Iron Oxide Pigment Selection Guide

The color spectrum and tinting characteristics of our basic iron oxide grades are evaluated using a standardized castor oil dispersion method. Pigments are ground in refined castor oil at a strict 1:4 weight ratio to ensure optimal wetting and dispersion.

- Full Shade : Represents the pure mass-tone of the pigment milled directly in the 1:4 castor-oil vehicle, demonstrating deep hiding power and inherent hue.
- ZnO Reduction Shade ( 1:10): Formulated by blending the iron oxide pigment with pure zinc oxide powder at a **1:10 weight ratio**, followed by dispersion and milling in the same proportional castor-oil vehicle. This reduction test highlights the tinting strength, undertone purity, and scattering performance of each grade.

Key Technical Parameters & Selection Guide

To assist procurement managers, formulators, and technical engineers in making the right choice, we have highlighted the most critical physical and chemical parameters from our data sheet:

① Fe₂O₃ Content (≥ 96%)

What it means: The chemical purity and concentration of iron(III) oxide. All our standard iron oxide red grades (F110, Y101, P130, 130S, 130A, 190) maintain a high purity of 96% or higher.

Selection tip: High Fe₂O₃ content translates directly to superior tinting strength, cleaner hues, and batch-to-batch consistency. It is ideal for high-end architectural coatings, automotive primers, and engineering plastics where performance is critical.

② Oil Absorption (15 ∼ 25 g/100g)

What it means: The amount of oil (or vehicle) required to wet a given weight of pigment. Our red pigment portfolio is tightly controlled within a low range of 15 to 25 g/100g.

Selection tip: Low oil absorption allows for higher pigment loading in paints, inks, and masterbatches without causing excessive viscosity buildup. This ensures excellent leveling, smooth application, and reduced binder demand.

③ Residue on 325 Mesh (≤ 0.3%)

What it means: The percentage of coarse particles failing to pass through a 325-mesh sieve.

Selection tip: A strict threshold of ≤ 0.3% ensures ultra-fine particle distribution. For spray applications, thin-film coatings, and fine plastic extrusions, low residue prevents nozzle clogging, surface pinholes, and coarse speckling.

④ Tinting Strength (95% ∼ 105% compared with standard)

What it means: The relative coloring power of the pigment measured against an agreed industry standard (100%).

Selection tip: Maintaining a tight variance range (95% ∼ 105%) guarantees reliable color matching across different production batches. This is vital for manufacturers producing colored concrete, asphalt, industrial coatings, and building materials who require strict color uniformity.