Blow Room Calculation A to Z: Essential 8 Formula and Abundant Practice

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The blow room is a critical stage in textile manufacturing that allows high-quality yarn to be produced. A blow room calculation must be efficient and accurate in order to ensure optimal productivity and uniformity. In order to optimize production processes, reduce waste, and ensure consistent yarn quality, you will need to master blow room calculations. In order to facilitate your ability to calculate blow room numbers, whether you work in a textile mill, are a student pursuing a textile-related course, or just have a passion for the industry, this guide will prove invaluable. Blow room calculation is the part of textile calculation.

Get ready to discover the secrets behind efficient blow room operations and take your textile expertise to new heights as we explore Blow Room Calculation A to Z: Essential Formulas and Exercises.

Some Important Conversion for Blow Room Calculation:

  1. 1 Pound (lbs)= 453.6 gm= 16 oz=7000 grains
  2. 1 Kg= 2.205 pound (lbs)
  3. 1 feet= 12 inch
  4. 1 yds= 36 inch
  5. 1 meter= 1.0936 yds= 39.37 inch=3.28 feet
  6. 1 inch= 2.54 cm=25.4 mm
  7. 1 lea= 120 yds
  8. 1 hank= 7 lea=840 yds

Some Important Formula for Blow Room Calculation:


Exercise-1: Cotton with 6% trash was processed in a blow room section and 1.5% trash was found in the lap. What is the cleaning efficiency of blow-room?

Exercise-2: Having 5% trash in Pakistani Cotton is processed in blow room and 1.4% trash is found in lap. Now find the cleaning efficiency of blow room. [Self-study, Answer: 72%] Exercise-3: Cotton with 5% trash was processed in a blow room section and 1% trash was found in the lap. How much is the cleaning efficiency in the blow-room? [Self-study, Answer: 80%]

Exercise-4: If 40 yds lap weight is 35 lbs, find the lap hank.

Exercise-5: If lap weight is 14 oz per yds, find the lap hank.

Exercise-6: If 12 yds lap weight is 50,000 grain, find the lap hank. [self study, Answer-0.002]

Exercise-7: If lap hank is 0.0013, find the lap weight per yds in oz. [ self study, Answer-14.65 oz]

Exercise-8:  Bottom calendar roller RPM is 12, diameter is 7 inch, lap hank is 0.0012, efficiency of blow room is 80%, No. of scatcher is 2. Now calculate the production of blow room per hour.

Exercise- 9:  Bottom calendar roller diameter = 7 inch, RPM of bottom calendar roller = 12, weight of every yard lap is 12 oz, efficiency = 72% and waste% = 6%. Find out the production of B/R per shift.

Exercise-10: If RPM of calendar roller= 10, Diameter of calendar roller= 3.50 inch, lap hank= 0.0014, efficiency= 75%, Find the production of blow room per shift in Ibs and Metric ton. [ self-study, Answer: 3738.10 lbs per shift, 1.696 metric ton per shift]

Exercise-11: RPM of calendar roller=12, diameter of calendar roller=3.5 inch, lap weight per yds. = 14 oz, efficiency of blow room 80%, find the production of blow room per shift in Kg [Self-study, Answer: 1116.95 kg per shift]

Exercise-12: If lap length constant is 703 and length of lap is 32 yds., find the lap length change pinion.

Exercise-13: If lap length constant is 703 and lap length change pinion is 20, find the lap length? [ Self-study, Answer- 35.15 yds. ]

Exercise-14 : Fine the lap length constant when number of teeth of knock wheel is 48, warm wheel 25, single warm wheel 1 and diameter of calendar roller is 7 inch.

Exercise-15:  Diameter of calendar roller 7 inch, teeth of single warm 1, teeth of warm wheel 24, cloth length change pinion 22, knock off wheel 48, now find lap length constant. [self-study, Answer: 703.36]


The information and calculations I have provided to you are all derived from a variety of sources. I have provided you with some exercises for self-study. Please practice them. If you run into problems when doing the exercises, let me know. I will provide you with a proper solution. Feel free to ask me any questions you may have about textile engineering. Stay with us and be an expert of textile calculation.

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