liquid.
RAW MATERIAL:
There are a number of ingredient types that are used. These basic components include:
film forming agents, resins and plasticizers, solvents, and coloring agents. The exact
formulation of a nail polish, apart from being a corporate secret, greatly depends upon
choices made by chemists and chemical engineers in the research and development
phase of manufacturing. Additionally, as chemicals and other ingredients become
accepted or discredited for some uses, adjustments are made. For example,
formaldehyde was once frequently used in polish production, but now it is rarely
used.
The primary ingredient in nail polish is nitrocellulose (cellulose nitrate) cotton, a
flammable and explosive ingredient also used in making dynamite. Nitrocellulose is a
liquid mixed with tiny, near-microscopic cotton fibers. In the manufacturing process,
the cotton fibers are ground even smaller and do not need to be removed. The
nitrocellulose can be purchased in various viscosities to match the desired viscosity of
the final product.
THE MANUFACTURING PROCESS:
One common technique was to mix cleaned scraps of movie film and other cellulose
with alcohol and castor oil and leave the mixture to soak overnight in a covered
container. The mixture was then strained, colored, and perfumed. Though
recognizable as nail polish, the product was far from what we have available today.
The modern manufacturing process is a very sophisticated operation utilizing highly
skilled workers, advanced machinery, and even robotics. Today's consumers expect a
nail polish to apply smoothly, evenly, and easily; to set relatively quickly; and to be
resistant to chipping and peeling. In addition, the polish should be dermatologically
innocuous
MIXING THE PIGMENT WITH NITROCELLULOSE AND PLATICIZER
1. The pigments are mixed with nitrocellulose and plasticizer using a "two-roll"
differential speed mill. This mill grinds the pigment between a pair of rollers
that are able to work with increasing speed as the pigment is ground down.
The goal is to produce fine dispersion of the color. A variation of this mill is
the Banbury Mixer (used also in the production of rubber for rubber bands).
2. When properly and fully milled, the mixture is removed from the mill in sheet
form and then broken up into small chips for mixing with the solvent. The
mixing is performed in stainless steel kettles that can hold anywhere from 5 to
2,000 gallons. Stainless steel must be used because the nitrocellulose is
extremely reactive in the presence of iron. The kettles are jacketed so that the
mixture can be cooled by circulating cold water or another liquid around the
outside of the kettle. The temperature of the kettle, and the rate of cooling, are
controlled by both computers and technicians.