JUTE

INTRODUCTION:-

Jute is a long, soft, shiny vegetable fiber that can be spun into coarse, strong threads. It is produced from plants in the genus Corchorus, family Tiliaceae. It falls into the bast fibre category (fibre collected from bast or skin of the plant) along with kenaf, industrial hemp, flax (linen), ramie, etc. The industrial term for jute fibre is raw jute. The fibres are off-white to brown, and 1–4 meters (3–12 feet) long.

CULTIVATION:-

Jute needs a plain alluvial soil and standing water. The suitable climate for growing jute (warm and wet climate) is offered by the monsoon climate during the monsoon season. Temperatures ranging 20˚ C to 40˚ C and relative humidity of 70%–80% are favourable for successful cultivation. Jute requries 5–8 cm of rainfall weekly with extra needed during the sowing period.

The jute fibre comes from the stem and ribbon (outer skin) of the jute plant. The fibres are first extracted by retting. The retting process consists of bundling jute stems together and immersing them in low, running water.
There are two types of retting: stem and ribbon. After the retting process, stripping begins. Women and children usually do this job. In the stripping process, non-fibrous matter is scraped off, then the workers dig in and grab the fibres from within the jute stem.

CHEMICAL COMPOSITION:-

Jute fibres are composed primarily of the plant materials cellulose (major component of plant fibre) and lignin (major components wood fibre). It is thus a ligno-cellulosic fibre that is partially a textile fibre and partially wood.

CHEMICAL PROPERTIES:-

۞ EFECT OF ACIDS:-
Concentrated mineral acids dissolve jute and dilute mineral acids rot it quickly.

۞ EFFECT OF SALT WATER:- Jute is especially weak in salt water.

۞ EFFECT OF BLEACHES:-
It is difficult to bleach jute and color it.

PHYSICAL PROPERTIES:-
۞ TENAITY:-
It has high tensile strength, low extensibility, and ensures better breathability of fabrics. Therefore, jute is very suitable in agricultural commodity bulk packaging.

۞ THERMAL CONDUCTIVITY:- It has a low thermal conductivity and manufacture with no skin irritations.

۞ ELASTIC PLASTIC NATURE:- It is lack of strenght and therefore it is very difficult to bleach it, to give maximum whitness.

۞ AGROSCOPIC NATURE:- Jute has a moderate moisture regain.

USES:-
1. Jute is used chiefly to make cloth for wrapping bales of raw cotton, and to make sacks and coarse cloth.2. The fibres are used alone or blended with other types of fibres to make twine and rope.3. Jute can be used to create a number of fabrics such as Hessian cloth, sacking, scrim, carpet backing cloth (CBC), and canvas.4. It is a strong, durable, color and light-fast fibre.5. Jute fibres are also being used to make pulp and paper.

SILK AND COMPOSITION 3

CHEMICAL PROPERTIES:-

Silk is made up of the amino acids GLY-SER-GLY-ALA-GLY and forms Beta pleated sheets. Interchange H-bonds are formed while side chains are above and below the plane of the H-bond network.

◘ EFFECT OF ACIDS:-
Silk is resistant to Mineral acids. It is yellowed by perspiration and will dissolve in Sulphuric acid.

◘ EFFECT OF ALKALI:-
Silk is damaged by strong alkaline solutions.

◘ EFFECT OF BLEACHES:-
Silk may be damage in Chlorine bleaches. How ever bleaches of Hydrogen-peroxide and Sodium Per borate are safe to use.

SILK AND COMPOSITION 2

CHEMICAL COMPOSITION:-

Silk is made up of Amino acids and it contains 15 amino acids in Polypeptide chains. It has amino groups (NH2) and carboxyl group (COOH).The molecular chains are fully extended and packed closely together. There are some amorphous regions between some crystalline regions, giving silk its elasticity.

PHYSICAL PROPERTIES:-

◘ THERMAL CONDUCTIVITY:- Silk is a poor conductor of electricity and thus susceptible to static cling.

◘ HYGROSCOPIC NATURE:-
It has good absorbency with a moisture regain 11%.Its good absorbency makes it comfortable to wear in warm weathers.

◘ COMFORT:-
Silk is smooth and soft and thus not irritating to the skin.

◘ TENACITY:-
Silk is one of the strongest Natural fibers. Its tenacity ranging from 3.5—5.0 g/d dry and it may lose up to 20% of its strength when wet.

◘ ELASTIC PLASTIC NATURE:-
Its elasticity is moderate to poor if elongated even a small amount, it remains stretched.

SILK AND COMPOSITION

INTRODUCTION:-

Silk is a Natural fiber, as it is a Protein fiber therefore it is composed of Amino acids arranged in Polypeptide chains. It has a unique combination of properties not possessed by any other fiber.

 “Dry” tactile hand. Natural luster.  Good moisture absorption. High strength.

SILK GENERAL PROPERTIES:-

Elongation at breaking Standard Wet 20% 30%Absorbency 11% Thermal Property Does not MeltSelf Ironing Temperature 300 ْ F 149 ْ C Sunlight Resistance PoorSolubility 70% in Sulfuric acid at 30 ْCDensity 1.25%Elastic Recovery 99 %

CULTIVATION:-

The cultivation of Silk is called Sericulture. Over 30 countries produce silk, and the major ones are China (54%), India (14%) and Japan (11%).Silk moths lay eggs on specially prepared paper. The eggs hatch and the caterpillars (silkworms) are fed fresh mulberry leaves. After about 35 days and 4 molting, the caterpillars are 10,000 times heavier than when hatched, and are ready to begin spinning a Cocoon. A straw frame is placed over the tray of caterpillars, and each caterpillar begins spinning a cocoon by moving its head. Two glands produce liquid silk and force it through openings in the head called Spinnerets.
Liquid silk is coated in Sericin, a water-soluble protective gum, and solidifies on contact with the air. Within 2-3 days, the caterpillar spins about 1 mile of filament and is completely encased in a cocoon. Most caterpillars are then killed by heat and some are allowed to metamorphose into moths to breed the next generation of caterpillars.