New TiO₂ Pigment Addresses Plastic Industry Challenges on Both Sustainability and Cost

TAGS:  Sustainability / Natural Solutions    

The plastics industry is facing new challenges, not just for the performance of plastic materials in their end-use applications, but also to deliver improvements in plastics processing alongside management of their sustainability footprint.

Plastic processors using TiO₂ pigment seek improvements in sustainability, but this should not be done at the expense of productivity and cost management.

While this certainly presents a challenge, there is now an opportunity to balance these needs for white masterbatch by choosing a newly developed TiO₂ pigment, Ti-Pure™ TS-1510.

Compared to traditional TiO₂ pigments, the enhanced processing performance of Ti-Pure™ TS-1510 unlocks up to 7% lower net carbon footprint as measured from pigment manufacture through masterbatch production. In this way, Ti-Pure™ TS-1510 improves profits while providing plastics processors the ability to gain sustainability improvements with TiO₂ material selection.

Let's review how this innovative Ti-Pure™ TS-1510 pigment from Chemours can impact the productivity and processing costs of masterbatch producers and compounders in the plastics industry while simultaneously supporting sustainability goals with lower energy usage and improved yield.

Is Sustainability Always an Added Cost to the Plastics Industry?

Improved sustainability is increasingly becoming not only a goal for the producers of masterbatches but also a requirement of many customers due to value chain demands, government regulations, and to manage climate change. With this, the plastics industry is recognizing that sustainability makes good business sense¹. Now more than ever in the dynamic global economy, alongside the pressure of achieving sustainability, the plastics industry is attempting to achieve balance within its cost structure and strains on margins and profitability.

The challenges originating from the dual attention to aggressive sustainability and business pressures include the following:

• Inflation impacting material costs
• High investment and interest rates for capital
• High energy costs with a need for carbon footprint management
• Production rate limitations
• Workforce wellness demands
• Life cycle analysis assessment of sustainability

These challenges are accentuated for masterbatch processers due to the downstream value chain pressures for performance and the continued need for higher pigment loadings, improved mixing and dispersion, and easier handling.

The elements that contribute to sustainability include the raw material ingredients, through their processing, and to the final functionality in the end-use application. A pigment provides a good example of how a formulation ingredient can influence the sustainability footprint of a plastic application. While the amount of pigment in an end-use application is usually relatively small, the impact on performance and sustainability across the entire value chain can be significant.

Life Cycle Assessment (LCA)² is a rigorous and well-defined approach for providing quantitative measures of sustainability impact. With the LCA approach, individual aspects of sustainability are not considered in isolation, but rather are quantified by consideration of their impact on the performance throughout the life cycle.

Role Played by TiO₂ Pigment in Plastics

Titanium dioxide plays an important role in the plastics industry, bringing fundamental performance to applications including opacity. It is a white pigment that can be dispersed with plastic resin using standard plastics processing approaches. It is used in many plastic systems, such as follows:

• polyolefins,
• polystyrene,
• ABS, and
• polyvinyl chloride.

TiO₂ pigments play an important role in enabling plastics to deliver value. Their effect on sustainability is often overlooked due to their low concentrations and common usage. However, TiO₂ pigments bring sustainability value downstream with measurable impacts. TiO₂ has high UV-absorptive and light-scattering power resulting in improved heat resistance, light resistance, and weathering performance.

This protects plastic products from ultraviolet rays and helps to retain their mechanical and electrical properties. As a result, exterior plastic products, such as plastic doors, window profiles, railings, and other building materials utilize TiO₂ as a pigment not only for its opacity and color but also to manage performance.

Many plastic applications require an intermediate concentrate of TiO₂ in a plastics matrix to deliver the materials to production. This concentrate, or masterbatch, comprises a mixture of pigments and/or additives which is manufactured using production processes that facilitate the incorporation of the TiO₂ into a resin matrix, often with other functional additives. Processing equipment, such as continuous mixers or twin screw extruders, involves heat and mechanical energy to achieve the uniform dispersion of the components.

While delivering essential value to plastics, the use of traditional TiO₂ has presented challenges to plastic processors and masterbatch producers. These challenges result from traditional TiO₂’s low bulk density, cohesive (stickiness), poor flow, and dustiness. To provide solutions to overcome these challenges, a transformative TiO₂ pigment like Ti-Pure™ TS-1510 addresses the plastics industry's needs while delivering multidimensions of value for processors and our planet.

Ti-Pure™ TS-1510: A Transformative TiO₂ Pigment

Ti-Pure™ TS-1510 provides sustainability and cost-reducing benefits in various plastics compounding and masterbatch processes as shown in Figure 1. It is a highly efficient rutile titanium dioxide pigment manufactured with a revolutionary proprietary processing technology. Ti-Pure™ TS-1510 was designed to significantly enhance the level of processing efficiency in plastics applications including POMB (polyolefin masterbatch).


Figure 1: Ti-Pure™ TS-1510 – A Transformative Pigment that Delivers Both Sustainability and Cost Reduction
Ti-Pure™ TS-1510 provides improved flowability, line productivity, energy savings, and labor efficiencies along with low-dusting properties that promote safer handling and material efficiency. It is also excellent for high-temperature plastics applications requiring outstanding dispersibility and the lowest possible volatility. The Ti-Pure™ TS-1510 grade has the properties shown in Table 1.

Physical Properties		General Properties
Titanium dioxide, wt %, min	97	Opacity strength	High
Alumina, wt %, max	1.7	Undertone tint	Neutral
Organic treatment, wt %, carbon	0.2	Dispersibility in:
Specific gravity	4.2	Thermoplastics	Excellent
Mean particle size, µm	0.29	Plasticized vinyl	Good
pH (acqueous slurry)	8.5	Plasticizers	Fair
Resistance (acqueous slurry), k ohm-cm, min	2	Effect on melt flow	Minimal
		Melt compounding operations	Excellent
		Weathering resistance	Chalking grade in PVC use

Table 1: Physical and General Properties of Ti-Pure™ TS-1510 Titanium Dioxide Pigment
This new TiO₂ offering provides the following benefits which primarily originate from its improvements in bulk density.

• Improved flowability and workability – lowers cost and improves consistency
• Reduced warehousing footprint for inventory management – the same weight of pigment in ½ the volume
• Improved processing rate – feed rate improvements, buildup reduction, better gravity flow
• Enhanced processing – consistent feed and quality, better compounding rate and dispersion, reduced energy consumption
• Sustainable – Carbon footprint reduction, material efficiency, energy reduction, low dusting.

Material Handling and Storage Efficiency

Ti-Pure™ TS-1510 provides greater than 100% improvement in bulk density (Figure 2). As a result, the same weight of pigment can be achieved with one-half the package volume. This reduces storage space and warehouse costs.


Figure 2: Simultaneous Improvements in Bulk Density and Flowability Enable Step Changes in Processing Performance
The increased bulk density over traditional TiO₂ pigment also provides vastly improved gravity flow rate and consistency. The Ti-Pure™ TS-1510 flows easily and steadily through office constrictions, leading to rapid and complete discharge from packaging. The improved flowability is quantified via shear testing, and it is maintained over a wide range of stresses as shown in Figure 3.


Figure 3: Flowability Index as a Function of Feed Bin Diameter
Measured volume fractions of generated dust from Ti-Pure™ TS-1510 are consistently lower than benchmark grades of TiO₂. Enhanced handling through low dusting reduces the potential for contamination. This leads to cleaner production areas, less pigment loss, and reduces dust collection system maintenance. There is no dusting during the packaging bag changeout. This leads to complete discharge of the contents of the bag and less waste. Packaging can be designed for ease of recycling and reduced material usage.

Ti-Pure™ TS-1510 pigment also has less cohesion or stickiness which means less frequent cleaning and less choking / rat-holing in plastic processing equipment. The self-abrasive flow keeps machinery surfaces smooth and consistent.

Improved Processing Rate

The increased bulk density and flowability result in exceptional improvements in pigment feed rate which leads to consistent masterbatch processing and quality. Double feeder rates are possible with Ti-Pure™ TS-1510, regardless of production scale as shown in Figure 4 (right), and 30% compounding rate improvements are also possible as shown in Figure 4 (left).


Figure 4: Feeder Rate Improvements of 100% (Right) and Improvement in Compounding Rates of 30% (Left) are Possible with Ti-Pure™ TS-1510 (Data Based on a Trial with a Farrel Continuous Mixer CP550 with 70% TiO₂ loading)
In factory trials with a twin screw extruder (Krauss-Maffei ZE65BP), Ti-Pure™ TS-1510 was able to provide a 280% increase in throughput over a benchmark TiO₂ pigment. The improvement is mainly due to the reducing limiting factors in the pigment feeder as shown in Table 2.

Pigment	Throughput (kg/hr)	Processing Rating Limiting Factor
Benchmark	500	Pigment feeder (bridging, lockup & feeder capacity)
Ti-Pure™ TS-1510	1400	Resin feeder (feeder capacity)

Table 2: Ti-Pure™ TS-1510 Provide 280% Increase in Twin Screw Extruder Throughput
The dispersion quality of the masterbatch is unchanged while achieving these improvements in processing rate (Figure 5).


Figure 5: The Dispersion Quality of Ti-Pure™ TS-1510 is Unchanged While Still Achieving Improvements in Processing Rate
The improved processing rate and flow also result in reduced energy consumption as shown in Figure 6. Up to 12.5% overall energy reduction with the use of Ti-Pure™ TS-1510 provides cost savings through efficiencies in processing. This enhanced processing capability also allows the unlocking of downstream capacity (via greater asset flexibility and capital avoidance) and improved labor productivity.


Figure 6: Improved Processing and Flow Results in Reduced Energy Consumption

Processing Efficiency Leads to Reduced Carbon Footprint

The data from masterbatch production by continuous mixer was used as input to a life cycle analysis (LCA). LCA has become an important measurement in determining the sustainability of a product or process. The Ti-Pure™ TS-1510 grade is so efficient, that the enhanced processing performance unlocks an up to 7% lower net carbon footprint when measured from the advanced pigment manufacturing process through masterbatch production. This reduced carbon footprint is realized while still improving profits.


Figure 7: Carbon Footprint Reduction Potential with Ti-Pure™ TS-1510 when Compared to Traditional TiO₂ Pigment

POMB Case Study

Ti-Pure™ TS-1510 was designed specifically to address the POMB (polyolefin masterbatch) industry challenges. Processing trials were used to produce a white masterbatch (70% TiO₂ loading in NA206 low-density polyethylene resin) using a CP550 Farrel Pomini Continuous Mixer.

The observed performance and sustainability benefits of Ti-Pure™ TS-1510 across all POMB operations were equivalent to those discussed in the paragraphs above. They include the following:

• Improved material handling
• Enhanced processing rates
• Reduction in energy consumption
• Enhanced material efficiency

In addition, Ti-Pure™ TS-1510 has a low level of crystalline and surface-adsorbed water that gives superior performance in high-temperature polyolefin extrusion coating operations that may be sensitive to lacing. Ti-Pure™ TS-1510 shows lower levels of volatile weight loss as measured via thermogravimetric measurements.

Conclusion

The improved properties of the Ti-Pure™ TS-1510 pigment enable up to 100% faster processing rates through key masterbatch production processes. This includes compounding rate improvements of 30% compared to traditional grades while reducing the energy consumption of these processes by up to 12.5%. These benefits offer greater line capacity and labor efficiency opportunities, enabling expanded production or capital avoidance. All of this is achieved while still delivering the foundational value of opacity and color delivered by traditional Ti-Pure™ TiO₂ pigments.