The present invention relates to a method of producing a plank product and
related components having a controllable and realistic wood-grain
appearance, the planks and related components having at least one accent
color, the method including the steps of: a) introducing into an extruder
a powdered or pelletized base material and accent color pellets, the base
material containing less than about 75% by weight wood flour, and having
a vicat softening temperature, the accent color pellets (i) having a
higher vicat softening temperature than said base material, and (ii)
including a styrene polymer having a high vicat softening temperature and
a melt flow index of greater than or equal to 1.0 gram per 10 minutes,
and at least one additional resin having a substantially lower vicat
softening temperature than the styrene polymer; and b) extruding said
base material and the accent color pellets through an extrusion die to
form a plank under processing temperatures whereby the accent color
pellets cause delayed introduction and controlled dispersion of the
accent color into the plank material.