D

Deflocculating additive
Additive used to wet and disperse by steric or electrostatic stabilization. Allows a higher filling rate thanks to its viscosity-reducing effect.

Defoamer
Chemical which reduces and/or eliminates foam. Mainly used in aqueous paints where it pops bubbles when squirted over water surfaces. (more about defoaming technology)
Syn. Foam control agent

Degreaser
Chemical solution or compound designed to remove grease, oil, and similar contaminants.

Delamination
Separation between layers of coats due to very poor adhesion.

Density
Mass per unit volume, usually expressed as grams per milliliter or pounds per gallon. The lower the density of the paint, the less weight added to the painted aircraft.

Deodorant
Chemical additive introduced to remove or mask undesired odor in liquid paints and applications. This type of additive is mainly used in DIY decorative and architectural paints.

Dew point
Temperature of a surface at which condensation of moisture will occur (under ambient temperature and relative humidity).

DFT
Dry film thickness.

Diluent
Portion of the volatile components of a coating which is not a true solvent. Has minimal effect on the viscosity and reduces the solids content in applied coating formulations.

Dip coating (extended definition)
Process that consists of applying a coating by simple dipping in a bath.

Dispersability
Level of dispersion of a pigment which depends on its chemical nature and particular structure, on the liquid phase in which it has been dispersed, on the method of dispersion... .

Dispersing agent
Surface-active substance used to facilitate the suspension of solid compounding materials in a liquid medium and to stabilize the dispersion thereby produced. An efficient dispersing agent can perform pigment wetting, dispersing, and stabilizing. Dispersing agents are different depending on the nature of the paint. Polyphosphates, styrene-maleinates and polyacrylates are used in water-based paints whereas lecytine, fatty acid derivatives and low molecular weight modified alkyd and polyester resins are used in solvent-based and solvent-free paints. (more about dispersion mechanism)
Syn. Dispersant

Dispersion
Suspension and distribution of tiny particles (pigments) in a liquid (polymer matrix).

Downdraft booth (extended definition)
Spray cabin in which the air movement is from the ceiling through the floor.

Drier
Chemical agent which promotes oxidation and drying of a coating film. Mainly used in oil based coatings, printing inks and varnishes. Driers are usually metallic compositions and are available in both solid and liquid forms. Different groups of driers are available: primary driers (active driers), secondary driers (auxiliary driers), and combination driers.
See Catalyst, Accelerator

Dry spray
Overspray or bounce back, producing a sandy finish due to the sprayed particles having partially dried before reaching the surface.

Dry fall
Coating which is designed to dry rapidly so that the overspray can be easily removed from the surfaces below.

Dry time
Time needed for an applied coating film to reach a set stage of cure or hardness.

Dry to tack free
Stage at which a coating film will form a skin to which dust will not adhere.

Dry to touch
State of dry at which a coating film will not transfer onto an item lightly touched against it.

Dry to handle
Degree of cure at which a film will resist deformation due to handling.

Dry to recoat
Time required for a cured film to dry prior to the application of a second coat.

Dulling
Coating defect: loss of gloss or sheen.

Dye
Colored sustance generally soluble in the polymer. Dyes exibit good transparency and high tinctorial strength. One critical property to consider is migration.