TIO2 Plastics

Table of Contents:

• TiO2: Why Does This Material Pose a Challenge for Heat Transfer?
• A wide variety of uses, all with the same standard of consistency
• Seamless and consistent transfer of TiO₂ with the TRANSITUBE flexible screw
• Effective extraction when the material clumps together
• Continuous dosing to maintain a stable ratio
• TiO2: Line Cleanliness and Operator Safety
• The Practical Benefits of Transferring TiO₂ Using a Flexible Screw Conveyor
• Technical specifications to help you determine the size of your transfer
• Start a Reliable Transfer Project with TIM

TiO2: Why Does This Material Pose a Challenge for Heat Transfer?

Titanium dioxide, also known as titanium oxide, is a compound of oxygen and titanium (formula TiO₂). Two main industrial processes dominate its production: the sulfate process, often associated with the anatase form, and the chlorine process, often associated with the rutile form. In the workshop, the main challenge lies less in the upstream process than in the behavior of the powder: a white, crystalline material that is highly opacifying… and very difficult to handle.

A few physical characteristics help explain the challenges encountered in the field: a high density (approximately 3.9 to 4.3 g/cm³ depending on the grade) and, depending on the grade, a significantly lower bulk density, which can change as a result of compaction and handling. TiO₂ compacts easily, leaves marks on walls, clings, and then begins to “stick” rather than flow.

In practice, these characteristics lead to recurring problems:

• vaults and bridges made of material stored in silos;
• clumps that disrupt the uniformity of extraction;
• fluctuations in flow rate that make dosing less reliable;
• dust emissions at the intake points when the circuit remains open.

A line designed for pellets may operate properly with PE or PP, but may malfunction as soon as a transfer of TiO₂ enters the equation. The difference does not stem from the “quality” of the pigment. The difference stems from the compatibility between the material and the extraction and transfer components.

A wide variety of uses, all with the same standard of consistency

Titanium dioxide is widely used in paint as a pigment; according to the INRS, it accounts for approximately 70% of global pigment production. The material is also used in plastics, pharmaceuticals, cosmetics (including certain sunscreens), paper, and the construction industry. In the food industry, TiO₂ has long been associated with the additive E171, with a history of use in certain applications.

In many of these sectors, the requirements remain the same: whiteness, opacity, and sometimes UV protection (particularly in the form of nanoscale powder, which has been known for about twenty years for its ability to absorb ultraviolet rays). In plastics, an operational consequence becomes immediately apparent: an irregular proportion results in a shifting color, less consistent opacity, and subsequent corrective adjustments during manufacturing.

The transfer of TiO₂ is therefore not simply a matter of internal transport. An irregular supply disrupts the production process, which is then reflected in the finished product. A reliable solution addresses the entire material flow: extraction, transfer, discharge point, environmental cleanliness, and operator safety.

Seamless and consistent transfer of TiO₂ with the TRANSITUBE flexible screw

For TiO₂, as with many bulk materials, we use a flexible TRANSITUBE mechanical feeder. The design prioritizes continuous operation and ease of use.

Material is conveyed through a sealed system, with no dust emissions. A material intake probe is mounted beneath a hopper, silo, or big bag. The spiral—the central component of the transfer system—is made of special spring steel and undergoes a treatment designed to enhance its strength and flexibility. Driven by a motor, the spiral forms a ring of material that moves through the tube to the discharge point.

Depending on the screw profile, the system conveys a wide variety of products: plastic pellets, regrind, powders (including PVC powder), additives, and blends. TiO₂ is one of the materials handled, with particular attention paid to leak prevention and flow stability.

Installation also becomes more flexible: the flexible transfer system bypasses obstacles, accommodates curved paths, and quickly adjusts during installation. The workshop retains some flexibility without imposing a rigid layout that is difficult to adapt.

Effective extraction when the material clumps together

Problems often begin in silos or hoppers. Powder with poor flowability can disrupt material transfer, even if the feeder is properly sized. Arches, material bridges, and clumps cause erratic operation: a sudden surge, followed by a lull, and then a blockage.

For these difficult-to-handle products, we offer a TRANSITUBE ZFP-type de-clogger and extractor. The equipment consists of a flat-bottom hopper equipped with a special de-clogger featuring flexible or semi-rigid blades, designed for materials that are difficult to handle, particularly powders. Target applications include talc, calcium carbonate (CaCO₃), certain elastomer compounds (SEBS-type TPEs), plasticized PVC, TiO₂, and film shreds.

The goal is to keep the material moving smoothly, without allowing the powder to “clump” and block the flow. The ZFP also allows for an adjustable flow rate depending on the required application. Once connected to a TRANSITUBE flexible mechanical feeder (PV series), the product is conveyed to the discharge point.

The equipment can be integrated into a multi-product system, alongside other dosing units, as part of a process that combines multiple components.

Continuous dosing to maintain a stable ratio

In a multiproduct process, even a single irregularity is enough to throw the recipe off. TiO₂ has a significant impact on the final appearance; an unstable proportion quickly results in a deviation in whiteness or opacity. Continuous and consistent dosing is therefore critical.

The ZFP dispenser-extractor enables continuous dosing with a specified accuracy of 0.5% to 3%, depending on the product. This performance is particularly valuable on production lines where consistent product appearance is a priority, resulting in fewer adjustments during production.

The system covers a wide operating range, depending on the configuration:

• flow rates ranging from 30 to more than 10,000 kg/h;
• transfer distances that can be extended by connecting relay feeders;
• the ability to be integrated into a volumetric dosing carousel, when the process requires it.

The system can also be integrated with other injection molding machine peripherals, as required by the line configuration: a grinder, dryer, dosing unit, color mixer, and pneumatic conveying system, depending on the specific application.

TiO2: Line Cleanliness and Operator Safety

TiO₂ is irritating, particularly to the eyes and respiratory tract. A production line that handles it must therefore limit operator exposure, reduce powder dust emissions, and prevent the product from dispersing into the work environment. Safety is not just a concern at the time of a spill; it is built in from the design phase by identifying points where powder may escape and then selecting solutions that contain the material as close as possible to its actual path.

The first strategy relies on containment. A closed-loop transport system significantly limits dust emissions at the most critical stages: retrieval from a hopper or silo, transfer, and then the discharge point. A closed-loop system also reduces contamination around the machinery, preventing the gradual buildup of deposits. With a “greasy” and sticky powder like TiO₂, these deposits often end up creating additional areas where the powder can get caught, leading to flow irregularities. Cleanliness thus becomes a factor in stability, not just a matter of hygiene.

The second factor concerns the design of equipment that comes into contact with the product. TiO₂ sticks, clumps, and forms lumps. An unsuitable system requires repeated interventions: tapping on a hopper, manual removal, opening hatches, and scooping with a bucket. Each intervention increases operator exposure, multiplies the number of handling steps, and opens the door to material loss or contamination. An extraction system designed for difficult-to-handle powders reduces these steps. It promotes a more consistent flow and limits the need to constantly “help the material” along.

A strategy of dedicated equipment often yields direct benefits. When TiO₂ shares the same transfer components with other materials, sticky residues build up, maintenance becomes more burdensome, and the risk of cross-contamination increases. A dedicated line—or at the very least, dedicated components at critical points—simplifies maintenance and ensures quality. This approach is particularly suitable when the pigment affects the final appearance or when internal cleanliness requirements mandate a clear separation of the processing circuits.

Finally, managing flowability requires a pragmatic approach. In some cases, fluidization can improve the flow of TiO₂, particularly when storage in silos leads to arching or compaction. The right choice depends on the actual bottleneck: extraction from the silo, material retrieval, transfer, or discharge point. A workshop-based study helps identify this point and then define useful options without overcomplicating the system.

The Practical Benefits of Transferring TiO₂ Using a Flexible Screw Conveyor

Flexible screw conveying is not used solely to move powder. Several beneficial effects occur, particularly with TiO₂:

• easier installation, thanks to the system's ability to navigate around obstacles and quickly adapt to the mounting conditions;
• homogenization of the mixture during transfer, even when densities and particle sizes differ;
• enhanced cleanliness, with no dust emissions and the material protected from environmental pollution;
• protection against ambient moisture, which is useful for dried or dehydrated products but may be less suitable for pneumatic conveying depending on the circumstances.

In terms of operating costs, one illustrative figure highlights the benefits of this approach: a flexible screw conveyor can consume as little as approximately 2.2 kW at a throughput of 5,000 kg/h over a distance of 6 meters, depending on the configuration. Proper sizing remains critical, but this order of magnitude provides a sense of the energy impact.

Technical specifications to help you determine the size of your transfer

The design of a TIO2 transfer system is based on mechanical choices that are consistent with the material and the installation. The available technical specifications include, in particular:

• a flexible, bendable design suitable for curved paths;
• a double-flanged motor;
• an antistatic design, when necessary;
• quick disassembly;
• white polyamide tubes;
• a radius of curvature of 1.5 to 3 m;
• a throughput of up to 12 metric tons per hour, depending on the model;
• a single length of up to 20 m, followed by extension in sections;
• different coil profiles (flat, round, square, bristle);
• diameters ranging from 43 to 110 mm (types 30, 39, 53, 70, 80, 100);
• a rotational speed of up to 1,500 rpm.

This data is only useful when considered within your specific context: the type of TiO₂, target flow rate, distance, number of bends, extraction stability, cleanliness requirements, building constraints, and operator safety.

Start a Reliable Transfer Project with TIM

A TIO2 project moves forward quickly with a simple scope defined based on workshop data, not on theoretical assumptions. The most useful information at the outset concerns:

• the flow rate of TIO2 , including any peaks and the operating mode (continuous or intermittent);
• the storage method (silo, hopper, big bag) and the restocking frequency;
• the distance and the route to be covered (height, length, turns, obstacles);
• the process's sensitivity to dosage, depending on the proportion in the recipe and the impact on the final appearance;
• cleanliness and safety requirements, particularly regarding dust and operator exposure.

On this basis, a proposed solution is developed starting from the point where the actual blockage occurs. An unstable extraction often requires a ZFP de-vaulting and extraction unit to prevent the formation of vaults and clumps, followed by a flexible conveyor that ensures continuity all the way to the drop point. Site constraints or the need for leak-tight operation, on the other hand, guide the selection of the coil, diameter, speed, and route of the TRANSITUBE, with relays if the distance requires them.

The expected result remains the same: TiO₂ that can be extracted without clogging, transferred without creating dust, and delivered to the right place at a steady flow rate.

To ensure the safe transfer of your TiO₂, all we need is a detailed description of your setup: storage method (silo, hopper, big bag), extraction conditions, distance and route to be covered (height, bends, obstacles), target flow rate during normal and peak operation, cleanliness and safety requirements, as well as the destination (mixer, machine hopper, buffer silo). Based on this information, we will provide a clear layout proposal and a transfer solution tailored to the actual conditions of titanium dioxide production, in order to stabilize the feed, limit flow rate variations, and reduce downtime caused by the powder’s behavior.

For more information: 

TiO2
CACO₃
Spiral Conveyor
Pneumatic transfer for plastics processing
Powder transfer
Plastic pellets