Drawframe:
Draw frame is a part of yarn manufacturing process in which slivers pass through pairs of rollers and get some elongation,draft,doubled, and drawn. That’s why it insures more straight, more combination and more uniformity of yarns. Dust removal is also like a four subject of this draw frame stage.
Technical specifications of an ideal drawframe:
- Delivery speeds should upto 800
- Production per delivery ( kg/hr) should upto 300
- Number of head per machine should 1-2
- Delivery per machine should 1 or 2
- Doubling per machine should 4-8
- Maximum feed weight(kg) should 55
- Delivery hank(ktex) should 3-7
- Waste,in % should 0.5-1
- Finding The Production of Draw frame:
Problem: 01
A conventional drawframe with 1.125 diameter front roller and running at 400 rpm suffers 20% stoppages while per delivery 0.14 hank sliver. Find the machine actual production per delivery per shift of 8 hours ?
Solution:
Surface speed of front roller = [ (π x Dia. X 400 ) ÷ 36 ] yards per minute
= [ ( 3.1416 x 1.125 x 400) ÷ 36 ] yards per minute
= 39.2857 yards per minute
Total yards delivery by each delivery is 8 hours with 20% stops,
= 39.2857 x [ (60 x 8 x 80 ) ÷ 100 ]
So Actual per delivery per shift production = 39.2857 x [ (60 x 8 x 80 ) ÷ (100 x 840 x 0.14) ]
= 128.2 pounds (ANS.)
Problem: 02
A drawframe having 1.25 front roller diameter makes 280 revolutions while producing sliver of 0.15 hank.Find the production in hanks as well as in lbs. per delivery per shift of 8 hours given that the total time lost is 40 minutes ?
Solution:
As we know the surface speed of roller = [ (π x Dia. X 400 ) ÷ 36 ] yards per minute
So 100% production in hanks = [ 3.1416 x 1.25 x ( 280/36 ) x{ ( 60 x 8 ) / 840 } ]
Actual production in hanks = [ 3.1416 x 1.25 x ( 280/36 ) x ( 440 / 840 ) ]
= 16 (approx.).
Actual production in pounds = [ 16 hanks / 0.15 hanks sliver ]
= 106.6 (ANS.)
