EmulsionEmulsion is a mixture of some lubricating agents which is applied on jute fibreto make the fibre soft and flexible. An emulsion is an intimate mixture of two immiscible liquids where one isdispersed in small globules on the other and addition of a third. Substancebrings stability .emulsion is made by splitting up oil into minute drops whichare prevented from reuniting in water.General recipe: Water : 72.5% Oil : 25.4% Emulsifier : 1.6% Urea : 0.5%Emulsifier: Emulsifier is surface active agents. These are soaps, detergents,wetting agents.Characteristic of good quality emulsion: It should be stable for certain time. It should have no bed effect on jute fiber. It should be colorless. It should have high softening capacity. The droplet of emulsion should be so small that it can easily penetrate in the fibre. It must be odorless. It must be cheap and available.Requirements of good batching oil: It must have no harmful effect on jute fibre. Its color must be acceptable so that it does not sustain on the fibre. There must be no damage 0f spontaneous combination. It should not be rancid or sticky on storage. It must be cheap and plentiful in supply It should have low viscosity. It should have high lubricating value.
FUNCTION OF EMULSION INGREDIENTSFunction of oil: It lubricates the fibre. It helps free movements of fibre during processing. It cleans pins and rollers of the machine. It makes fiber soft and gives good spinning property.Function of water: It increases extensibility of fiber which resists fiber breakage during processing, It gives sufficient dampness and flexibility.Function of Emulsifier: It removes temporary hardness of water, It reduces surface tension, It stabilizes the emulsion.Function of urea: It helps easy penetration of emulsion into the fiber. It helps the fibre to be soften quickly, It reduces maturity time to half. Generally, fibre is stored 48 hours incase of normal emulsion. Whencontain urea, it keeps maturity time 24 hours. DEFECTS IN EMULSIONCREAMING:When an emulsion is prepared it is impossible to make all the drops exactly thesame size, some will be much smaller than others and there will be a few quitelarge drops .In general, the smaller the drops and the less scatter. There is intheir diameter the better is the emulsion. If there are a number of comparativelylarge drops of oil they will slowly rise to the tops of the emulsion because oftheir lower specific gravity until a large of them forms at the surface of theemulsion. This is known as creaming. This can be overcome by arranging aslow running paddle to keep the contents of all emulsion storage tank in gentlemotion as creaming will only occur in a standing emulsion.
BREAKING:Breaking can be regarded as the opposite of emulsification where the droplets ofthe internal oil phase unite to form large drops, which then float to the surfaceof the emulsion. It is a sign of instability in the emulsion and once begun cannotbe arrested. No amount of re-agitation will split these drops once they haveformed and a broken emulsion is useless. TYPES OF EMULSION MAKING MACHINE Paddle mixture and agitators-(OD batch mixer m/c), Homogenizers, Colloid mills, Ultra sonic emulsion plant.Paddle mixture and agitators-(OD batch mixer m/c):The simplest type of emulsifying plant and one that is common in jute industryconsists of a tank with a rotating paddle inside it .there are usually three tankssituated above the mixing tank so that their contents can be fed to it by gravity.the dimension of the are in direct proportion to the amounts needed for theemulsion, one the hold water, another hold the oil, and the third the emulsifyingagent. To stop the content of the mixing tank swirling as a mass when thepaddle is running, baffles must be fitted to sides of the tank. These break up themotion of the liquids and give the shearing action which is so necessary. Fig: OD batch mixer m/c.
It is good practice to have a small well in the foot of the mixing tank withemulsifier and water which are added first are mixed efficiently from the mixingthe emulsion is pumped to a storage tank this type of equipment will prepareemulsion which are adequate for jute batching but, nevertheless, the emulsionare not a high standard. Where an emulsion does not have to remain stable forlong periods of the time there is no need to install highly efficient emulsifyplant, and as most jute emulsions are used within a few hours of mixing adoptthe view that good emulsifying machinery is not too expensive and is worthinstalling for the sank of getting correct emulsification with the minimum ofmistakes.Viscolizer vacuum homogeneous emulsion machine:Adopts upper coaxial tertiary mixer, hydraulic pressure lift cover opening,rotate speed of rapid homogenate stirring0-4500r/Min (frequency control),rotate speed of slow scrapping mixer10-100r/Min (frequency control), thehomogenate head adopts high shear turbulent emulsification mixer, slowscrapping stirring automatic cling to the bottom of the pot and thewall. Viscolizer vacuum homogeneous emulsion machine adopts vacuumsuction, vacuum suction, to powder material avoids dust flying specially. Theentire working procedure carries under vacuum condition, prevents the materialproducing bubble after high speed stirring to reach sanitary and aseptic. Fig: Viscolizer vacuum homogeneous emulsion machine. This system equips with CIP cleaning system, the contact department ofvessel and material are SUS316L material, the internal surface mirror surfacepolish 300EMSH (hygienic level) in order to guarantee the control section to bestable.
COLLOID MILLS:This machine are capable of producing extremely fine droplets and, likehomogenizers, they usually work on course pre mixed emulation, basically, themachine consist of a high speed rotating disk on or cone fitting closely inside ashield .The liquid passes between the disk & the shield and in so doing issubjected to strong sharing forces which reduce the practical size .Collide millsmay carry out the work of emulsification or reduce the droplet size of a coursepremixed emulsion. Fig: Colloid mills for jute emulsion.ULTRASONIC EMALCIFACIATION MACHINE:A plant based on ultrasonic emulsification has been used for a few years .theprincipal is analog that use a wood wind musical instruments in this air frommouth is blow across thin reed causing it to vibrate .the vibration produce airwaves which the air interprets as a sound . Ultrasonic vibrations are similarpressure waves but a frequency too great for the air to detect .in ultrasonichomogenizer a jet of liquid strikes the edge of a thin blade, setting up vibrationsof the order of 22000c/s .these extremely rapid vibrations cause miniatureexplosions’ whet in the liquid, tearing in to the fine drops. Fig: Ultrasonic emulsification machine.