This document provides an overview of rubber materials, including:
1. Natural rubber comes from latex extracted from rubber trees, while synthetic rubber is made through polymerization processes.
2. Rubber is classified based on its source and monomers used. The main types discussed are natural rubber, styrene-butadiene rubber, and chloroprene.
3. Rubber undergoes processes like mastication to break down polymer chains, compounding to add ingredients, and forming processes like calendaring, coating, extrusion, and molding to produce rubber products.
Natural rubber is obtained from latex extracted from rubber trees. It is composed primarily of the monomer isoprene. Throughout history, various advancements were made in rubber technology, including vulcanization which allows rubber to retain its shape. There are now many types of both natural and synthetic rubbers produced for various applications. The basic rubber compound involves mixing the rubber polymer with sulfur, zinc oxide, stearic acid, and accelerators. Additional components like fillers and plasticizers are often included to modify the properties of the cured rubber material. Rubber is processed using equipment like mills, mixers, extruders, calenders, and molds.
This document discusses rubber compounding and the various materials involved. It provides information on 3 students, the properties and applications of rubber, raw materials in rubber compounds including polymers, fillers, antioxidants, oils and cures. It also discusses different types of rubbers like CPE, EDPM, natural rubber, NBR, SBR and classifications of materials used in rubber compounding.
The objective of this presentation is to give an overview of rubber compounding. We will briefly focus on:
Elastomer System
Filler System
Protection system
Process Aids
Cure System
Rubber Processing and Profiting: Compounding, Mixing, Vulcanization, Extrusio...Ajjay Kumar Gupta
Methods for processing rubber include mastication and various operations like mixing, calendering, extrusion, all processes being essential to bring crude rubber into a state suitable for shaping the final product. The former breaks down the polymer chains, and lowers their molecular mass so that viscosity is low enough for further processing. After this has been achieved, various additions can be made to the material ready for cross-linking. Rubber may be masticated on a two-roll mill or in an industrial mixer, which come in different types.
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Basic compounding and processing of rubber, Business guidance for rubber processing, Business guidance for rubber compounding, Business guidance to clients, Business Plan for a Startup Business, Business plan on Rubber, Business start-up, How is rubber made?, How to Start a Rubber business?, How to Start a Rubber Production Business, How to start a successful Rubber Processing business, How to Start Rubber processing Business, How to Start Rubber Processing Industry in India, Manufacture of Rubber Products, Most Profitable Rubber Processing Business Ideas, Natural Rubber Processing Line, Natural rubber processing method, Natural Rubber Processing, New small scale ideas in Rubber processing industry, Opportunities in Rubber industries for new business, Processing and Profiting from Rubber, Processing methods for rubber materials, Profitable Rubber Business Ideas Small Scale Manufacturing, Profitable small and cottage scale industries, Profitable Small Scale Rubber Manufacturing, Rubber and Rubber Products, Rubber based Industries processing, Rubber Based Small Scale Industries Projects, Rubber business plan, Rubber Chemistry, Rubber compounding, Rubber Compounding & Mixing, Rubber compounding ingredients, Rubber compounding method, Rubber compounding process, Rubber compounding technology, Rubber Extrusion, Rubber mixing process, Rubber Mixing, Rubber Principles, Rubber processing, Rubber Processing & Rubber Based Profitable Projects, Rubber Processing and Profiting, Rubber Processing Business, Rubber Processing Industry in India, Rubber processing methods, Rubber Processing Projects, Rubber processing technology, Rubber Products manufacturing, Rubber Products, Rubber technology, Rubber Technology and Manufacturing Process of Rubber Products, Rubber Vulcanization, Rubbers processing technology, Setting up of Rubber Processing Units, Small scale manufacturing business in rubber industry, Small Scale Rubber Processing Projects, Small scale Rubber production line, Small Start-up Business Project, Starting a Rubber Processing Business, Start-up Business Plan for Rubber Processing, Steps in processing of rubber, Vulcanization of rubber, Vulcanization of rubber compounds, Vulcanized rubber properties, Rubber processing and compounding
Rubber can be natural or synthetic. Natural rubber comes from latex extracted from plants like rubber trees. It is stretchy and flexible. Synthetic rubber is man-made using a polymerization process and common types include polybutadiene and styrene-butadiene. Vulcanization is a process that converts natural or synthetic rubber into a more durable material by adding sulfur or other compounds, which causes cross-linking between polymer chains. This makes the rubber stronger and able to withstand a wider range of temperatures compared to natural rubber.
Butyl Rubber (IIR) Production. Synthetic Rubber Manufacturing Industry
Butyl rubber (IIR), also called isobutylene-isoprene rubber, a synthetic rubber produced by copolymerizing isobutylene with small amounts of isoprene. Valued for its chemical inertness, impermeability to gases, and weather ability, butyl rubber is employed in the inner linings of automobile tires and in other specialty applications.
Butyl Rubber Applications
Butyl rubber is one of the most commonly used rubber materials used in the manufacturing of a wide range of industrial rubber products. The remarkable properties of butyl rubber like excellent impermeability/air retention and good flex properties, make it a key polymer for a wide range of technical rubber applications. For more information on this type of rubber, check out our section on Butyl Rubber. We present below the use of butyl rubber in various applications:
• Automotive Tires
One of the most popular use of butyl rubber is in the making of automotive tires. The first commercial use of butyl rubber was seen in the tire inner tubes. Regular butyl provide excellent inflation pressure retention for truck, bicycle, industrial, agricultural and specialty tires. Butyl rubber is capable to produce more durable tubeless tires with the air retaining inner liner chemically bonded to the body of the tire.
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Niir Project Consultancy Services
An ISO 9001:2015 Company
106-E, Kamla Nagar, Opp. Spark Mall,
New Delhi-110007, India.
Email: npcs.ei@gmail.com , info@entrepreneurindia.co
Tel: +91-11-23843955, 23845654, 23845886, 8800733955
Mobile: +91-9811043595
Website: www.entrepreneurindia.co , www.niir.org
Tags
Butyl Rubber Production, Butyl Rubber, Chemical Compound, Production of Butyl Rubber, Process for Production of Butyl Rubber, Butyl Rubber, Synthetic Rubber, Preparation of Butyl Rubber, Butyl Rubber Formula, Butyl Rubber Properties, Butyl Rubber Manufacture, Butyl Rubber Uses, Butyl Rubber Manufacturing Process, Manufacture of Butyl Rubber, Butyl Rubber and Process for Production, Butyl Rubber Plant, Butyl Rubber Properties & Applications, Butyl Rubber (IIR), Synthetic Rubber Industry, Butyl Rubber Manufacturing Plant, Butyl Rubber (IIR) Products for Industrial Use, Butyl Rubber Manufacturing Process, Butyl Rubber Industry, Project Report on Butyl Rubber Production Industry, Detailed Project Report on Butyl Rubber Production, Project Report on Butyl Rubber Production, Pre-Investment Feasibility Study on Butyl Rubber Production, Techno-Economic feasibility study on Butyl Rubber Production, Feasibility report on Butyl Rubber Production, Free Project Profile on Butyl Rubber Production, Project profile on Butyl Rubber Production, isobutylene-isoprene rubber, Download free project profile on Butyl Rubber Production, Butyl Rubber Manufacturing Business, Halogenated Butyl Rubber, Production of Halogenated Butyl Rubber
ABOUT ELASTOMER TYPES AND VULCANISATIONmannukumar24
This document provides an overview of polymeric materials called elastomers. It discusses different classes of elastomers including natural rubber, synthetic rubbers, and thermoplastic elastomers. Key points covered include the properties of natural rubber, the vulcanization process, common rubber additives and modifiers, commercial elastomers like styrene-butadiene rubber and their applications. Thermoplastic elastomers are also summarized, focusing on their production methods and advantages over traditional vulcanized rubbers.
This document discusses three types of rubber: natural rubber, synthetic rubber, and neoprene rubber. Natural rubber comes from latex and trees, was used by ancient civilizations, and is used today mainly for tires and hoses. Synthetic rubber is made from petroleum, was invented in 1909 as a cheaper alternative to natural rubber, and accounts for two-thirds of rubber production today. Neoprene is a synthetic rubber made from chloroprene polymerization that is chemically stable over a wide temperature range and used for products like wetsuits and boots.
Natural rubber is obtained from latex extracted from rubber trees. It is composed primarily of the monomer isoprene. Throughout history, various advancements were made in rubber technology, including vulcanization which allows rubber to retain its shape. There are now many types of both natural and synthetic rubbers produced for various applications. The basic rubber compound involves mixing the rubber polymer with sulfur, zinc oxide, stearic acid, and accelerators. Additional components like fillers and plasticizers are often included to modify the properties of the cured rubber material. Rubber is processed using equipment like mills, mixers, extruders, calenders, and molds.
This document discusses rubber compounding and the various materials involved. It provides information on 3 students, the properties and applications of rubber, raw materials in rubber compounds including polymers, fillers, antioxidants, oils and cures. It also discusses different types of rubbers like CPE, EDPM, natural rubber, NBR, SBR and classifications of materials used in rubber compounding.
The objective of this presentation is to give an overview of rubber compounding. We will briefly focus on:
Elastomer System
Filler System
Protection system
Process Aids
Cure System
Rubber Processing and Profiting: Compounding, Mixing, Vulcanization, Extrusio...Ajjay Kumar Gupta
Methods for processing rubber include mastication and various operations like mixing, calendering, extrusion, all processes being essential to bring crude rubber into a state suitable for shaping the final product. The former breaks down the polymer chains, and lowers their molecular mass so that viscosity is low enough for further processing. After this has been achieved, various additions can be made to the material ready for cross-linking. Rubber may be masticated on a two-roll mill or in an industrial mixer, which come in different types.
See more
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http://goo.gl/eUrr6y
http://goo.gl/MxxyTW
http://www.entrepreneurindia.co/
Tags
Basic compounding and processing of rubber, Business guidance for rubber processing, Business guidance for rubber compounding, Business guidance to clients, Business Plan for a Startup Business, Business plan on Rubber, Business start-up, How is rubber made?, How to Start a Rubber business?, How to Start a Rubber Production Business, How to start a successful Rubber Processing business, How to Start Rubber processing Business, How to Start Rubber Processing Industry in India, Manufacture of Rubber Products, Most Profitable Rubber Processing Business Ideas, Natural Rubber Processing Line, Natural rubber processing method, Natural Rubber Processing, New small scale ideas in Rubber processing industry, Opportunities in Rubber industries for new business, Processing and Profiting from Rubber, Processing methods for rubber materials, Profitable Rubber Business Ideas Small Scale Manufacturing, Profitable small and cottage scale industries, Profitable Small Scale Rubber Manufacturing, Rubber and Rubber Products, Rubber based Industries processing, Rubber Based Small Scale Industries Projects, Rubber business plan, Rubber Chemistry, Rubber compounding, Rubber Compounding & Mixing, Rubber compounding ingredients, Rubber compounding method, Rubber compounding process, Rubber compounding technology, Rubber Extrusion, Rubber mixing process, Rubber Mixing, Rubber Principles, Rubber processing, Rubber Processing & Rubber Based Profitable Projects, Rubber Processing and Profiting, Rubber Processing Business, Rubber Processing Industry in India, Rubber processing methods, Rubber Processing Projects, Rubber processing technology, Rubber Products manufacturing, Rubber Products, Rubber technology, Rubber Technology and Manufacturing Process of Rubber Products, Rubber Vulcanization, Rubbers processing technology, Setting up of Rubber Processing Units, Small scale manufacturing business in rubber industry, Small Scale Rubber Processing Projects, Small scale Rubber production line, Small Start-up Business Project, Starting a Rubber Processing Business, Start-up Business Plan for Rubber Processing, Steps in processing of rubber, Vulcanization of rubber, Vulcanization of rubber compounds, Vulcanized rubber properties, Rubber processing and compounding
Rubber can be natural or synthetic. Natural rubber comes from latex extracted from plants like rubber trees. It is stretchy and flexible. Synthetic rubber is man-made using a polymerization process and common types include polybutadiene and styrene-butadiene. Vulcanization is a process that converts natural or synthetic rubber into a more durable material by adding sulfur or other compounds, which causes cross-linking between polymer chains. This makes the rubber stronger and able to withstand a wider range of temperatures compared to natural rubber.
Butyl Rubber (IIR) Production. Synthetic Rubber Manufacturing Industry
Butyl rubber (IIR), also called isobutylene-isoprene rubber, a synthetic rubber produced by copolymerizing isobutylene with small amounts of isoprene. Valued for its chemical inertness, impermeability to gases, and weather ability, butyl rubber is employed in the inner linings of automobile tires and in other specialty applications.
Butyl Rubber Applications
Butyl rubber is one of the most commonly used rubber materials used in the manufacturing of a wide range of industrial rubber products. The remarkable properties of butyl rubber like excellent impermeability/air retention and good flex properties, make it a key polymer for a wide range of technical rubber applications. For more information on this type of rubber, check out our section on Butyl Rubber. We present below the use of butyl rubber in various applications:
• Automotive Tires
One of the most popular use of butyl rubber is in the making of automotive tires. The first commercial use of butyl rubber was seen in the tire inner tubes. Regular butyl provide excellent inflation pressure retention for truck, bicycle, industrial, agricultural and specialty tires. Butyl rubber is capable to produce more durable tubeless tires with the air retaining inner liner chemically bonded to the body of the tire.
See more
http://goo.gl/MwYpVf
https://goo.gl/P10f1y
Contact us:
Niir Project Consultancy Services
An ISO 9001:2015 Company
106-E, Kamla Nagar, Opp. Spark Mall,
New Delhi-110007, India.
Email: npcs.ei@gmail.com , info@entrepreneurindia.co
Tel: +91-11-23843955, 23845654, 23845886, 8800733955
Mobile: +91-9811043595
Website: www.entrepreneurindia.co , www.niir.org
Tags
Butyl Rubber Production, Butyl Rubber, Chemical Compound, Production of Butyl Rubber, Process for Production of Butyl Rubber, Butyl Rubber, Synthetic Rubber, Preparation of Butyl Rubber, Butyl Rubber Formula, Butyl Rubber Properties, Butyl Rubber Manufacture, Butyl Rubber Uses, Butyl Rubber Manufacturing Process, Manufacture of Butyl Rubber, Butyl Rubber and Process for Production, Butyl Rubber Plant, Butyl Rubber Properties & Applications, Butyl Rubber (IIR), Synthetic Rubber Industry, Butyl Rubber Manufacturing Plant, Butyl Rubber (IIR) Products for Industrial Use, Butyl Rubber Manufacturing Process, Butyl Rubber Industry, Project Report on Butyl Rubber Production Industry, Detailed Project Report on Butyl Rubber Production, Project Report on Butyl Rubber Production, Pre-Investment Feasibility Study on Butyl Rubber Production, Techno-Economic feasibility study on Butyl Rubber Production, Feasibility report on Butyl Rubber Production, Free Project Profile on Butyl Rubber Production, Project profile on Butyl Rubber Production, isobutylene-isoprene rubber, Download free project profile on Butyl Rubber Production, Butyl Rubber Manufacturing Business, Halogenated Butyl Rubber, Production of Halogenated Butyl Rubber
ABOUT ELASTOMER TYPES AND VULCANISATIONmannukumar24
This document provides an overview of polymeric materials called elastomers. It discusses different classes of elastomers including natural rubber, synthetic rubbers, and thermoplastic elastomers. Key points covered include the properties of natural rubber, the vulcanization process, common rubber additives and modifiers, commercial elastomers like styrene-butadiene rubber and their applications. Thermoplastic elastomers are also summarized, focusing on their production methods and advantages over traditional vulcanized rubbers.
This document discusses three types of rubber: natural rubber, synthetic rubber, and neoprene rubber. Natural rubber comes from latex and trees, was used by ancient civilizations, and is used today mainly for tires and hoses. Synthetic rubber is made from petroleum, was invented in 1909 as a cheaper alternative to natural rubber, and accounts for two-thirds of rubber production today. Neoprene is a synthetic rubber made from chloroprene polymerization that is chemically stable over a wide temperature range and used for products like wetsuits and boots.
Natural rubber is a type of polyisoprene made of cis-linked isoprene units that gives it an elastic structure. It is obtained commercially from the latex of the Para rubber tree. Rubber is vulcanized to improve its mechanical properties like tensile strength and hardness. Natural rubber composites are made by reinforcing rubber with fibers, fillers like carbon black, or nanoparticles to enhance properties. Natural rubber finds applications in tires, hoses, footwear and other products where elasticity and vibration absorption are important.
The document discusses properties and applications of rubber. It begins by introducing the group members and providing an overview of natural and synthetic rubber. It then discusses various properties of rubber including its flexibility, elasticity, water resistance and insulation properties. Various applications of rubber are also presented, including use in rubber flooring, adhesives, bearings pads, and expansion joints. The document concludes that both natural and synthetic rubber have many uses in construction and other industries.
Styrene-butadiene rubber (SBR) is a synthetic rubber derived from styrene and butadiene monomers. There are two main types - emulsion polymerized SBR (E-SBR) and solution polymerized SBR (S-SBR). E-SBR accounts for over 50% of car tire production and is also used in conveyor belts, footwear, adhesives and more. S-SBR offers improved properties for tires and is increasingly used. The document discusses the production, properties and applications of SBR.
Short Description related to the rubber filler properties and Rubber filler types ( Reinforcing fillers, Semi- reinforcing fillers and Non-reinforcing fillers). e.g.:- Carbon Black, Silica, Calcium Carbonate, Clay and Miscellaneous Fillers
This document discusses natural and synthetic rubber. It notes that natural rubber comes from the latex of rubber trees, while synthetic rubber is produced from petroleum byproducts. The two main types are natural rubber and synthetic rubbers such as styrene butadiene rubber (SBR). SBR production has largely replaced natural rubber and is now the most widely used synthetic rubber, commonly made through emulsion polymerization.
This document discusses the history and chemistry of vulcanization and curing systems for rubber. Some key points include:
- Charles Goodyear discovered in 1839 that heating rubber with sulfur produced an elastic product that did not become sticky or brittle at high/low temperatures, launching the vulcanization process.
- Sulfur has remained the most important vulcanizing agent, though other chemicals have also been examined. Accelerators were later developed to speed up the vulcanization reaction.
- Efficient vulcanization systems using sulfur donors and accelerators produce vulcanizates with mainly mono- and disulfide crosslinks rather than unstable polysulfide crosslinks and pendant groups. This improves aging
This document provides information on the production of rubber footwear. It discusses the traditional hand assembly process and more modern direct moulding and injection moulding techniques. It describes the various materials used such as natural rubber, synthetic rubbers, fillers and chemicals. Specific compound formulations are provided for shoe uppers, soles and industrial boots. The production process involves preparing lasts, assembling parts, varnishing, and vulcanization. Compression moulding and injection moulding of soles and heels are also summarized.
This document provides an overview of rubber processing operations. It begins by defining rubber as a material that can be stretched and returns to its original shape. Natural rubber comes from the latex of rubber trees, while synthetic rubber is produced from petrochemicals. Natural rubber is too soft on its own. The key process is vulcanization, discovered by Charles Goodyear, which involves adding sulfur to produce cross-linking that makes rubber stronger and more elastic. The two basic steps in production are making the raw rubber, and then processing it through compounding, mixing, shaping and vulcanizing into finished goods like tires.
What is and what is the function of a rubber seal
The Increasing of the speed of mechanical systems, driven by the desire for greater productivity, leads to higher operating temperatures and reduced fluid viscosities. This, coupled with higher pressures, causes an increasing tendency for fluid to leak. This leak in fuel systems that handle highly flammable solvents cannot be overlooked as there is a high probability of a fire hazard.
For this reason it has become common practice to include a safe leak path in the system design, to an escape or collection point, in order to minimize risk.
Seals prevent fluid from escaping from a hollow cylinder when a shaft penetrates the cylinder wall. Most commonly, the axis will have a rotary or linear motion. If a seal is not made for functional requirements, or installed and maintained properly, it can fail, causing fluid loss. The two main functions of a seal are to keep the fluid in while keeping dirt and debris out.
Zinc oxide (ZnO) is added to rubber compounds to activate sulfur vulcanization and thereby reduce the vulcanization time. ... The release of zinc into the environment from rubber occurs during the production, disposal, and recycling of rubber products (e.g., through leaching in landfill sites).
Its most common application is as a vulcanization activator in conjunction with stearic acid. Its addition is recommended at the beginning of the mixture, after the addition of stearic acid - its addition before stearic acid causes difficulty in incorporation and problems with dispersion.
This document discusses different types of polymer fibers and their production methods. It begins by describing extrusion as a common way to shape polymers into fibers through a die. Two main fiber production methods are then covered: melt spinning, where fibers are extruded from a melt through a spinneret, and wet spinning, where polymers are extruded from a solution. Specific high-strength fibers are also summarized like Kevlar, polyethylene, and carbon fibers produced from polyacrylonitrile. The document aims to explain how polymer structure impacts fiber properties at the macro and microscale.
This document presents information about nylon 6,6 polymer. It discusses the history of nylon 6,6's development beginning in 1927. It then describes the synthesis of nylon 6,6 which involves a step-growth polymerization of hexamethylene diamine and adipic acid. The document outlines the physical and chemical properties of nylon 6,6 including its elasticity, stiffness, melting point, and resistance to chemicals. Common applications of nylon 6,6 are mentioned such as uses in pipes, machine parts, carpets, and tires due to its strength, rigidity, and stability at high temperatures. Finally, advantages like heat and chemical resistance and disadvantages such as water absorption are highlighted.
High Performance Fibers- Aramid fibers- Their Spinning Techniques-Naveed Ahmed Fassana
A brief introduction of High Performance fibers and spinning techniques through which these fibers are produced are mentioned in these slides. Also there is a brief explanation of Aramid, Kevlar, and Nomex fibers with respect to their properties with the help of graphs etc.
In 1938, Paul Schlack of IG Farben created Nylon 6 by polymerizing Caprolactum into a homopolymer called polyhexano-6-lactum. Nylon 6 has high tensile strength, toughness, elasticity, and resistance to abrasion and chemicals. It is used for applications like bristles, gears, threads, ropes, surgical sutures and knitted garments. While some bacteria and fungi can degrade Nylon 6 oligomers, polymers are not easily biodegraded.
This document provides an overview of latex ingredients and compounding formulations for latex products. It discusses the key components of natural rubber latex and synthetic lattices like SBR, neoprene, and nitrile. It describes the processes used to concentrate and preserve latex, including centrifuging and the use of ammonia or ammonia with bactericides. The document also covers the dispersion and emulsification of solids and liquids for addition to latex, and the roles of auxiliary chemicals like stabilizers, wetting agents, and thickening agents in compounding latex and achieving desired product characteristics.
Natural rubber is a natural polymer obtained from the latex of the rubber tree Hevea brasiliensis. It is composed of polyisoprene, which is a long chain of the monomer isoprene. Latex is a white fluid that is coagulated to form solid natural rubber through the addition of bacteria or acids that lower the pH. Vulcanization improves the properties of natural rubber by adding sulfur to form cross-links between polymer chains, making the rubber more durable and elastic.
This document provides an overview of styrene-butadiene rubber (SBR), including its history, raw materials, manufacturing processes, properties, structure, and applications. Some key points:
- SBR is a random copolymer of styrene and butadiene that accounts for around half of global synthetic rubber production. Its main use is in tire manufacturing.
- SBR was developed in the 1920s-1930s as a replacement for natural rubber. Modern solution and emulsion polymerization techniques were established in the 1950s.
- SBR can be produced via emulsion or solution polymerization. Emulsion SBR dominates tire applications due to its oil-extendability and dynamic properties.
The document provides an overview of natural rubber, including its sources, properties, uses, and production process. It defines natural rubber as a natural polymer obtained from the latex of the rubber tree. Key points include natural rubber's monomer (isoprene), how coagulation occurs through acid/base reactions, the vulcanization process involving sulfur to improve properties, and natural rubber's contributions to Malaysia's economy through industries like rubber gloves.
This document discusses chloroprene rubber, a synthetic rubber introduced in 1932. It summarizes that chloroprene rubber is produced through the emulsion polymerization of chloroprene monomers. It can be produced through two main processes - one using sulfur modification and one using chain transfer agents like mercaptans. The document also lists some key properties of chloroprene rubber, including good resistance to ozone, heat aging and chemicals. Finally, it outlines some common applications for chloroprene rubber like gaskets, cable jackets and hoses due to its temperature resistance and chemical resistance.
The document discusses rubber, including its properties, types (natural and synthetic), production processes, and applications. It describes how natural rubber is obtained from rubber trees by tapping latex and coagulating it. It also explains various synthetic rubbers like SBR, butyl, EPDM, and nitrile. Key applications mentioned include rubber flooring, adhesives, expansion joints, and bearing pads.
Natural rubber is a type of polyisoprene made of cis-linked isoprene units that gives it an elastic structure. It is obtained commercially from the latex of the Para rubber tree. Rubber is vulcanized to improve its mechanical properties like tensile strength and hardness. Natural rubber composites are made by reinforcing rubber with fibers, fillers like carbon black, or nanoparticles to enhance properties. Natural rubber finds applications in tires, hoses, footwear and other products where elasticity and vibration absorption are important.
The document discusses properties and applications of rubber. It begins by introducing the group members and providing an overview of natural and synthetic rubber. It then discusses various properties of rubber including its flexibility, elasticity, water resistance and insulation properties. Various applications of rubber are also presented, including use in rubber flooring, adhesives, bearings pads, and expansion joints. The document concludes that both natural and synthetic rubber have many uses in construction and other industries.
Styrene-butadiene rubber (SBR) is a synthetic rubber derived from styrene and butadiene monomers. There are two main types - emulsion polymerized SBR (E-SBR) and solution polymerized SBR (S-SBR). E-SBR accounts for over 50% of car tire production and is also used in conveyor belts, footwear, adhesives and more. S-SBR offers improved properties for tires and is increasingly used. The document discusses the production, properties and applications of SBR.
Short Description related to the rubber filler properties and Rubber filler types ( Reinforcing fillers, Semi- reinforcing fillers and Non-reinforcing fillers). e.g.:- Carbon Black, Silica, Calcium Carbonate, Clay and Miscellaneous Fillers
This document discusses natural and synthetic rubber. It notes that natural rubber comes from the latex of rubber trees, while synthetic rubber is produced from petroleum byproducts. The two main types are natural rubber and synthetic rubbers such as styrene butadiene rubber (SBR). SBR production has largely replaced natural rubber and is now the most widely used synthetic rubber, commonly made through emulsion polymerization.
This document discusses the history and chemistry of vulcanization and curing systems for rubber. Some key points include:
- Charles Goodyear discovered in 1839 that heating rubber with sulfur produced an elastic product that did not become sticky or brittle at high/low temperatures, launching the vulcanization process.
- Sulfur has remained the most important vulcanizing agent, though other chemicals have also been examined. Accelerators were later developed to speed up the vulcanization reaction.
- Efficient vulcanization systems using sulfur donors and accelerators produce vulcanizates with mainly mono- and disulfide crosslinks rather than unstable polysulfide crosslinks and pendant groups. This improves aging
This document provides information on the production of rubber footwear. It discusses the traditional hand assembly process and more modern direct moulding and injection moulding techniques. It describes the various materials used such as natural rubber, synthetic rubbers, fillers and chemicals. Specific compound formulations are provided for shoe uppers, soles and industrial boots. The production process involves preparing lasts, assembling parts, varnishing, and vulcanization. Compression moulding and injection moulding of soles and heels are also summarized.
This document provides an overview of rubber processing operations. It begins by defining rubber as a material that can be stretched and returns to its original shape. Natural rubber comes from the latex of rubber trees, while synthetic rubber is produced from petrochemicals. Natural rubber is too soft on its own. The key process is vulcanization, discovered by Charles Goodyear, which involves adding sulfur to produce cross-linking that makes rubber stronger and more elastic. The two basic steps in production are making the raw rubber, and then processing it through compounding, mixing, shaping and vulcanizing into finished goods like tires.
What is and what is the function of a rubber seal
The Increasing of the speed of mechanical systems, driven by the desire for greater productivity, leads to higher operating temperatures and reduced fluid viscosities. This, coupled with higher pressures, causes an increasing tendency for fluid to leak. This leak in fuel systems that handle highly flammable solvents cannot be overlooked as there is a high probability of a fire hazard.
For this reason it has become common practice to include a safe leak path in the system design, to an escape or collection point, in order to minimize risk.
Seals prevent fluid from escaping from a hollow cylinder when a shaft penetrates the cylinder wall. Most commonly, the axis will have a rotary or linear motion. If a seal is not made for functional requirements, or installed and maintained properly, it can fail, causing fluid loss. The two main functions of a seal are to keep the fluid in while keeping dirt and debris out.
Zinc oxide (ZnO) is added to rubber compounds to activate sulfur vulcanization and thereby reduce the vulcanization time. ... The release of zinc into the environment from rubber occurs during the production, disposal, and recycling of rubber products (e.g., through leaching in landfill sites).
Its most common application is as a vulcanization activator in conjunction with stearic acid. Its addition is recommended at the beginning of the mixture, after the addition of stearic acid - its addition before stearic acid causes difficulty in incorporation and problems with dispersion.
This document discusses different types of polymer fibers and their production methods. It begins by describing extrusion as a common way to shape polymers into fibers through a die. Two main fiber production methods are then covered: melt spinning, where fibers are extruded from a melt through a spinneret, and wet spinning, where polymers are extruded from a solution. Specific high-strength fibers are also summarized like Kevlar, polyethylene, and carbon fibers produced from polyacrylonitrile. The document aims to explain how polymer structure impacts fiber properties at the macro and microscale.
This document presents information about nylon 6,6 polymer. It discusses the history of nylon 6,6's development beginning in 1927. It then describes the synthesis of nylon 6,6 which involves a step-growth polymerization of hexamethylene diamine and adipic acid. The document outlines the physical and chemical properties of nylon 6,6 including its elasticity, stiffness, melting point, and resistance to chemicals. Common applications of nylon 6,6 are mentioned such as uses in pipes, machine parts, carpets, and tires due to its strength, rigidity, and stability at high temperatures. Finally, advantages like heat and chemical resistance and disadvantages such as water absorption are highlighted.
High Performance Fibers- Aramid fibers- Their Spinning Techniques-Naveed Ahmed Fassana
A brief introduction of High Performance fibers and spinning techniques through which these fibers are produced are mentioned in these slides. Also there is a brief explanation of Aramid, Kevlar, and Nomex fibers with respect to their properties with the help of graphs etc.
In 1938, Paul Schlack of IG Farben created Nylon 6 by polymerizing Caprolactum into a homopolymer called polyhexano-6-lactum. Nylon 6 has high tensile strength, toughness, elasticity, and resistance to abrasion and chemicals. It is used for applications like bristles, gears, threads, ropes, surgical sutures and knitted garments. While some bacteria and fungi can degrade Nylon 6 oligomers, polymers are not easily biodegraded.
This document provides an overview of latex ingredients and compounding formulations for latex products. It discusses the key components of natural rubber latex and synthetic lattices like SBR, neoprene, and nitrile. It describes the processes used to concentrate and preserve latex, including centrifuging and the use of ammonia or ammonia with bactericides. The document also covers the dispersion and emulsification of solids and liquids for addition to latex, and the roles of auxiliary chemicals like stabilizers, wetting agents, and thickening agents in compounding latex and achieving desired product characteristics.
Natural rubber is a natural polymer obtained from the latex of the rubber tree Hevea brasiliensis. It is composed of polyisoprene, which is a long chain of the monomer isoprene. Latex is a white fluid that is coagulated to form solid natural rubber through the addition of bacteria or acids that lower the pH. Vulcanization improves the properties of natural rubber by adding sulfur to form cross-links between polymer chains, making the rubber more durable and elastic.
This document provides an overview of styrene-butadiene rubber (SBR), including its history, raw materials, manufacturing processes, properties, structure, and applications. Some key points:
- SBR is a random copolymer of styrene and butadiene that accounts for around half of global synthetic rubber production. Its main use is in tire manufacturing.
- SBR was developed in the 1920s-1930s as a replacement for natural rubber. Modern solution and emulsion polymerization techniques were established in the 1950s.
- SBR can be produced via emulsion or solution polymerization. Emulsion SBR dominates tire applications due to its oil-extendability and dynamic properties.
The document provides an overview of natural rubber, including its sources, properties, uses, and production process. It defines natural rubber as a natural polymer obtained from the latex of the rubber tree. Key points include natural rubber's monomer (isoprene), how coagulation occurs through acid/base reactions, the vulcanization process involving sulfur to improve properties, and natural rubber's contributions to Malaysia's economy through industries like rubber gloves.
This document discusses chloroprene rubber, a synthetic rubber introduced in 1932. It summarizes that chloroprene rubber is produced through the emulsion polymerization of chloroprene monomers. It can be produced through two main processes - one using sulfur modification and one using chain transfer agents like mercaptans. The document also lists some key properties of chloroprene rubber, including good resistance to ozone, heat aging and chemicals. Finally, it outlines some common applications for chloroprene rubber like gaskets, cable jackets and hoses due to its temperature resistance and chemical resistance.
The document discusses rubber, including its properties, types (natural and synthetic), production processes, and applications. It describes how natural rubber is obtained from rubber trees by tapping latex and coagulating it. It also explains various synthetic rubbers like SBR, butyl, EPDM, and nitrile. Key applications mentioned include rubber flooring, adhesives, expansion joints, and bearing pads.
Polymer are long chains of small molecules called monomers. There are different types of polymers including thermoplastics, thermosets, and natural polymers like rubber. The physical properties of polymers depend on factors like chain length, side groups, branching, and cross-linking. Rubber is a natural polymer made of isoprene monomers. It is elastic, flexible, resistant to chemicals and heat, and a good insulator. The main uses of rubber include tires, footwear, seals, bearings, and expansion joints in construction.
The document discusses the history, types, properties, and applications of rubber. It begins by defining rubber as a stretchy material that rapidly returns to its original shape. It then outlines the timeline of rubber's discovery and development, including the Mayans first using it in the 16th century and the invention of vulcanization in 1839. The document describes the two main types as natural rubber from latex-producing plants and synthetic rubbers produced from petroleum products. It provides examples and properties of various natural and synthetic rubbers and discusses their advantages and applications.
The presentation describes about the butyl rubber about its properties, compounding, categories, applications, new innovations, advantages and disadvantages. The references are added at the end
Rubbers, also known as elastomers, are linear polymers that exhibit distinct elastic properties. Natural rubber is obtained from the latex of the Hevea brasiliensis tree. The latex undergoes various processing steps including coagulation, creping, and smoking to produce rubber sheets. Rubber is then masticated and compounded with chemicals like sulfur for vulcanization to improve properties like tensile strength and heat resistance. Styrene-butadiene rubber is a synthetic rubber produced by copolymerizing butadiene and styrene, giving properties like abrasion resistance useful in tires. Conducting polymers can transport charge and conduct electricity through conjugated systems and doping to generate charge carriers along polymer chains.
The document provides an overview of rubber processing technology used to manufacture tires and other rubber products. It discusses the two basic steps of rubber goods production: producing the raw rubber (natural or synthetic) and processing it into finished goods through compounding, mixing, shaping, and vulcanizing. Tire production specifically involves preforming components, building the carcass by adding components, and molding and curing the assembled components into a finished tire.
To improve the properties of rubber, Charles Good in 1839 compounded the raw rubber with some chemicals and heated to 100 - 140°C. Finally the compounded and vulcanized rubber is draw in the form of sheet by calendaring process.
This document discusses natural rubber, including its monomer (isoprene), polymerization, properties, and uses. It explains how natural rubber latex is prevented from coagulating through the addition of hydroxide ions. The key process of vulcanization is described, which cross-links rubber molecules with sulfur atoms to improve elasticity, strength, and heat and chemical resistance compared to unvulcanized rubber. Common uses of natural rubber are mentioned like tires, footwear, and vibration absorption applications due to its elastic properties.
Rubber is a hydrocarbon polymer that is produced from the milky latex of rubber trees. It exists in both natural and synthetic forms. Natural rubber comes from the rubber tree, while synthetic rubber is made from petroleum byproducts. The process of vulcanization converts rubber into more durable materials by adding sulfur. Rubber can be soft, hard, or foam. Soft rubber is used for tires and hoses while hard rubber is used for electrical and chemical applications. Rubber is a green material that can be recycled for uses like flooring, bridges, and insulation.
This document summarizes information about rubber. It discusses that rubber is a hydrocarbon polymer found in the sap of plants as latex. It can be classified into natural rubber extracted from plants like rubber trees or synthetic rubber made from petroleum. Natural rubber undergoes vulcanization through adding sulfur to become more durable materials. Rubber is used for many applications due to its elasticity, flexibility and resistance to abrasion and chemicals. It can be recycled as an environmentally friendly material.
Natural rubber is obtained from latex in rubber trees, while synthetic rubber is produced through polymerization of petroleum-based monomers like butadiene and styrene. The most common types of synthetic rubber are styrene butadiene rubber (SBR) and nitrile butadiene rubber (NBR). Rubber production involves compounding, mixing, shaping, and vulcanization. Natural rubber is used mainly in tires while synthetic rubbers find applications in various industries due to their oil and temperature resistance. However, synthetic rubber production produces soot that contributes to climate change.
This document provides an introduction to polymers and rubbers. It defines polymers as large chains of repeating molecules or monomers that are attached end to end. Polymers are classified as natural or synthetic. Natural rubber is a polymer of isoprene that comes from rubber trees, while synthetic rubbers are manufactured polymers that act as substitutes for natural rubber. The document discusses different types of synthetic rubbers and their properties, as well as uses of both natural and synthetic rubbers. Vulcanized rubber is also introduced as a hardened type of rubber produced through sulfurization.
This document discusses styrene-butadiene rubber (SBR), a type of thermoplastic elastomer. It is produced through the copolymerization of butadiene and styrene monomers. SBR can be synthesized through either solution polymerization using an anionic initiator, or emulsion polymerization. The document outlines the properties and applications of SBR, including its use in tires, footwear, cables, hoses and more due to its good abrasion resistance, strength and processability.
This document discusses various types of elastomers including their properties and applications. It provides details on natural rubber, synthetic rubbers like styrene-butadiene rubber, and thermoplastic elastomers. The key points are: natural rubber is processed from latex and used mainly in tires; styrene-butadiene rubber is one of the most inexpensive and widely used synthetic rubbers; thermoplastic elastomers can be melted and reshaped like plastics but have rubber-like flexibility.
Rubber is an elastic material that can be produced from natural or synthetic sources. Natural rubber comes from the latex sap of rubber trees, while synthetic rubber is produced from petroleum byproducts through chemical processes. There are advantages to both natural and synthetic rubbers, as natural rubber is more flexible while synthetic rubbers are less expensive and not vulnerable to supply issues. The document outlines the key properties, advantages, and disadvantages of both natural and synthetic rubbers.
This document discusses polymers classified by their applications, focusing on elastomers. It defines elastomers as polymers with both elasticity and viscosity, and provides examples such as natural rubber, synthetic rubbers like polybutadiene and butyl rubber, and silicone rubber. The document explains the processes of obtaining natural rubber from trees and vulcanization. It discusses key elastomer properties like glass transition temperature and applications in industries and products like tires, hoses and coatings.
This document discusses different types of modified bituminous materials used in pavement construction including polymer modified bitumen, bitumen rubber mixes, stone matrix asphalt, and warm mix asphalt. It provides details on the composition and properties of these materials. Polymer modified bitumen involves adding polymers like SBS or EVA to bitumen to improve its high temperature stability and resistance to deformation. Stone matrix asphalt contains a high percentage of coarse aggregate that forms an interlocking skeleton structure, filled with bitumen and filler, to provide durability and resist permanent deformation on heavily trafficked roads.
This presentation discusses the usefulness of Ellingham diagrams in metallurgy. An Ellingham diagram graphs the temperature dependence of metal oxide stability and is used to evaluate the ease of reducing metal oxides. It was first constructed by Harold Ellingham in 1944 and can predict equilibrium reactions between metals, oxygen, and other non-metals. Ellingham diagrams are useful for determining free energy changes and partial pressures of oxygen during metal oxide formation reactions. They allow metallurgists to select suitable reducing agents, guide purification processes, and understand the comparative stability of metal oxides.
This document introduces Habibur Rahman and their department at BSMRSTU. It then discusses surface active substances, including their definition and classifications like cationic, anionic, zwitterionic, and non-ionic. Soap is explained as the sodium or potassium salt of higher fatty acids. Soaps are classified as hard, soft, or insoluble. Hard soap is moderately soluble in water, soft soap dissolves in water, and insoluble soap is used as a lubricant. The cleaning action of soap is that the hydrophobic tail dissolves in grease while the hydrophilic head dissolves in water. Finally, the document outlines the raw materials and process for manufacturing soap through either hot or
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Potash fertilizer is any salt containing potassium in a water-soluble form. Common sources of potash include sylvite, carnallite, and sylvanite minerals. There are two main processes to produce potash fertilizer - fractional crystallization and flotation. Fractional crystallization uses unit operations to produce a highly pure potassium chloride, while flotation uses hydrometallurgical processes to produce a lower purity product at a lower cost. Potash fertilizer has advantages like increased crop yields and profits but also disadvantages as potassium chloride can harm seeds and young plants.
Urea is a nitrogen-rich fertilizer produced from ammonia and carbon dioxide. It contains 46% nitrogen and exists in both prilled and granular forms. Urea is synthesized through a two-stage reaction involving the formation of ammonium carbamate and its subsequent dehydration. The urea synthesis process involves ammonia pumping, carbon dioxide compression, urea production in a tower, distillation, evaporation, and prilling. Urea is widely used as a fertilizer to promote plant growth and is advantageous due to its high nitrogen content and low production costs.
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This presentation provides an overview of cement industries. It defines cement as a powdered material that hardens when mixed with water. There are four main types of cement: Portland, pozzolana, calcium aluminate, and special or corrosion resistant cement. The history, manufacturing process, raw materials, reactions, and uses of cement are described. Cement production involves mining limestone and clay, crushing and mixing them, burning the mixture in a kiln to form clinker, and grinding the clinker with gypsum. The main constituents of cement are lime, silica, alumina, and iron oxide. Cement is primarily used in construction applications such as buildings, roads, bridges, and more.
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3. Crevice corrosion which occurs in tight spaces like joints or under deposits.
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Newtonian and non((( HABIB............BSMRSTU)))habib chowdhury
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detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
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1. CONTENT OF TABLE
Serial No Title Page No
01 Introduction 01
02 Rubber 02
03 Importance of Rubber 03
04 Classification of Rubber 03
05 There are four types of rubber generally 04
06 Natural rubber 06
07 Recovering the Rubber 06
08 Grade of rubber 06
09 Refining of crude Rubber 07
10 Two-roll mil 07
11 Banbury Mixer (Internal Mixer) 08
12 Compounding 08
13 Filler 09
14 Plasticizer 09
15 Age resistors (antidegradants) 09
16 Vulcanizing 10
17 Special-purpose ingredients 10
18 Mixing 10
19 Forming Process 10
20 Calendering process 11
21 Coating or Impregnating Fabrics with Rubber 11
22 Extrusions process 12
23 Molding 14
24 Injection molding 14
25 Advantages of injection molding 15
26 Synthetic rubbers 15
27 Common monomer production 17
28 Production of SBR 20
29 Cold rubbers ,Silicone Rubber ,NBR 21
30 Neoprene, Thiokol, Butyl Rubber 26
31 Conclusion 27
2. 1.0 Introduction:
The rubbers materials can be classified into natural rubber and synthetic rubber.
Natural rubber is exhibit many outstanding properties, such as good oil
resistance, low gas permeability. The natural rubber coming from latex that
bleeds from the wounding in plants. Synthetic rubber is any type of artificially
made by man from petrochemical feedstock obtained by emulsion addition
polymerization and condensation polymerization.In1615, the first practical use of
rubber in the waterproofing footwear, when peoples of South America extracted
this substance from trees Rubber often called "Hevea Brasiliensis" and "Para
Rubber" trees, meaning "weeping wood", these trees represents sources of
natural rubber, that begin grew in the Amazon forests in 1873. At that time the
natural rubber became first demand of a product in world, this is lead to
Amazonas becomes the economic heart of Brazil. During the middle of the 18th
century to about the end of 20th century, the rubber industry experienced those
important steps of development. At that time most rubber tree plantation grew in
British and British Colonies in South and Southeast Asia particularly in Thailand,
Malaysia, India, China and Indonesia, today rubber tree are grew in Africa such as
Nigeria, which became important producers of natural rubber. The history of
natural rubber in Europeans began from the second half of the 19th century,
when increasing demand of the natural rubber. In 1820, British industrialist
produced rubber and attempted to use them in clothing. The first bicycle tire
product in 1830, while in 1832, the first factory was set up rubber product. In this
process, because of added sulfur, the rubber becomes cross linked and also has
better elasticity. In 1845, R.W. Thomson invented the pneumatic tire and the
inner tube, in 1869 made the solid rubber balls and hollow rubber balls for the
golf and tennis, and in 1888, first use of rubber to form of rain jackets.
Fig: Typical Rubber Plantatio
3. 2.0 Rubber:
Rubber is a polymer with inherent thermoplastic and elastomeric qualities, meaning it
can be stretched to great lengths without permanent deformation and can withstand
both electric and thermal strain. Elastomers are sometimes called rubber or rubbery
materials. Elastomers are usually thermosets but may also be thermoplastic .
Common characteristics;
– Large elastic elongation (i.e.200%)
– Can be stretched and then immediately return to their original length when the
load was released
An elastomer is a cross-linked or vulcanized polymer. Cross-linking is a chemical way of linking
the long polymer chains. A way to think of this would be to take the bowl of spaghetti and tie
them together with a piece of thread where ever the pieces of spaghetti touch each other
Fig: (1 ) Rubber Vulcanization
There are several ways to crosslink rubber, but the most common is through the use of sulfur.
Sulfur, with the addition of heat and pressure, will crosslink rubber. They connect up the long
individual polymer chains into what is literally a single unit.
4. 2.1 Importance of Rubber:
Rubber is a polymer with inherent thermoplastic and elastomeric qualities, meaning it
can be stretched to great lengths without permanent deformation and can withstand
both electric and thermal strain.
Flexibility is another important property of rubber.
strength as well as toughness are notable properties of rubber due to which its elastic
property may be put to be used even under abnormal condition.
Rubber is highly impermeable to water and air.
highly resistant to cutting, tearing and abrasion over a wide range of temperatures.
Not attacked by atmospheric gases and chemicals have no corrosive effects on it.
3.0 Classification of Rubber:
A. According to source
Natural rubber: latex, Gutta Purcha etc
Synthetic rubber: SBR, IR, NBR etc
B. According to initial raw materials
Rubbers made from single monomer: Butadiene rubber (BR)
Rubbers made from two/more monomers: styrene-Isoprene rubber (SIR)
C. Depending on application, they are classified as
General purpose rubber:
Special purpose rubber:
D. General classification of rubber:
3.1 There are four types of rubber generally-
Elastomer
Hard plastic
Reinforcing
Paint vehicle
5. Another classification Depending on the dry and latex form of rubber shall be classified and
coded from chemical composition of polymer chain –
M—Rubbers having a saturated chain of the polymethylene type.
N—Rubbers having nitrogen, but not oxygen or phosphorus, in the polymer chain.
O—Rubbers having oxygen in the polymer chain.
R—Rubbers having an unsaturated carbon chain, for example, natural rubber and
synthetic rubbers derived at least partly from diolefins.
Q—Rubbers having silicon and oxygen in the polymer chain.
T—Rubbers having sulfur in the polymer chain.
U—Rubbers having carbon, oxygen, and nitrogen in the polymer chain.
Z—Rubbers having phosphorus and nitrogen in the polymer chain.
The “M” class includes rubbers having a saturated chain of the polymethylene type.
ACM—Copolymers of ethyl or other acrylate and a small amount of monomer which
facilitates vulcanization.
AEM—Copolymers of ethyl or other acrylates and ethylene.
ANM—Copolymers of ethyl or other acrylate and acrylonitrile.
BIMSM—Brominated polymers derived from a copolymer of isobutylene and p-
methylstyrene.
CM—Chloro-polyethylene.
CFM—Polychloro-trifluoro-ethylene.
CSM—Chloro-sulfonyl-polyethylene.
EOM—Copolymers of ethylene and an octene
The “R” class shall be defined by inserting the name of the monomer or monomers before the word
“rubber” from which it was prepared
The following classification shall be used for rubbers of the “R” class:
ABR—Acrylate-butadiene.
BIIR—Bromo-isobutene-isoprene.
BR—Butadiene.
CIIR—Chloro-isobutene-isoprene.
CR—Chloroprene.
ENR—Epoxidized natural rubber.
HNBR—Hydrogenated acrylonitrile-butadiene.
6. 4.0 Natural rubber:
Natural rubber is tapped from rubber trees (Hevea brasiliensis) as latex.The trees are grown on
plantations in Southeast Asia and other parts of the world.Latex is a colloidal dispersion of solid
particles of the polymer polyisoprene in water. Polyisoprene is the chemical substance that
comprises rubber, and its content in the emulsion is about 30%.The latex is collected in large
tanks, thus blending the yield of many trees togetherThe more the latex is removed, the more
the plant regenerates it.
Latex composition:
water- 60%, rubber polymer- 35%
protien,enzyme and nucleic acid- 3%; fatty acid and ester- 1%;
inorganic salt- 0.5%
4.1 Recovering the Rubber:
The preferred method of recovering rubber from latex involves coagulation - adding an acid
such as acetic/formic acid (HCOOH); coagulation takes about 12 hours
The coagulum, now soft solid slabs, is then squeezed through a series of rolls which drive out
most of the water and reduce thickness to about 3 mm (1/8 in)
The sheets are then draped over wooden frames and dried in smokehouses
– Several days are normally required to complete the drying process
– It is then treated for preparing different grade natural rubbers.
4.2 Grade of rubber:
The resulting rubber, now in a form called ribbed smoked sheet, is folded into large bales for
shipment to the processor - It has a characteristic dark brown color.
In some cases, the sheets are dried in hot air rather than smokehouses, and the term air
‑dried sheet is used; this is considered to be a better grade of rubber
A still better grade, called pale crepe rubber, involves two coagulation steps, followed by warm
air drying
7. ribbed smoked air‑dried sheet pale crepe
Fig:(2) Grade of rubber
4.3 Refining of crude Rubber:
1. Breakdown: The polymeric chains of the rubber are broken by masticating/kneading the
raw rubber between the warm rollers. During breakdown, the rubber loses its
reversibility gradually and turns plastic.
2 Mastication :Mastication is a preliminary stage of processing the raw rubber. At low
temperatures the process cut the rubber molecules into smaller units. It improves the
plasticity and reduces the viscosity. Mastication is a mechanical shearing process using
two roll mill for reduced the molecular weight, reduced the viscosity and to soften the
raw rubber.
After mastication the processing will be much easier and increased the effectiveness of
dispersions of compounding ingredients.
4.4 Two-roll mil:
There are one pair of rollers with a vertical ‘nips’ between them
The polymer and additives are subjected to high shear in the nip as the rolls rotate in
opposite directions
Two-roll mill mixing started with rubber processing, now exist for various function
Mixing on two-roll mill is time consuming, 2 h for a 200 kg mix on a 84” wide mill.
Fig: (3) Schematic illustration of two-roll mill
8. 4.5 Banbury Mixer (Internal Mixer):
2 rotors-counter-rotating within a chamber
Each has two or four ‘blades’ which mix by smearing the materials against the chamber
wall
A weighted ram keeps the mix in place inside the chamber
The rate of output (200 kg batch of rubber compound would take 2 h- two-roll mill. A
number 11 Banbury mixer produce 350 kg in 15 min or less)
Fig:(4) Banbury Mixer (Internal Mixer):
4.6 Compounding:
The compounding process uses the two roll mill and internal mixer.Rubber compounding is the
way of making useful products from raw rubber. The process involves the addition of additives
to change the masticated raw rubber to rubber compound before a forming process (Shaping
process).
Rubber is always compounded with additives
Compounding adds chemicals for vulcanization, such as sulfur .
9. The various ingredients may be classified according to their specific functions in the following
groups:
4.6.1 Filler:
The single most important reinforcing filler in rubber is carbon black, a colloidal form of carbon,
obtained by thermal decomposition of hydrocarbons.
Carbon black also provides protection from ultraviolet radiation.
Most rubber parts are black in color because of their carbon black content.
Carbon black forms strong bonds with rubber. It is assumed that carbon particles
possess unsaturated atoms on their surface which act as bonding sites on the rubber
molecules, thus reinforcing the rubber.
China clays - hydrous aluminum silicates (Al2Si2O5(OH)4) provide less reinforcing than
carbon black but are used when black is not acceptable.
4.6.2 Plasticizer :A substance which incorporated into rubber to increase its flexibility,
workability is called plasticizer. Plasticizers include a large variety of organic liquids e.g.,
petroleum fractions, coal tar distillates, animal fats, plant extracts, etc.
Protect rubber goods from attack by oxygen and ozone in the atmosphere.
They are classified as antioxidants, antiozonants, or anti-cracking agents.
4.6.3 Age resistors (antidegradants) : Age resistors Protect rubber goods from attack by
oxygen and ozone in the atmosphere. The age-resistors used must be capable of reacting with
the agents to prevent the polymer breakdown.
The loss in physical properties caused by crosslinking, or some form of chemical
alteration of the polymer chains.
Commercial age resistors are the amine type or the phenolic type.
Amines are strong protective agents.
Examples: N-Phenyl-2-naphthylamine, alkylated diphenylamine
4.6.4 Vulcanizing : Vulcanization process is the process that produce a crosslinking i.e sulfur,
sulfur monochloride, selenium, tellurium, thiuram disulfides, p-quinone, dioximes, polysulfide
polymers.
Vulcanization agents increase vulcanization process and reduce the time of vulcanization.
10. Example: 2-Mercaptobenzothiazole, zinc diethyldithiocarbamate, tetramethylthiuram disulfide,
tetramethylthiuram monosulfide, 1,3-diphenylguanidine
4.6.5 Special-purpose ingredients :
Coloring pigments: Carbon black, zinc oxide, certain clays, calcium carbonate,
titanium dioxide
Blowing agents: Sodium or ammonium bicarbonate, diazoaminobenzene,
fluorocarbons, etc.,
Flame retardants
Antistatics agents retarders
Peptizers: Aromatic mercaptan (thiophenols)
5.0 Mixing :The mixing process is performed in heavy internal mixers, capable of processing
200 kg batch weight in two minutes.
This process has two functions:
Firstly, to soften the rubber (this is often known as mastication) and,
Secondly, the rubber with the compounding ingredients, which may include fillers,
vulcanizing agents, protective agents. This technique is known as compounding.
After mixing, the compounded rubber is plastic and is ready to be shaped. This is done in a
variety of ways and is frequently combined with vulcanization in which the rubber undergoes a
chemical reaction at a high temperature and converted from the plastic state into a strong,
highly elastic material.
6.0 Forming Process (Shaping):
After all compounding ingredients have been properly mixed the compounded green
stock is tacky and thermoplastics
In this plastic condition, the stock can be shaped by the applications of force.
This can be accomplished by
i. Calendering
11. ii. Coating
iii. Extruding
iv. Molding and casting
6.1 Calendering process:
In the calendering process, rubber is passed through a three- to five-roll calender either
to produce a sheet of controlled thickness or to force the rubber into close contact with
a textile or metal cord.
Stock is passed through a series of gaps of decreasing size made by a stand of rotating
rolls.
Rubber sheet thickness determined by final roll gap.
Figure:(5) Calendering Figure:(6) Roller die process - rubber extrusion
followed by rolling
6.2 Coating or Impregnating Fabrics with Rubber:
Rubber compounds are applied to fabric by calendering, i.e., rolling the rubber
compound into the fabric on multiroll calender machines.
Tire cord is a special case in which cotton, rayon, nylon, or polyester cords are arranged
in parallel and bound together by rubber on a calendar.
12. Figure: (7) Coating of fabric with rubber using a calendering process
6.3 Extrusions process:
During the rubber extrusions process, rubber material is processed through a screw
extruding machine very similar to those used in extruding plastic.
Rubber extruders consist of a heated shearing screw conveyor or twin screw conveyor
and a die through which the plasticized and pressurized rubber is squeezed.
Pre-heating of the material is optional, depending on the precision of the die and the
desired qualities of strength.
Stock rubber material enters the screw conveyor channel, often by way of an attached
hopper.
It is softened through heating and shearing, and the stock material is then pressurized
through the rotation of a screw.
Heaters around the extruder’s barrels heats the stock and liquefies them
The pressure pushes the rubber through the die, which is located at the end of the
extruder.
The rubber then emerges from the extruder in a profile resembling the die shape
After being extruded, the material is cured and sometimes vulcanized using various
methods.
13. Fig: (8) Extrusions process
Basically an extruder screw has three different zones
• Feed zone:
The function of feed zone is to preheat the plastic and convey it to the subsequent zones.
• Compression zone:
In compression zone the screw depth gradually decreases so as to compact the plastic. This
compaction has the dual role of removing any trapped air pockets and improving the heat
transfer through the reduced thickness of material.
• Metering Zone:
In metering zone the screw depth is again constant but much less than the feed zone. In the
metering zone, the melt is homogenized so as to supply at a constant rate, material of a
uniform temperature and pressure to the die.
14. 7.0 Molding:
Principal molding processes for rubber are:
Compression molding
Transfer molding, and
Injection molding
7.1 Injection moulding:
Injection moulding is a process in which the compound is forced under high pressure into a
mould cavity through an opening (sprue).
The rubber material in form of strips is fed into an injection moulding machine. The
material is then conveyed forward by a feeding screw and forced into a split mould,
filling its cavity through a feeding system with sprue gate and runners.
An injection moulding machine is similar to an extruder.
The main difference between the two machines is in screw operation.
In the extruder type the screw rotates continuously providing output of continuous
long product (pipe, rod, sheet).
Fig: (9) Injection moulding is a proces
15. 7.2 Advantages of injection molding:
The complete elimination of pre-forms. The production and need for pre-forms is a
labor intensive step that can potentially affect the finished product through variability in
pre-form weight and shape.
Elimination of operator placement of pre-forms. Since pre-forms are eliminated, the
need for operators to place the pre-forms in a cavity or pot is removed.
Injection screw pre-heats material before forcing it into cavities. This process decreases
the viscosity of the material.
Reduced cycle time
Economical process for high volumes of medium to high precision components
Minimal material waste
8.0 Synthetic rubbers:
Synthetic rubbers are complex chemical compounds formed through the polymerization
of monomers.
Synthetic rubber production starts with the refining process of oil, coal or other
hydrocarbons with naphtha as one of the desired products.
The naphtha is then combined with natural gas to produce monomers.
Typical monomers used for production feed material include butadiene, styrene,
isoprene, chloroprene, acrylonitrile, ethylene or propylene.
These monomers are then polymerized using catalyst and process steam to form chains
of polymers which results in rubber intermediaries.
These substances are then processed to their final rubber products by vulcanization
17. 9.1 Common monomer production:
Styrene:
The production of styrene is via ethylbenzene, which is made by alkylating benzene with
ethylene and dehydrogenating to styrene over an aluminium chloride, solid phosphoric acid, or
silica-alumina catalyst.
1,3 Butadiene:
(A) From ethyl alcohol
(B) From petroleum
Butene is passed over calcium nickel phosphate catalyst stabilized with 2% chromium oxide at
625-700°C and a low butene pressure. The overall conversion is about 40-50%.
Acrylonitrile:
Acrylonitrile is produced by the sohio process that reacts with propylene with air and ammonia
in a catalytic reactor.
18. Chloroprene:
Chlorloprene is manufactured from acetylene and hudrogen chloride. Acetylene is dimerized to
monovinylacetylene, which in turn reacted with hydrogen chloride to form chloroprene
19. 10.0Crumb:
The emulsion and solution type of polymerization reaction are used to produce styrene-
butadiene copolymers. The emulsion products can be sold as a granular solid form,
known as crumb.
Another definition,The acid and brine mixture causes the emulsion to break, releasing
the styrene-butadiene copolymer as crumb product. The coagulation vessels are open to
the atmosphere. At this point, the product is called “crumb”
Production of crumb rubber by emulsion polymerization has been the traditional
process for the production of synthetic rubber.
Emulsion crumb production involves producing an emulsion of raw materials, resulting
in bulk polymerization of droplets of monomers suspended in water.
Copolymers containing less than 45 weight percent styrene are known as styrene-
butadiene rubber (SBR).
Production of crumb rubber by emulsion polymerization has been the traditional
process for the production of synthetic rubber.
It is the most commonly used method, accounting for 90% of the world’s production of
SBR.
Solution crumb production involves mixing the raw materials in a homogeneous
solution, wherein polymerization takes place.
11.0 Latex:
The emulsion and solution type of polymerization reaction are used to produce styrene-
butadiene copolymers. The emulsion products can be in a liquid form, known as latex.
20. 12.0 Production of SBR:
12.1 The flow diagram for SBR production
Fig.: (11)simplified flow diagram for SBR production
21. 12.2 Cold rubbers:
Cold rubbers have improved properties, compared with hot rubbers but require more
extensive process management.
The emulsified mixture resulting from the initial mixing of monomers and additives must
be kept cool by means of an ammonia refrigerant prior to entering the reactors.
12.3 Silicone Rubber:
Silicone rubber is a“Organosiloxanes Polymer”.It has been originated from its
unique molecular structure that carry both inorganic and organic properties . In other words,
due to the Si-O bond of Silicone Rubber and its inorganic properties, Silicone Rubber is superior
to ordinary organic rubbers in terms of heat resistance, chemical stability, electrical insulating,
abrasion resistance, weather ability and ozone resistance etc...
Fig:(12) Silicone Rubber
12.3.1 Why silicone rubber is the better choice
Longer service life in adverse environments, Virtually unaffected by weather --
rain, snow, humidity, ozone, or the sun's damaging ultraviolet rays.
Wider operating temperature range -- from -100 to 316ºC Organoelastomers
soften and deform irreversibly at temperatures >100ºC ,they become brittle at
temperatures <-25ºC .
Inherently good electrical insulating qualities that do not change significantly
under exposure to severe environmental stress (heat, cold, moisture, oil, ozone,
UV rays)
Retains its natural flexibility and resilience across a wider temperature range
22. Enhances the comfort and feel of consumer goods
Excellent sealing performance
Inert (no taste or smell); many food-contact options
More fabricating options , increased productivity
12.4.0 Nitrile Butadiene Rubber – NBR:
Nitrile Rubber (NBR) is a co-polymer of 75% butadiene and 25% acrylonitrile monomer.This is
prepared by emulsion polymerization same as SBR. Nitrile rubber, also known as Buna-
N, Perbunan, acrylonitrile butadiene rubber.
NBR, is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. Trade names
include Nipol, Krynac and Europrene.
12.4.1 Physical properties of NBR:
It is generally resistant to oil, fuel and other chemicals. Increase in acrylonitrile content
increase the resistance.
The freezing point also increase with the increase in nitrile content.
NBR’s has the ability to withstand a range of temperatures from -40 °C to +125 °C.
. It has inferior strength and flexibility, compared to natural rubber.
This rubber is also resistant to aliphatic hydrocarbons. It is less resistant to ozone,
aromatic hydrocarbons, ketones, esters and aldehydes.
This is low in tensile strength as the chain structure of polymer is irregular.
23. 12.4.2 Production processes of Nitrile Rubber:
Fig:(12) Simplified flow diagram for NBR production
12.4.2.1 Types of NBR :
(A) Cold NBR:
Cold NBR has a wide variety of compositions. Acrylonitrile content ranges from 15% to 51%.
Mooney values range from a very tough 110, to pourable liquids, with 20-25 as the lowest
practical limit for solid material.
24. (B) Hot NBR :
Hot NBR polymers are polymerized at the temperature range of 30 to 40°C. This process
produce highly branched polymers. Branching supports good tack and a strong bond in
adhesive applications.
(C) Crosslinked Hot NBR :
Crosslinked hot NBR are branched polymers that are further cross-linked by the addition of a di-
functional monomer. These products are used in molding forces, or back pressure to eliminate
trapped air. Another use is to provide increased dimensional stability .
Figure : (13) HNBR Production Process
25. (D) Neoprene:
Chloroprene Rubber is known as Neoprene.
It is the first oil resistant synthetic rubber.
It has better chemical, oil, ozone and heat resistance than natural rubber .
Chloroprene tends to slowly absorb water and its electrical properties are poor.
Its gas permeability is fairly low and flame resistance is excellent.
(E) Thiokol:
Thiokol is a polymer of ethylene polysulphide. It can be prepared by the condensation of 1,2-
dichloroethane with sodium polysulphide
26. Properties:
Thiokol is resistant to the action of oxygen and ozone.
It is also resistant to the action of petrol lubricants and organic solvents
Thiokol films are impermeable to gases to a large extent.
Thiokols are vulcanized with metal oxides such as zinc oxide.
Uses:
Thiokol mixed with oxidizing agents is used as a fuel in rocket engine.
It is used to engine gaskets and other such products that come into contact with oil.
Thiokols are used for hoses and tank lining for the handling and storage of oils and
solvents
(F) Butyl Rubber:
Butyl Rubber is a copolymer of 98% isobutene and 2% butadinene or isoprene. The butadinene
is added to introduce the necessary ethylenic linkages for vulcanization.
Properties
Very high tensile strength
Very impermeable to gases including air.
Excellent resistance to heat, abrasion, ageing and chemical.
Soluble in hydrocarbon solvents (benzene) but highly insoluble in polar solvents
(alcohol, acetone etc.)
High resistance to ozone.
It can be vulcanized but cannot be hardened much because of very low unsaturation.
27. 13.0 Conclusion:
It is cheaper, stable in price and contributes to consistency in qualities of the products Speeds up mixing
operation, breaks down quickly, wets pigments and blend the mixture
together with ease. Imparts firmness to compounds making the processing easier. It permits faster and
safer extrusion and calendering. Reclaim rubber decreases shrinkages of uncured compound before and
during curing is made faster thus reducing mould or press time. Introduction of reclaimed rubber
imparts excellent ageing properties It is cheaper, stable in price and contributes to consistency in
qualities of the products.Speeds up mixing operation, breaks down quickly, wets pigments and blend
themixture together with ease Imparts firmness to compounds making the processing easier. It permits
faster and safer extrusion and calendering.Reclaim rubber decreases shrinkages of uncured compound
before and during curing.curing is made faster thus reducing mould or press time.Introduction of
reclaimed rubber imparts excellent ageing propertiesThe basic structure of an HNBR elastomer is
provided in Figure 1. As outlined below, the process begins with the production of an emulsion-
polymerized NBR. This polymer is then dissolved in an appropriate solvent. After the dissolution
process is complete, the addition of hydrogen gas, in conjunction with a precious metal catalyst
at a designated temperature and pressure, brings about a selective hydrogenation to produce a
“highly saturated nitrile” (HSN) polymer. The solvent and catalyst are then recovered and the
remaining crumb is dried.