Palm | Kelapa Sawit

About Rubber, agricultural commodities - The rubber was known to indigenous peoples in the America before the arrival of European explorers. In 1525, reported from Padre d'Anghieria, he had seen Mexican tribes playing with rubber band balls. The first scientific study of the rubber was made by Charles de la Condamine, when he found it during his trip to Peru in 1735. A French engineer who Condamine met in Guyana, Fresnau studied rubber on its home ground, and concluded that it was nothing but a "type of  condensed resin oil."

The first use of rubber is an eraser. It was Magellan, a descendant of the famous Portuguese navigator, who suggested this use. In England, Priestley popularized it as they became known as India rubber. The word rubber in Portuguese - borracha - comes from one of the first applications of this product, when used to replace the leather containers Borrachas the Portuguese used to transport wine.

Returning to the work of La Condamine, Macquer suggested that the rubber could be used to produce flexible tubes. Since then, a number of craftsmen have been involved in the rubber goldsmith Bernard, Winch herbalist, Grossart, Landoll and others. In 1820, British industrialist Nadier produced rubber threads and tried to use in clothing accessories. This was the moment when America was captured by the rubber boom and waterproof footwear used by indigenous peoples has become a success. Waterproof fabrics and snow boots were manufactured in New England.

In 1832, the factory was established, Rosburg. Unfortunately, the cold affect the natural vulcanized rubber products, in which case they are fragile and tend to gum together if left in the sun, all to discourage the consumer. For a long time trying to develop a method to update properties of the rubber (as well as nitric acid) that almost destroyed it in 1840, Goodyear discovered vulcanization, almost by accident.

An interesting fact: in 1815, a humble Sawyer - was one of the leading manufacturers in the UK - Hancock. He had invented a rubber mattress and through an association with the Macintosh, he produces the famous raincoat called "Macintosh." He also discovered how to cut, roll and press the rubber on an industrial scale. He also noted the importance of heat during the pressing process, and built a machine for this purpose.

MacIntosh discovered the use of benzene as a solvent, while Hancock has found that, before peeling and heating were needed to ensure that the rubber is completely dissolved. Hancock also discovered how to make rubber balls. Finally, in 1842, Hancock came into possession of vulcanized rubber produced by Goodyear, search and find the secret of vulcanization, which brought him an immense fortune.

In 1845, RW Thomson invented the pneumatic tire, the inner ring, and a textured tread. In 1850, the toy is made of rubber, as well as solid and hollow balls for golf and tennis. Velocipede invention by Michaux that in 1869 led to the discovery of solid rubber, after which a hollow rubber, and finally re-invented the tire, because Thomson's discovery was forgotten. The physical properties of rubber were finally studied, Bouchardt discovered how to polymerize isoprene between 1879 and 1882, obtaining products with properties similar to rubber. The first is a bicycle tire in 1830, and in 1895, Michelin was bold idea to adapt the tire to the car. Since then, the rubber was an excellent position in the global market.

As Rubber is an important raw material, which has a major role in modern civilization, chemists soon became curious to learn more about its composition, in order to synthesize it. In the nineteenth century, the work has focused on this goal, soon discovered that the rubber is an isoprene polymer.

The Russians and Germans broke fresh ground efforts to synthesize rubber. But the resulting products can not compete with natural rubber. Until the First World War that Germany - put pressure on the environment - has been developed in industrialized countries a synthetic version of this product. This was the beginning of a massive development in the field of synthetic rubber in the world, the production of elastomers.

ABSTRACT: A Study of Chunk Rubber from Recycled Tires as a Road Construction Material; Abstract: - The feasibility of using large rubber chunks from shredded tires as aggregates in coldmixes for road construction was investigated in this study. The research was directed toward development of a chunk rubber asphalt concrete mix design for low volume road construction using local aggregate, shredded tire rubber chunks and a cationic emulsion.

A set of mixes using different combinations of chunk rubber content, emulsion content and fly ash content were tested. Marshall stability results of mixes with 10% Type C fly ash showed optimum emulsion contents of 6.8, 7.3 and 7.8% for 2, 4 and 6% rubber, respectively. The Marshall stability values decreased for increasing rubber contents. The target Marshall stability value of a suitable cold mix at 43ºC was required to be 2225 N. A mix with 10% Type C fly ash, 2% rubber and 7% emulsion showed an average Marshall stability value of 1600 N. Based on the Marshall stability results, some of these mixes appeared to be suitable as binder courses or stabilized drainable bases for low volume roads. If 9 kg of chunk rubber equivalent is produced per tire, then a one km long and 7.3 m wide low-volume road with a 100 mm thick base built with this mix can incorporate approximately 3350 tires. This application can minimize the scrap-tire waste problems of rural communities.

By: M. Hossain1, M. Sadeq1, L. Funk1 and R. Maag2, 1Department of Civil

Engineering, Kansas State University, Manhattan, KS 66506 and 2Kansas

Department of Transportation, Topeka, KS 66611

indian rubber prices june 9 2011, india agriculture commodities - Harrisons Malayalam to ink Africa deal in 3-4 months: To acquire 10,000 hectares, invest Rs. 400-500 crore in the deal. Sees its FY12 tea exports rising 56%, production 12%. Sees FY12 rubber output stable, prices firm. Mumbai: Tea and rubber producer Harrisons Malayalam , an RPG Group company, is planning to announce a plantation deal in Africa in three-four months, a top official said on Thursday.

Harrisons, which is India’s largest rubber producer and south India’s biggest tea maker, plans to acquire about 10,000 hectares of land and invest Rs. 400-500 crore in the deal.

“We are in the due diligence process. We are assessing the political risk which is what is taking a bit of time but in the next 3-4 months, we will make the announcement,” Pankaj Kapoor, managing director, said on the sidelines of the Centrum Investor Conference.

The plantation land will be used for rubber, tea and oil palm, Kapoor added.

In India, Harrison has invested about Rs. 70-75 crore in replantation over the past three-four years. It expects its replanted rubber plantations to yield its first crop in 2012.

rubber price news this week, global agribusiness agriculture - Rubber futures were also inflated this week, as the market took its cues from the local spot market. The spot market was left with little arrivals last week and the onset of monsoons has also been contributing towards tightness in the market.

However, the expectations of higher produce in the coming days might be a solace for the market and might result in prices stepping back in the days to unfold. According to the Association of Natural Rubber Producing Countries (ANPRC), the production is estimated to have increased 5.6 per cent in the first quarter of 2011.

The production is also estimated to rise by another 7.2 percent in the second quarter of the year, added ANRPC. Rubber futures for the most active June contract climbed above Rs.230 per Kg briefly during the final trading day of the week, and closed at Rs.227.97 per Kg on Friday, up 6.13 percent as compared to the previous week’s closing.

Charles Marie de La Condamine is credited with introducing samples of rubber to the Académie Royale des Sciences of France in 1736. In 1751, he presented a paper by François Fresneau to the Académie (eventually published in 1755) which described many of the properties of rubber. This has been referred to as the first scientific paper on rubber.

The para rubber tree initially grew in South America, and the first European to return to Portugal from Brazil with samples of water-repellent rubberized cloth so shocked people that he was brought to court on the charge of witchcraft. When samples of rubber first arrived in England, it was observed by Joseph Priestley, in 1770, that a piece of the material was extremely good for rubbing out pencil marks on paper, hence the name rubber.

South America remained the main source of what limited amount of latex rubber was consumed during much of the 19th century. However in 1876, Henry Wickham gathered thousands of seeds from Brazil, and these were germinated in Kew Gardens, UK. The seedlings were then sent to Ceylon (Sri Lanka), Indonesia, Singapore and British Malaya. Malaya (now Malaysia) was later to become the biggest producer of rubber. About 100 years ago, the Congo Free State in Africa was also a significant source of natural rubber latex, mostly gathered by forced labor. Liberia and Nigeria also started production of rubber.

Commercial latex pigmenting liquid

Latex is usually pigmented by preparing a pigment dispersion and then mixing this with the latex to provide the final colored product. By using the same procedure as in master-batching; i.e., taking a crude dispersion of the pigment, adding this slurry to the latex and homogenizing the two materials, a phase transfer can be achieved in which the pigment is removed from the aqueous phase and deposited inside the latex particles. 

This provides a more intense color, improves washability and fade resistance and, generally, improves the physical characteristics of the paint. This process has made possible the use of the acrylic artists' watercolors. Without homogenization it would not be possible to achieve the brilliance and depth of color.

Pearl pigment for latex

The use of mineral oils in the compounding of rubber has been standard for many years to improve the working characteristics of the rubber and reduce the cost of the final compound. Oil can be introduced into the latex as an emulsion and mixed with the latex emulsions or, simply, as oil mixed with the latex emulsion, but none of these provide a true, uniform, stable mixture of oil and latex. Mixing oil and latex together and then homogenizing will produce a uniform product having superior physical characteristics.

Many of the synthetic resin latices are extremely hard and brittle, but for a number of applications they must be modified to have greater flexibility and improved adhesion. Plasticizers normally used with these synthetic resins are commonly mixed with the latices under continuous agitation, heat, and pressure in an autoclave for one and one-half hours or longer to cause the plasticizer to migrate into the latex particle. By use of the

homogenizer both the time and temperature may be materially reduced in this operation.

In the emulsion polymerization of latices, many of the small polymer particles tend to loosely join together forming agglomerates. In some polymerization reactions the total quantity of agglomerates can reach 10% of the batch. If the latex is to be used for paint or fine-coating applications, these must be filtered out prior to use. By homogenizing, 90% of this agglomerated material can be separated back to the original particle size, reducing the load on the filter to 1% and saving up to 9% of the latex that would formerly have been lost.

For latex processing the APV homogenizers are operated in the pressure range of 2000 psig (13.8 MPa) to 8000 psig (55.2 MPa). These machines should have special wearing parts, when they are used to disperse solids or pigments.

The methods and type of equipment used cover approximately everything used in the paint and rubber fields. The microscope, however, is extremely useful to analyze solid dispersions, and a viscometer would be used for thread or for growing of latex particle operations.

In the manufacture of foam rubber, it is desirable to have a latex solids content of 60 to 65% and still have a workable viscosity of not over 2000 cP, prior to foaming. Lower solids content will result in cells of insufficient wall thickness, causing collapse of the foam with light loads.

There are a number of methods of preparing the latex, so that it may be concentrated without acquiring an excessive viscosity. These methods are:

Only the latter three are used commercially, and homogenization is the preferred method. Various parameters will affect the extent of agglomeration: pH, solids content, temperature, soap-to-rubber ratio and homogenizing pressure. 

Thread from Latex

Thread is usually made from natural latex, although there is an increasing use of some of the synthetics in this application. Thread is manufactured by dispersing into this latex: vulcanizing agents, antioxidants, fillers, opacifiers, etc. Frequently, when these materials have been incorporated in latex, the viscosity of the latex is increased. Since the latex thread is manufactured by gravity flow of latex through a spinnerette and into a coagulating bath, any change in viscosity will result in a change in the thread diameter or, in extreme cases, breakage of the thread. It has been found that passing the latex through the homogenizer stabilizes the viscosity and ensures a uniform compound.

In normal master-batching, a latex is coagulated, washed, dried and then mixed in a rubber mill with carbon black or other reinforcing agents to provide a fine, uniform dispersion of the reinforcing agent to obtain maximum strength in the elastomer. There are processes for mixing carbon black dispersions with liquid latex prior to coagulation, but these methods do not achieve the same tensile strength as the dry mixing method. By mixing a crude carbon black aqueous dispersion with a latex and homogenizing the mixture, it is possible to obtain an intimate combination of the carbon black and the latex, which results in a rubber having higher tensile strength than rubber made by the normal methods of master-batching.

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All latices, both natural and synthetic, are shear-sensitive to varying degrees. This means that under shear these materials can coagulate. Raw natural latex is matured with time to produce a more stable product. If raw latex is not allowed to mature, processing becomes very difficult because of agglomeration. Raw latex may contain soaps and ammonium hydroxide to maintain stability. This shear instability makes it difficult to process latices with high shear equipment such as mixers or colloid mills. However, the homogenizer has been extremely successful in this operation. The success of the homogenizer is due to the fact that the instability of latex is a function of the degree of shear and the time to which it is exposed to this shear. In the homogenizing valve the degree of energy input is high, but the time is essentially zero, thus permitting the processing of the most shearsensitive latices with the minimum of coagulation. However, even in the best processing conditions, latex may agglomerate inside the homogenizer pump requiring routine cleaning of the machine to maintain good pumping action.

The homogenizer has a number of applications in the processing of latex. The following list indicates the diversity of its usage in the field.

The objectives for these various latex applications cover a range of goals that sometime seem contradictory. For example, a latex particle can be either increased or decreased in size by the same piece of equipment; i.e., the APV homogenizer, depending upon the conditions of operation and the type and percentage of surfactant present in the formulation. A brief summary of the objectives for each application follows.