Vdef25rty

Aluminum

Paste
, also called

Floating Aluminum Paste or

Aluminum Pigment Paste is a mixture of solvent or

water and aluminum pigments with particle shapes and sizes that have

been manipulated through a milling process to create aesthetic

properties. Both chemical solvents and water can be used as a liquid

when producing aluminum paste.


Aluminum paste is a packaged metallic pigment or dust. Aluminum

pigments are used to create the metallic aesthetics found in a wide

range of paints, coatings and inks. Manipulating the particle shape

and size within the coating, ink or masterbatch (ink for Graphic Arts

and masterbatch for plastics) creates different effects. It is not

enough to simply add pigments to a paint or ink. The aluminum pigments

are combined with a dispersant comprised of solvent or water to create

a paste. Often, the Paste is referred to a slurry or a pigment slurry.


The reason for not using dry pigments is that dry pigments are not

typically used is for safety and easy handling. Aluminum flake and

dust are referred to as fines. These airborne fines can quickly spread

heat when ignited. If exposed to electricity, phenomena known as arch

flash will occur. The very dust used intentionally to aid rocket

boosters and pyro techniques, presents severe hazards as a machining

and thermal spray byproduct. Additionally, manufactures of coatings,

inks or masterbatched containing aluminum metallic pigments do not

want to create this hazardous dust during their production.


A variety of solvents can be used to create paste. While the solvent

used will depend on the end use, mineral spirit is common. Even water

can be used should the paste be needed for water based coatings. Water

based aluminum paste is also used in lightweight concrete. A water and

alkaline solution, mixed with aluminum, will give off gasses that

result in small air pockets within the concrete. The result is a

lighter concrete known as "aerated concrete." Generally,

Aluminum flake pigments can react with water. When the two are

combined, they create hydrogen. Hydrogen is a flammable and dangerous

gas if not properly handled.



Metallic Aluminum Paste are used in the paints

and coatings industry for both their optica effects as well as for

their functionality. Effect pigments are always lamellar (flakes) and

their particle diameter is larger than the one of color pigments. And

the Aluminum Paste is often made by

Aluminum

Powder
like Atomized Aluminum Powder,

Spherical Aluminum Powder,



Aluminum Silver Powder
and so on. While the particle size of

color pigments is in the wavelength range of visible light, the flake

diameter effect pigments is generally around 5-45 μm. And there are

many different kinds of Aluminum Paste like

Fine White Aluminum Pigment and

Sparkle Aluminum Paste.


In many cases the properties of metallic effect pigments can be

deduced directly from the production process. The gold bronze pigments

are dry milled in ball mills (Hametag process), but for safety reasons

aluminum pigments are produced almost exclusively in a wet milling

process adding white spirit (Hall process).The raw material -

atomized, spattered aluminum with a minimum purity of 99.5% according

to EN 576 – is milled respectively shaped to flake-like particles in

ball mills, filled with grinding aids (lubricant).

The milling parameters and the lubricant are determined by the

application for which the aluminum paste pigment is intended. The

pigment slurry is screened, pressed on filter presses and adjusted in

mixers to a ratio of 65% solids and 35% solvent. The final product can

be tailor-made for its later application by the addition of particular

solvents or additives to the filter cake.