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.

 

ANRPC Publishes Monthly NR Statistical Report For October 2025

ANRPC Publishes Monthly NR Statistical Report For October 2025

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

According to the report, the global natural rubber market in October was characterised by a distinct bearish trend in pricing. This decline can primarily due to a significant surge in production and export activities, which were initially stimulated by the higher prices seen earlier in the year. Meanwhile, overall demand has remained relatively subdued.

Looking ahead to the full year, projections indicate a modest 1.3 percent increase in global production for 2025, a figure that follows a recent downward revision for Indonesia. On the demand side, consumption is anticipated to grow by a slight 0.8 percent, influenced by an upward adjustment to Indonesia's consumption data. Despite the current price pressures, market sentiment shows some mixed signs of improvement, particularly within the tyre trade of certain specific markets.

DuPont Breaks Ground On Major MOLYKOTE Lubricants Plant In China

DuPont Breaks Ground On Major MOLYKOTE Lubricants Plant In China

DuPont commenced construction on a new MOLYKOTE speciality lubricants production facility in Zhangjiagang, Jiangsu Province, East China, on 18 November 2025 with a groundbreaking ceremony that was attended by Senior DuPont leadership from the MOLYKOTE business and the Asia-Pacific region, alongside government officials and key customers. This strategic investment, situated within the Yangtze River International Chemical Industrial Park, is projected to be fully operational by the beginning of 2027. The initiative is a key component of the brand's global expansion, designed to significantly enhance its responsiveness to regional market needs and foster local innovation.

The new plant will primarily focus on meeting the robust and growing demand for advanced lubricant solutions across several critical sectors in China, including transportation, industrial manufacturing, energy and electronics. By establishing a local manufacturing presence, DuPont aims to create a dynamic platform for collaboration with regional customers. This will enable the company to deliver next-generation lubricants with greater speed, precision and agility, ultimately shortening lead times and strengthening supply chains.

The MOLYKOTE brand, with a legacy spanning over 75 years, is globally recognised for its expertise in solving complex lubrication challenges and improving energy efficiency. Its comprehensive product portfolio, which includes greases, oils, anti-friction coatings and pastes, serves the automotive and industrial maintenance, repair and overhaul markets worldwide. Supported by a global network of manufacturing and research facilities, the brand continues to build on its reputation for performance and reliability.

Eugenio Toccalino, Vice President and General Manager, DuPont MOLYKOTE, said, “Today’s groundbreaking is the beginning of a new chapter in our journey to better serve our customers in China, innovate faster and to be a partner of choice for solving wear and friction challenges across industries. This facility will boost local capabilities for application and new formulation development, empowering customer collaboration and response in real time.”

Yi Zhang, Global VP and Regional President, DuPont Asia Pacific, said, “We are thrilled to be breaking ground on the MOLYKOTE China production facility in Zhangjiagang. This manufacturing unit will enable us to address current needs and future trends for speciality lubricants. It reflects our confidence in the long-term potential of customers in China and Asia-Pacific region and reinforces our commitment to deliver faster, more resilient and locally tailored solutions.”

Bekaert Introduces inhera Sustainability Label For Net-Zero Transition

Bekaert Introduces inhera Sustainability Label For Net-Zero Transition

In a significant move to formalise and advance its environmental strategy, Bekaert has launched 'inhera., a new sustainability label. This initiative underscores the company's dedication to a net-zero future by identifying its most impactful innovations that help industrial customers decarbonise more rapidly. The label serves as a mark of performance and trust, spotlighting solutions that meet stringent, externally validated criteria aligned with frameworks such as the EU Taxonomy Regulation.

The core purpose of inhera is to provide clarity and assurance, demonstrating how specific Bekaert products enable tangible progress in reducing carbon emissions, enhancing resource efficiency and promoting circular economic models. This is increasingly critical in a business landscape where demonstrable sustainability is a strategic necessity rather than an optional consideration. The label currently features a curated selection of eight high-performing solutions across sectors like construction, energy and automotive.

These labelled innovations illustrate a practical path toward cleaner industrial processes. For instance, Ampact magnet wire for electric motors cuts direct CO₂ emissions by 10 percent, while Flexisteel hoist ropes for elevators can reduce daily energy consumption by up to 36 percent. Other products, such as Elyta Ultra tyre reinforcements, deliver significant CO₂ savings per tyre and support circular reuse. Material efficiency is another key focus, exemplified by high tensile steel cores for power lines that use over 30 percent less steel and a next-generation Hose Wire that requires 28 percent less wire. Further offerings, including Bezinal Vineyard Plus and subsea cable armouring wire, utilise low-carbon materials and recycled content to achieve CO₂ reductions exceeding 50 percent.

The name 'inhera' was chosen to reflect the company's belief that sustainability is an inherent component of its corporate identity, deeply embedded within its innovation processes and overall mindset. Bekaert positions the label as more than a certification; it represents a partnership with customers to create measurable environmental impact. Ann-Françoise Versele, VP Sustainability, explained, “Sustainability is inherent in everything we do at Bekaert. Through our products and processes, we aim to leave a legacy of sustainability for future generations. Our partners who choose inhera solutions are choosing to accelerate sustainability and create real impact.”

Nynas Powers Croatia's First Green Transformer With NYTRO BIO 300X Renewable Insulating Fluid

Nynas Powers Croatia's First Green Transformer With NYTRO BIO 300X Renewable Insulating Fluid

Nynas has played a pivotal role in a landmark achievement for Croatia's energy sector by supplying its advanced NYTRO BIO 300X insulating liquid. This fully renewable fluid has been used for the first time in the Croatian market to fill a 630 kVA distribution transformer. The unit, manufactured by KONČAR – Distribution & Special Transformers, was recently installed in Zagreb for HEP ODS, the national Distribution System Operator.

This collaboration marks the inaugural deployment of a ‘Green Transformer’ in Croatia, representing a significant advancement for the country's distribution network. The project underscores a unified drive towards greater sustainability and a reduced environmental footprint for critical power infrastructure. For Nynas, this milestone highlights the practical application and reliability of its bio-based product portfolio.

NYTRO BIO 300X is engineered to provide a drop-in solution that combines high oxidation stability and superior cooling performance, allowing operators to enhance their ecological standards without compromising on operational reliability or transformer longevity. The successful installation stands as a testament to how industry partnerships are actively accelerating the transition to a more sustainable energy future.

Ivanka Radić, responsible for transformer oils at KONČAR - D&ST, said, “The thermal and dielectric tests on the transformer filled with NYTRO BIO 300X were successfully completed, and the unit is now fully operational. As expected, all test results were within the required limits, confirming the reliability and stability of this innovative fluid.”

Daniele Frustagli, General Manager Italy & the Balkans at Nynas, said, “We are very proud to have been entrusted with this project by KONČAR - D&ST and HEP ODS Zagreb, allowing us to showcase to them and the entire electrical industry the advantages of this fully renewable, bio-based hydrocarbon liquid. In addition to meeting and exceeding the IEC 60296 ed. 5 (2020) specification, the product is readily biodegradable, fully bio-based and has ultra-low viscosity.”

Vanja Burul, President of the Management Board at KONČAR - D&ST, said, “This project reflects our ongoing efforts to explore more sustainable insulating fluids. We see great potential for further use of NYTRO BIO 300X in future applications.”