Dupont Nylon 612 Bristles

DuPont Tynex® 612 Nylon Filament Product Characteristics

Premium-quality Tynex® filaments, the result of DuPont’s advanced research and engineering,
meet the most demanding requirements of brush makers and consumers for toothbrushes and
personal-care brushes of the highest quality.Significant benefits and extra values are:

Surface Finish
DuPont’s proprietary finish enhances tufting efficiency and productivity. This finish complies
with United States Food and Drug Administration (FDA) regulations.

Packaging
The diameter consistency of DuPont’s paperwrapped hanks meets or exceeds the stringent
requirements of new autoload toothbrush machines.

End-Rounding
High quality materials and precise process control give optimum end-rounding performance.

Color Uniformity
Pigmenting technology and special colormeasuring methods maintain close color tolerances.

Caliper Uniformity
DuPont technology and high-precision laser micrometers assure maximum control of filament diameter.

Chemical Properties
Tynex® 612 nylon filaments are not affected by chlorinated solvents, such as carbon tetrachloride,chloroform, trichlorethylene; petroleum hydrocarbons, such as gasoline, benzene,
naptha, toluene, kerosene; ester solvents, such as butyl acetate, amyl acetate; or detergents,
such as soap, trisodium phosphate, trisodium phosphate-soda ash.

Tynex® may become limp in contact with methanol or ethanol, but will regain its original stiffness after evaporation of these solvents.Other alcohols have little or no effect on
Tynex®.Tynex® is more resistant to attack by acids than many other brush filling materials. However,acids may cause some degradation of Tynex® depending upon the nature and concentration of the acid and the conditions under which the filaments are used. Before using Tynex® with acids, it is recommended that tests be made under conditions which may be expected in actual use.Tynex® filaments are attacked by phenol and chemically related compounds.Effect of Moisture Tynex® 612 nylon filaments absorb small quantities of water. The effect of this water absorption is a temporary decrease of stiffness and bend recovery while they are wet. This effect is compared below with commercial Nylon 66.


End-rounding performance is unsurpassed using Tynex® nylon filaments. DuPont’s proprietary extrusion process and optimized 612 nylon polymer provide superior results using conventional toothbrush making equipment.In this magnified toothbrush tuft, note the smoothness of individual ends in this scanning electron microscope (SEM) photograph of Tynex® 8 mil
(0.20 mm) diameter natural color nylon filament.Water absorption Tynex® 612 Nylon 66
50% relative humidity 1.4% 3.2%
100% relative humidity 3.0% 9.0%

Resistance to Fungi, etc.
Tynex® 612 nylon filaments are resistant to attack by rodents, insects, and fungi, and thus
may be safely stored for long periods without damage.

Effect of Temperature
The properties of Tynex® 612 nylon filaments are not permanently affected by continuous exposure to temperatures up to 65°C (149°F).They do become slightly degraded on long exposure at high temperatures.For example, they begin to show a slight loss in strength after several months at 100°C (212°F); and after days at 180°C (356°F)—all in the presence of air. Melting point for Tynex® is approximately 212°C (412°F). Extended exposure at 150°C (302°F) in an inert atmosphere has no lasting effect. Continued exposure to steam, especially in the presence of acids or bases, will gradually weaken Tynex® filaments.