Technical Spinning Information and Formulas:-
1) Constant
One pound is 7000 grains = 453.59 grams
One skein is 120 yards = 109.7 meters
One yard = 36 inches = 0.9144 meters
One hank is 840 yards = 768.1 meters
The yarn count and hank roving number equals the number of hanks in
one pound.
To find the hank roving number from number of grains per yard:
Divide 8.33 by the number of grains per yard.
Hank roving number = 8.33 x yard
Grains
2) To find the speed of the front roll
Divide the revolutions per minute of the spindle by the product
of the twist per inch, multiplied by the circumference in inches
of the front roll
Front roll speed = Spindle R.P.M diameter of front roll
3) To find the Spindle Speed
Multiply the R.P.M. of the front roll by the twist per inch and this
product by the circumference of the front roll.
Spindle speed = FRS x T.P.I x X diameter of front roller
4) To find the standard twist per inch
Multiply the twist multiple by the square root of the yarn count.
T.P.I. = T.M. x yarn count
5) To find the draft
Yarn Count (Ne) divided by hank roving equals the draft.
6) To find hank roving
Yarn Count (Ne) divided by draft equals hank roving.
7) To find the Draft
The product of the back roll gear, crown gear and diameter in
inches of the front roll, divided by the product of the front roll
gear and diameter of the back roll equals the draft constant.
Constant divided by draft gear equals draft.
Draft = Draft Constant
Draft Change Gear
8) To find the required draft gear when changing from one yarn
count to another, without changing the roving
Multiply the number of teeth in the draft gear in use by the yarn
count spun. Dividing this product by the yarn count desired will
give the required draft gear.
9) To find what draft gear will be required when changing from
one yarn count to another, the draft and roving both being
changed
Multiply the yarn count being spun by the new hank roving and
this product by the number of teeth in the draft gear being
used; divide this product by the yarn count desired, multiplied
by the hank roving being used. The quotient is the draft gear
required.
10) To find the twist per inch
Spindle speed divided by the inches of Yarn delivered per
minute of the front roll equals twist per inch.
11) To find inches delivered per minute
Multiply the R.P.M.'s of the front roll by the circumference in
inches of the front roll.
12) Spinning production calculations
Delivery:
L = n = m/min L = Delivery in m/min
T/m
Ppr = Production in practice
Production:
n = Spindle speed in min-1
Ppr = L x tex x 60 x .= g/h
1000 T/m = Twists per m
or
g/h = Gram/hour (spindle)
Ppr = L x tex x 60 x . = g/h
T/m x 1000 . = Efficiency
Note: . = 3.1416
0 Comments
If you have any doubts, Pls let me know