This document discusses different types of paints and their properties, as well as the paint preparation process. It describes various paint sheens like matte, eggshell, semi-gloss and gloss and their characteristics. It also outlines the steps to prepare paint, including mixing pigments, solvents and resins to form a paste, grinding the pigment particles, thinning the paste to the desired consistency, and finally canning the finished paint.
2. Types of Paints
Matte paint:
is the least reflective sheen available
has a velvety texture
helps hides imperfections in walls and ceilings
offers great depth of color
is generally considered the standard sheen for walls
can sometimes be difficult to clean
Eggshell and satin paint (satin is slightly glossier than eggshell):
have some reflectivity
offer improved durability
are frequently used in demanding environments, like kitchens and
bathrooms, where easy cleanup without a highly glossy finish is desired
3. Contd
Semi-gloss and gloss paint:
are the most reflective sheens
are highly durable and stand up to multiple cleanings
are traditionally used on baseboards, moldings, and doors
can make a statement, but also highlight imperfections
Primer - These may be oil or water based and are used to seal unpainted
surfaces to prevent covering coats of paint soaking in. The appropriate type
of primer should be used for the surface being painted - wood, metal, plaster
or tiles. There are some 'all purpose primers' available which are designed for
two or more of these surfaces.
4. Contd
Undercoat - Usually oil-based, undercoat is applied on top of the primer. The
undercoat should be of the correct colour to provide the right colour base for
the finishing coats.
Radiator paint - For use on central heating pipes and radiators, it will stand
up to the high temperatures without discoloring as other paints are prone to
do.
Fire-retardant - These special paints contain an additive to provide a fire-
resistant quality, they do not resist fire completely, but has a greater flame
resistance than ordinary paint and will reduce their spread.
5. Contd
Emulsion Paints - Modern Emulsions are water-based, with vinyl or acrylic
resins added to make them more hard-wearing than traditional emulsions.
This results in varying degrees of sheen in the finish; as the shine increases,
the paint tends to be more hard wearing. The ranges usually offer matt,
eggshell, silk, satin and full gloss.
6. Preparation of Paints
A paint is composed of pigments, solvents, resins, and various additives. The
pigments give the paint color; solvents make it easier to apply; resins help it
dry; and additives serve as everything.
Making the paste - Pigment manufacturers send bags of fine grain pigments
to paint plants. There, the pigment is premixed with resin (a wetting agent
that assists in moistening the pigment), one or more solvents, and additives
to form a paste.
Dispersing the pigment - The paste mixture for most industrial and some
consumer paints is now routed into a sand mill, a large cylinder that agitates
tiny particles of sand or silica to grind the pigment particles, making them
smaller and dispersing them throughout the mixture. The mixture is then
filtered to remove the sand particles.
7. Contd
Instead of being processed in sand mills, up to 90 percent of the water-based
latex paints designed for use by individual homeowners are instead processed in
a high-speed dispersion tank. There, the premixed paste is subjected to high-
speed agitation by a circular, toothed blade attached to a rotating shaft. This
process blends the pigment into the solvent.
Thinning the paste - Whether created by a sand mill or a dispersion tank, the
paste must now be thinned to produce the final product. Transferred to large
kettles, it is agitated with the proper amount of solvent for the type of paint
desired.
8. Contd
Canning the paint - The finished paint product is then pumped into the
canning room. For the standard 8 pint (3.78 liter) paint can available to
consumers, empty cans are first rolled horizontally onto labels, then set
upright so that the paint can be pumped into them. A machine places lids
onto the filled cans, and a second machine presses on the lids to seal them.
From wire that is fed into it from coils, a bailometer cuts and shapes the
handles before hooking them into holes precut in the cans. A certain number
of cans (usually four) are then boxed and stacked before being sent to the
warehouse.