Glossary

Glossary

Aluminium atomized powder

Raw material for aluminium pigments that is created by atomising aluminium melt at high pressures.

Bonding

Technique that fixes the metallic effect pigment to a powder coating matrix in order to prevent separation, e.g. during transport.

Brightness

The sensation of colour intensity

Brilliance

The term brilliance is used of metallic effect pigments that have a bright and metallic appearance

Circulation stability

Circulation stability is a value to characterise the stability of effect pigments in paint formulations. Due to its shape and chemistry metal pigments can be stressed with high shear energy caused by the recirculation systems with high pressures and flow. This could lead to deformation or fracture of the pigments resulting in colour deviations.

Colour pigment

Pigments that are neither black nor white

Colour saturation

The attribute of a colour that enables an observer to judge its proportion of pure chromatic colour

Cornflake

Standard form of metal effect pigments, irregular edges, relatively high light scattering.

Coverage

The ability of a pigmented coating, at a specific layer thickness, to mask the colour differences of the substrate. In the case of metallic effect pigments, the following generalisation holds true: "The greater the proportion of fine particles, or the finer the pigment, the better the covering power."

Effect pigment

Collective term for pigments that have special properties as a result of reflections, optical refraction, interference or similar optical phenomena.

Flop, flip-flop

Change in the perception of brightness and/or colour when viewed from different angles.

Florida test

Weathering test, international standard in, for example, the automotive industry.

Flotation effect

The greater surface tension of the pigment relative to the solvent results in the air "sticking" to the pigment; this creates the uplift necessary to make the pigment float to the surface of the coating. The wetting behaviour of the pigment is said to be poor.

Form factor

Ratio of the thickness of a platelet-shaped pigment to its diameter.

Gassing resistance

The gassing resistance is a measure of the degree to which the stabilisation is able to prevent the above-mentioned reaction.

Goniophotospectrometer

Measuring device for determining the degree of gloss.

Hue

Previous name for shade, describes the "type" of colour.

Image sharpness

DOI, (Distinctiveness Of Image). The distinctiveness of an image that can be reflected on a surface coated with metallic effect pigments.

Leafing pigment

Metallic pigments that float to the surface of the drying film due to their wetting behaviour

Non-leafing pigment

Metallic pigments that, due to their wetting behaviour, orient themselves throughout the film, preferably towards the substrate.

Particle size distribution

Frequency of particles of a certain size in a pigment powder / pigment paste.

Pearlescent pigment

An effect pigment that, due to its layer-like structure, displays multi-coloured shimmer effects (similar to mother-of-pearl).

Pigment coating

In order to create specific optical or chemical properties, platelet-shaped pigments can be covered with a coating of, for example, organic polymers, inorganic polymers or a combination of active ingredients.

Pigment concentrate

A pigment concentrate is a pigment preparation, such as pigment paste, pigment suspension or solid-in-solid preparations, in which the pigments are dispersed in a low binder content.

Pigment dispersion

Pigment dispersion is the distribution and optimum wetting process of a pigment in the coating.

Pigment orientation

Alignment of the aluminium pigments in the coating film. Optimum orientation would mean that all pigments are parallel to the substrate.

Pigment oxidation

The controlled oxidation of metallic effect pigments can create various colours

Pigment paste

As the pigment suspension, a solid-liquid mixture that does not have good flow properties. (ratio of solid-liquid e.g. 2:1).

Pigment suspension

Suspension of a pigment in a liquid. Unlike pigment paste, the suspension has good flow properties (ratio of solid-liquid e.g. 1:2).

Polychromatic effect

Angular-dependent colour change as a result of reflections, light diffraction, interference or similar optical phenomena.

Salt-and-pepper effect

Optical effects caused by very poor pigment orientation

Sieve analysis

Earlier method for determining the particle size distribution; this involves the use of several superimposed sieves in order to separate an inhomogeneous pigment powder out into individual fractions. The fractions can then be recorded quantitatively.

Silk gloss type

Fine, light aluminium pigment with a narrow particle size distribution.

Silver dollar

Special form of metallic effect pigments (ideally circular) that have a shorter periphery than cornflakes resulting in less light scattering and greater brilliance.

Solid content

Also non-volatile content, refers to the mass content in a coating that remains as residue when the coating is evaporated under certain conditions.

Sparkle effect, glitter effect

An effect that is predominantly observed with relatively coarse metallic effect pigments and that is caused by high reflection and little scattering of light. Individual pigment platelets can clearly be seen.

Stabilisation

Aluminium reacts with water to generate hydrogen according to the following reaction equation.
2 Al + 6 H2O ^ 2 Al(OH)3 + 3H2

Wetting behaviour

A liquid's ability to form an interface with a solid, or the property of a pigment that enables the liquid to do this.

Glossary