“Destructive test” equipment used to determine the layer thickness values of different layers in a coating system separately by punching a conical hole in the paint film and observing the layers with a scaled magnifier. A paint borer consists of a right triangle shaped steel knife rotating around its perpendicular edge and a scaled magnifier.

Destructive measuring device used to determine the thickness of paint film by incising a V-groove through the film and observing the thickness with a microscope bearing a measuring scale.

In this paint production approach, a resin with a high compatibility range is selected as main dispersion resin and different pigments are dispersed separately to a certain grain size using this resin. Color matching is performed using this pigment pastes and letdown is done by adding remaining ingredients after a proper calculation. The main advantages of this approach are, better optimization of capacity of production equipment (especially the mills) and storage areas in addition to reduced production times. It is achieved by producing common pigment pastes, which can be used in various product groups owing to the compatible resin used. The drawback of this approach is the difficulties in sensitive color matching because of highly concentrated pigment pastes in addition to the possibility of decrease in color strength, gloss as well as haze and formation of particles due to pigment flocculation during storage.

Auxiliary material used to remove the dried coating film from the surface. Paint removers contain strong solvents gelled by various binders and additives, and provide removal of the coating film by inflating/swelling effect of solvents. Paint removers should be miscible with water to allow rinsing of the swelled coating.

A simple paint application tool with a rolling cylindrical core. They are preferred because of their time efficiency. Application viscosity in roller applications should be in the same range of that in brush application. The roller frame is made of fibre reinforced plastic or metal. The pile fabric of roller cover is made of polyester, nylon, mohair or lamb’s wool. Fibre length of fabric is between 5 mm and 20 mm. Furthermore, relatively less skill is required with roller applications.

Paints applied to various agricultural machines, tankers, valves, tanks, plows and other agricultural equipment in addition to some parts of agricultural hand tools like shovel, scissor and handsaw. Paints for agricultural tools are designed to have high resistance against wear, chemicals and corrosion.

A polymer consists of 10 to 100 formaldehyde units. Not only the hazardous effects to human health and environment but also the difficulties in processing and storing of formaldehyde gas leads to paraformaldehyde use in formaldehyde resins. Paraformaldehyde decomposes into the formaldehyde at nearly 150°C.
Chemical formula:

Varnish applied on indoor parquet floors to increase their durability against water, household chemicals and most importantly against abrasion, while enhancing their appearance.

OICA (The International Organization of Motor Vehicle Manufacturers) defines the passenger cars as: Vehicles used for passenger transportation purposes with at least four wheels and 9 seats -including the driver seat- are defined as “passenger cars”. See Also Motor vehicles

Motor vehicles

A vehicle with at least four wheels whose propulsion is provided by an engine and used for transport of passengers as well as for carriage of goods on highways is a motor vehicle. According to the International Organization of Motor Vehicle Manufacturers (OICA), motor vehicles are classified as follows.

Distinction between light commercial vehicles and other commercial vehicles is drawn according to their transport capacity. Changing from country to country this distinction is in between 3,5 tons and 7,0 tons. In Turkey, vehicles having a transport capacity below 3,5 tons are defined as light commercial vehicle.

Paste

Viscous dispersions of abrasives in liquid phase that are used to eliminate defects and scratches or chalking, which occur over time on the glossy paints or clearcoats. Pastes are used in the first stage of polishing to smooth the rough surface.

Pigment paste

Paint semi-product which has a higher pigment content and generally a higher viscosity then the finished paint.

Paint production using monopigmented pigment pastes

In this paint production approach, a resin with a high compatibility range is selected as main dispersion resin and different pigments are dispersed separately to a certain grain size using this resin. Color matching is performed using this pigment pastes and letdown is done by adding remaining ingredients after a proper calculation. The main advantages of this approach are, better optimization of capacity of production equipment (especially the mills) and storage areas in addition to reduced production times. It is achieved by producing common pigment pastes, which can be used in various product groups owing to the compatible resin used. The drawback of this approach is the difficulties in sensitive color matching because of highly concentrated pigment pastes in addition to the possibility of decrease in color strength, gloss as well as haze and formation of particles due to pigment flocculation during storage.

Test method used to determine the surface hardness of a dry organic coating film using a pencil with standart hardness. For pencil hardness test, pencils of following standarts are used arranged in increasing hardness level: 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H. Coated surface is scratched with a pencil tip, square shaped with sand paper. A coating’s pencil hardness is defined as the hardness that is one level softer than the softest pencil leaving a permanent mark on the surface.

An oscillating pendulum, which is in contact with the paint film through two semi spherical touch points, damps according to non-elastic response of the paint film in due course and eventually stops. The time passed for the swing of the pendulum to be damped, is accepted as a measure of paint film hardness.

Polyol prepared by polymerization of acetaldehyde and formaldehyde in a basic environment. It is used as a raw material for the preparation of alkyd and polyester resins.
Chemical name: tetramethylolmethane, 2,2-Bis(hydroxymethyl)-1,3-Propanediol
Chemical formula: 
Melting point: 262°C

Bisphenol A

Type of polyol obtained from the reaction of phenol and acetone under strongly acidic conditions and used for production of epoxy resins. It is also the main building structure of polycarbonate polymer.
Chemical name: Diphenylolpropane
Chemical formula: 
Melting point: 155°C

Bisphenol F

Type of polyol obtained from the reaction of phenol and formaldehyde under strongly acidic conditions and used for production of epoxy resins with smaller molecular weight and higher functionality.
Chemical name: Dihydroxydiphenylmetane
Chemical formula: 
Melting point: 163°C

Phenol

White and crystalline chemical substance used as raw material for phenolic resins.
Chemical formula: 

Phenolic resins

General name for resins, formed by reaction of phenol and aldehydes, having outstanding thermal and chemical resistance.

General name for resins, formed by reaction of phenol and aldehydes, having outstanding thermal and chemical resistance.

Surface treatment performed to improve adhesion of coating to metal surfaces and to reduce corrosion tendency (inactivation) of metal surfaces. Phosphating is carried out either by using iron phosphate solutions resulting in more limited protection or by using solutions containing one or more of zinc, manganese and nickel phosphate salts resulting in thicker coatings. The latter case provides better adhesion and higher corrosion resistance.

Some objects absorb some of the light energy and reflect the rest, while returning most of the absorbed light energy to its surrounding in the form of light energy, similar to fluorescence but with a time lag. This fact is called phosphorescence. 

Phosphorescent pigments, following absorption of the UV spectral part of the light, return some of the energy as heat energy; after a time lag they emit the rest of the energy in the form of a blue visible light. Therefore, phosphorescent pigments continue to emit a blue light also after removal of the light source.

Breaking up of polymers (meanwhile dried coating films) into smaller molecules with the effect of visible or UV light.

See Initiators

General name for chemicals that activate the unsaturated reactive molecule by converting the molecule to a free radical, an organic cation or an organic anion during addition polymerization. Most widely used initiators are, peroxide compounds, azo compounds, alkaline metal alkyls and boron trifloride. The initiators that start to act under the influence of light energy (e.g. UV) are called photoinitiators.

Chemical substance obtained by oxidation of o-xylene or naphthaline. Phtalic anhydride is the most widely used polyacid in alkyd resin and polyester resin synthesis.
Chemical formula:

Boiling point: 131°C

Hexahydrophthalic anhydride

Chemical formula: 

Melting point: 35°C

In roller coating applications, pick-up roller immersed in a paint pan, moves around its axis and transfers the paint on its surface as a film. See Also Roller coating applications

Roller coating applications

Paint application performed by using three parallel rollers named as pick-up, feeding and applicator. Pick-up roller immersed in paint pan, moves around its axis and transfers the paint to the feeding roller which it is in touch with. Feeding roller transfers the paint to the applicator roller in contact with it. Application roller, transfers the coating onto the material to be coated which is moving on a conveyor belt. See Also Direct roller application, Reverse roller application

Direct roller application

Type of roller applications, which are based on coating flat panels with rollers on a moving conveyer. In direct roller applications, rotation direction of “application roll” is the same as the conveyer’s moving direction. Having a lower shear than reverse roller application, direct roller application provides good results in primer and non-glossy top coat applications. See Also Reverse roller application, Roller coating applications

Reverse roller application

Paint application method where the applicator rolls run in the opposite direction to the conveyor movement. In this application, better levelling is achieved on the surface because sheer stress exerted on the paint film is higher than in direct rolling application. Reverse roller application method is preferred especially in glossy topcoats. See Also Roller coating applications, Direct roller application

Aluminum pigments

Aluminum pigments are used to create a metallic effect on painted surfaces. They are composed of pure aluminum platelets of 10-30 micrometers diameter and of 0,1-0,9 micrometer thickness. See Effect pigments

Anti-corrosive pigments

Functional pigments added to the paint formulation in order to improve the corrosion resistance of the paint. Most widely used anticorrosive pigments are: chromates, phosphate, phosphosilicate and borosilicate salts, having controlled water solubilities and inactivating the metal surfaces; zinc powder, cathodically protecting the coated metal surfaces; and micaceous iron oxide (MIO or MIOX), having a plate-like structure and acting as a water barrier for metal surfaces.

Iron oxide pigments

Natural or synthetic oxides of iron are considered to be the oldest and the most widely used pigments. Oxides of the Fe2O3 structure are red, Fe2O3xH2O structure are yellow, Fe3O4 structure are black, and different mixtures of FeO and Fe2O3 are used as brown pigments.

Fluorescent pigments

Flourescent pigments, after absorbing the UV spectral part of the light, return the UV light energy in the form of a blue visible light together with some heat energy. Therefore, flourescent pigments emit more visible light than they are exposed to.

Phosphorescent pigments

Phosphorescent pigments, following absorption of the UV spectral part of the light, return some of the energy as heat energy; after a time lag they emit the rest of the energy in the form of a blue visible light. Therefore, phosphorescent pigments continue to emit a blue light also after removal of the light source.

Effect pigments

Pigments added to coating formulations to provide an appealing look, besides coloring the coating. For this purpose, aluminum pigments and mica based pearlescent pigments of platelet shape are widely used. There is a special aesthetical expectation from basecoat applications containing metalic or pearlescent (or micaceous) pigments: the flip-flop property. This coating property, formed by parallel allignment of aluminum or pearlescent platelets to the surface, leads to a mirror-like appearance when looked from the front, and to a dark color appearance when looked from a very low angle. Transparency of the film formed by binders enhances the flip-flop effect.

Inorganic color pigments

Inorganic based pigments, most of which are formed by metal oxides, metal oxide mixtures and carbon black. Almost all inorganic pigments used today are obtained synthetically.

Critical pigment volume concentration (CPVC)

Pigment volume concentration at which all the binder in a coating formulation is used up to wet the pigments and to fill up the pigment pores, leaving no free binder.

Organic color pigments

Group of pigments synthesized from basic organic molecules and possessing the ability to enhance the aesthetics in paint industry by virtue of their wide range of colors.

Pigment

Pigments are finely ground, organic solvent and water insoluble chemical substances that impart color, various visual effects and in some cases corrosion resistance to paint. Two main differences between pigments and dyestuffs are pigments are insoluble in both organic solvents and water and pigments have better exterior durability than dyestuffs.

Pigment volume concentration (PVC)

The percentage ratio of the volume of total pigment (and extender) to the volume of total nonvolatile material present in paint formulation.

Pigment affinic groups

Chemical groups present in dispersion additives to ease the attachment to the surfaces of polar pigments. Pigment affinic groups comprise carboxylic acid, amine, isocyanate and their derivatives.

Pigment paste

Paint semi-product which has a higher pigment content and generally a higher viscosity then the finished paint.

Clusters of pigments and extenders

Although pigments and extenders are produced as primary particles, they form aggregates and agglomerates when they are in touch with each other in bulk phase. In dispersion stage, these pigment clusters are tried to break down to primary particles. If dispersed pigments are not stable, they form loosely combined units called flocculates. Since, the distinction between these three terms might not be clear, for a better understanding a schematic representation is given below.

Dispersion of pigments and extenders

Breaking down of pigment flocculates which are combined as agglomerates or aggregates, in a binder and solvent medium. Dispersion of pigments and extenders is performed using high-speed dispersers and wet mills.

Pigment/binder ratio

The ratio by weight of pigment content to solid binder content in paint formulation. See Also Solid binder content

Nacreous pigments / Pearlescent pigments

Pigments produced by coating TiO2 or some other oxides at varying thickness from 120 nm to 160 nm on the mica flakes of 100–500 nm (0,1–0,5 µm) thick. Nacreous pigments are perceived in different colors and sheen depending upon the viewing angle. Mica based nacreous pigments impart color to the coating by light interference caused by mica flakes of the same thickness with the wavelengths in visible light spectrum (100–500 nm). See Also Effect pigments

Paint production using monopigmented pigment pastes

In this paint production approach, a resin with a high compatibility range is selected as main dispersion resin and different pigments are dispersed separately to a certain grain size using this resin. Color matching is performed using this pigment pastes and letdown is done by adding remaining ingredients after a proper calculation. The main advantages of this approach are, better optimization of capacity of production equipment (especially the mills) and storage areas in addition to reduced production times. It is achieved by producing common pigment pastes, which can be used in various product groups owing to the compatible resin used. The drawback of this approach is the difficulties in sensitive color matching because of highly concentrated pigment pastes in addition to the possibility of decrease in color strength, gloss as well as haze and formation of particles due to pigment flocculation during storage.

Chemical groups present in dispersion additives to ease the attachment to the surfaces of polar pigments. Pigment affinic groups comprise carboxylic acid, amine, isocyanate and their derivatives.

Paint semi-product which has a higher pigment content and generally a higher viscosity then the finished paint.

The percentage ratio of the volume of total pigment (and extender) to the volume of total nonvolatile material present in paint formulation.

Aluminum pigments

Aluminum pigments are used to create a metallic effect on painted surfaces. They are composed of pure aluminum platelets of 10-30 micrometers diameter and of 0,1-0,9 micrometer thickness. See Effect pigments

Anti-corrosive pigments

Functional pigments added to the paint formulation in order to improve the corrosion resistance of the paint. Most widely used anticorrosive pigments are: chromates, phosphate, phosphosilicate and borosilicate salts, having controlled water solubilities and inactivating the metal surfaces; zinc powder, cathodically protecting the coated metal surfaces; and micaceous iron oxide (MIO or MIOX), having a plate-like structure and acting as a water barrier for metal surfaces.

Iron oxide pigments

Natural or synthetic oxides of iron are considered to be the oldest and the most widely used pigments. Oxides of the Fe2O3 structure are red, Fe2O3xH2O structure are yellow, Fe3O4 structure are black, and different mixtures of FeO and Fe2O3 are used as brown pigments.

Fluorescent pigments

Flourescent pigments, after absorbing the UV spectral part of the light, return the UV light energy in the form of a blue visible light together with some heat energy. Therefore, flourescent pigments emit more visible light than they are exposed to.

Phosphorescent pigments

Phosphorescent pigments, following absorption of the UV spectral part of the light, return some of the energy as heat energy; after a time lag they emit the rest of the energy in the form of a blue visible light. Therefore, phosphorescent pigments continue to emit a blue light also after removal of the light source.

Effect pigments

Pigments added to coating formulations to provide an appealing look, besides coloring the coating. For this purpose, aluminum pigments and mica based pearlescent pigments of platelet shape are widely used. There is a special aesthetical expectation from basecoat applications containing metalic or pearlescent (or micaceous) pigments: the flip-flop property. This coating property, formed by parallel allignment of aluminum or pearlescent platelets to the surface, leads to a mirror-like appearance when looked from the front, and to a dark color appearance when looked from a very low angle. Transparency of the film formed by binders enhances the flip-flop effect.

Inorganic color pigments

Inorganic based pigments, most of which are formed by metal oxides, metal oxide mixtures and carbon black. Almost all inorganic pigments used today are obtained synthetically.

Critical pigment volume concentration (CPVC)

Pigment volume concentration at which all the binder in a coating formulation is used up to wet the pigments and to fill up the pigment pores, leaving no free binder.

Organic color pigments

Group of pigments synthesized from basic organic molecules and possessing the ability to enhance the aesthetics in paint industry by virtue of their wide range of colors.

Pigment

Pigments are finely ground, organic solvent and water insoluble chemical substances that impart color, various visual effects and in some cases corrosion resistance to paint. Two main differences between pigments and dyestuffs are pigments are insoluble in both organic solvents and water and pigments have better exterior durability than dyestuffs.Pigment volume concentration (PVC)The percentage ratio of the volume of total pigment (and extender) to the volume of total nonvolatile material present in paint formulation.

Pigment volume concentration (PVC)

The percentage ratio of the volume of total pigment (and extender) to the volume of total nonvolatile material present in paint formulation.

Pigment affinic groups

Chemical groups present in dispersion additives to ease the attachment to the surfaces of polar pigments. Pigment affinic groups comprise carboxylic acid, amine, isocyanate and their derivatives.

Pigment paste

Paint semi-product which has a higher pigment content and generally a higher viscosity then the finished paint.

Clusters of pigments and extenders

Although pigments and extenders are produced as primary particles, they form aggregates and agglomerates when they are in touch with each other in bulk phase. In dispersion stage, these pigment clusters are tried to break down to primary particles. If dispersed pigments are not stable, they form loosely combined units called flocculates. Since, the distinction between these three terms might not be clear, for a better understanding a schematic representation is given below.

Dispersion of pigments and extenders

Breaking down of pigment flocculates which are combined as agglomerates or aggregates, in a binder and solvent medium. Dispersion of pigments and extenders is performed using high-speed dispersers and wet mills.

Pigment/binder ratio

The ratio by weight of pigment content to solid binder content in paint formulation. See Also Solid binder content

Nacreous pigments / Pearlescent pigments

Pigments produced by coating TiO2 or some other oxides at varying thickness from 120 nm to 160 nm on the mica flakes of 100–500 nm (0,1–0,5 µm) thick. Nacreous pigments are perceived in different colors and sheen depending upon the viewing angle. Mica based nacreous pigments impart color to the coating by light interference caused by mica flakes of the same thickness with the wavelengths in visible light spectrum (100–500 nm). See Also Effect pigments

Paint production using monopigmented pigment pastes

In this paint production approach, a resin with a high compatibility range is selected as main dispersion resin and different pigments are dispersed separately to a certain grain size using this resin. Color matching is performed using this pigment pastes and letdown is done by adding remaining ingredients after a proper calculation. The main advantages of this approach are, better optimization of capacity of production equipment (especially the mills) and storage areas in addition to reduced production times. It is achieved by producing common pigment pastes, which can be used in various product groups owing to the compatible resin used. The drawback of this approach is the difficulties in sensitive color matching because of highly concentrated pigment pastes in addition to the possibility of decrease in color strength, gloss as well as haze and formation of particles due to pigment flocculation during storage.

Solvent vapour and other gas bubbles present in wet paint film, tend to make holes while leaving the film during drying process. Drying results in an increase in viscosity, in turn, makes it impossible for paint film to level this holes out and a paint defect called pinholing defect will occur.

When the film thickness of applied paint increases, release of solvent vapour and other gases will be retarded. Since paint film starts to get hardened during this period, the holes formed by solvent vapours and other gases become permanent if the thickness of the film is above a certain limit. The dry film thickness of paint film at which this defect starts to occur is called pinholing limit.

Plasticizers are used as softening additive in paints based on resins like cellulose nitrate. These resins have large molecules, are hard and mostly brittle.

End cut and edge cut thin wood panels of the same number with 1 mm thickness are glued and pressed together such that adjacent plies have different wood grain at right angles to each other. Wood panels obtained by this technique are called plywood.

Anodic polarization

Slowdown of electrochemical processes in an electrolysis circuit, as a result of increased circuit resistance due to accumulation of a liquid or gas layer with a comparably high electrical resistance on anodic surface.

Cathodic polarization

Process that causes a decrease in corrosion rate as a result of less conductive depositions on cathode surfaces.

Polarization

Deposition of solid or gas phase insulation materials on an anode or cathode in an electrochemical cell hinders the current generation. This phenomenon is called electrode polarization. If the electrochemical cell is a corrosion battery, polarization increases corrosion rate.

Transparent and wax-like substances that fill the pores/pinholes on a surface upon polishing increasing the gloss of a surface. However, in Turkey, varnishes applied on wood surfaces are also referred to as polishes.

Parquet varnish

Varnish applied on indoor parquet floors to increase their durability against water, household chemicals and most importantly against abrasion, while enhancing their appearance.

Poly(tetrafluoroethylene) is synthesized by free radical polymerization of tetrafluoroethylene under high pressure and aqueous medium. It is a highly crystalline, linear and orientable polymer. Solvent and corrosion resistance is high but surface tension and friction coefficient are low. It has by far the lowest dielectric constant for all known polymeric materials. It is used in non-stick paints for painting kitchen items, hygienic bathroom and toilets.

It is a plastic material having a melting point of 170ºC and a 50% crystalline structure. It is durable against shape deformation and creep at high and low temperatures. PVDF, is used in production of coil coating topcoats with high exterior durability.

General name of acids having more than one reactive hydrogen atoms in their structure. They are known as polybasic acids as well.

Surface additives that prevent defects by forming a thin continuous layer on the surface. These additives are designed with limited compatibility with the paint binders and solvents so that they can migrate to the surface. See Also Surface additives

Surface additives

Surface additives are added to paint formulation to prevent film defects. They either have surface tensions lower than paint ingredients (silicone and fluoride compounds) or they are compounds having limited compatibility. They migrate to the surface and form a thin layer. Hence, surface tension gradients that cause defects on paint film are prevented.

Amide functional macromolecules formed by controlled polyaddition of polamides with various compounds especially epoxy resins. Polyamide adducts, due to their higher glass-transiton temperature (Tg) than polyamides, provide a partial physical drying ability for epoxy resins which in turn leads to an increase in cure rate.

Hardener for epoxy resins, composed of aliphatic polyamide resins which can crosslink with oxirane groups of epoxy resins using the active hydrogens it possesses.

An amine and amide functional hardener for epoxy resins which can crosslink with oxirane groups of epoxy resins using the active hydrogens it possesses.

See Polyacid

General name of acids having more than one reactive hydrogen atoms in their structure. They are known as polybasic acids as well.

Hard thermoplastic polyester resin synthesized by polymerization of 1,4-Butanediol and pure terephthalic acid according to process which became wide spread in the last decade. Formerly, it was synthesized using dimethyl terephthalate instead of terephthalic acid.

Thermoplastic organic polymers with carbonate group as a repeating unit. Generally, they are produced by reacting bisphenol A with organic carbonate (diphenyl carbonate) or phosgene gas. Carbonate group is given below.

Formerly, polychromatic light was defined as visible light array composed of many light rays in various colors. With the semantic extension in the course of time, this definition has changed to define light composed of light rays with many different wavelengths irrespective of whether it is in visible region or not.

Polydispersity

The ratio of weight average molecular weight to number average molecular weight of a polymer is defined as polidispersity or polidispersity index.

Polydispersity

indexSee Polydispersity

See Polydispersity

Polydispersity

The ratio of weight average molecular weight to number average molecular weight of a polymer is defined as polidispersity or polidispersity index.

Polydispersity

indexSee Polydispersity

Name given to putties that unsaturated polyester resins or epoxy resins are used as binders and that reaches to very high stiffness after spatula application and drying.

Ester based polymers derived from polycondensation of polyols and polyacids. Although their backbone structure is similar, to point out the difference from the fatty acid containing alkyd resins, they are called oil-free polyesters. If the polyols and polyacids contain unsaturation, polyester resins are called “unsaturated polyester resins”, if not, they are called “saturated polyester resins”

Unsaturated polyester resins

See Polyester resins

Saturated polyester resins

See Polyester resins

Oil-free polyester resins

See Polyester resins

Thermoplastic polyester resin synthesized by condensation polymerization of terephthalic acid or terephthalic acid dimethyl ester with ethylene glycol.

General name of alcohols having more than one hydroxyl groups. They are also known as polyalcohol or polyhydric alcohol.

Step-growth polymerization

See Condensation polymerisation

Living polymers

See Group transfer polymerization

Crosslinked polymers

Crosslinked polymers are formed by the reaction of at least two initially linear or branched polymers over their active functional groups. Functionalities of the monomers constituting these polymers cannot be less than 2, and at least one of the monomers should have a functionality of F=3 or more. Crosslinked polymers are of thermosetting nature.

Branched polymers

General name for polymers having three or more polymer segments connected to a branch point. They are formed by reaction of di-functional monomers bearing at least one of their functional groups on their central parts allowing branching. For step growth polymerization, small amounts of monomers with F=3 is used. For addition polymerization, small amounts of initiators with tendency to branch or monomers with F≥4 are used. Some common branched polymer types are shown below:

Branched polymers can be of thermoplastic or thermosetting nature.

Fluoropolymers

General name for polymers, structural units of which contain fluoro compounds. Polytetra fluoroethylene (PTFE), polyvinylidendifloride (PVDF or PVF2) and polyvinylidenfloride (PVF) can be mentioned among the main fluoropolymers that are used in organic coatings having superior thermal resistance, chemical resistance and outdoor durability.

Group transfer polymerization

Type of polymerization that allows growth of the polymer chain on different ends as a result of a silicone structured initiator activating alternating ends of polymer chain in turns or activating ends of two separate chains in turns during growth. Monomers used in group transfer polymerization should contain carbonyl or nitrile groups. Such growing polymers are also called living polymers.

Homopolymer

A polymer is called a homopolymer if it grows by repetition of a single monomer (e.g., -AAAAA-, A being the monomer). Examples are polyethylene, polypropylene etc.

Isocyanate prepolymers

General name for compounds, having NCO functional groups, formed by reaction of polyisocyanate monomers with their own kind or with polyols over some of their isocyanate (NCO) groups (e.g., Toluenediisocyanate and trimethylol propane prepolymers, biurets of hexamethylenediidocyanate, isophorone diisocyanate and water prepolymers etc.).

Addition polymerization

Polymerization of unsaturated reactive molecules by addition over their unsaturated sections via activation by chemicals, also known as initiators. Addition polymerization is comprised of four steps: Initiation, propagation, chain transfer and termination. Addition polymerization reactions forming free radicals, organic cations or organic anions via initiators are named as follows: Free radical polymerization, Cationic polymerization, Anionic polymerization.

Cationic polymerization

See Addition polymerization

Polymerization of unsaturated reactive molecules by addition over their unsaturated sections via activation by chemicals, also known as initiators. Addition polymerization is comprised of four steps: Initiation, propagation, chain transfer and termination. Addition polymerization reactions forming free radicals, organic cations or organic anions via initiators are named as follows: Free radical polymerization, Cationic polymerization, Anionic polymerization.

Copolymer

Polymers having more than one type of repetitive units such as –ABABAB– or –AAABBBAAA–, where A and B are two separate units. (e.g., ethylene vinyl acetate copolymer)

Lineer polymers

See Chain polymers

They are called as linear polymers as well. Their structure is a linear chain. They are composed of monomers with double functionality (F=2). Typically, they are of thermoplastic type.

Polymer

A large molecule composed of numerous number of repeating structural units called monomers typically connected by covalent chemical bonds.

Polymeric dispersing additives

Dispersion additives having a branched/chained backbone which is compatible with paint resins and solvents in addition to having pigment affinic groups. Owing to their large molecules, polymeric dispersing additives form a layer around the pigment molecule they attach to so that other pigments are prevented from coming close. Therefore, they provide dispersion stabilization by steric hindrance.

Polymeric thickeners

Polymeric thickeners are polymeric in nature and impart shear-thickening to the paint. They prevent pigment settling and sagging by forming a network in wet paint by entangling themselves with polymer branches of the resin. Since polymeric thickeners contain oxygen and nitrogen atoms, they impart thixotropy to paint by forming hydrogen bonds.

Free radical polymerization

The most common type of addition polymerization. Monomers transform into free radicals and become activated with the help of an initiator and the polymerization starts.

Waterborne emulsion polymers

Waterborne emulsion polymers are suspensions of small polymer droplets which are stabilized by emulsifiers in water. If the polymerization occurs in the droplets formed by raw materials, the emulsion is called “primary emulsion”. If the solution of a solventborne polymer is emulsified in water, than it is called “secondary emulsion”.

Condensation polymerization

Since water is formed as a side product during this type of polymerization reaction, it is called condensation polymerization. In condensation polymerization, starting from the initiation, in every step during the polymerization, a repeatable unit forms from the reaction of two molecules and this structural unit combines to the chain. Therefore, condensation polymerization is also called “step-growth polymerization”.

Chain polymers

They are called as linear polymers as well. Their structure is a linear chain. They are composed of monomers with double functionality (F=2). Typically, they are of thermoplastic type.

 

Dispersion additives having a branched/chained backbone which is compatible with paint resins and solvents in addition to having pigment affinic groups. Owing to their large molecules, polymeric dispersing additives form a layer around the pigment molecule they attach to so that other pigments are prevented from coming close. Therefore, they provide dispersion stabilization by steric hindrance.

Polymeric thickeners are polymeric in nature and impart shear-thickening to the paint. They prevent pigment settling and sagging by forming a network in wet paint by entangling themselves with polymer branches of the resin. Since polymeric thickeners contain oxygen and nitrogen atoms, they impart thixotropy to paint by forming hydrogen bonds.

General name of thermoplastic polymers synthesized by polymerization of propylene. In paint industry, polypropylene is encountered as a substrate material since its impact resistance is high. On the other hand, low surface tension of propylene (30,1 mN/m) makes the substrate difficult for wetting and adhesion of paint.

General name of surface additives that prevent surface defects like craters, orange peel, telegraphing etc. by virtue of their compatibility with paint ingredients as well as lower surface tension they have than other paint ingredients. See Also Surface additives

Surface additives are added to paint formulation to prevent film defects. They either have surface tensions lower than paint ingredients (silicone and fluoride compounds) or they are compounds having limited compatibility. They migrate to the surface and form a thin layer. Hence, surface tension gradients that cause defects on paint film are prevented.
 

It is a transparent thermoplastic polymer. It can easily be made to take on various colors and it can be processed easily. Although it is brittle, its mechanical and thermal properties are suitable for production of everyday goods such as packaging, household items, home decoration as in film or foam.

See Urethane resins

Polyurethane resins

See Urethane resins

Urethane resinsUrethane resins are formed by reactions of compounds bearing at least two isocyanate groups with molecules with more than one hydroxyl groups. Urethane coatings have high water, solvent and chemical resistance. Urethane coatings with no aromatic groups have superior UV resistance.

It has white, dark white, yellowish white and brown heartwood depending on the species. Growth rings and grains are not distinctive. It has a very soft, coarse and loose structure. It sticks well with glue. It has a low physical strength. Large diameter poplar trees are commonly used in veneer and plywood industry. Poplar timber is used in match making. Furthermore, poplar is used in the production of packing boxes, barrels to keep dry stuff and chipboards.

Powder coatings

Solvent free coatings which use resins with glass transition temperatures higher than room temperature. Powder coatings are comminuted to 20-100 microns. Powders clung to the surface forms a thin film after high temperature baking.

Electrostatic spray applications of powder coatings

Through these applications, powder coating fluidized by mixing with air is sprayed using a powder gun with an orifice. A high voltage of 40-100 kV connected to a negative electrode at the orifice ionizes air molecules. This cloud of ions is called “corona”. Powder particles pick-up anions when passing through the corona and become negatively charged. Since the object to be coated has become anode because of grounding it attracts particles to its surface. Particles are neutralized when they reach the surface. Loose powder coating film, turns to a tough, durable, continuous, film with good adhesion after baking.

Flow coating applications

Application of coating to the surface by pouring the coating by means of a hose etc. Coating is then collected in a bottom container to be pumped back to flow coating process.

Copper Accelerated Salt Spray Test (CASS)

Type of accelerated test to determine the performance of organic coatings in preventing the corrosion of the metal surface they are applied to. Different from the standard Salt Spray Test, the aqueous solution sprayed on the coated panel includes 0,025% copper chloride dihydrate, in addition to the 5% sodium chloride.

Bell applications

Bells rotating at a speed of 25,000-60,000 rpm are used for spray applications, which are especially utilised in otomotive OEM coatings. Paint is broken into tiny droplets as a result of the centrifugal force arising from high rotation speed and sprayed on the application surface. Electrostatic methods are used for these kind of applications due to transfer effectiveness.

Dipping applications

Coating application performed by dipping the object into a vessel or tank filled with wet paint at application viscosity. Possible coating defects such as sagging; settling, foaming and non-homogeneous film thickness can be avoided by complete control over application variables.

Deep cupping

Test performed by pushing a knob with a constant speed against the back side of a coated panel causing deformation. During the test, also called Erichsen deformation test, knob is stopped when the first sign of crack formation is observed, deformation depth is measured in mm and this value is defined as deep cupping resistance.

Direct roller application

Type of roller applications, which are based on coating flat panels with rollers on a moving conveyer. In direct roller applications, rotation direction of “application roll” is the same as the conveyer’s moving direction. Having a lower shear than reverse roller application, direct roller application provides good results in primer and non-glossy top coat applications. See Also Reverse roller application, Roller coating applications

Boot topping

Part of a ship between submerge levels of empty and fully loaded conditions. Surfaces at boot topping part are exposed to frictional effects by guide boats, piers and buoys. In addition, depending on the loading level, it can be exposed to spattering of sea water or can be fully submerged.

Air spray applications

Applications based on breaking and spraying the liquid paint in tiny droplets to surfaces with the help of pressurized air. Spray applications performed by air spray guns using pressurized air at 2,5-5,5 atm. are widely used especially for industrial coating applications. In air spray applications, paint is sprayed in droplets of 20-50 micron diameter.

Airless spray applications

Spraying of paint through a thin nozzle at 5-35 atm pressure. In airless spray applications, the paint can be sprayed as droplets of 70-150 micrometer diameter by means of an airless spray gun. The bouncing effect and related paint loss is less compared to air spraying applications.
 

Conventional air spray application

Application of paints and varnishes by spraying in tiny droplets using air guns with air at 2,5-5,5 atm pressure. Feeding of coating to the gun is achieved either by gravitational forces from a cup placed on top of the gun, or by suction from a cup placed under the gun or by pressurizing the paint.

Corona discharge (in powder coating applications)

Electrostatic coating method used to coat a positively charged surface with little loss, using powder coating particles charged by air molecules ionized under high voltage.

Polypropylene (PP)

General name of thermoplastic polymers synthesized by polymerization of propylene. In paint industry, polypropylene is encountered as a substrate material since its impact resistance is high. On the other hand, low surface tension of propylene (30,1 mN/m) makes the substrate difficult for wetting and adhesion of paint.

PP/EPDM alloys

Mixture of polypropylene with rubber which is also a polymerization product of ethylene, propylene and diene monomers. See Also Ethylene propylenediene

Roller coating applications

Paint application performed by using three parallel rollers named as pick-up, feeding and applicator. Pick-up roller immersed in paint pan, moves around its axis and transfers the paint to the feeding roller which it is in touch with. Feeding roller transfers the paint to the applicator roller in contact with it. Application roller, transfers the coating onto the material to be coated which is moving on a conveyor belt. See Also Direct roller application, Reverse roller application

Strip coats / Strippable coatings / Peelable coatings

Paints that can provide protection for a certain time to the surface on which they applied and after this period, they can be easily removed from the surface.

Reverse roller application

Paint application method where the applicator rolls run in the opposite direction to the conveyor movement. In this application, better levelling is achieved on the surface because sheer stress exerted on the paint film is higher than in direct rolling application. Reverse roller application method is preferred especially in glossy topcoats. See Also Roller coating applications, Direct roller application

Electrostatic spray applications of powder coatings

Through these applications, powder coating fluidized by mixing with air is sprayed using a powder gun with an orifice. A high voltage of 40-100 kV connected to a negative electrode at the orifice ionizes air molecules. This cloud of ions is called “corona”. Powder particles pick-up anions when passing through the corona and become negatively charged. Since the object to be coated has become anode because of grounding it attracts particles to its surface. Particles are neutralized when they reach the surface. Loose powder coating film, turns to a tough, durable, continuous, film with good adhesion after baking.

Application roller

Name of the roller which transfers the paint to the sheet to be coated on the conveyor belt. If the application roller runs in the same direction (at different speed) with the conveyor line, the process is called direct roller application, if roller runs in the opposite direction it is called reverse roller application. See Also Direct roller application, Reverse roller application

Application viscosity

The most suitable viscosity at which paint can be applied by the chosen method with ease.

Material obtained by coating the coils with high temperature cured coatings on high speed lines. Pre-coated metal is an interesting solution for: 1) quality and durability due to the usage of specially designed coatings 2) environment due to burning of the released VOC in after-burners and recycling as energy 3) efficiency due to high speed application.

See Volatile organic compounds

The amount of volatile organic compounds in grams per 1 liter of liquid organic coating.
 

The first pigmented layer of a multi-layer coating system.

Adhesion promoter / Adhesion promoter primer

Primers applied as a thin layer to promote interlaminar adhesion on surfaces difficult to adhere. The surfaces difficult to adhere are mainly polyolefinic structured plastic surfaces like polyethylene and polypropylene etc. and some aluminium alloy surfaces. Examples of adhesion promoters are chlorinated polyolefin, organosilanes and polyvinylbutyral based primers.

Wash primer

Anti corrosive primer applied on ferrous or light alloy surfaces at 4-7 mm dry film thickness. Since first applications were done by washing the object with the primer, they are called “wash primers”. Wash primers are formulated with polyvinylbutyral as well as epoxy and phenolic resins. In the last two decades, wash primers included zinc phosphate pigments instead of zinc chromates due to hazards caused by Cr+6 to the environment and human health. Wash primers are catalyzed with acid-catalysts for a good adhesion on the metal surface. Applying layers with basic resins on the wash primer films with acid molecules left inside may result in intercoat adhesion failure. Therefore, attention should be paid to wash primer application.

Assessment of how close the characteristics of a product and service are after production process, relative to those projected during design stage. See Also Design quality

Design quality

Total quality arisen from the predicted qualifications of a product or a service during the design stage. For instance, a pizza shop could be founded to take orders of 10 different pizzas of which ingredients are predefined, via internet and deliver these orders to all locations in the city within 20 minutes in a hot and hygienic condition. (See Peelable coatings). On the other hand, another pizza shop, could be founded to serve pizzas in the shop in which its temperature is held constant in summer and winter at 25ºC and there are fresh flowers in a vase at each table. Customers choose the ingredients of pizza and they will be served at most 15 minutes. The difference between two services is stem from the difference between their design qualities.
See Also Production quality

Strip coats / Strippable coatings / Peelable coatings

Paints that can provide protection for a certain time to the surface on which they applied and after this period, they can be easily removed from the surface.
 

See Shear thinning fluids

Shear thinning fluidsFluids that undergo a viscosity decrease upon exposure to shear force (e.g., mixing or shaking). They regain their original viscosity after removal of the shear force. Pseudoplastic fluids regaining their viscosity a while after shear force removal are called thixotropic fluids. An important portion of coatings demonstrate thixotropic behaviour.

Organic coating material that contains extenders above the Critical Pigment Volume Concentration (CPVC). Putties are used to fill holes, cracks, and eliminate roughness on the substrate. Putties can be applied using spatula and rollers due to their high viscosity.

Critical pigment volume concentration (CPVC)Pigment volume concentration at which all the binder in a coating formulation is used up to wet the pigments and to fill up the pigment pores, leaving no free binder.

Polyester Putty / Knife Putty

Name given to putties that unsaturated polyester resins or epoxy resins are used as binders and that reaches to very high stiffness after spatula application and drying.

Insulating putties

Insulating putties found applications in automotive OEM, automotive refinish aerospace industry and water craft industry. Main purpose of using insulating putties is to prevent transfer of water, humidity, chemical and gas by elastically sealing of edge joint points and junction points of coated objects. Furthermore, providing a sound insulation by its flexible and porous (some types) structure and again providing heat insulation by its low heat conductivity and porous (some types) structure are the main purposes of using insulating putties.
 

Paints produced using PVC plastisol resins. PVC plastisol resins are prepared by dissolving plasticizers like dibutyl phthalate or benzylbutylphthalate in thermoplastic PVC resin. PVC plastisol based coatings have remarkable properties like water and chemical resistance in addition to corrosion resistance when they are applied as topcoat of 100-200 mikrometer thickness in metal coating industry.