1. To open the compressed bales of fibers
2. Remove dirt and dust, broken leaf, seed particles or any other foreign impurities from the fibers
3. To transfer the opened and cleaned fibers into a sheet form of definite width uniform weight per unit length which is called lap.
4. To roll the lap of predetermined length into a cylindrical shape around a lap pin.
5. To transfer the lap from the lap pin to a lap rod to a suitable and feed it to the subsequent m/c (carding).
Action of blow room line
I. Action of opposing spikes
II. Action of air currents
III. Action of beaters
IV. Regulating action
Wastage in blow room
1. Dropping
2. Dust
3. Filter waste
Faults in blow room
1. Irregular lap
2. Knocking off before completion of full lap
3. Rough appearance of full lap
4. Lap sheet thicker at one side than the other
5. Soft lap
6. Lap licking
7. Dropping under beater & grid bars
8. Formation of conical lap
9. Formation of split lap
10. Barrel shaped lap
11. Ragged lap selvedges
Types of beater in blow room
1. Porcupine beater
2. Bladed beater
3. Krishner beater