Important formulas for looms and plant (woven sacks)

This formulas will come in handy if you are working in a plastic woven sacks manufacturing unit as production manager

Formulas

1. Picks per minute = cam RPM x Number of shuttles
2. Weaving Ring I.D = 2 x fabric Dfl. (mm) OR = 2 x fabric Dfl. x 25.4/ 3.14 (inch)
3. Elongation = Increase in length x 100 / Initial sample length
4. Number of warp = 2 x fabric Dfl x Warp Mesh (Inches)
   = 2 x fabric Dfl x Warp Mesh /10 ( Fabric Dfl = centimeter, Warp Mesh= DM )
5. Fabric Production = 1.54 x pick/minute/Weft mesh (inches)
   = 6 x pick/minute/weft mesh (DM)
6. Fabric GSM = Warp mesh x Warp Denier + Weft mesh x Weft Denier/228.6
7. Bags Weight = 50.8 x fabric Dfl x Cut length x Warp mesh x Warp Denier + Weft mesh x Weft Denier/ 90,00,000
   = Fabric Dfl. x Cut length X GSM/ 5000 ( warp mesh and weft mesh in inches, fabric dfl and cut length in inches)

» For PP Unlaminated Fabric

For Example, If you want to Produce 60cm x 90cm single fold bottom stitch 90 gram bag.
For Production you need Two Things
1. Cut Length and
2. Denier

1. For Cut Length : 
   Your Bag Length is 90cm + 4cm for single fold = 94cm is your final length. Width will remain same = 60cm.
2. For Denier : 
   Now, we have to calculate Sq. Meter of Bag. = Length x (Width x 2) in meter
   = 0.94 x ( 0.6 x 2 ) { cm/100 = meter }
   = 1.128 sq. meter.
3. So, your 90gm Bag weight is of 1.128 sq.meter. i.e. GSM of the Bag is 90/1.128 = 79.79 GSM
4. Now, follow below Thumb Rule Table for How much denier to set in Tape Plant ? 

Mesh Size	Denier/GSM
8 x 8	13.33
9 x 9	12.22
10 x 10	11.11
12 x 12	09.26

Base Thumb Rule taken is 1000 Denier = 90 GSM

Now, Coming to our Bag Sample, for 10x10 Mesh, We have to Produce 11.11 (As per Table) x 79.79GSM of the Bag = 887 Denier in the Plant.