Coating defect described by runny and non-levelled appearance after applying the coating to a vertical surface and giving enough time to the coating to form a solid film. The possibility of sagging increases with increasing coating thickness. The maximum possible film thickness that a coating can be applied to a vertical surface without observing sagging is called the “sagging limit”.

See Sagging

Coating defect described by runny and non-levelled appearance after applying the coating to a vertical surface and giving enough time to the coating to form a solid film. The possibility of sagging increases with increasing coating thickness. The maximum possible film thickness that a coating can be applied to a vertical surface without observing sagging is called the “sagging limit”.

It is an accelerated test to assess how efficiently the paint film protects the substrate against corrosion. Coated steel panels scribed through the coating, exposing the bare steel, are hung on in a 35ºC chamber by non-metal grids, where they are exposed to a continuous mist of 5% NaCl salt solution. For industrial coatings, after a test period of a few hundred hours to a few thousand hours, the panels are examined for degradation of the paint film and corrosion of the substrate.

Surface preparation treatment performed to remove dirt, oil, rust etc. from application surfaces (metal, concrete etc), and to increase surface roughness for improved adhesion. For sand blasting process, high silica sand, hard metalic abrasives; for more sensitive surfaces (e.g., plane bodies) hazelnut shells, plastic granules etc. are sprayed to the surface via pressurized air. Regarding sand blasting, SSPC (Steel Structures Painting Counsel) standards are widely used in industry.

Mills that aim to grind pigment aggregates using high silica sand as the grinder. See Also Bead mill

Consists of a cylindrical shape metal cup. There are various steel discs on the rotating mill along the axis of the cup. Hard beads of 0,5-3,0 mm diameter are placed in the mill together with the pigment paste to be grinded. The pigment agglomerates between the moving beads are grinded with the help of the friction between the beads that are moving with the whirling effect of rotating discs. Until recently, similar mills containing high silica sand instead of beads were widely used. These mills were called sand mills.
 

Sanding is mechanically removing a layer of material from a wood, coated or a metal surface by using sandpaper. Sanding is performed to prepare surfaces to application in paint industry. Thus, by sanding, physical imperfections on the surface and deposited grease that can reduce surface adhesion can be removed. Since, sanding increases surface area by making the surface rougher, adhesion improves further.

Sandpaper is a form of paper or cloth where an abrasive material has been embedded to its surface. It is used to remove small amounts of material from surfaces. There are different types of sandpapers for use on bare or painted metal and wood surfaces. Sanding papers are used by mounting on electrically powered rotating discs or by covering it with a wedge for manual operations. The abrading particles on sanding papers are garnet, aluminum oxide or silicon carbide and they come in different grit sizes. Grits are designed by different symbols ranginf from P12 to P2500. The higher the number, the smaller is the grit size.

A precious tree grown in tropic regions in Africa. Its reddish-brown wood resembles Mahogany. It is an extremely durable tree with an attractive surface because of its growth rings. It is used for the production of furniture, musical instruments in addition to interior decoration and parquet flooring. In Turkish furniture sector, it is also called “sapelli”.

One of the three components used to define a color (other two are "hue" and "lightness"). Saturation describes the concentration of color components constituting the hue. The terms chroma and purity are also used in place of saturation.

Hue

Main component of color that makes it possible to perceive color as red, yellow, blue, violet. Besides hue, chroma and lightness are the other components of color. See Also Chroma, lightness

Lightness

One of the three components used to define a color (other two are hue and saturation). Highest lightness corresponds to white, while lowest lightness corresponds to black. Therefore, by lightness, darkness-lightness state of a color on the black-white axis is meant.

Although its wood is easily processable, it has a low mechanical strength. Its timber is used for mould making in construction, package industry and wood chip production.

Formation of irreversible little cavities on the organic coating film surface is called scratching. Organic coatings with high “scratch resistance” either have high resistance to scratching or scratches dissappear after a while due to the nature of the coating.

Big metal box used for sea transportation of goods. Sea containers are 20 ft (~6 meters) or 40 ft (~12 meters) long.

Sea container coatings

Coatings used for interior and exterior surfaces of sea containers. Primary function of exterior coatings is high resistance against corrosion and water. For this purpose, epoxy based primers and, acrylic, chlorinated rubber or alkyd based top coats are used. Interior coatings are expected not to be affected by the dry load carried in the container and to prevent contamination of the dry load by container’s interior surface or the coating itself.

Coatings used for interior and exterior surfaces of sea containers. Primary function of exterior coatings is high resistance against corrosion and water. For this purpose, epoxy based primers and, acrylic, chlorinated rubber or alkyd based top coats are used. Interior coatings are expected not to be affected by the dry load carried in the container and to prevent contamination of the dry load by container’s interior surface or the coating itself.

Settling of pigments, fillers and other solid particles in the paint formulation under the influence of gravity, leaving the suspension state. If the settled particles can be homogenized by mixing, the phenomenon is called “soft sedimentation”. If the settled particles cannot be dispersed even with vigorous mixing, the phenomenon is called “hard sedimentation”.

Self polishing coatings are mainly applied to submerged surfaces and produced using binders that undergo controlled hydrolization in sea water. Residues accumulated on the surface, leaves the surface together with the top coat binder as a result of water contact. Thus, leaving a clean and polished surface.

Alkyd resins containing semi-drying oils in their backbone.

General name of oils, formed by reaction of glycerine with fatty acids with limited unsaturation. (Semi-drying oils do not have a certain definition as the drying oils). Practically, it is conveninent to define oils as semi-drying if they have an approximately 1.5 - 2 unsaturation per fatty acid chain.

Shear

Separation of a substance’s neighbouring particles from each other by applying different parallel forces causing different particle velocities. (e.g., knives of scissors cut a piece of paper by applying forces in two opposite directions normal to paper surface. These forces are called shear forces. Shear force is applied to the paint formulation by mixer blade while mixing.)

Shear thinning fluids

Fluids 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.

Shear thickening fluids

Fluids that undergo a viscosity increase upon exposure to shear force (e.g., mixing or shaking). They regain their original viscosity after removal of the shear force. Some pigment pastes with high pigment loading demonstrate shear thickening behaviour.

Fluids that undergo a viscosity increase upon exposure to shear force (e.g., mixing or shaking). They regain their original viscosity after removal of the shear force. Some pigment pastes with high pigment loading demonstrate shear thickening behaviour.

Fluids 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.

Ethyl silicates

Group of coating binders that is obtained by reaction of silica with ethyl groups and that provides high corrosion resistance. Most widely used example is tetraethylorthosilicate monomer. They are used in production of zinc-rich waterborne primers.

Silica

Abridged name of silicon dioxide, which is an abundant mineral on earth. In paint industry, porous and pyrogenic silica and colloidal silica produced by burning of organosilicone compounds, are used to adjust sagging, leveling and settling behavior of paint. Larger and grinded in micron scale silica dust is used as a matting agent. Precipitated silica in proper solvent and/or resin vehicle is used to improve scratch and flame resistances of paints.

Silica extenders

Quartz powder which is obtained by grinding amorphous quartz is widely used in paint industry as matting additive. Furthermore, SiO2 based on diatomaceous earth is used for the same purpose. Moreover, pyrogenic silica obtained by burning of silicon tetrachloride (SiCl4) is used as rheology modifier in paints.

Silicate based binders

Alkali metal silicates like sodium and potassium silicates have limited use as inorganic paint binder. Furthermore, ethyl silicate is used as a binder in anti-corrosive paints, especially in high corrosion resistant zinc-rich primers.

Quartz powder which is obtained by grinding amorphous quartz is widely used in paint industry as matting additive. Furthermore, SiO2 based on diatomaceous earth is used for the same purpose. Moreover, pyrogenic silica obtained by burning of silicon tetrachloride (SiCl4) is used as rheology modifier in paints.

Alkali metal silicates like sodium and potassium silicates have limited use as inorganic paint binder. Furthermore, ethyl silicate is used as a binder in anti-corrosive paints, especially in high corrosion resistant zinc-rich primers.

See polysiloxane surface additives

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

Heat resistant coating resins produced by copolymerization of silanediol and silanetriol in different ratios. Hardness, flexibility, chemical and heat resistance as well as solubility depends on hydrocarbon segments borne by silane compounds and diol/triol ratio.

Coating defect seen in brush applications described by glittery marks of thread or fiberlike appearance paralel to the brush application direction. This defect is caused by fillers with big particle sizes. In addition, similar marks can be observed in dipping applications. In this case, coating defect is caused by the surface tension differences.

The grains on the wood surface are destroyed during sanding. The grains on the surface are filled with dilute thermoplastic aqueous varnishes by a process called sizing. Destroyed grains swell and jut themselves out of the surface during sizing. Sanding is performed after flash-off of sizing varnish; a second sanding should be performed to remove these protruded grains. Consequently, wood surface becomes ready for paint application.

Weight percent of non volatile substances present in an organic coating.

Wooden material obtained by giving a shape to timber cut from log or by joining different timbers. The difference of solid wood from MDF, particle board and hardboard is its natural wood structure.

Medium Density Fiberboard

It is a panel shaped product formed by breaking down of wood chips into fibres under steam, adding urea formaldehyde and a little amount of paraffin wax, and drying under high temperature and pressure. MDF has a typical density of 600-800 kg/m³. Since the chips in MDF are broken down as wood fibres, mechanical strength and humidity resistance of MDF is higher than fiberboards like chipboard. MDF is used in production of kitchen and bathroom cabinets, drawers, shelves, bookcase and office furniture as well as for interior decoration.

Chipboard (U.K.) / Particle board (Amerikan)

Panels with various thicknesses, produced by mixing wood chips with certain chemical binders and compressing. It is frequently used in furniture sector. Chipboards have poor resistance against water and flame.. Kitchen cabinets, wardrobes and shelves that are used for carrying lightweight objects, some office furnitures and shelves are made from chipboard.

Hardboard

Wooden sheet that’s smooth on one side and porous on the other side. Hardboards are produced by a process in which pine, oak, beech chips are made fibrous by swelling and shaped by wet-processing after some adhesive is added.

Parameters, proposed by Hildebrand based on the structural properties of a chemical, demonstrating the dissolving characteristics of a chemical. Later on, Hansen developed a more advanced three component (dispersion forces, polar forces and hydrogen bridges) “three dimensional solubility parameter” system.

Solvent or solvent blend property that describes the capability of the solvent/solvent blend to dissolve a polymeric binder and to decrease the solution’s viscosity.

Organic liquid of mostly volatile nature that is used in the coating formulation to dissolve the binder.

Aliphatic hydrocarbon solvents

General name for solvents having a linear structure and are able to dissolve low polarity binders such as long oil alkyd resins. These types of solvents are produced from distillation of high aliphatic content petroleum. Hexane, heptane and white spirit are a few of the aliphatic hydrocarbon solvents

Aromatic hydrocarbon solvents

Common name of strong solvents -with a benzene ring on their structure- for dissolving many of the binders, especially alkyd, polyester and acrylic resins. They are obtained from distillation of fossil fuels, especially from high aromatic content petroleum (e.g, Toluene, Xylene,

Solvent-free liquid coatings

Coatings having viscosities low enough to enable the application even if they do not include solvents in their formulations. Solvent-free liquid coatings are produced with binders obtained from low molecular weight polymers, oligomers or reactive monomers. (e.g, Radiation curable coatings, solventless epoxy coatings etc.)

Surface cleaning by solvent

Removal of dirt, oil or other contaminants from the paint application surface by using strong oil dissolving solvents.

Solvent-borne paints / Solvent-based paints

Coatings containing binders that are soluble in organic solvents.

Solvent-based paints

Coatings containing binders that are soluble in organic solvents.

Tail solvent

Solvent added in small amounts to organic coating formulations as the last solvent to leave the coating film due to being less volatile compared to other solvents in the formulation.

Terpenes / Terpene solvents

Solvent group obtained from roots and trunks of some of the pine trees and used in long-oil alkyds based coatings. Terpene solvents have the general formula of (C5H8)n. The most widely used terpene solvents are turpentine and Dipentene with an empirical formula of C10H16. In the mean time, use of terpene solvents decreased since they are superseded by petroleum based white spirit.
 

Heavy solvent Naphta

Mixture of solvents obtained at 226-285°C interval during distillation of aromatically rich petroleum. Evaporation number relative to ether: >1000; specific gravity: 0,990; refractive index: 1,591; flash point: 102°C

Medium heavy solvent naphta

Mixture of distillation products composed predominantly of aromatics. Chemical structure: No definite chemical structure.
Boiling range: ~180-210°C; Evaporation number based on the ether: 115 (for Solvesso 150), 148 (for Shelsol AB); Specific gravity: 0,894-0,895; Refractive index: 1,512; Flash point: 62°C

Solvent naphta

Solvent mixture obtained in a boiling range of 150-195°C during distillation of petroleum products rich in aromatics. Evaporation number based on the ether: 35-46; Specific gravity: 0,872-0,875; Refractive index: 1, 50; Flash point: ~42°C. (Commercial samples: Solvesso 100, Shelsol A etc.)

Coatings containing binders that are soluble in organic solvents.

Solvent-based paints

Coatings containing binders that are soluble in organic solvents.

Coatings having viscosities low enough to enable the application even if they do not include solvents in their formulations. Solvent-free liquid coatings are produced with binders obtained from low molecular weight polymers, oligomers or reactive monomers. (e.g, Radiation curable coatings, solventless epoxy coatings etc.)

Soybean oil is a vegetable oil extracted from soybeans. It is used in food industry and synthesis of alkyd resins. Soybean oil is semi-drying oil, which have a similar fatty acid composition and drying characteristics to sun flower oil. Soybean oil contains %51 of linoleic acid (two unsaturated bonds) and %25 oleic acid (single unsaturated bond).

Amount of energy required to increase the temperature of 1 gram of a pure substance by 1°C.

Colors in the visible color spectrum each of which are lights of certain wavelength.

In wet paint applications, a spray dust fallen on a still wet paint film from the paint itself or another paint applied nearby at the same time may cause visual defects as particles , craters or orange peel. The property of a paint causing this phenomenon is known as spray dust sensitivity.

Its timber is flexible and tough with a high humidity resistance. Spruce is frequently used in all types of construction works, outdoor and indoor woodworks, flooring and in staircases. Since, spruce can be polished it is used in making of furnitures. Furthermore, spruce is used for production of plywood, matches, paper and rayon.

Process of preserving the homogeneous and dispersed state of the pigments in the paint. Stabilization is achieved by two basic mechanisms: (a) Pigment interfaces are electrically charged using convenient additives, therefore repulsion force between particles of similar charge keeps the pigments from agglomeration; (b) Polymeric dispersion additives carrying pigment-loving groups prevents the pigments from agglomeration by forming a polymer layer around the pigment particle (: steric hindrance)

Dryness state at which coated pieces can be stacked without sticking to each other is defined as stackability. Safe dry to stack time of a coating for a certain application material is determined by “dry to stack test” at laboratory conditions.

1) Organic coating containing dyestuff and transparent pigments of several microns applied as a thin layer on mostly wood substrates. Stain is impregnated on wood surfaces by spraying, brush or pad application.
2) Component having a high pigment concentration such that when added to a paint mixture it changes the color.

See Condensation polymerisation

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”.

Various segments on a molecule make it difficult for other chemically affinic molecules to approach another part on the same molecule. This hindrance completely arises from the shielding effect caused by spatial arrangement of that molecule.

Resistance of coatings especially applied on exterior parts of vehicles, against the impacts by stones thrown-up from road. The paint film should have strong and elastic chemical bonds so that the impacts are damped without deforming the coating. Therefore, aliphatic polyurethanes are preferred for high stone chip resistant coatings.

Baking of high temperature drying coating systems in high temperature ovens.

Coating defect described by dull or blurry appearance of topcoat due to the migration of some of the binder to the previous wet paint layer in wet on wet applications.

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.

Phase transition of a solid element or compound to gas phase without passing through liquid stage.

Vegetable oil obtained from sun flower oil seeds, and used widely in food industry and in production of alkyd resins. It is a semi-drying oil due to the existence of 52% di-unsaturated linoleic acid and 29% mono-unsaturated oleic acid in its structure.

Fluorocarbon surface additives

Similar to polysiloxane surface additives; fluorocarbon surface additives, having low surface tensions and compatibility with the coating formulation, migrate to the surface to avoid formation of film defects.

Polyacrylate surface additives

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

Polysiloxane surface additives

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

Silicon additives / Silicon based surface additives

See polysiloxane 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.

Removal of dirt, oil or other contaminants from the paint application surface by using strong oil dissolving solvents.

A process in which unwanted particles presented in paint are retained on a certain mesh size sieve.

Surface tension

Forces which tend to reduce surface area of any liquid. Depending on the type of liquid, all liquids have intermolecular attractions. Molecules deep within a liquid, are attracted equally in all directions by similar neighbouring molecules. Hence, they are in a stage of balanced equilibrium with their surroundings. Nevertheless, a molecule at the surface (the vapour-liquid interface) is pulled only by the molecules under and near and not by those above, due to the fact that vapour phase density is much lower than that of liquid phase. Work should be done against cohesion forces between liquid molecules, to increase the free surface area by taking the molecules to the surface from bulk liquid. Consequently, molar free energy of surface is higher than molar free energy of other parts of liquid. (Note: Another definition of surface tension is the free surface energy per unit surface area of liquid).

Surface tension measurement

There are various methods to determine the surface tension of liquids. Four of them is frequently used in paint industry.
(a) Du Noüy Ring method for liquid paints.
(b) Wilhelmy plate method for liquid paints.
(c) Measuring the contact angle for liquid paints. (Sessile drop method)
(d) Test ink method for cured paint films

There are various methods to determine the surface tension of liquids. Four of them is frequently used in paint industry.
(a) Du Noüy Ring method for liquid paints.
(b) Wilhelmy plate method for liquid paints.
(c) Measuring the contact angle for liquid paints. (Sessile drop method)
(d) Test ink method for cured paint films

Contracted from English word (Surface+active+agent). Surfactants are used to reduce surface tensions of organic coatings. Surfactants comprise one polar group at one edge and one organophilic (high compatibility with solvent and resins) group at another end. They are used in preparation of emulsions, aqueous pigment dispersions and also as defoamers.

Sweating is a paint defect where the ingredients of a paint film, which are liquid at room temperature, exude through the surface causing a sweating appearance.

Paints produced using synthetic resins as binders instead of natural oils or resins, during the first period of industrialized paint production. Since, first resins that became widespread were alkyd resins, historically, synthetic paints and alkyd resin terms are used interchangeably. Although most of the paint resins used nowadays are synthetic, use of synthetic paint term for defining alkyd resins is still common.

Wax polymers produced synthetically for various purposes. Polyethylene, polypropylene, polytetrafluoroethylene and polyvinyl acetate are frequently used in paint industry to increase scratch resistance in addition to matting and rheology modification. See Also Wax

Wax

General name of low molecular weight polymeric materials that are solid at room temperature and can soften at nearly 50-100°C. Waxes are traditionally produced from animals (e.g., Beeswax, Spermaceti), plants (e.g., Carnauba wax, from the leaves of the Carnauba palm) and petroleum products (e.g., Paraffin wax). Waxes are chemically synthesized by polymerization of ester, alcohol and carboxylic acid or their mixtures. Other than natural waxes there are specific purpose synthetic waxes. Some of these waxes are used as additives in paint. See Also Synthetic waxes

Synthetic waxes

Wax polymers produced synthetically for various purposes. Polyethylene, polypropylene, polytetrafluoroethylene and polyvinyl acetate are frequently used in paint industry to increase scratch resistance in addition to matting and rheology modification. See Also Wax