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Weaving Calculations · Lecture 10
Warping Speed and Preparatory Capacity
From drum rpm to yards per shift, and two problems on how many warpers and sizers a loom shed needs.
Drum speedYards per shiftSizing capacityWarpers needed
Speed of a warping drum
| A | B | |
|---|---|---|
| 1 | Drum speed (rpm) | |
| 2 | Drum diameter (in) | |
| 3 | Shift (hours) | |
| 4 | Efficiency | |
| 5 | Revolutions per hour | 18,000 |
| 6 | Circumference (in) | 94.25 |
| 7 | Inches per hour | 1,696,460 |
| 8 | Yards per hour | 47,124 |
| 9 | Yards per shift (100%) | 376,991 |
| 10 | Yards per shift at efficiency | 301,593 |
blue = input (edit me)grey = formula (click to see it)
Problem 1 — time to fill a beam
| A | B | |
|---|---|---|
| 1 | Warping speed (m/min) | |
| 2 | Efficiency | |
| 3 | Beam length (yd) | |
| 4 | Ends on beam | |
| 5 | Count Ne | |
| 6 | Speed (yd/min) | 984 |
| 7 | Time to fill (min) | 32.5 |
| 8 | Yarn on beam (yd) | 16,400,000 |
| 9 | Weight on beam (lb) | 651 |
blue = input (edit me)grey = formula (click to see it)
Problem 2 — preparatory machines for 200 airjet looms
200 looms × 500 m/day of 20×16/128×60, 63" is 100,000 m of fabric a day. How many sizing machines and warpers keep them fed?
| A | B | ||
|---|---|---|---|
| 1 | Looms | ||
| 2 | Fabric per loom per day (m) | ||
| 3 | Warp contraction | ||
| 4 | Ends per inch | ||
| 5 | Width (in) | ||
| 6 | Warper creel capacity | ||
| 7 | Sizing speed (m/min) | ||
| 8 | Sizing efficiency | ||
| 9 | Warping speed (m/min) | ||
| 10 | Warping efficiency | ||
| 11 | Sizing | ||
| 12 | Fabric per day (m) | 100,000 | |
| 13 | Sized warp needed per day (m) | 110,000 | |
| 14 | One sizing machine per day (m) | 108,000 | |
| 15 | Sizing machines required | 1.02 | |
| 16 | Warping | ||
| 17 | Total ends | 8,064 | |
| 18 | Warper’s beams per set | 10 | |
| 19 | Yarn to be warped per day (m of beam) | 1,100,000 | |
| 20 | One warper per day (m) | 864,000 | |
| 21 | Warpers required | 1.27 | |
blue = input (edit me)grey = formula (click to see it)
One sizing machine almost copes (1.02), but the warper must run 10 beam-lengths for every sized beam, so 1.27 warpers are needed — two warpers, or one warper with a larger creel (fewer beams per set, see Lecture 11).