scratch-resistant coating on plastics and other materials eg. titanium nitride to reduce the loss of scratches and abrasion
- Barrier coatings on concrete, metal and alloys affected by erosion/abrasive attacks
- Anti-corrosion - ensuring metal components have the longest life span.
- Cover underneath the car body
- Many plating products
- Preserve equipment and structural steel from degradation
- Under thermal insulation and under flame retardant for structural steel
- Passive fire protection
- Isolation
- Waterproof cloth and waterproof paper
- Anti-graffiti
- Antimicrobial surface
- Foul release and anti-fouling
- Most coatings or surface paints to some extent protect the substrate eg.
- Magnetic properties such as for magnetic media such as cassettes, floppy disks, and some mass transit tickets
- Electrical or electronic properties
- Conformal Antennas, for example, metal coating on plastic airframes
- Conductive layer for example to produce some type of resistor
- Insulating layer for example on magnetic cable used in transformer
- Scent properties such as stickers and scratch and sniff labels
- Decorative - often gives a certain color, but also to create certain reflective properties such as gloss or matt.
Maps Coating
Coating process
The coating process can be classified as follows:
Vapor emptying
Chemical vapor deposition
- Organic vapor phase epitaxy
- electrostatic vapor assisted steam deposition (ESAVD)
- Sherardizing
- Some forms of Epitaxy
- Molecular beam epitaxy
Automatic steam deposition
- Cathodic arc deposition
- Physical liquid steam deposit (EBPVD)
- Ionic coating
- Establishment of ion-assisted ions (IBAD)
- Magnetron sputtering
- Pulsed laser deposition
- Sputter Deposition
- Vacuum thinning
- Vacuum evaporation, evaporation (deposition)
- Pulsed electron deposition (PED)
Chemical and electrochemical engineering
- Conversion coating
- Autophoretic, registered trade name of a special series of special autodepositing coatings for iron metal substrates
- Anodising
- Merge the conversion layer
- Plasma electrolytic oxidation
- Phosphate (coating)
- Ion Mixing
- Pickled and oiled, a layer of steel plate
- Plating
- Electrolysis coating
- Electroplating
Spraying
- Spray painting
- High speed oxygen fuel (HVOF)
- Plasma Spray
- Thermal spraying
- Kinetic metallization (KM)
- Plasma transfer thermal spray wire bowl
- The general form of Powder coating
Roll-to-roll coating process
Common roll-to-roll coating processes include:
- Air blade coating
- Anilox coater
- Flexo coater
- Gap Coating
- Roll-over coating
- Gravure layer
- Hot melt coating - when the required layer viscosity is achieved by temperature rather than polymer solution etc. This method usually implies a slot-die layer above room temperature, but it is also possible to have a hot melt roller coating; heat-melting metering-rod coating, etc.
- Layer of dyed dye
- Layer kiss
- Metering rod coating (Meyer bar)
- Roller coating
- Advanced rollers
- Reversed roll layer
- Silk Screen Skins
- Play screen
- Layer Slot Die
- The extrusion layer - generally high pressure, often high temperature, and with web travel faster than the speed of the extruded polymer.
- Curtain - low viscosity coating, with a vertical slot over a net and a gap between the slotdie and the web.
- Slide-coating the bead layer with a sloping slide between slotdie and bead. Commonly used for multilayer coatings in the photography industry.
- Slot die bead coating - usually with web supported by a very small roller and slot between the slotdie and the web.
- A tightened web slotdie layer - no support for the web.
- Inkjet Printing
- Lithography
- Flexibility
Physical coating process
- Langmuir-Blodgett
- Spin coating
- Dip Coating
See also
References
- Titanium and titanium alloys , edited by C. Leyens and M. Peters, Wiley-VCH, ISBN 3-527-30534-3, table 6.2: an overview of some coating systems and fabriction processes for titanium alloys and titanium aluminides (changed)
- Coating Materials for Electronic Applications: Polymers, Processes, Reliability, Testing by James J. Licari; William Andrew Publishing, Elsevier, ISBNÃ, 0-8155-1492-1
- High Performing Organic Layer, ed. US Khanna, Elsevier BV, 2015, ISBN 978-1-84569-265-0
Source of the article : Wikipedia
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