Technical point in blow room

1. Opening in blow room means opening into small flocks. Technological operation of opening means volume of the flock is increased while the number of fibres remains constant i.e. the specific the material is reduced

2. The larger the dirt particle, the better they can be removed Since almost every blow room machine can shatter particles, as far as possible a lot of impurities should be eliminated at the start of the process Opening should be followed immediately by cleaning, if possible in the same machine

3. The higher the degree of opening, the higher the degree of cleaning. A very high cleaning effect is almost always purchased at the cost of a high fibre loss. Higher roller speeds give a better cleaning effect but also more stress on the fibre

4. Cleaning is made more difficult if the impurities of dirty cotton are distributed through a larger quantity of material by mixing with clean cotton

5. The cleaning efficiency is strongly dependent on the TRASH %. It is also affected by the size of the particle and stickiness of cotton. Therefore cleaning efficiency can be different for different cottons w the same trash %. There is a new concoct called CLEANING RESISTANCE. Different cottons have different cleaning resistance

6. If cotton is opened well in the opening process, cleaning becomes caries because opened cotton has been more therefore cleaning is more efficient

7. If automatic bale opener is used. the tuft size should be as small as possible and the machine stop should be reduced to the minimum Level possible

8. If Manual Bale openers are used, the tuft size fed to the feed lattice should be as small as possible. Due to machine harvesting; cotton contains more and more impurities, which furthermore are shattered by hard ginning. Therefore cleaning is always an important basic operation

9. In cleaning, it is necessary to release the adhesion of the impurities to the fibres and to give the part surface area an opportunity to separate from the stock. The former is achieved mostly by picking of flocks. The later is achieved by leading the flocks over a grid.

10. Using inclined spiked lattice for opening cotton in the initial stages is always a better way of opening the cotton with minimum damages. Of course the production is less with such type of machines. But should bear in mind that if material is recycled more in the lattice, neps may increase. Traditional methods use more number of machines to open and clean natural fibres

11. Mechanical action on fibres causes some deterioration on yam quality, particularly in terms of neps

12. Moreover it is true that the staple length of cotton can be significantly shortened Intensive opening n the initial machines like Bake breaker and blending machines means that shorter overall cleaning lines are adequate

13. In a beating operation the flocks are subjected to a sudden strong blow. The inertia of the Impurities accelerated to a high speed is substantially greater than that of the opened flocks due to the low air resistance of the impurities. The later are hurled against the grid and because of their small size pass between the grid bars into the waste box, while the flocks continue around the periphery of the rotating beater by using a much shorter machine sequence. fibres with better classic properties and improved spinnability can be produce

14. Air steams are often used in the latest machine sequence, to separate fibres from trash particles by buoyancy deference rather than beating the material against a series of grid bars

15. Cotton contain very little dust before ginning Dust is therefore caused by working of the material on machine. New dust is being created through shattering of impurities and smashing and rubbing of fibre

16. However removal of dust is not sample Dust particles are very light and therefore float with the cone n the transport stream Furthermore the particles adhere quite strongly to the fibres It they are to be eliminated

17. Removal of finest particles of contaminants and fibre fragments can be accomplished by release the dust into the air. like by turning the material over, and then removing the dust-contaminated air

18. Releasing the dust into the air occurs wherever the raw material is rolled, beaten or thrown about Accordingly the air at such positions is sucked away perforated drums, stationary perforated drums 2 stationary combs etc are some instruments used to remove dust.