CMG INTERNATIONAL TRADING DALIAN CO. ,mainly in regard of foreign trade of rubber machinery,manages all kinds of rubber machinery&equipment such as rubber mixing mill,internal mixer(banbury),dispersion mixe(kneader) ,rubber calender,rubber extruder,plate vulcanizer machine,rotary curing machine,precure tread liner moulding press machine,rubber powder and reclaimed rubber equipment,rubber hoses production line,rubber strip production line,tire building machine,heating water deaerator,tire shaping& curing press,cord splitting machine,cycle tire equipment,raw material machinery,check & measuring equipment,etc.

We warmly welcome new and old customers home and abroad,friends from all walks of life to negotiate and cooperate with us.Let's co-create a better future!

Current sources

Close to 21 million tons of rubber were produced in 2005 of which around 42% was natural. Since the bulk of the rubber produced is the synthetic variety which is derived from petroleum, the price of even natural rubber is determined to a very large extent by the prevailing global price of crude oil[citation needed]. Today Asia is the main source of natural rubber, accounting for around 94% of output in 2005. The three largest producing countries (Indonesia, Malaysia and Thailand) together account for around 72% of all natural rubber production.

Cultivation

Rubber latex is extracted from Rubber trees. The economic life period of rubber trees in plantations is around 32 years – up to 7 years of immature phase and about 25 years of productive phase.

The soil requirement of the plant is generally well-drained weathered soil consisting of laterite, lateritic types, sedimentary types, nonlateritic red or alluvial soils.

The climatic conditions for optimum growth of Rubber tree consist of (a) Rainfall of around 250 cm evenly distributed without any marked dry season and with at least 100 rainy days per annum (b) Temperature range of about 20°C to 34°C with a monthly mean of 25°C to 28°C (c) High atmospheric humidity of around 80% (d) Bright sunshine amounting to about 2000 hours per annum at the rate of 6 hours per day throughout the year and (e) Absence of strong winds.

Many high-yielding clones have been developed for commercial planting. These clones yield more than 2,000 kilograms of dry Rubber per hectare per annum, when grown under ideal conditions.

Collection

In places like Kerala, where coconuts are in abundance, the shell of half a coconut is used as the collection container for the latex but glazed pottery or aluminium cups are more common elsewhere. The cups are supported by a wire that encircles the tree.This wire incorporates a spring so that it can stretch as the tree grows. The latex is led into the cup by a galvanised "spout" that has been knocked into the bark. 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 is between 450 and 650 trees. Trees are usually tapped alternate or third daily although there are many variations in timing, length and number of cuts. The latex, which contains 25 - 40% dry rubber, is in the bark so the tapper must avoid cutting right through to the wood or the growing cambial layer will be damaged and the renewing bark will be badly deformed making later tapping difficult. It is usual to tap a pannel at least twice, sometimes three times, during the trees' 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 is 25cm (vertical) bark consumption per annum. The latex 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 will 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 then start collecting the latex at about midday. Some trees will continue to drip after the collection and this leads to a small amount of cup lump which 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 the dry rubber produced.

The latex can be collected in its liquid state. It is sometimes necessary to add a few drops of ammonia solution to the cup, or to the transport tank, to prevent precoagulation of the latex before it reaches the factory. It can also be left in the cup to coagulate naturally into cup lump for collection before the next tapping, although this will produce a lower grade of product.

Latex is generally processed into either latex concentrate for manufacture of dipped goods or it can be coagulated under controlled, clean conditions using formic acid. The coagulated latex can then be processed into the higher grade technically specified block rubbers such as TSR3L or TSRCV or used to produce Ribbed Smoke Sheet grades.

Naturally coagulated rubber (cup lump) is used in the manufacture of TSR10 and TSR20 grade rubbers. The processing of the rubber for these grades is basically a size reduction and cleaning process in order to remove contamination and prepare the material for the final stage drying.

The dried material is then baled and palletized for shipment.

Uses

The use of rubber is widespread, ranging from household to industrial products, entering the production stream at the intermediate stage or as final products. Tires and tubes are the largest consumers of rubber, accounting for around 56% total consumption in 2005. The remaining 44% are taken up by the general rubber goods (GRG) sector, which includes all products except tires and tubes.

Other significant uses of rubber are door and window profiles, hoses, belts, matting, flooring and dampeners (anti-vibration mounts) for the automotive industry in what is known as the "under the bonnet" products. Gloves (medical, household and industrial) are also large consumers of rubber and toy balloons, although the type of rubber used is that of the concentrated latex. Significant tonnage of rubber is used as adhesives in many manufacturing industries and products, although the two most noticeable are the paper and the carpet industry. Rubber is also commonly used to make rubber bands and pencil erasers.

Additionally, rubber produced as a fiber sometimes called elastic, has significant value for use in the textile industry because of its excellent elongation and recovery properties. For these purposes, manufactured rubber fiber is made as either an extruded round fiber or rectangular fibers that are cut into strips from extruded film. Because of its low dye acceptance, feel and appearance, the rubber fiber is either covered by yarn of another fiber or directly woven with other yarns into the fabric. In the early 1900’s, for example, 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. Seeking a way to address these shortcomings, the textile industry has turned to Neoprene (polymer form 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.

Natural rubber is often vulcanized, a process by which the rubber is heated and sulfur, peroxide or bisphenol are added to improve resilience and elasticity, and to prevent it from perishing. Vulcanization greatly improved the durability and utility of rubber from the 1830s on. The successful development of vulcanization is most closely associated with Charles Goodyear. Carbon black is often used as an additive to rubber to improve its strength, especially in vehicle tires.

CMG International Trading Dalian Co,Ltd

Contact Person: William Yang

MSN: williamy98@hotmail.com

Telephone: 86-0411-82766648

Fax: 86-0411-82766647

E-Mail: williamy98@yahoo.com.cn

Address: 22th floor,wan ke mansion,NO.67 Tong Xing street,zhong shan district,Dalian,Liaoning provice,China