Industries

Paint & Pigmentfor abrasive pigments and extenders.

Titanium dioxide is the most expensive thing in the batch and the most destructive thing in the pipeline. A paint plant's handling system is judged on wear life and dosing accuracy.

Pigment and extender handling equipment in a paint manufacturing plant

In short

Paint industry powder handling covers the intake, storage, conveying, sieving and dosing of pigments, extenders and additives such as titanium dioxide, calcium carbonate, talc and silica. Because these powders are abrasive and dosed to tight tolerance, systems favour low-velocity conveying, wear-resistant components and accurate minor ingredient weighing.

In detail

How these materials behave.

Pigments and extenders are hard, angular mineral powders, and in a pneumatic line hardness plus velocity equals wear. Erosion is not spread evenly: it concentrates at bends, at diverter bodies and immediately downstream of any point where the stream changes direction, because that is where particles strike the wall instead of sliding along it. Since erosive wear rises steeply with velocity, the cheapest reliability improvement in most pigment lines is to slow the material down. Dense phase conveying at low velocity, long-radius or wear-backed bends, and correctly sized pickup points all buy pipe life that no amount of wall thickness will.

Dosing accuracy is the commercial constraint. Colour is a formulation outcome, so a small error in a pigment or tinter addition shows up as a batch that has to be corrected, re-tested or written off. That pushes the design towards separating bulk additions from minor ones: bulk extenders charged from silos or big bag unloaders against a coarse tolerance, actives and colourants dosed through metering feeders sized for the small mass, each weighing on instrumentation appropriate to its range.

Raw material condition matters as much as the equipment. Extenders arrive with a moisture and lump history from storage and transport, and calcium carbonate or clay that has consolidated in a bag will bridge over a discharge outlet and then flood when it collapses. Sieving at intake protects the mill and the mixer from lumps, bag fibre and tramp material, and discharge aids on silos and hoppers keep flow steady rather than intermittent — which is also what the weighing system needs to hit tolerance.

Dust control has two separate jobs in a paint plant. One is product quality and housekeeping: fine pigment migrates, cross-contaminates colours and settles onto everything, so capture at the point of generation is worth more than a large collector at the end of a long duct. The other is safety. Many organic pigments and additive powders are combustible, and solvent-borne areas carry their own area classification, so extraction, earthing and equipment selection have to follow the zoning of the room they sit in.

Scope

What PTP supplies to this sector.

RM / FG storage management (rigid and flexible silos)

Bulk material transfer (bulkers) with solutions for loading, unloading and handling

Pneumatic conveying (lean phase — positive pressure / vacuum, and dense phase — positive pressure / vacuum)

Mechanical conveying solutions

RM sieving solutions

Minor ingredients automation

Dust collectors (centralised and individual)

Industrial control systems

Selection

Process requirements.

Typical materials: Titanium dioxide, calcium carbonate, talc, silica, clays, organic pigments
Primary risk: Abrasive wear at bends, diverters and direction changes
Wear control: Low conveying velocity, long-radius or wear-backed bends
Dosing: Bulk extenders separated from minor pigment and additive additions
Flow aids: Discharge aids for consolidated, bridging extenders
Area classification: Combustible dusts and solvent-borne zones drive equipment selection

FAQ

Frequently asked questions.

Why does titanium dioxide wear out conveying pipework so quickly?

TiO2 is a hard, angular mineral, and erosive wear in a pneumatic line rises steeply with particle velocity. Damage concentrates where particles strike the wall rather than slide along it — at bends, diverter bodies and just after direction changes. Reducing velocity extends pipe life far more effectively than adding wall thickness.

Is dense phase conveying worth it for pigments?

Usually, where abrasion or long routes are involved. Moving material as slow-moving slugs at low velocity cuts erosion at the wear points, reduces attrition of the powder itself, and lowers conveying air volume, which in turn shrinks the filtration and venting the line needs. The trade is a higher-pressure air supply and a more considered pipeline design.

How is colour consistency protected during handling?

By keeping bulk and minor additions on separate weighing systems, by giving the feeder a steady inlet condition so it can trickle accurately to target, and by capturing fine pigment at the point of generation so it does not migrate and cross-contaminate other colours through the building.

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