• 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

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

  

   

• 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’.

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.

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.

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Birla Carbon, a leading global manufacturer and supplier of high-quality carbon materials, has been awarded the prestigious Platinum sustainability rating by EcoVadis, ranking it within the top one percent of all assessed companies globally. This honour recognises the firm’s enterprise-wide leadership in integrating sustainability across its operations, innovation and value chain.

The evaluation specifically commended its strong performance across four key areas: Environment, Labor & Human Rights, Ethics and Sustainable Procurement. This achievement is further validated by extensive third-party certifications, with over 75 percent of operations certified to international standards including ISO 14001, ISO 50001, ISO 45001, SA8000 and ISO 27001, underscoring the consistency and strength of its sustainability management systems.

John Loudermilk, President and CEO, Birla Carbon, said, “This Platinum rating reflects the steady progress we are making in embedding sustainability at the core of our business. Our growth strategy is geared towards delivering sustainability through innovation, operational excellence and responsible practices across our global footprint. We continually invest in sustainability and circularity-driven processes, keeping our operations sustainably efficient while creating long-term value for our customers, partners, communities and employees. Our sustainability strategy, Share the Future, serves as a roadmap to a sustainable future and guides our actions towards our aspiration of reaching net zero carbon emissions over the next 25 years. Being recognised among the top one percent of companies globally is a testament to the commitment of our teams worldwide.”

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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.

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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.

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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.

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