These are starting point rubber compounding formulations for providing guide. Mastication and compounding of natural rubber in an oxygen. Epoxidized natural rubber rubber chemistry and technology. Types of polyisoprene that are used as natural rubbers are classified. They are elastomer as a major component, curatives for crosslink formation, antidegradants for protection, fillers for reinforcement and cost dilution and processing additives for ease of processing. The rubber production process begins with natural or synthetic rubber. Natural rubber, also called by other names of india rubber, latex, amazonian rubber, caucho or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds, plus water. For example, addition of natural rubber to a compound with a high. Pdf compounding and processing of rubberrubber blends. Rubbers, just like any other chemical compounds, can participate in other chemical reactions. When natural rubber is epoxidized under carefully controlled conditions, it can be converted to a totally new polymer with some properties more akin to speciality rubbers and some properties that appear to be advantageous for tire treads. By convention, mix formulations begin with the amount of the designated elastomerfor instance, natural rubber nr, butadiene rubber br, or styrenebutadiene rubber sbrgiven as 100 parts by weight. Blooming is a typical phenomenon observed in rubber compounds which could lead to problems such as discoloration and poor appearance of products as well as loss of adhesion. Rubber latex is a stable dispersion of polymeric substances in aqueous medium and is essentially a two phase system.
Most of the rubber products can also contain reinforcing materials fibers, filaments. As if compounding wasnt already difficult enough, compounding rubber can be even more difficult because its a natural product. The rubber reclaiming industry is a specialized industry that resembles its parent industry in development and growth. Accelerators which normally provide fast cures are found to cause more severe reversion than slower accelerators. The chemicals materials used in latex compounding can be divided into three general classifications. Compounding of rubber presented by devansh gupta m. Rubber compounds for in ubber compounds for industrial. Natural rubber natural rubber nr has vegetable origin. The elastic properties are produced by mix raw rubber latex with specific additives during rubber compounding. It starts to be effective in the lower temperature range of compounding and can be used for mastication in a separate stage as well as for single stage mixing.
The standard product range comprises at present approximately 700 different formulas. A listing of commercially available precipitated silica products by surface area is provided in appendix a. Bulletin of the transilvania university of bra sov vol. Rubber compounding rubber compounding is the complex, multidisiplinary science of selecting and blending the appropriate combination of elastomers and other ingredients to meet the performance, manufacturing, environmental, and cost requirements for rubber goods made and used in commerce. Nr latex foam, alternative compounding formulation, biodegradable. Liquid natural rubber improves rubber and polymer compounding. Hence antioxidants are added to protect the rubber against oxygen attack while antiozonants are added to protect the rubber against ozone attack. There are five 5 major categories of compounding ingredients. Compounding precipitated silica in natural rubber nr 3 elastomer. Sources of natural rubber worldwide world nr production 2014 ranking country 000 tons % 2014 20 1 1 thailand 4,099. A rubber soluble zinc soap of high molecular weight that leads to a faster physical peptizing of natural rubber. Dpr liquid natural rubber is available in several grades that vary by molecular weight. It provides advantages of lower cost, lower toxicity, better compatibility with other compounding additives and predictable vulcanisation properties 1. Most of the rubber products can also contain reinforcing.
Due to the shortage of natural rubber during 2nd world war, usa took charge for. A number of ingredients are added to both natural and synthetic rubber in order to obtain certain desirable properties. Engineering sciences mechanical properties of rubber an overview al. Natural iber of comerce is the product of a tree known as hcvea. In radial ply tires, natural rubber is also widely used in the sidewalls due to its lower heat generation and better fatigue resistance. The work presented in this paper describes an alternative compounding formulation for natural rubber nr latex foam. Gordon whaley, senior geneticist, rubber plant investigations, bureau of plant industry, soils, and agricultural engineering, and john s. Natural rubber in all forms 55,522,538 79,920,336 61,625,867 74,457,931 78,978,123. Rubber compounding is the complex technology of selecting and blending the optimum combination of elastomer and other ingredients that meet the performance, processing, environmental, and cost. The list of ingredients in phr parts per hundred rubber called rubber compound recipe. Raw materials for a compound are generally selected in the following order. Even if the compound formula is perfect, there can still be differences in the properties of the final compound due to natural variances in the rubber itself. You may purchase all three online courses at the same time for one employee as well.
This type was produced by thermally decomposing natural magnesites mgco2. Rubber compounding ingredients rubber compounds and. Rubber compounds a market opportunity study september 2011. It is created by enyzmatic processes in many plants, belonging mainly to families of euphorbiacea. They include styrenebutadiene rubber sbr, butadiene rubber br, and polyisoprene rubber both natural nr and synthetic ir. Some elastomers such as natural rubber, neoprene, and butyl rubber have high regularity in their 33. Typical applications dpr liquid rubber provides all the performance properties of natural.
Adhesion smr 3 min mill 150 m2g silica whiting tp90b tall oil pine tar aminox rf resin 1501 100 25 25 5 3 6 1 2. It acts as a plasticizer to reduce cycle time and energy consumption. Scrap rubber, unlike scrap steel, undergoes a special process before it can be reused and the rubber that is obtained at the end of this process is known as reclaimed rubber. Process oil is generally classified as mineral oils natural products synthetic plasticisers. This revised and expanded singlesource reference analyzes all compounding material classes of dry rubber compounds, such as carbon blacks, platicizers and age resisters, integrating detailed information on how elastomers are built up. Several studies have been carried out to reuse scraptires in a variety of rubber and plastic products, incineration for production of electricity. Jul 20, 20 an antidegradant is a compounding ingredient added into a rubber compound to retard the deterioration caused by oxidation, ozone, light or combination of these. Such abbreviations are used also in this paper for marking of the rubbers. Whether natural or synthetic, rubber continues through four steps.
Thailand and indonesia are two of the leading rubber producers. Wood 1950 mastication and compounding of natural rubber in an oxygenfree atmosphere. Cardanolformaldehyde cf novolak curing resin can be used with hmta to cure a natural rubber compound so as to impart good aging properties. The work provides practical compounding tips on how to avoid oil or antioxidant bloom, how to adjust electrical conductivity and how to meet. Not only can we improve an elastomers physical strengths by compounding other ingredients into the mixture of elastomer and sulfur, but also we can improve other characteristics and even create some that do not naturally occur. Therefore, this solutions brochure will discuss less of the compounding of natural rubber and focus more on the natural rubber products that akrochem offers both the general purpose, technically specified. The reasons for this trend are increasing narrow quality requirements, significantly simplified and automated processes resulting in lower manpower necessary and the possibility to achieve unprecedented degree of dispersion. The use of natural oils in rubber compounds has already been commercially. Rubber compounding an overview sciencedirect topics. Rubber compoundingformulation of rubber compounds dr jakub kadlcak manager material development automotive dr matthias soddemann head of material development automotive rieg conference, 7th and 8th december 2016, london, uk.
Rubber compounding free download as powerpoint presentation. Both natural and synthetic elastomers are available for compounding into rubber products. Blooming is a diffusion process whereby compounding ingredients dispersed in rubber matrix migrate to the rubber surface and appears as a layer of white crystalline material. Russian dandelion koksaghyz an emergency source of natural rubber compiled by w. Pdf blending of polymers and specifically elastomers is carried out. Even natural rubber can have its very good physical traits enhanced by putting in other ingredients in the mixture. The effect of several compounding ingredients on the reversion of accelerated sulphur vulcanization of natural rubber nr has been examined. The effects of compounding variables on the reversion process.
Since it cures by the same mechanism as natural rubber, it becomes part of the polymer matrix and remains nonfugitive. The american society for testing and materials astm designation and composition of some common elastomers are shown in table 33. Never use nickel dibutyldithiocarbamate nbc in a natural rubber compound because nbc is a strong prooxidant and degradant to nr. The standard product range comprises at present approximately 700 different formulas that are constantly being improved and expanded. Rubber compounding natural rubber natural materials. It is classified as natural rubber and synthetic rubber. Introduction rubber is a polymeric material that are characterized by its ability of reversible deformation under influence of external deformation forces. Pdf rubber compounding from formulation to compounding. Jan 23, 2017 ingredients in rubber compound is a large group of components, including curing agents, accelerators and vulcanization activators, antioxidants, plasticizers, fillers and special additives blowing agents, dyes, etc. There is a wide variety of elastomers and ingredients that are available in. Natural rubber is a coherent elastic 9 id obtained from a milky liquid known as latex which occur in special vessela in the bark and in the roots, stem, branches, leaves and fruit of a wide assortment of plaats howing, for the mc part, in the tropics. Effects of accelerators on the cure characteristics and. Natural rubber nr latex is natural a commodity that has tremendous economic and strategic importance.
Rubber compounding from formulation to compounding submitted to dr. The chemicals materials dispersion and prepared by grinding them together with the dispersing in water. The resultant grade was often impure, not very active and had a large particle size. Struktol rubber processing additives product overview. Ingredients in rubber compound is a large group of components, including curing agents, accelerators and vulcanization activators, antioxidants, plasticizers, fillers and special additives blowing agents, dyes, etc. Reclaimed rubber is a rubber compounding ingredient.
At goodyear, we have access to world class custom compound development and rubber mixing. It is expected that modifications may be necessary to produce satisfactory commercial products. Since it cures by the same mechanism as natural rubber, it becomes part. Compounding precipitated silica in natural rubber natural rubber formulary 89 compounding precipitated silica in elastomers the silica surface areas indicated in the following compounds are n2sa bet surface areas. Elastomer is the key ingredient and thus always at the top of the formulation list. Also helps in lowering the tg of the rubber compound, elevating electrical conductivity, increasing the flame protection. These are starting point rubber compounding formulations for providing guide lines only and should be confirmed by laboratory trials. The effects of compounding variables on the reversion. This novel formula is designed to address the environmental control and health. In order to alleviate this strain, natural oil alternatives to petroleum plasticizers are of novel research interest and are investigated in this thesis project. Natural and synthetic rubber phoenix compounding technology. Introduction a sulphurcured system is the most commonly used curing method in the rubber industry.
787 1376 378 683 845 1107 283 955 740 704 390 877 53 800 1146 475 625 39 247 954 914 64 237 1304 1272 643 652 774 305 724 379 640 1193 83 602 1208 969 837 635 505 385 1442