Fluoropolymer Processing Aid Dosing Economics under High Shear Profile Tooling
Optimize fluoropolymer dosing between 400 and 800 ppm to balance wall slip against startup induction scrap and avoid masterbatch working capital drag.
Titanium Dioxide Scouring
Meaning
Abrasive wear of metal machinery parts caused by the hard particles used as pigments or opacifiers in polymer and paint production. Titanium dioxide scouring occurs when the mineral crystals act as a polishing agent against extruder screws, barrels, feed throats and spinning nozzles. This constant friction removes microscopic layers of steel, leading to dimensional changes in precision equipment.
It is a major factor in the lifespan of components in the fiber and coatings industries.
Particle Hardness
Mineral grade and crystal structure dictate the severity of the abrasion. During titanium dioxide scouring, the anatase form is generally less abrasive than the rutile form due to its lower Mohs hardness. Surface treatments applied to the pigment can also mitigate the impact on metal surfaces.
Selecting the correct pigment grade is a balance between optical performance and equipment longevity.
Velocity Impact
Flow speed of the material through the orifice increases the rate of metal loss. In a titanium dioxide scouring scenario, high shear zones experience the most rapid degradation. Periodic measurement of clearance between moving parts is necessary to track this erosion.
Metallurgy Solution
Hardened alloys and ceramic coatings provide resistance against the abrasive pigment. Preventing titanium dioxide scouring often involves using tungsten carbide or nitrided steels for critical wear zones. These materials increase the initial cost of the machinery but reduce the frequency of replacement.
Scheduled maintenance allows for the rotation of parts before they fail completely.