WHEN ADDITIVES BECOME FUNCTIONAL, NEW POSSIBILITIES EMERGE!
- By Colin Clarke
- December 23, 2020
Polymer producers have responded to the changing tyre industry expectations, their innovations take into account a more reactive functionality within polymer architecture, and this is closely matched by increasingly greater degrees of filler surface chemistry. As a result, tyre compound properties may now be tailored to meet quite specific tyre performance targets.
Tyre processing methods also underwent progressive stages of modernisation in recent years, for example, more sophisticated reactive mixing technology together with high-speed extrusion systems allowing for direct extrusion onto the building drum become established as cost effective production routes for many of the major producers.
These advancements however bring about their own conflicts, processing pathways involving multiple stages, often with the ability to rework compound or adjust rheological properties by additional time or energy input during the process are no longer viable options for most tyre producers. It has thus become necessary to achieve processability through an increasingly narrow operating window.
Formulations optimised to achieve peak tyre performance in most cases also tend towards more challenging processing characteristics. This is to be expected; the use of high and narrow molecular weight reactive polymers alongside fillers having high surface area and chemistry, often in loadings above that of the polymer are the norm. The trend towards usage of high loading of plasticiser and resinous materials to adjust tyre tread grip and traction response all contribute to a less forgiving processing nature. Often those compounds that are highly reinforced appear the most fragile during processing and poor green strength with an easily tearing or crumbly compound appearance are often-discussed processability issues. By contrast, the use of high loadings of resins and plasticisers, for example in winter or high-performance tyre formulations, results in compounds that during processing can more resemble chewing gum than tyre treads!
The use of process additive chemicals in an attempt to overcome the processing limitations observed gives rise to further conflicts; Lubricant additives might improve compound surface appearance; however, green strength will probably further reduce due to the unwanted softening effect. The same is true for release additives where lower tack unfortunately remains at a higher value than the also lowered tensile strength of the compound. Filler dispersion is often targeted by additives, however higher loading of fillers mandate equally higher additive loadings, we should more accurately discuss loading as “parts per hundred of filler” not rubber, and under the appropriately higher additive loading, the risk of interference with vulcanisation properties or even additive migration leading to surface bloom become realistic concerns.
Conflicting performance characteristics
The development team at Schill + Seilacher has recognised the need to decouple conflicting performance characteristics found within conventional process additive chemistries. As a result, innovation within our Struktol® range offers tyre compounders opportunities to achieve processability without compromise.
Reduced viscosity leading to better extruder flow properties and improved surface appearance, whilst at the same time achieving an increased compound green strength can be realised by use of Struktol HT 300, a new generation of reactive process additive.
An extract of key processing and property influence in a typical highly silica filled sSBR tread compound are highlighted in the following data.
|
|
Control |
Struktol HT 300 6 phr |
Struktol HT 300 12 phr |
|
Mooney ML (1+4) 100 °C (MU) |
75 |
65 |
53 |
|
Loss of batch weight due to sticking in the mixer (%) |
1.9 |
0.6 |
0.4 |

Significantly lowered Mooney viscosity as well as better mixer batch off with reduced sticking to the mixer rotor and gate with Struktol HT 300 are observed.
An increase in compound green strength was obtained by the addition of Struktol HT 300; this is the opposite of expectation for conventional process additive chemistry, where reduced viscosity is obtained. In addition, the filler dispersion as evidenced by a reduction in the so-called “Payne Effect” as tested in uncured compound by means of RPA strain sweep, is also improved.
Lab extrusion trials, using cold feed extruder demonstrate improved surface appearance and lower compound pressure achieved by use of Struktol HT 300, both desirable processing conditions.


|
|
Control |
HT 300 6 phr |
HT 300 12 phr |
|
Hardness |
66 |
67 |
65 |
|
Abrasion loss (DIN) |
113 |
102 |
106 |
Physical properties are also acceptable, with a progressive increase in tensile strength an elongation and maintenance of stiffness with loading of 6 phr of process additive, only at higher loading of 12 phr would a balancing slight reduction in process oil be required.
Compound hardness remained unchanged alongside improved wear resistance, as measured by DIN abrasion loss testing, even when using higher loading of process additive, are important aspects.
The ability to decouple the relationship between lubrication, important for improved rheological behaviour, and the maintenance of strength and stiffness in both the uncured and vulcanised condition is only possible with such new and innovative class of process additive. This departure from conventional thinking offers the tyre compounder significant degree of freedom to retain the benefits in terms of easier processability without sacrifice of key tyre performance properties.
In this example, the use of Struktol HT 300 prioritised green strength alongside reduced viscosity. By contrast, our new Struktol HT 250 decouples release from other properties, especially effective for winter tyre tread; compound stickiness is resolved without compromise of viscoelasticity.
Ensuring that migration and ultimately bloom within rubber compounds is kept to the lowest level is important for final article aesthetics, for tyres additional considerations arise; they are composite structures, therefore it is imperative that chemicals do not migrate across boundary layers in an uncontrolled manner, which could result in changed behaviour or interfacial adhesion failure over time. In order to limit migration, the compatibility, solubility and concentration of chemicals are carefully considered. However, one method of ensuring long-term stability involves chemically binding the additive within the vulcanisation network.
At Schill + Seilacher, we have achieved this degree of crosslinking capability for a number of new-generation Struktol process additives. Their usage allows the compounder to avoid completely the risk of migration and bloom due to additive presence.
Photographs of two vulcanised rubber sheets based on the same formulation. On the left-hand side, evidence of typical surface bloom, which may occur due to migration of a conventional process additive, on the right, containing reactive additive Struktol HT 600 as replacement, it can be seen that bloom was eliminated.
This technology also opens tremendous opportunities to “fix” process additives in place within the respective component, the role of additives withinthe cross-linking mechanism may additionally lead to vulcanisate performance characteristics.
One interesting tyre related example involves the development of a superior tyre curing bladder performance, here we have developed new reactive plasticisers called Struktol HT 815 and Struktol HT 820, their use is directed towards resin-cured butyl rubber. This combination of polymer and curing system provides for superior heat resistance with excellent flex fatigue resistance and is used as the basis for tyre curing bladders. Here the replacement of widely used castor oil as plasticiser with new Struktol HT 800 series product leads to a significantly improved bladder performance life, with greater stability in viscoelastic properties. Reduced stiffening of the bladder, due to lower degree of plasticiser migration translated into a much lower flex-cracking rate, especially after high temperature steam ageing.
Reactive Struktol plasticisers, HT 815 and HT 820 exhibit a significantly reduced flex cracking rate when compared to the widely used castor oil, which readily migrates from the bladder; as a result, significant extension of bladder service life is possible.
New reactive process additives, with tailored functionality to closely match the specific chemistry of polymers, fillers and cure systems are actively developed. These innovative products under the Struktol brand offer tyre compounders a more comprehensive toolkit in order to tailor compound performance to meet tyre performance demands. The conflicts of property versus processability diminish and new possibilities emerge!
- HS HYOSUNG ADVANCED MATERIALS
- Rooftop Solar Power Installation
- Tyre Cords
- Smart Green Factory
- Renewable Energy
HS HYOSUNG Powers Vietnam Subsidiary With 17.5-MWp Solar Power Installation
- By TT News
- March 31, 2026
HS HYOSUNG ADVANCED MATERIALS has completed and commenced operation of a 17.5-MWp rooftop solar power installation at its facility in Vietnam’s Nhon Trach Industrial Park, located within Dong Nai Province. This marks a significant step in the company’s broader effort to reshape its Vietnam operations – its largest global manufacturing base for tyre cords and technical yarns – into what it terms a ‘Smart Green Factory’. By merging renewable energy infrastructure with digital energy management systems, developed in partnership with the energy IT specialist Nuriflex, the firm is positioning this site at the forefront of its transition towards becoming a global eco-friendly manufacturing hub.
A key element of this transformation is the deployment of an Internet of Things based energy management system, which allows for real-time oversight of electricity generation and equipment performance. This digital layer not only streamlines operational efficiency but also contributes to greater equipment reliability and overall productivity gains, ensuring that the integration of renewable energy delivers tangible improvements beyond simple power generation.
With further solar installations set to be completed by August, total rooftop capacity at the Nhon Trach site will reach 37.5 MWp. Once fully operational in the latter half of the year, HS HYOSUNG ADVANCED MATERIALS anticipates annual electricity cost savings exceeding KRW 6 billion (approximately USD 3.94 million), bolstering its cost competitiveness. The expansion is also expected to deliver meaningful reductions in greenhouse gas emissions, reinforcing the company’s long-term commitment to sustainable management practices.

Through advanced energy IoT solutions, the Vietnam subsidiary now systematically manages carbon reduction data generated from its solar power operations. This capability enables a more structured response to rising demands from major global customers – including Michelin, Bridgestone, Goodyear, Continental and Pirelli – for verified renewable energy usage and carbon emissions information. By strengthening its ESG performance across the supply chain, the company is leveraging its solar infrastructure and smart energy management not merely as facility investments but as strategic tools to enhance environmental responsibility and competitiveness in a market where sustainable value chains are increasingly essential.
“Starting with our Vietnam production base, we are simultaneously promoting renewable energy transition and energy efficiency improvements across our operations. By expanding solar power facilities, we will strengthen both cost competitiveness and ESG capabilities while proactively responding to the evolving requirements of our global customers,” said an official from HS HYOSUNG ADVANCED MATERIALS.
- Association of Natural Rubber Producing Countries
- ANRPC
- Natural Rubber
- Monthly NR Statistical Report
- Middle East Crisis
ANRPC Publishes Monthly NR Statistical Report For February 2026
- By TT News
- March 31, 2026
The Association of Natural Rubber Producing Countries (ANRPC) has released its Monthly NR Statistical Report for February 2026, detailing a period of significant market activity influenced by geopolitical tensions, macroeconomic changes and shifting supply-demand dynamics within the global natural rubber sector.
As per the report, global natural rubber production for 2026 is forecast to reach 15.324 million tonnes, a 2.2 percent increase from the 14.996 million tonnes recorded in 2025. February output alone is projected at 994,000 tonnes, marking a 3.4 percent year-on-year rise due to favourable weather and higher rubber prices. Despite this overall growth, production trends vary among member nations. While Thailand is expected to remain the top producer, Indonesia and Vietnam face short-term constraints from structural and agronomic issues. Meanwhile, Malaysia is advancing efforts to restore abandoned plantations, with the Rubber Production Incentive activated in Sarawak and Sabah and the Malaysian Rubber Board targeting the rehabilitation of 4,137 hectares of idle land in 2026.

Physical and futures markets saw notable price increases across major grades in February. In Kuala Lumpur, SMR-20 averaged USD 2.01 per kilogramme, a 5.13 percent monthly gain, while STR-20 in Bangkok rose 5.12 percent to USD 2.11 per kilogramme. Sheet rubber grades also strengthened, with RSS-3 increasing 7.84 percent to USD 2.35 per kilogramme and RSS-4 in Kottayam surging 10.38 percent to USD 2.34 per kilogramme. Centrifuged latex in Kuala Lumpur closed the month at USD 1.61 per kilogramme. Futures mirrored this firming trend, as the Shanghai Futures Exchange May 2026 contract averaged roughly 16,508 CNY (approximately USD 2,388) per tonne and the SGX contract averaged USD 1.92 per kilogramme, supported by strong demand and tightening supply expectations ahead of the seasonal low-yield period from February to May.
Crude oil volatility added further complexity, with Brent averaging USD 70.89 per barrel in February – up 6.43 percent from January – before spiking to approximately USD 104 per barrel in early March following military actions in the Middle East and the closure of the Strait of Hormuz, a conduit for nearly 20 percent of global oil supply. This has introduced a risk premium with implications for synthetic rubber competitiveness and natural rubber demand. Currency shifts also play a role, as the Malaysian Ringgit appreciated modestly to 3.89 MYR per USD and the Thai Baht strengthened to around 31.08 THB per USD by late February, affecting trade competitiveness. Looking ahead, rising automotive production, especially of new energy vehicles in China, India and Southeast Asia, is expected to sustain demand and support prices. However, risks persist from US-China trade tensions, Middle East geopolitical instability, weather uncertainties during the low-yield season and currency fluctuations tied to US monetary policy, all of which could disrupt supply chains and export revenues.
Tokyo Zairyo Expands Indian Operations With New Chennai Branch Office
- By TT News
- March 26, 2026
Tokyo Zairyo Co., Ltd., a wholly owned subsidiary of Zeon Corporation, marked a significant milestone in November 2025 by establishing a new branch office in Chennai, Tamil Nadu, India. Following the completion of all necessary preparations, this location has now commenced full-scale operations. The move represents a deliberate effort to broaden the company’s commercial reach across the Indian market while simultaneously constructing an organizational structure capable of responding with greater agility to the evolving and increasingly diverse requirements of its customers.
This southern expansion comes approximately 15 years after the company first established its Indian subsidiary, Tokyo Zairyo (India) Pvt. Ltd., with an office in Gurugram, Haryana, in 2011. By positioning a second office in Chennai, the firm now operates a coordinated network spanning the northern and southern regions of the country. Close collaboration between the two locations is intended to strengthen information services and enhance user support, leveraging both internal capabilities and external partnerships to better serve Japanese automotive parts manufacturers and processors operating throughout India.
Through this dual-office structure, Tokyo Zairyo is poised to advance its core business of purchasing and selling a broad spectrum of materials, including rubber, resins and elastomers. The synchronised operations in Gurugram and Chennai enable the company to deliver more responsive support, ensuring that clients across the Indian automotive supply chain benefit from efficient service and a reliable supply of essential materials.
Kuraray Announces Price Hike For Liquid Rubber And ISOBAM
- By TT News
- March 24, 2026
Kuraray Co., Ltd. has announced a comprehensive global price adjustment for its portfolio of Liquid Rubber products and ISOBAM alkaline water-soluble polymer. These changes, which are set to take effect on 16 April 2026, will see prices rise by at least USD 2 per kg.
The driving forces behind these significant pricing actions are multifaceted, rooted in substantial disruptions to global supply chains. These disruptions are largely attributed to the ongoing conflict in the Middle East, which has had a cascading effect on logistics. Compounding this issue are the sharply rising costs associated with transportation and essential raw materials.
This strategic move is essential for the company to maintain operational stability and continue the supply of Liquid Rubber and ISOBAM amidst the volatile market conditions.



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