Blow room is the initial process of the spinning operation where the fibre is opened, cleaned, mixed, micro dust removed and evened thus passed to carding machine without increasing fibre rupture, fibre neps , broken seed particles and without removing more good fibres. The fundamental functions of blow room are opening, cleaning and dust removal, blending and evenly feeding the material on the card.
Object of Blow room:
- To open the baled fibres into small tufts which allow foreign matter to be separated from the fibres & prepare the material for easy carding. [Opening]
- To clean the fibres by removing the foreign matter as the waste. [Cleaning]
- To mix thorough the different component fibres of a mixing. So as the give a homogeneous blending. [Mixing]
- To from a compact & uniform sheet of fibres the lap. OR to feed blended material to the chute feed system.
Basic operation in the Blow room:
- Mixing or Blending
- Micro dust removal
- Uniform feed to the carding machine
- Recycling the waste
Technological points in Blow room
- Opening in Blow room means opening into small flocks. Technological operation of opening means the volume of the flock is increased while the number of fibres remains constant. i.e. the specific density of the material is reduced.
- 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.
- 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 speed gives a better cleaning effect but also more stress on the fibre.
- Cleaning is made more difficult if the impurities of dirty cotton are distributed through a larger quantity of material by mixing with clean cotton. 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 with the same trash %. There is a new concept called CLEANING RESISTANCE. Different cottons have different cleaning resistance.
- If cotton is opened well in the opening process, cleaning becomes easier because opened cotton has more surface area, therefore cleaning is more efficient.
- If automatic bale opener is used, the tuft size should be as small as possible and the machine stop time should be reduced to the minimum level possible.
- 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 further more are shattered by hard ginning. Therefore cleaning is always an important basic operation. In cleaning, it is necessary to release the adhesion of the impurities to the fibres and to give the particles an opportunity to separate from the stock. The former is achieved mostly by picking of flocks, the latter is achieved by leading the flocks over a grid.
- 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 one 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. Mechanical action on fibres causes some deterioration on yarn quality, particularly in terms of neps . Moreover it is true that the staple length of cotton can be significantly shortened. Intensive opening in the initial machines like Bale breaker and blending machines means that shorter overall cleaning lines are adequate.
Conventional Blow-room line:
- Hopper bale opener
- Step cleaner
- Vertical cleaner
- Hooper feeder-1
- Porcupine opener
- Hooper Feeder-2
Modern Blow-room line:
Rieter Blow-room line Trutzschler Blow-room line (Germany)
1. Unifloc (A11) 1. GBR
2. Uniclean (B11) 2. Axiflow cleaner
3. Unimix (B7/3) 3. Multiplex mixer
4. Uniflex (B60) 4. CVT
5. Vission shield (Jessi) 5. ASTA
6. Condenser 6. Duste
Defects in Blow room:
- Irregularity lap
- Dirty lap
- Conical shaped lap
- Barrel shaped lap
- Lap linking
- Split up
- Soft lap
- Rogged selvedge lap
- Rieter machine works limited, Switzerland
- Lakshmi machine works limited combatore, India
- Irutzchler Gmbh, Germany
- Marzoli spa, Italy
- Crosrol Textile Machinery limited, UK
- Fine Tex machine co-limited, Tuiwan