Polyamide hardener

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

Hardener

Component that starts hardening by cross-linking when mixed with binder containing component known as first component. Hardener may consist of cross-linkers or a catalyst.

Transition of liquid organic coating on a surface, into a tough and durable dry film. Curing may take place (a) by solvent evaporation in liquid paints (b) by melting of coated powder into a film and then cooling to ambient temperature in powder coatings. (c) by polymerization reaction happening inside the film in liquid paints or powder coatings that contain heat-curing resins.

Measure of resistance of a paint film to scratch, indentation and fatigue deformation.

Hardness tests

Vast majority of tests for measuring the hardness of organic coatings are based on the following three principles: scratch resistance, indentation resistance and fatigue resistance against periodic deformation.

Widely used scratch resistance test is the pencil hardness test. Pencils with varying hardnesses are used to scratch the paint film. The hardness of the film is reported as the grade of pencil that does not cause any scratching on the surface.

In indentation resistance tests, an indenter harder than the organic coating is forced against the film under a fixed load. The size of the indentation indicates the resistance of the paint. Buchholz hardness test and Tukon (Knoop) hardness test are the most known indentation hardness tests.

Pendulum hardness test is the most common test relateed to fatigue resistance against periodic deformation. The damping time or number of swings made by the pendulum required to make permanent deformation of paint film under periodic load is determined.

See Also Pencil hardness , Buchholz hardness, Knoop hardness, Pendulum hardness

Pencil hardness test

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.

Buchholz hardness

Test that aims to determine hardness of a coating film by measuring the depth of a V-shaped cavity formed by running a sharp metal wheel carrying a constant weight on dried coating film.

Knoop hardness

Hardness measured by marking the coating film using a diamond tip that carries a certain weight. Knoop hardness is calculated by dividing the mass, that applies the weight, by the area of the mark observed on the surface.

Pendulum hardness

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.

Hardness tests

Vast majority of tests for measuring the hardness of organic coatings are based on the following three principles: scratch resistance, indentation resistance and fatigue resistance against periodic deformation.

Widely used scratch resistance test is the pencil hardness test. Pencils with varying hardnesses are used to scratch the paint film. The hardness of the film is reported as the grade of pencil that does not cause any scratching on the surface.

In indentation resistance tests, an indenter harder than the organic coating is forced against the film under a fixed load. The size of the indentation indicates the resistance of the paint. Buchholz hardness test and Tukon (Knoop) hardness test are the most known indentation hardness tests.

Pendulum hardness test is the most common test relateed to fatigue resistance against periodic deformation. The damping time or number of swings made by the pendulum required to make permanent deformation of paint film under periodic load is determined.

See Also Pencil hardness , Buchholz hardness, Knoop hardness, Pendulum hardness

Pencil hardness test

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.

Buchholz hardness

Test that aims to determine hardness of a coating film by measuring the depth of a V-shaped cavity formed by running a sharp metal wheel carrying a constant weight on dried coating film.

Knoop hardness

Hardness measured by marking the coating film using a diamond tip that carries a certain weight. Knoop hardness is calculated by dividing the mass, that applies the weight, by the area of the mark observed on the surface.

Pendulum hardness

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.

Chemicals that predicted to cause cancer or other serious health issues such as in reproduction system, congenital anomalies or to the environment. Benzene is considered as HAPs and is found as an impurity in liquid petroleum. Perchloroethylene, is emitted from dry cleaning shops, methylene chloride is used as solvent and paint remover. Moreover, dioxins, chromium and lead compounds are also known as hazardous air pollutants.

On the high gloss paint surfaces, the incident light coming from an angle of 20º reflects mostly at 20º and a small part of the light scatters around 20º. This defect is perceived by the eye as haze on the paint surface.

Class of motor vehicles with a minimum loading capacity of 3,5 tons, including buses for minimum 8 persons (excluding the driver) and load trucks. Also called “heavy vehicle”.

See Also 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.
 

General term for coatings with superior corrosion resistance and mechanical properties for protection of the surfaces prone to corrosion.

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

Fineness of grind gauge with the deepest edge of 100 microne depth marked as “zero” and the shallowest edge of zero depth marked as “eight”. Therefore, in Hegman gauge, each unit between zero to eight corresponds to 12,5 micron fineness.

Chemical formula: 

Melting point: 35°C

Monomeric melamine formaldeyde subjected to complete etherification with methanol. Its low molecular weight and solubility in both water and organic solvents enables its usage as high solid content coating input. Because it is completely etherified, acid catalysts need to be added to the coating formulations in order to enhance the reaction tendency, which is lower compared to butylated melamine formaldehyde resins.

Diisocyanate used to produce polyurethane coatings with high flexibility and high outdoor durability. Non-volatile biuret or its trimers are used as hardeners instead of volatile HMDI for occupational health concerns.
Chemical formula: 

Boiling point: 140-142°C

Ability of any pigmented organic coating to hide or obscure the surface of the substrate. Hiding power is assessed by applying successively increased thickness of paint over a black/white contrast strips or checkerboard squares until the color difference in the background contrast could be no longer noted. The dry film thickness at this point refers to hiding power and it is defined in micrometers. Hiding power directly changes with the opacity of the applied coating film. See Also Opacity

OpacityA property of matter that prevents light from passing through it or a condition of being non-transparent. If an object consumes all the light coming to it by reflection, scattering, and/or absorbtion, this object is said to be opaque.

Industrial hiding

Hiding of paint over the real subtrate to be coated is called industrial hiding. It is determined by applying gradually increasing subsequent layers on the real substrate (sometimes it can be a bare surface or primed surface with a certain color.) If the color difference obtained by color measuring device, between two subsequent layers (a thicker film after a thin film) is less than 0.3 (DE<0.3), the film thickness at that point is defined as industrial hiding.

A common type of polyethylene and it has a less branched structure than LDPE. Nevertheless, its density and crystallization ratio is higher. The tensile strength of HDPE is higher but shape formation and biodegrading properties are lower than LDPE.

Coated surfaces, giving a gloss value over 80 when measured at 60° with a glossmeter, are called high gloss paints.

General name of liquid paints with a solid content considerably higher than that of the conventional paint. High solids coatings are gaining attention because of reduced effects on environment due to low volatile content and short application times owing to the fact that with high solid content less time is needed to achieve the same dry film thickness. The aim of high solid coating formulation is, achieving application viscosity by adding minimum amount of solvent to the non-volatile constituents. Therefore, use of reactive monomers or oligomers, low molecular weight polymers, dispersion additives that can considerably reduce pigment paste viscosity, in addition to use of solvents that can reduce binder viscosity and reactive diluents which stays in the film by participating in crosslinking reaction are the main strategies in designing high solids coatings.

During the paint production, either in premix or in difficult homogenising processes, high-speed dispersers are utilized. Cowles type dissolver discs are typically used in high-speed dissolvers.

Using 0.2-07 atm pressure instead of 2.5-5.5 atm air in conventional spray guns. But the volume of the low pressure air made is higher. Special channels in the spray gun allow the adequate atomization of low pressure air. Therefore, bounce back effects are reduced and transfer efficiency is increased at low pressure.

Additives that absorb and destroy free radicals, which occur due to UV light and can degrade paint film. HALS decompose themselves as they destroy the free radicals. Using HALS will greatly improves the exterior durability of paint. See Also UV stabilizers

General name of additives used to prevent degradation of organic coating films exposed to UV light. UV stabilizers are classified into two groups. UV stabilizers (also called as UV absorbers). They convert the absorbed UV energy into heat and this heat is then dissipated through the substrate. Benzophenones and benzotriazole derivatives are commonly used UV stabilizers. The other group is free radical scavengers. They act by trapping the free radicals formed by UV light and decompose these radicals along with themselves hereby suppress the degradation of coating. Hindered amine light stabilizers (HALS) are used as free radical scavengers.

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.

Its timber is dense and tough. Hornbeam timber is not suitable to use in construction carpentry and cabinetry. It gives best results in producing small scale but tough objects. It is used in flooring and production of wooden parts of laboratory equipment.

Sheet shaped products obtained by passing carbon steel billets heated above their recrystallization temperature, through a set of work rolls so that thinner cross sections form.

It is the process of coating iron or carbon steel with a thin zinc layer, by passing the metal through a molten bath of zinc at a temperature of around 460°C. Since Zinc is more prone to corrosion than iron or steel, zinc layer acts as a sacrificial anode and protects the metal from corrosion.

Chemicals; detergents, alcohols, ammonia, sodium hypochloride, soaps, oils, vinegar etc.; that have destructive effects on coated surfaces of household objects such as furniture, home appliance, electronic devices and parts such as flooring, walls and doors etc.

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

Chroma

See Saturation

Saturation

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.

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.

Resistance of cured paint film against degradation caused by humidity. Humidity resistance of painted film is measured in closed cabinets where temperature and relative humidity is kept constant. The change in gloss, hardness, adhesion and appereance of the film is observed after keeping it inside the cabinet for a certain time. See Also Condensing humidity test, Non-condensing humidity test

Condensing humidity test

Accelerated test for measuring the water resistance of coatings were preformed in test cabinets where the sides of the cabinets are covered with test panels and inside is filled with saturated air at test temperature. Adjusting inside temperature of the cabinet by at least 10ºC higher than outside temperature, condensation of the water vapour in cabinet atmosphere, on the coated surface facing inside is accomplished. Hence, a thin boundary layer is deposited on the coated side of the panel, throughout the test. Condensing humidity tests are carried out at temperatures between 40ºC and 60ºC and for 5 to 20 days.See Also Non-condensing humidity test

Non-condensing humidity test

In non-condensing humidity test panels are suspended in the constant temperature cabinets. The air inside the cabinet should be saturated. In this stage, condensation leads to formation of random water films on panels which are also at the same temperature with the inside air. Calling this test non-condensing should not be misleading. Difference between condensing and non-condensing humidity test is, a continuous film formed on panels in the former test whereas random (from place to place or time to time) film formation is seen on the latter test. Temperature and humidity of non-condensing humidity test can be kept in the same range in condensing humidity test. In these tests, it is advisable to evaluate performance of a coating with respect to reference paint.
See Also Condensing humidity test

General name of materials that do not have a tendency to absorb water or a strong affinity to water.