Preparation of the Base Oil-Wax System
Oils-such as castor oil, mineral oil, or vegetable oils-are combined with waxes-such as beeswax or carnauba wax-in a heating vessel according to specific formulation ratios. The mixture is heated to a specific temperature until completely melted and thoroughly blended, ensuring the waxes are uniformly dissolved within the oil phase to form a stable base matrix. This critical step determines the lipstick's hardness, gloss, and molding properties.
Pigment Pre-treatment and Dispersion Preparation
Powdered pigments-including iron oxides, titanium dioxide, organic colorants, or pearlescent powders-undergo pre-grinding or wetting treatments to facilitate their dispersion within the oil-wax system. Subsequently, the mixture is subjected to multiple dispersion cycles using equipment such as three-roll mills, high-shear dispersers, or homogenizers. This process further refines the pigment particle size, ensuring color uniformity and a smooth, grain-free texture, while simultaneously enhancing color payoff and product fineness.
Mixing and Molding Phase
The uniformly dispersed pigment slurry is added to the base oil-wax system and thoroughly mixed until homogeneous. The mixture is then filled and molded under controlled temperature conditions, flowing into lipstick molds or tubes to cool and solidify. The resulting molded products undergo rigorous stability testing-including assessments of heat resistance, color consistency, and structural integrity-to ensure that the final lipstick product maintains optimal performance characteristics across various environmental conditions.