Sitiawan (alternate spelling: Setiawan ; origin: from Malay , a portmanteau of Setia Kawan , meaning "Loyal Friend") is a mukim and town in Manjung District , Perak , Malaysia .
93-478: The region spans an area of 331.5 square kilometers (128.0 sq mi). In the year 2000, the population was 95,920 and by 2015, has grown to more than 150,000. Sitiawan ( mukim ), is located at 4°13′N 100°42′E / 4.217°N 100.700°E / 4.217; 100.700 . Folklore makes reference to Sitiawan of the past as Kampung Sungai Gajah Mati. It was a thriving settlement for Fuzhounese (Foochow) migrants. They were predominantly from
186-672: A loanword in English . However, it was also originally a loanword in Malay from the Arabic word: مقيم (meaning resident ). The closest English translation for mukim is township . In Brunei , a mukim is the immediate subdivision of a district ( Malay : daerah ). The equivalent English word for 'mukim' is 'township'. There are 38 mukims in Brunei . Each mukim is an administrative area made up of several kampung ( Malay for "village"). A mukim
279-474: A Permanent Forest Reserve but the state government re-gazetted it to an ‘Industrial Zone’. The Perak Department of Wildlife and National Parks said that the area is rich in flora and fauna and protected under the Wildlife Protection Act 1972. The site is surrounded by mature and regenerating natural primary forest whilst the bird life and mammals are protected by national and international laws. The area
372-531: A Royal Malaysian Customs Gazetted Port, is a river port, located along the banks of the Dindings River. The Terminal is an integrated common user port facility, and is International Ship Port Security code compliant. Since 1995, the Terminal has been improved and upgraded and its facilities have been extended to include additional open and covered storage. The main berth has been extended for another 280m in 2001, with
465-512: A clay oven), as well as "Go-row" ( Min Dong Chinese : 高肚 ; a thick sweet and sour broth cooked with fish maw) are cooked in both restaurants and homes. Local dishes such as red rice wine and Fuzhou vermicelli continue to play an important role in the livelihood and traditions of those living in or from Kampung Koh. In recent years, intense development on routes connecting Lumut, Seri Manjung and Sitiawan have brought prosperity and pollution to what
558-785: A cultivar of the Kazakh dandelion ( Taraxacum kok-saghyz ) that is suitable for commercial production of natural rubber. In collaboration with Continental Tires , IME began a pilot facility. Many other plants produce forms of latex rich in isoprene polymers, though not all produce usable forms of polymer as easily as the Pará. Some of them require more elaborate processing to produce anything like usable rubber, and most are more difficult to tap. Some produce other desirable materials, for example gutta-percha ( Palaquium gutta ) and chicle from Manilkara species. Others that have been commercially exploited, or at least showed promise as rubber sources, include
651-629: A dedicated terminal to handle coal for Station Janakuasa Sultan Azlan Shah (TNBJ) in Seri Manjung. An industrial zone, Lumut Port Industrial Park (LPIP), located within Lumut Port itself with direct sea, trade access, is home to various industries and companies. LPIP is home to companies such as Sapura Kencana Petroleum Berhad, an oilfield service company, Kencana Torsco Sdn. Bhd., B.I.G. Industrial Gas Sdn. Bhd., IMPSA, etc. In recent years, bio-diesel, oleo and palm oil based companies have been set up due to
744-447: A fiber, sometimes called 'elastic', had significant value to the textile industry because of its excellent elongation and recovery properties. For these purposes, manufactured rubber fiber was made as either an extruded round fiber or rectangular fibers cut into strips from extruded film. Because of its low dye acceptance, feel and appearance, the rubber fiber was either covered by yarn of another fiber or directly woven with other yarns into
837-510: A form of assisted biological coagulation. Little care is taken to exclude twigs, leaves, and even bark from the lumps that are formed, which may also include tree lace. Earth scrap is material that gathers around the base of the tree. It arises from latex overflowing from the cut and running down the bark, from rain flooding a collection cup containing latex, and from spillage from tappers' buckets during collection. It contains soil and other contaminants, and has variable rubber content, depending on
930-752: A given strain, thereby increasing the elastic force constant and making the rubber harder and less extensible. Raw rubber storage depots and rubber processing can produce malodour that is serious enough to become a source of complaints and protest to those living in the vicinity. Microbial impurities originate during the processing of block rubber. These impurities break down during storage or thermal degradation and produce volatile organic compounds. Examination of these compounds using gas chromatography / mass spectrometry (GC/MS) and gas chromatography (GC) indicates that they contain sulfur, ammonia, alkenes , ketones , esters , hydrogen sulfide , nitrogen, and low-molecular-weight fatty acids (C2–C5). When latex concentrate
1023-419: A large remainder of the rubber estates underwent mass conversions into oil palm plantations, due to better yield and profits compared to rubber sheets and latex. Oil palm is less labour-intensive crop compared to rubber, as rubber needs to be tapped regularly. Tourism has not been a major economic activity, but the town centre derives some economic advantages from its close proximity to Pangkor Island which
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#17328478878671116-515: A large stretch ratio and high resilience and also is buoyant and water-proof. Industrial demand for rubber-like materials began to outstrip natural rubber supplies by the end of the 19th century, leading to the synthesis of synthetic rubber in 1909 by chemical means. The major commercial source of natural rubber latex is the Amazonian rubber tree ( Hevea brasiliensis ), a member of the spurge family , Euphorbiaceae . Once native to Brazil,
1209-432: A petroleum refinery or other natural incineration processes, is sometimes used as an additive to rubber to improve its strength, especially in vehicle tires. During vulcanization, rubber's polyisoprene molecules (long chains of isoprene) are heated and cross-linked with molecular bonds to sulfur, forming a 3-D matrix. The optimal percentage of sulfur is approximately 10%. In this form, the polyisoprene molecules orientation
1302-435: A point where it shares properties of both; i.e., if it is heated and cooled, it is degraded but not destroyed. The final properties of a rubber item depend not just on the polymer, but also on modifiers and fillers, such as carbon black , factice , whiting and others. Rubber particles are formed in the cytoplasm of specialized latex-producing cells called laticifers within rubber plants. Rubber particles are surrounded by
1395-451: A significant amount of rubber. Gloves (medical, household, and industrial) and toy balloons were large consumers of rubber, although the type of rubber used is concentrated latex. Significant tonnage of rubber was used as adhesives in many manufacturing industries and products, although the two most noticeable were the paper and the carpet industries. Rubber was commonly used to make rubber bands and pencil erasers . Rubber produced as
1488-453: A single phospholipid membrane with hydrophobic tails pointed inward. The membrane allows biosynthetic proteins to be sequestered at the surface of the growing rubber particle, which allows new monomeric units to be added from outside the biomembrane, but within the lacticifer. The rubber particle is an enzymatically active entity that contains three layers of material, the rubber particle, a biomembrane and free monomeric units. The biomembrane
1581-534: A subdivision of an autonomous sub-district ( daerah kecil ), as per Section 11(c) of the National Land Code 1965. However, in Putrajaya the designation mukim is not used; the term presint (Malay for "precinct") is used instead. The northern state of Perlis , due to its small size, is not divided into daerahs , but directly into mukims . In Kelantan , the term daerah corresponds to
1674-620: A violent conflict in Fujian in 1901 known as the Boxer Rebellion . The Chinese Christians were led by two Chinese pastors and settled down in what is today known as Kampung Koh. Most of these immigrants worked in rubber plantations in Sitiawan. The Fuzhou settlers also built four wells, two in the 1930s and another two in the 1950s. These heritage wells still exist but are no longer used. Chin Peng , who led
1767-401: A wire that encircles the tree. This wire incorporates a spring so it can stretch as the tree grows. The latex is led into the cup by a galvanised "spout" knocked into the bark. Rubber tapping normally takes place early in the morning, when the internal pressure of the tree is highest. A good tapper can tap a tree every 20 seconds on a standard half-spiral system, and a common daily "task" size
1860-442: Is 25 cm (vertical) bark consumption per year. The latex-containing tubes in the bark ascend in a spiral to the right. For this reason, tapping cuts usually ascend to the left to cut more tubes. The trees drip latex for about four hours, stopping as latex coagulates naturally on the tapping cut, thus blocking the latex tubes in the bark. Tappers usually rest and have a meal after finishing their tapping work and then start collecting
1953-593: Is a crowded bus terminal. Instead of a spirit, a middle age old man nicknamed "Hei Ren" can often be seen selling bus tickets. In September 1903, the settlement experienced an influx of more than 360 Christian Fuzhou immigrants seeking refuge from violence during the Qing dynasty. The Chinese Christians were attacked by the Boxer rebels, also known as Yihetuan in Chinese (义和团), and the Qing dynasty government supported their cause, causing
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#17328478878672046-565: Is a famous niche tourist destination. The development of the town had been rapid in the 1990s. One of the main reasons was the establishment of the Royal Malaysian Navy 's Naval Base in Lumut , approximately 10 km from the town centre. The Naval Base is currently the largest in Malaysia. The base has acted as a catalyst for the development of commercial activities in the town, serving both
2139-418: Is a natural polymer of isoprene (polyisoprene), and an elastomer (a stretchy polymer). Polymers are simply chains of molecules that can be linked together. Rubber is one of the few naturally occurring polymers and prized for its high stretch ratio, resilience, and water-proof properties. Other examples of natural polymers include tortoise shell , amber , and animal horn . When harvested, latex rubber takes
2232-532: Is a sticky, milky and white colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex then is refined into the rubber that is ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup. The coagulated lumps are collected and processed into dry forms for sale. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has
2325-807: Is also home to leopards, white-bellied eagles and the endangered palm plant, Phoenix paladosa . Another major industry is its rich rubber latex resource, YTY Industry Sdn Bhd, a world leader in Nitrile Gloves production for examination and surgical use, TNB JanaManjung Sdn Bhd an independent power generation company, TNB's Sultan Aziz Shah Coal-Fired Power Plant and several other industrial manufacturing and mining companies. There are many schools in Sitiawan, such as Sekolah Menengah Kebangsaan Ahmad Boestamam , Sekolah Menengah Jenis Kebangsaan Nan Hwa, Sekolah Menengah Kebangsaan Convent Sitiawan, Sekolah Menengah Kebangsaan ACS (Anglo Chinese School) Sitiawan , Sekolah Menengah Kebangsaan Tok Perdana. The first mentioned school
2418-415: Is between 450 and 650 trees. Trees are usually tapped on alternate or third days, although many variations in timing, length and number of cuts are used. "Tappers would make a slash in the bark with a small hatchet. These slanting cuts allowed latex to flow from ducts located on the exterior or the inner layer of bark ( cambium ) of the tree. Since the cambium controls the growth of the tree, growth stops if it
2511-440: Is cut. Thus, rubber tapping demanded accuracy, so that the incisions would not be too many given the size of the tree, or too deep, which could stunt its growth or kill it." It is usual to tap a panel at least twice, sometimes three times, during the tree's life. The economic life of the tree depends on how well the tapping is carried out, as the critical factor is bark consumption. A standard in Malaysia for alternate daily tapping
2604-414: Is designed to bring in incoming iron ore from the largest bulk carrier of 400,000 DWT Valemax, and to export it with a maximum of 80,000 DWT panamax size vessel. The project has been controversial due to environmental concerns. Fears expressed by civic groups and local residents concern the destruction of the environment, the livelihood of locals, particularly fishermen, and beach-side tourism. Nevertheless,
2697-558: Is headed by a penghulu (Malay for "headman"), which is an elected office. The number of mukims in each of the districts in Brunei is as follows: The smallest mukim by area is Mukim Saba in the Brunei-Muara District. The largest mukim by area is Mukim Sukang in the Belait District . The last change in the mukim boundaries was in the late 1990s when Mukim Kumbang Pasang was merged into Mukim Kianggeh and Mukim Berakas
2790-438: Is held tightly to the rubber core by the high negative charge along the double bonds of the rubber polymer backbone. Free monomeric units and conjugated proteins make up the outer layer. The rubber precursor is isopentenyl pyrophosphate (an allylic compound), which elongates by Mg -dependent condensation by the action of rubber transferase. The monomer adds to the pyrophosphate end of the growing polymer. The process displaces
2883-558: Is known for the Tua Pek Kong temple located 15 minutes from the town. The temple has monumental statues and structures. A row of statues carved to resemble Chinese deities are situated in the garden area of the temple facing the Pasir Panjang seashore. Mukim A mukim is a type of administrative division used in Brunei , Indonesia , Malaysia and Singapore . The word mukim is
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2976-556: Is low and strain results from small changes of bond lengths and angles: this caused the Challenger disaster , when the American Space Shuttle 's flattened o-rings failed to relax to fill a widening gap. The glass transition is fast and reversible: the force resumes on heating. The parallel chains of stretched rubber are susceptible to crystallization. This takes some time because turns of twisted chains have to move out of
3069-635: Is named after Ahmad Boestamam , an historical figure who helped to gain independence from the British . SMJK Nan Hwa was previously a private Chinese school which had been converted into a partially subsidised government school which uses the Chinese medium. Nan Hwa was founded in 1935 from the amalgamation of the High School section of 4 Chinese primary schools (Chung Cheng Primary School, Kuok Min Primary School, Uk Dih Primary School and Uk Ing Primary School) in
3162-892: Is not cultivated widely in its native continent of South America because of the South American leaf blight , and other natural predators there. Rubber latex is extracted from rubber trees. The economic life of rubber trees in plantations is around 32 years, with up to 7 years being an immature phase and about 25 years of productive phase. The soil requirement is well-drained, weathered soil consisting of laterite , lateritic types, sedimentary types, nonlateritic red or alluvial soils. The climatic conditions for optimum growth of rubber trees are: Many high-yielding clones have been developed for commercial planting. These clones yield more than 2,000 kilograms per hectare (1,800 lb/acre) of dry rubber per year, under ideal conditions. Rubber production has been linked to deforestation. Rubber therefore
3255-582: Is one of seven commodities included in the 2023 EU Regulation on Deforestation-free products (EUDR), which aims to guarantee that the products European Union (EU) citizens consume do not contribute to deforestation or forest degradation worldwide. In places such as Kerala and Sri Lanka, where coconuts are in abundance, the half shell of coconut was used as the latex collection container. Glazed pottery or aluminium or plastic cups became more common in Kerala-India and other countries. The cups are supported by
3348-449: Is produced by smallholders, who collect rubber from trees far from the nearest factory. Many Indonesian smallholders, who farm paddies in remote areas, tap dispersed trees on their way to work in the paddy fields and collect the latex (or the coagulated latex) on their way home. As it is often impossible to preserve the latex sufficiently to get it to a factory that processes latex in time for it to be used to make high quality products, and as
3441-529: Is produced from rubber, sulfuric acid is used for coagulation. This produces malodourous hydrogen sulfide. The industry can mitigate these bad odours with scrubber systems . Rubber is the polymer cis-1,4-polyisoprene – with a molecular weight of 100,000 to 1,000,000 daltons . Typically, a small percentage (up to 5% of dry mass) of other materials, such as proteins , fatty acids , resins , and inorganic materials (salts) are found in natural rubber. Polyisoprene can also be created synthetically, producing what
3534-553: Is sometimes applied to the tree-obtained version of natural rubber in order to distinguish it from the synthetic version. The first use of rubber was by the indigenous cultures of Mesoamerica . The earliest archeological evidence of the use of natural latex from the Hevea tree comes from the Olmec culture, in which rubber was first used for making balls for the Mesoamerican ballgame . Rubber
3627-402: Is sometimes referred to as "synthetic natural rubber", but the synthetic and natural routes are distinct. Some natural rubber sources, such as gutta-percha , are composed of trans-1,4-polyisoprene, a structural isomer that has similar properties. Natural rubber is an elastomer and a thermoplastic . Once the rubber is vulcanized, it is a thermoset . Most rubber in everyday use is vulcanized to
3720-472: Is still random but they become aligned when the rubber is stretched. This sulfur vulcanization makes the rubber stronger and more rigid, but still very elastic. And through the vulcanization process, the sulfur and latex are meant to be totally used up in individual form. Natural rubber latex is shipped from factories in Southeast Asia , South America , and West and Central Africa to destinations around
3813-667: The mukim level in other states, whilst for Sabah and Sarawak in East Malaysia , owing to its large sizes, they are directly divided into divisions and in turn, divisions are divided into districts and the subdivision of each district is termed as a mukim instead. Each mukim is divided into a village or villages ( kampung or kampong ). In Singapore , a Mukim is a survey district. There are 34 Mukim survey districts in Singapore, as well as 30 Town Subdivision survey districts. The Town Subdivision survey districts are located in
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3906-641: The Gutian County in Fuzhou , China. According to the folklore, Kampung Sungai Gajah Mati (literally: "Dead Elephant River Village") was the place where two large elephants drowned after one of them, overladen with tin ore, got stuck in the mud of the Dinding River at low tide. Efforts to save the elephant were in vain and eventually, everyone gave up and left. However, the second elephant refused to budge and hung on to its friend, resulting in them drowning together in
3999-530: The Malayan Communist Party for many years, was born in Sitiawan in 1924. Sitiawan has a Tropical rainforest climate (Af). Sitiawan's population is primarily Chinese—56.2% Chinese, 23.9% Malay, 19.4% Indian and 0.5% other. Ethnic breakdown of Sitiawan's electorate as of 2022 The representative of Sitiawan in the Federal Parliament ( Dewan Rakyat ) List of Sitiawan representatives in
4092-496: The Mullins effect and the Payne effect and is often modeled as hyperelastic . Rubber strain crystallizes . Because there are weakened allylic C-H bonds in each repeat unit , natural rubber is susceptible to vulcanisation as well as being sensitive to ozone cracking . The two main solvents for rubber are turpentine and naphtha (petroleum). Because rubber does not dissolve easily,
4185-697: The Putumayo genocide . Between the 1880s–1913 Julio César Arana and his company that would become the Peruvian Amazon Company controlled the Putumayo river. W.E. Hardenburg, Benjamin Saldaña Rocca and Roger Casement were influential figures in exposing these atrocities. Roger Casement was also prominent in revealing the Congo atrocities to the world. Days before entering Iquitos by boat Casement wrote "'Caoutchouc
4278-557: The cytosol . In plants, isoprene pyrophosphate can also be obtained from the 1-deox-D-xyulose-5-phosphate/2-C-methyl-D-erythritol-4-phosphate pathway within plasmids. The relative ratio of the farnesyl pyrophosphate initiator unit and isoprenyl pyrophosphate elongation monomer determines the rate of new particle synthesis versus elongation of existing particles. Though rubber is known to be produced by only one enzyme, extracts of latex host numerous small molecular weight proteins with unknown function. The proteins possibly serve as cofactors, as
4371-452: The Académie (published in 1755) that described many of rubber's properties. This has been referred to as the first scientific paper on rubber. In England, Joseph Priestley , in 1770, observed that a piece of the material was extremely good for rubbing off pencil marks on paper, hence the name "rubber". It slowly made its way around England. In 1764, François Fresnau discovered that turpentine
4464-455: The British to plant rice. The settlers, however, found that paddy-planting is not suited to the soil of the region and so they switched to livestock farming before discovering that the land was much better suited for rubber plantations. The rapid development of urban settlements saw the plantation and estate areas develop, and eventually converted into residential and commercial areas. In the 1980s,
4557-649: The Congo Free State for more information on the rubber trade in the Congo Free State in the late 1800s and early 1900s.) The rubber boom in the Amazon also similarly affected indigenous populations to varying degrees. Correrias, or slave raids were frequent in Colombia, Peru and Bolivia where many were either captured or killed. The most well known case of atrocities generated from rubber extraction in South America came from
4650-738: The Manjung community established the Ong Seok Kim Memorial Education Fund in his honour. The Fund offers scholarships and loans to students in the Manjung District, irrespective of ethnicity. SMK Methodist ACS Sitiawan, formerly an English school, was founded by Christian missionaries back in 1903. It is currently a national school under the Malaysian education system and subjects are taught in Bahasa Malaysia. Its 100th anniversary
4743-882: The Sitiawan area. Ong Seok Kim was elected as first Chairman of the School Board in 1936 and again in 1946 to 1947. Its 70th anniversary was celebrated on 1 September 2006 in SMJK Nan Hwa school hall. A thousand-person dinner was held at the Ku Tien Association Hall to commemorate that auspicious day. There are 24 Chinese primary schools and 5 Chinese secondary schools in the district. Of these, 5 schools were founded by Ong Seok Kim . They are SJK (C) Chung Cheng , Sitiawan in 1920, SMJK Nan Hwa (which split into Sekolah Tinggi Nan Hwa, Ayer Tawar Road in 1984) in 1935, SJK (C) Ping Min , Lumut in 1951 and SMJK Dindings , Lumut in 1953. Ong Seok Kim died in 1964. The following year,
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#17328478878674836-478: The State Legislative Assembly of Perak Sitiawan is one of the driest places after Kuala Klawang Town (Jelebu), Malacca City (Malacca) and Lubok Merbau (Perak) in Malaysia with average annual rainfall of a little under 2,000 mm (79 in). Most of the time, the average rainfall is just above 100 mm (3.9 in) with October and November being wetter months while June is the driest month of
4929-451: The alongside depth of 12m ACD, resulting in a total overall linear berth length of 510m. LBT is a deepwater seaport, and with a natural depth of 20 metres, LBT is currently South-East Asia's largest dry bulk unloading facility. The terminal is capable of berthing an entire range of vessels in Panamax and Capemax ships up to 165,000 DWT. LBT is designed to handle dry bulk cargoes. It currently is
5022-409: The amount of contaminants. Earth scrap is collected by field workers two or three times a year and may be cleaned in a scrap-washer to recover the rubber, or sold to a contractor who cleans it and recovers the rubber. It is of low quality. Latex coagulates in the cups if kept for long and must be collected before this happens. The collected latex, "field latex", is transferred into coagulation tanks for
5115-604: The city area, while the Mukim survey districts are located in the outer regions surrounding the former. This article about geography terminology is a stub . You can help Misplaced Pages by expanding it . This Malaysian location article is a stub . You can help Misplaced Pages by expanding it . This Brunei location article is a stub . You can help Misplaced Pages by expanding it . Rubber Rubber , also called India rubber , latex , Amazonian rubber , caucho , or caoutchouc , as initially produced, consists of polymers of
5208-407: The dry rubber produced. Latex that drips onto the ground, "earth scrap", is also collected periodically for processing of low-grade product. Cup lump is the coagulated material found in the collection cup when the tapper next visits the tree to tap it again. It arises from latex clinging to the walls of the cup after the latex was last poured into the bucket, and from late-dripping latex exuded before
5301-654: The early 1900s, the Congo Free State in Africa was also a significant source of natural rubber latex, mostly gathered by forced labor . King Leopold II's colonial state brutally enforced production quotas due to the high price of natural rubber at the time. Tactics to enforce the rubber quotas included removing the hands of victims to prove they had been killed. Soldiers often came back from raids with baskets full of chopped-off hands. Villages that resisted were razed to encourage better compliance locally. (See Atrocities in
5394-421: The export of seeds or plants. In 1876, Henry Wickham smuggled 70,000 Amazonian rubber tree seeds from Brazil and delivered them to Kew Gardens , England. Only 2,400 of these germinated. Seedlings were then sent to India , British Ceylon ( Sri Lanka ), Dutch East Indies ( Indonesia ), Singapore , and British Malaya . Malaya (now Peninsular Malaysia ) was later to become the biggest producer of rubber. In
5487-636: The fabric. Rubber yarns were used in foundation garments. While rubber is still used in textile manufacturing, its low tenacity limits its use in lightweight garments because latex lacks resistance to oxidizing agents and is damaged by aging, sunlight, oil and perspiration. The textile industry turned to neoprene (polymer of chloroprene ), a type of synthetic rubber, as well as another more commonly used elastomer fiber, spandex (also known as elastane), because of their superiority to rubber in both strength and durability. Rubber exhibits unique physical and chemical properties. Rubber's stress–strain behavior exhibits
5580-477: The first technique for tapping trees for latex without causing serious harm to the tree. Because of his fervent promotion of this crop, he is popularly remembered by the nickname "Mad Ridley". Before World War II significant uses included door and window profiles, hoses, belts, gaskets, matting , flooring, and dampeners (antivibration mounts) for the automotive industry. The use of rubber in car tires (initially solid rather than pneumatic) in particular consumed
5673-544: The form of latex, an opaque, white, milky suspension of rubber particles in water. It is then transformed through industrial processes to the solid form widely seen in manufactured goods. Natural rubber is reactive and vulnerable to oxidization, but it can be stabilized through a heating process called vulcanization. Vulcanization is a process by which the rubber is heated and sulfur , peroxide , or bisphenol are added to improve resistance and elasticity and to prevent it from oxidizing. Carbon black , which can be derived from
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#17328478878675766-459: The higher-grade, technically specified block rubbers such as SVR 3L or SVR CV or used to produce Ribbed Smoke Sheet grades. Naturally coagulated rubber (cup lump) is used in the manufacture of TSR10 and TSR20 grade rubbers. Processing for these grades is a size reduction and cleaning process to remove contamination and prepare the material for the final stage of drying. The dried material is then baled and palletized for storage and shipment. Rubber
5859-431: The international market spot price of a seemingly more profitable crop (for example palm oil ) surges in relation to rubber. For instance, during the 2020 and 2021 international COVID-19 pandemic , demand for rubber gloves surged, leading to a spike in rubber prices of about 30%. In addition to the pandemic, demand exceeded supply in part because long term plantations had been torn out and replaced with other crops over
5952-402: The latex would anyway have coagulated by the time it reached the factory, the smallholder will coagulate it by any means available, in any container available. Some smallholders use small containers, buckets etc., but often the latex is coagulated in holes in the ground, which are usually lined with plastic sheeting. Acidic materials and fermented fruit juices are used to coagulate the latex –
6045-434: The latex-carrying vessels of the tree become blocked. It is of higher purity and of greater value than the other three types. 'Cup lumps' can also be used to describe a completely different type of coagulate that has collected in smallholder plantations over a period of 1–2 weeks. After tapping all of the trees, the tapper will return to each tree and stir in some type of acid, which allows the newly harvested latex to mix with
6138-416: The latex. There is growing concern for the future supply of rubber due to various factors, including plant disease, climate change, and the volatile market price of rubber. Producers of natural rubber are mostly small family-held plantations, often serving large industrial aggregators. High volatility in the price of rubber affects rubber plantation investment, and farmers may remove their rubber trees if
6231-443: The liquid "field latex" at about midday. The four types of field coagula are "cuplump", "treelace", "smallholders' lump", and "earth scrap". Each has significantly different properties. Some trees continue to drip after the collection leading to a small amount of "cup lump" that is collected at the next tapping. The latex that coagulates on the cut is also collected as "tree lace". Tree lace and cup lump together account for 10%–20% of
6324-399: The material is finely divided by shredding prior to its immersion. An ammonia solution can be used to prevent the coagulation of raw latex. Rubber begins to melt at approximately 180 °C (356 °F). On a microscopic scale, relaxed rubber is a disorganized cluster of erratically changing wrinkled chains. In stretched rubber, the chains are almost linear. The restoring force is due to
6417-413: The nearby Outward Bound School has alleged that part of the jungle is inaccessible to its teams. Other education and training institutions are also barred from entering the area. Consumer and environmental groups have joined in the condemnations with claims that the ecosystem of the area, formerly gazetted as a forest reserve, would be destabilised. The plant is located on a 450-acre site which was originally
6510-455: The organic compound isoprene , with minor impurities of other organic compounds. Thailand , Malaysia , Indonesia , and Cambodia are four of the leading rubber producers. Types of polyisoprene that are used as natural rubbers are classified as elastomers . Currently, rubber is harvested mainly in the form of the latex from the Pará rubber tree ( Hevea brasiliensis ) or others. The latex
6603-561: The plantation expanded to Karnataka , Tamil Nadu and the Andaman and Nicobar Islands of India. Today, India is the world's 3rd largest producer and 4th largest consumer of rubber. In Singapore and Malaya, commercial production was heavily promoted by Sir Henry Nicholas Ridley , who served as the first Scientific Director of the Singapore Botanic Gardens from 1888 to 1911. He distributed rubber seeds to many planters and developed
6696-589: The preparation of dry rubber or transferred into air-tight containers with sieving for ammoniation. Ammoniation, invented by patent lawyer and vice-president of the United States Rubber Company Ernest Hopkinson around 1920, preserves the latex in a colloidal state for longer periods of time. Latex is generally processed into either latex concentrate for manufacture of dipped goods or coagulated under controlled, clean conditions using formic acid. The coagulated latex can then be processed into
6789-400: The preponderance of wrinkled conformations over more linear ones. For the quantitative treatment see ideal chain , for more examples see entropic force . Cooling below the glass transition temperature permits local conformational changes but a reordering is practically impossible because of the larger energy barrier for the concerted movement of longer chains. "Frozen" rubber's elasticity
6882-422: The previously coagulated material. The rubber/acid mixture is what gives rubber plantations, markets, and factories a strong odor. Tree lace is the coagulum strip that the tapper peels off the previous cut before making a new cut. It usually has higher copper and manganese contents than cup lump. Both copper and manganese are pro-oxidants and can damage the physical properties of the dry rubber. Smallholders' lump
6975-555: The proximity to its raw material source. A secondary jetty, located at Teluk Rubiah is built and managed by Vale Malaysia Minerals Sdn Bhd, a Brazilian mining giant. It was built as a transshipment hub for iron ore. The raw material is brought in from Brazil in gigantic 400,000 DWT bulk carriers some 360 metres in length. The Vale Jetty serves a maximum 90 million tonnes per annum of iron ore and functions as entry and exit points for all material including iron ore, sinter pellets, blast furnace pellets and pelletizing plant additives. The jetty
7068-539: The residents of the base and sailors visiting from other countries. Located at the western coast of Perak with direct access to the Straits of Malacca, it is no surprise that port-related activities, marine services and industries play a major role. Its main port, Lumut Port consists of the Lumut Maritime Terminal (LMT) and Lekir Bulk Terminal (LBT) and it serves the surrounding regions and the state of Perak. LMT,
7161-408: The rising tide. Thus the setia kawan (loyal friend) name was derived. In late 19th century, tin ores and rubber sheets were main commodities for commerce. They were often transported by elephants and then loaded onto steamships heading for Penang . During the 1870s, a smallpox outbreak struck the settlement and locals chose to rename the locality Setia Kawan — the "loyal friend"—to honor and appease
7254-420: The rubber fig ( Ficus elastica ), Panama rubber tree ( Castilla elastica ), various spurges ( Euphorbia spp.), lettuce ( Lactuca species), the related Scorzonera tau-saghyz , various Taraxacum species, including common dandelion ( Taraxacum officinale ) and Kazakh dandelion, and, perhaps most importantly for its hypoallergenic properties, guayule ( Parthenium argentatum ). The term gum rubber
7347-566: The same quality as the natural rubber from rubber trees . In the wild types of dandelion, latex content is low and varies greatly. In Nazi Germany , research projects tried to use dandelions as a base for rubber production, but failed. In 2013, by inhibiting one key enzyme and using modern cultivation methods and optimization techniques, scientists in the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) in Germany developed
7440-454: The species is now pan-tropical. This species is preferred because it grows well under cultivation. A properly managed tree responds to wounding by producing more latex for several years. Congo rubber , formerly a major source of rubber, which motivated the atrocities in the Congo Free State , came from vines in the genus Landolphia ( L. kirkii , L. heudelotis , and L. owariensis ). Dandelion milk contains latex. The latex exhibits
7533-421: The spirits of the dead elephants. This action is also in line with the Chinese beliefs of naming a place to enhance its feng-shui . Over time, the name is shortened and eventually became Sitiawan . Another folkloric story mentions an ancient tree located in Sitiawan, with an old man's spirit often wandering around the tree. The ancient tree was once located at the now famous Shi Zi Lu crossroads. Today, Shi Zi Lu
7626-564: The synthetic rate decreases with complete removal. More than 28 million tons of rubber were produced in 2017, of which approximately 47% was natural. Since the bulk is synthetic, which is derived from petroleum, the price of natural rubber is determined, to a large extent, by the prevailing global price of crude oil. Asia was the main source of natural rubber, accounting for about 90% of output in 2021. The three largest producers, Thailand , Indonesia, and Malaysia, together account for around 72% of all natural rubber production. Natural rubber
7719-435: The terminal high-energy pyrophosphate. The reaction produces a cis polymer. The initiation step is catalyzed by prenyltransferase , which converts three monomers of isopentenyl pyrophosphate into farnesyl pyrophosphate . The farnesyl pyrophosphate can bind to rubber transferase to elongate a new rubber polymer. The required isopentenyl pyrophosphate is obtained from the mevalonate pathway, which derives from acetyl-CoA in
7812-453: The way of the growing crystallites . Crystallization has occurred, for example, when, after days, an inflated toy balloon is found withered at a relatively large remaining volume. Where it is touched, it shrinks because the temperature of the hand is enough to melt the crystals. Vulcanization of rubber creates di- and polysulfide bonds between chains, which limits the degrees of freedom and results in chains that tighten more quickly for
7905-442: The world. As the cost of natural rubber has risen significantly and rubber products are dense, the shipping methods offering the lowest cost per unit weight are preferred. Depending on destination, warehouse availability, and transportation conditions, some methods are preferred by certain buyers. In international trade, latex rubber is mostly shipped in 20-foot ocean containers. Inside the container, smaller containers are used to store
7998-529: The year. In recent years Sitiawan has suffered from haze swept in by winds from raging open fires in Sumatra, Indonesia. Sitiawan grew from a small settlement with rubber tapping and latex processing as its main economic activities. The town was flanked by various Chinese settlements composed mostly of the descendants of immigrants from the Kutien district of Fuzhou , China. The original settlers were encouraged by
8091-468: Was a rubber solvent . Giovanni Fabbroni is credited with the discovery of naphtha as a rubber solvent in 1779. Charles Goodyear redeveloped vulcanization in 1839, although Mesoamericans had used stabilized rubber for balls and other objects as early as 1600 BC. South America remained the main source of latex rubber used during much of the 19th century. The rubber trade was heavily controlled by business interests but no laws expressly prohibited
8184-413: Was celebrated in 2003 and it is also the oldest secondary school in Sitiawan. ACS is the first school in Manjung district to have established a scout troop. Sitiawan is known for its strong Fuzhou heritage. Various traditional Foochow dishes such as red rice wine vermicelli, "Kompiang" or "Kong Piang" (traditional Fuzhou buns made with a type of unleavened flatbread stuffed with seasoned pork and baked in
8277-518: Was directed to the planned township of Seri Manjung. All local government administrative offices were also relocated to Manjung in recent years. This development renders shop and small business owners in Kampung Koh and Simpang Empat obsolete, resulting in many businesses shutting down. Empty shop lots were later converted to become shelters for swiftlets. At its peak about 8–10 years ago, swiftlet breeding caused property prices to skyrocket. Sitiawan also
8370-479: Was divided into Mukim Berakas A and Mukim Berakas B. The number of mukims remained at 38. In Indonesia , mukim means 'a place to stay' or 'the one who stays', while pemukiman means 'a settlement'. The term mukim is used only in Aceh as a subdivision of a district . A mukim contains several villages . In Malaysia , a mukim can either be a subdivision of a daerah ( district or county ) or
8463-736: Was first called 'india rubber,' because it came from the Indies, and the earliest European use of it was to rub out or erase. It is now called India rubber because it rubs out or erases the Indians." In India , commercial cultivation was introduced by British planters, although the experimental efforts to grow rubber on a commercial scale were initiated as early as 1873 at the Calcutta Botanical Garden . The first commercial Hevea plantations were established at Thattekadu in Kerala in 1902. In later years
8556-518: Was later used by the Maya and Aztec cultures: in addition to making balls, Aztecs used rubber for other purposes, such as making containers and to make textiles waterproof by impregnating them with the latex sap. 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
8649-483: Was once a relatively quiet town. The primary industries within Sitiawan are rubber production, manufacturing of rubber gloves, palm oil production, mineral ores, fishing, fisheries and shipbuilding. Around the year 2000, Sitiawan residents began to get involved in swiftlet bird breeding activity. This activity was partly attributed to the development of two major roads which indirectly "disconnect" Kampung Koh and Simpang Empat from traffic travelling to Lumut. All traffic
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