TITANIUM DIOXIDE POWDER FOR PAPER MAKING

Industry-specific attributes

Lead time

1. Core optical performance indicators
   Ultra high whiteness
   Brightness standard: The whiteness should reach ISO brightness ≥ 97% (blue light wavelength 457nm reflectivity), higher than ordinary industrial grade titanium dioxide (usually 94% -95%), to ensure that the paper presents a pure background color.
   Hue control: By using surface coating technology (such as silicon aluminum composite treatment) to adjust the hue to be blue or red, it can adapt to the design needs of different paper types (such as cultural paper preferring a cool white tone).
   Excellent covering power
   Theoretical basis: The refractive index is as high as 2.7 (rutile type), significantly higher than cellulose (1.5), and the coverage efficiency per unit dosage is 8-10 times higher than that of calcium carbonate.
   Application advantages: Adding 0.5% -3% can cover the base color of wood pulp fibers, reduce the proportion of high white pulp used, and save 15-30 US dollars per ton of paper cost.
2. Physical form and dispersibility
   Ultrafine particle size distribution
   Optimal range: The median particle size (D50) should be controlled between 0.2-0.3 μ m, and the particle size distribution span (SPAN value) should be less than 1.2 to avoid large particles causing rough coating surface (Ra>0.8 μ m affects printing suitability).
   Crushing process: using airflow crushing+grading technology to ensure no hard aggregates.
   High dispersion stability
   Surface treatment: Coating with organic silicon/polyol dispersant to ensure the Zeta potential absolute value of the slurry is greater than 30mV, ensuring that the suspension time of titanium dioxide in the coating solution is greater than 48 hours without settling.
   Rheological properties: viscosity ≤ 200 mPa · s (25 ℃, Brookfield viscometer, 60rpm), suitable for high-speed scraper coating machine (vehicle speed ≥ 1200m/min).

3. Chemical stability and compatibility
acid and alkali resistance
Compatibility of coating solution: The coating layer does not hydrolyze within the pH range of 7-10, and the whiteness loss is less than 0.5% in the alkali resistance test (soaking in 10% NaOH solution for 24 hours).
Reduction resistance: Resists reducing substances such as sulfides and sulfites in the wet end system of papermaking, avoiding TiO ₂ from being reduced to Ti ³+and causing graying.
Low photocatalytic activity
Lattice doping: By doping elements such as zirconium and aluminum, the photocatalytic activity is reduced (H ₂ O ₂ production under ultraviolet light is less than 50ppm/h), preventing fiber oxidation and brittleness after long-term storage of paper.