DIFFERENT WAXES IN RUBBER INDUSTRY

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  • June 26, 2020
DIFFERENT WAXES IN RUBBER INDUSTRY
  • Plastic ( soft or malleable) at normal ambient temperatures
  • A melting point above approximately 45 °C.
  • A  relatively low viscosity when melted (unlike many plastics)
  • Insoluble in water
  • Hydrophobic
Fig No 1

We shall be discussing here on the waxes which are only being used in the rubber and plastic industry. Beeswax, perhaps , is the first wax which used by human in the beginning of our civilization, was one of the important renewable source of fuel. The honey comb formed by bees has typical hexagonal geometric pattern (Fig.1). Bees wax is used in tire building drum, if the rubber is too sticky, it can also be used in two roll mill to take care of rubber sticking to the rolls. It is frequently being used in the BC, MC, PC, TB  inner-tube making industry during pre-forming operation in the green stage when inner-tubes are expanded under mild air pressure just before curing in mold.

 

The main commercial source of wax is, however, crude oil but not all crude oil refiners produce wax. "Mineral" wax can also be produced from lignite. Plants, animals and even insects produce materials sold in commerce as "wax". There are five categories of waxes being used in rubber industries :

  • Bees Wax
  • Paraffin Wax - made of long-chain alkane hydrocarbons
  • Microcrystalline Wax - with very fine crystalline structure
  • Chlorinated Paraffin Wax
  • Polyethylene Wax
  • Chlorinated Polyethylene Wax

The major uses of petroleum based waxes are in rubber, cosmetics and in Candle industry. They are generally white in color but show usual brown color (Fig.2) due to contaminated with oil traces. Two types of waxes, in general, are used in rubber industry, Paraffinic wax and Microcrystalline wax. Its normal dose is 1-3 phr and high level of wax impairs low temperature flexibility and compression set. Rubber compounder considers wax as a very important processing aid because it has following advantages:

 

  • Improves mixing properties
    Fig No 2
    Petroleum Based Wax

     

  • Improves dispersion of filler and other ingredients
  • Improves extrusion properties
  • Improves upon extrudate and calendared surface finish
  • Protects surface and acts as antioxidant /antiozonate

 

 

Paraffin and Microcrystalline waxes are derived from petroleum. They are easy to recover and offer a wide range of physical properties that can often be tailored by refining processes. Most producers offer two distinct types of petroleum waxes: paraffins, which are distinguished by large, well formed crystals; and microcrystallines, which are higher melting waxes with small, irregular crystals. Microcrystalline wax contains substantial proportions of branched and cyclic saturated hydrocarbons in addition to normal alkanes.

Some producers also sell "intermediate" wax, in which the boiling range is cut where the transition in crystal size and structure occur. Petroleum wax producers also characterize wax by degree of refinement; fully refined paraffin has oil content generally less than 0.5% and fully-refined micro-crystalline less than 3%. Paraffin wax produced from petroleum is essentially a pure mixture of normal and iso-alkanes without the esters, acids, etc. found in the animal and vegetable-based waxes.

Paraffin wax (or simply "paraffin") is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 47-64 °C  and having a density of around 0.9 g/cm3. It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents, but burns readily. Paraffin wax is generally unbranched hydrocarbon having carbon above C17 and  are solid at room temperature. Their carbon atoms typically ranges between C17 - C30 and having typical melting point around 60°C. All paraffinic wax are recovered from fractional distillation of petroleum.The name paraffin implies that it contains straight hydrocarbon structure but it has branch also. Branched paraffins are called ‘Isoparafins’ and cyclic parafins are called ‘Cresines’ or ‘Isoceresies’.

Fig.3: Paraffinic  Wax
Fig.4: Micro Crystalline Wax

 

 

 

 

 

 

Pure paraffin wax dose in rubber compounding varies from 1-3 phr. Pure paraffin wax is rarely used these days in rubber industry as it has oozing character and in excess it causes blooming on green rubber components, that results in reduction in compound tack. They are frequently blended with microcrystalline wax in rubber compounding therefore.

Pure paraffin wax is an excellent electrical insulator, with an electrical resistivity of between 1013 and 1017 ohm meter. This is better than nearly all other materials except some plastics (notably teflon or polytetrafluoroethylene). It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron. Paraffin wax (C25H52) is an excellent material to store heat, having a specific heat capacity of 2.14–2.9 J g–1 K–1 (joule per gram per kelvin) and a heat of fusion of 200–220 J g–1(joule per gram). This property is exploited in modified drywall for home building material.

Microcrystalline waxes: This is produced by de-oiling petrolatum, as part of the petroleum refining process. Microcrystalline wax contains a higher percentage of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons. It is characterized by the fineness of its crystals in contrast to the larger crystal of paraffin wax. It consists of high molecular weight saturated aliphatic hydrocarbons with comparatively higher melting point than paraffinic wax. It is generally darker, more viscous, denser, tackier and more elastic than paraffin waxes. The elastic and adhesive characteristics of microcrystalline waxes are related to the non-straight chain components which they contain. Typical microcrystalline wax crystal structure is small and thin, making them more flexible than paraffin wax. It is commonly used in rubber formulation and cosmetic formulations.

Its usual carbon atom ranges from C40–C70 , having comparatively higher melting point (Fig.4) between 80-105 0C because they have higher number of carbon. Common dose in rubber compounding is between 1-3 phr. Some time higher dose of  100% Micro crystalline wax is difficult to process and as a result they are often blended with paraffinic wax for rubber use. Blending is also done for economical reasons as microcrystalline wax is comparatively costlier. Paraffinic wax, having smaller molecular weight bleeds faster in cured rubber article, whereas, 100% micro crystalline wax  will have inherent resistance to faster volatilization and eventually, blended wax will have an intermediate property. Refineries may also utilize blending facilities to combine paraffin and microcrystalline waxes. This type of activity is prevalent especially for industries such as tire and rubber industries.

Higher dose of antioxidant and anti ozonates are always advised to add along with microcrystalline wax because the later help slower migration of antioxidant and antiozonates on the product surface and thereby increase on the product durability against ageing process. Tire curing bladder is often blended with 1-3 phr of microcrystalline wax.

Fig.5: Polyethylene, Fig.6: Polyethylene wax
Fig.7: Chlorinated Polyethylene waxes (CPE)

Chlorinated Paraffin Wax

Upon chlorination of paraffinic wax we get Chlorinated Paraffin Wax(CPW). This is available in batch process that is processed from effective exothermic reaction. This reaction generates a by-product hydrochloric acid that is later removed out of the solution. Finally stabilizer and solution is mixed that provide the required final product, which is used in various industrial applications. With 30 to 70% chlorine and insolubility in water, these CPWs have low vapor pressure. Chlorinated Paraffin Wax is highly inert, insoluble in water and they have low vapor pressure. Generally used as plasticizers in plastic and elastomers, where flame retardant property is important.

Polyethylene waxes (PE-Wax)

Polyethylene waxes or PE-Wax is same familiar polyethylene chemical structure (Fig.5) but with lower molecular weight , generally around or less than 3000.This is a processing aid in elastomer and plastics but basically they are a form of synthetic resins. It is a white solid product (Fig.6) appears in the market as powdery, lumpy, or flaky product. It is a non-toxic product having concentrated distribution of molecular weight of 1500 with specific gravity about 0.94 with high softening point but low fusion viscosity with melting point; 112 - 118°C, melt peak 110 °C, flash point 210°C, minimum. It has excellent stability against polishing, scratch resistance, metal mark resistance, scuff resistance. PE-Wax is resistant to water and chemical materials.

 

Yokohama Rubber And RAOT Hold 10th Joint Seminar For Thai Natural Rubber Farmers

Yokohama Rubber And RAOT Hold 10th Joint Seminar For Thai Natural Rubber Farmers

The Yokohama Rubber Co., Ltd. recently conducted an educational seminar for local natural rubber farmers in partnership with the Surat Thani branch of the Rubber Authority of Thailand (RAOT). This marked the 10th such event since the programme's inception in 2020, involving 50 local farm households. Attendees received complimentary fertiliser, developed with RAOT's expertise, as part of the ongoing support.

The seminar curriculum covered essential agricultural topics, including soil and plant nutrition, correct fertiliser application and methods to prevent contamination in natural rubber. To commemorate the 10th seminar, the programme was expanded to include guest speakers from local government, police and healthcare. These guests addressed broader community and safety issues, such as human rights for foreign and minority workers, road safety and occupational health. A particular focus was placed on practical well-being, with the local hospital director offering guidance on preventing injuries during tree tapping and managing encounters with poisonous insects.

Post-event feedback from participants was overwhelmingly positive. Many expressed that they gained new, systematic knowledge about cultivation practices, despite years of experience. Several noted that hearing directly from a rubber manufacturer reinforced the critical importance of purity in their product. Others found the health and safety advice immediately useful. The engaging delivery of the seminar was also highlighted, with one farmer mentioning a desire to recommend the valuable and enjoyable experience to peers.

This initiative is a direct implementation of a memorandum of understanding (MoU) signed between Yokohama Rubber and RAOT in January 2020. The MoU focuses on economic support for farmers and improving supply chain traceability, aligning with the company's Procurement Policy for Sustainable Natural Rubber. Hosted in the region where Yokohama’s Thai natural rubber processing subsidiary, Y.T. Rubber Co., Ltd. (YTRC), operates, the seminar exemplifies the policy's guideline to support small-scale farmers within the supply chain.

As a founding member of the Global Platform for Sustainable Natural Rubber (GPSNR), Yokohama Rubber is committed to advancing these principles. The company views such efforts as integral to creating shared value under its sustainability slogan, ‘Caring for the Future’, and contributes to broader United Nations Sustainable Development Goals through the promotion of sustainable raw material procurement.

Rubber Research Institute Of India Develops Latex-Based Paint

Rubber Research Institute Of India Develops Latex-Based Paint

In a significant event for India’s rubber sector, Minister for Ports, Co-operation & Devaswoms V N Vasavan inaugurated a ceremony for the transfer of innovative latex-based paint technology. This eco-friendly paint, a product derived from natural rubber, was developed by the Rubber Products Incubation Centre of the Rubber Research Institute of India. The technology was formally handed over to Kerala Paints Industries Private Ltd., with the Minister highlighting the event's historic nature for launching a sustainable product and stressing the importance of increasing domestic natural rubber consumption to improve grower returns.

Rubber Board Executive Director M Vasanthagesan outlined the centre's role in converting research into market-ready goods, reaffirming the Board's dedication to creating innovative, value-added rubber products. The gathering also heard remarks from several key figures, including Mahatma Gandhi University's K V Dayal, RRII Director Dr Debabrata Ray, RRII Senior Scientist Dr Shera Mathew and Kerala Paints' Managing Director Midhun P Pullumettel.

ANRPC Publishes Monthly NR Statistical Report For November 2025

ANRPC Publishes Monthly NR Statistical Report For November 2025

The Association of Natural Rubber Producing Countries (ANRPC) has released its Monthly NR Statistical Report for November 2025, providing an overview of key developments in the global natural rubber sector.

While a modest rise in global production of 1.3 percent is anticipated for the year, this follows a revised, lower output forecast for Indonesia. Concurrently, worldwide demand is projected to grow by a more subdued 0.8 percent, bolstered by an upward adjustment in Indonesia's own consumption figures.

Recent price pressures have emerged due to this combination of uncertain supply, influenced by unpredictable weather patterns and generally muted demand. However, there are sporadic positive indicators, including noticeable recoveries within the tyre sector across some regional markets.

Port of Antwerp

Bolder Industries is positioning itself at the forefront of circular economy innovation with its next-generation Antwerp facility, promising to recycle 6.6 million tyres annually while slashing greenhouse gas emissions by over 80 percent. While the company has proven its technology in the US with BolderBlack and BolderOil, scaling operations to Europe will test both supply chain resilience and market adoption. Beyond environmental claims, the facility’s success will hinge on replicating consistent product quality at commercial volumes, navigating regulatory frameworks and maintaining customer confidence amid global demand for sustainable industrial materials.

Bolder Industries recently secured a EUR 32 million grant from the EU Innovation Fund and an additional EUR 2 million from the Flanders region to support its Antwerp facility, which will recycle over six million tyres annually.

Scheduled to begin operations by 2027, the plant will utilise wind power and on-site heat to produce sustainable materials like BolderBlack and BolderOil, significantly reducing greenhouse gas emissions. Construction is set to commence in 2026, marking a major step towards sustainable manufacturing in Europe.

The plant will serve as a cornerstone for Europe’s circular economy ambitions and strengthen the company’s position in the growing global market for sustainable industrial materials.

Speaking exclusively to Tyre Trends, Chief Executive Officer Tony Wibbeler shared a thorough insight into the company’s strategy and technology, reflecting the company’s readiness to scale proven solutions to commercial volumes.

“Bolder is beyond an ambitious idea. Since 2019, we have demonstrated years of commercial success with BolderBlack and BolderOil, which are now supplied across thousands of applications in tyres, rubber, plastics and coatings. Our US operations have proven our technology at scale and the Antwerp facility is not a pilot project; it is backed by the European Commission’s Innovation Fund through CINEA as part of the NextGen Thermal Tire Re-use (N2TR) project with full capacity targeted for spring 2027,” explained Wibbeler.

“We’ve built traceability and certification frameworks like ISCC Plus, ensuring customers receive validated, circular and consistent materials. We’re not proving the concept, we’re scaling a proven solution to meet accelerating global demand,” he added.

BolderBlack, the company’s flagship product, is already integrated into more than 3,000 global applications including tyres, manufactured rubber goods, inks, coatings and plastics. BolderOil complements this by serving high-value markets such as petrochemicals, solvents, carbon black feedstocks and sustainable fuels.

“We do not focus on what others are doing. Our steadfast focus is on delivering consistent, high-quality solutions to customers who demand reliability. Our technology has consistently delivered high-quality products for over five years, making us one of the few companies with a proven commercial-scale history,” Wibbeler noted.

The company sources its feedstock exclusively from post-consumer and post-industrial end-of-life tyres and scrap rubber obtained through partnerships in the US and Europe. “Because we are not tied to oil markets, our products are shielded from oil volatility and tariffs. That

stability enables predictable pricing, typically at a discount to virgin carbon black,” contended Wibbeler.

QUALITY STANDARDS

Meeting stringent tyre maker quality standards is a continuous process. Aside from traditional certifications like ISO 9001, the company has learned a tremendous amount from its customers. “While audits can be daunting, we embrace their experiences and utilise their suggestions to improve our manufacturing processes continually,” noted Wibbeler.

The Port of Antwerp facility is designed to recycle approximately 6.6 million tyres annually at full operation. The process achieves an over 80 percent reduction in greenhouse gas emissions and reduces water use by more than 90 percent compared to conventional carbon black production. This represents a major step forward from traditional tyre disposal methods such as landfilling and incineration, which are resource-intensive and environmentally harmful.

Strategically located on a 55,152-square-metre site within the NextGen District, the Antwerp facility will house four proprietary reactors and a state-of-the-art finishing line. The plant will be powered predominantly by renewable energy including wind power and recovered heat, underscoring the company’s commitment to environmental stewardship.

Complementing the Antwerp operation, Bolder’s US expansion in Terre Haute, Indiana, will recycle a comparable volume of tyres, producing 18,000 metric tonnes of BolderBlack and 21,000 metric tonnes of BolderOil.

“Together, these two facilities create a robust transatlantic supply network that guarantees customers consistent and reliable volumes,” Wibbeler highlighted.

CIRCULAR HUB

The Antwerp facility also contributes to regional economic growth, creating at least 50 new jobs in Flanders and reinforcing Antwerp’s standing as a circular economy hub. Cleaner production, strategic port access and integration within Europe’s largest petrochemical cluster further enhance the plant’s operational advantages.

The company’s resilience stems from multiple business safeguards. These include geographic diversification, alignment with ISCC Plus and European Union frameworks and securing commercial offtake agreements before capacity expansions.

The company recently secured a significant equity investment from Tiger Infrastructure Partners, a private equity firm with expertise in scaling infrastructure projects across the US and Europe, to support growth.

“Our customer base spans the largest tyre manufacturers globally and smaller players alike. This segmentation strategy places BolderBlack into thousands of products, from performance tyres to wetsuits, exemplifying our market reach,” Wibbeler affirmed.

While BolderBlack is already in mainstream production for some manufacturers, others remain in pilot phases. Multi-year offtake contracts ensure operational stability for existing and future capacities.

Regarding the pyrolysis oil produced in the recycling process, the company emphasises a commitment to true circularity. “Our primary markets for BolderOil are carbon black oil feedstock and petrochemicals, supporting circularity goals in tyre and rubber goods industries. We anticipate entering sustainable fuels markets in Europe, though nothing has been finalised currently,” stated the executive.

Addressing concerns around pyrolysis potentially delaying landfill issues, Wibbeler said, “That critique is both misinformed and shortsighted. Pyrolysis is just one step in our broader process. Our traceable tyre-to-tyre reuse model effectively solves the problem rather than delaying it.”

Bolder Industries is actively engaged in industry forums and circular economy initiatives, promoting sustainable materials and tyre recycling advancements, highlighting its leadership role beyond operational activity. The company has achieved multiple certifications and complies rigorously with environmental and quality standards and maintains a Silver EcoVadis rating, reflecting corporate responsibility.

The growing global recycled materials market further positions it to capture market share as industries elevate environmental compliance and sustainability.

Wibbeler concluded with an ambitious outlook, stating, “The industry faces many challenges ahead. Our aim for the next decade is to expand globally, deepen partnerships and deploy a range of technologies to deliver scalable, traceable circular solutions. That’s the role we are committed to playing.”