What is mastication process?
Chewing or mastication is the process by which food is crushed and ground by teeth. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed.
How is mastication of rubber done?
Rubber processing consists of four basic steps: (1) mastication, when the elastomer is sheared and the molecules are broken down to give easier flow, (2) mixing, usually carried out immediately after mastication, when additives are incorporated, (3) shaping of the viscous mass, for example, by extrusion or molding, and …
What is compounding of rubber?
Rubber compounding or formulation refers to the addition of certain chemicals to raw rubber in order to obtain the desired properties. Through formulation long-chain molecules are chemically linked together, forming networks and transforming the material from a viscous liquid to elastic solid.
What is the process of natural rubber?
Natural rubber is made by extracting a liquid sap, called latex, from certain types of tree. Latex is gathered from the trees by making a cut in the bark and collecting the runny sap in cups. This process is called tapping. In order to prevent the sap from solidifying, ammonia is added.
What is Mooney viscosity in rubber?
Mooney viscosity is defined as the shearing torque resisting rotation of a cylindrical metal disk (or rotor) embedded in rubber within a cylindrical cavity. The dimensions of the shearing disk viscometer, test temperatures, and procedures for determining Mooney viscosity are defined in these test methods.
What is mastication class 7th?
ANSWER 🙂 The process of chewing the food and conversion of the food to bolus is known as mastication. The process takes place in the mouth. The teeth are mainly responsible for the process of mastication. The teeth are involved in the chewing, crushing and conversion of the particles of the food.
What is vulcanisation of rubber?
Vulcanization is a chemical process in which the rubber is heated with sulphur, accelerator and activator at 140–160°C. The process involves the formation of cross-links between long rubber molecules so as to achieve improved elasticity, resilience, tensile strength, viscosity, hardness and weather resistance.
What is the main ingredient in rubber?
The main chemical constituents of rubber are elastomers, or “elastic polymers,” large chainlike molecules that can be stretched to great lengths and yet recover their original shape. The first common elastomer was polyisoprene, from which natural rubber is made.
What chemicals are in rubber?
Natural rubber is a polymer of isoprene (also known as 2-methylbuta-1,3-diene) with the chemical formula (C5H8)n. To put it more simply, it’s made of many thousands of basic C5H8 units (the monomer of isoprene) loosely joined to make long, tangled chains.
What is the composition of natural rubber?
Besides the hydrocarbon portion, natural rubber contains approximately 6\% non-rubber constituents; ~2.2\% proteins, ~3.4\% lipids (fatty acids), glycolipids and phospholipids, and ~0.4\% carbohydrates.
What is natural rubber made of?
Formed in a living organism, natural rubber consists of solids suspended in a milky fluid, called latex, that circulates in the inner portions of the bark of many tropical and subtropical trees and shrubs, but predominantly Hevea brasiliensis, a tall softwood tree originating in Brazil.
What is natural rubber viscosity?
The natural rubber was a sample of pale crepe, having a viscosity average molecular weight of about 2,100,000.
What materials are used to make rubber?
Quick Answer. Natural rubber is made from the sap of a tree, and synthetic rubber is created from chemicals found in petroleum . Rubber trees first originated in South America, and the sap is called latex. The latex oozes from the bark of the rubber tree and can be easily collected to form balls or other objects. Continue Reading.
What chemicals is rubber made of?
Rubber has the chemical formula C5H8. It is made primarily of hydrogen and carbon. Rubber regains its original shape after being stretched, and it resists damage from weather. Rubber is a naturally occurring substance that is also known as gum-elastic.
What are the products of rubber?
Most rubber products are made from hard raw rubber, although some are made from latexes, for example, seamless gloves with thin walls, rubber thread, and foam-rubber seats for automobiles and furniture. The technological process used in the production of rubber products from hard raw rubber consists of two major stages.
What material is rubber made from?
Natural rubber is made from a runny, milky white liquid called latex that oozes from certain plants when you cut into them. (Common dandelions, for example, produce latex; if you snap off their stems, you can see the latex dripping out from them.