Brush Construction Variables
Brush construction plays a big part in determining brush
stiffness. Figure 4 is for brushes of like construction. It would
be impractical to develop a chart that includes all of the various
brush constructions. In most brushes, one filament touches
another and, therefore, does not function as an individual
filament but as a family of filaments. Their interaction varies with
each type of construction (strip brush, tuft-staple set, tuft-wire
drawn, tuft-adhesive set, etc.). This interaction will also vary with
tuft size, trim length, and the rigidity of the tuft in the brush.
Crimping is one way to increase the apparent mass (bushiness)
of the filaments. Natural bristles, as a result of their rough
surfaces, have more interaction between fibers than noncrimped
nylon filament. A brush filled with crimped nylon filament more
nearly duplicates the “feel” of a natural fiber brush and gives the
bushiness usually associated with a natural fiber.