In readymade garment, one of the most important material is Poly bag. Calculating the garment costing, poly bag effect on total price of the product. As we know, poly bag cost is effected on the total price of the product, so this article will help those people who don’t know the way to calculate poly bag costing.
Commonly poly bag known as polythene bag, because as we know poly bag is produced from polymer. In garment industry, poly bag is used for product safety, protect from dust and moisture. Mostly used poly bags in garment industries are PP (polypropylene) poly bags, PE (polyethylene) & LDPE (low density polyethylene), HDPE (high density polyethylene) etc. Used material in poly bag, LDPE (low density polyethylene) can be recyclable but others can’t be recycled.
In readymade garment industry, we called single poly when we used in one garment and insert several garments in one poly bag, we called it “blister poly”. Sometimes, we used poly bag in printed T-shirt to protect the print on the garment. When we used rubber print on t-shirt or any garment, poly bag used for print safety because garment will be attached each other if we didn’t use poly bag for each garment. To measure poly bag’s thickness, there are three different ways;
In conversion, 1 mil = 25 microns = 100 gauges. Also note that, gauge is the most useful system of counting poly bags thickness worldwide.
To measure poly bag costing, at first we need to get below information:
- Poly bag length in inch or centimeter
- Poly bag Width in inch or centimeter
- Thickness of poly bag in gauge
- ½ flap of poly bag (flap is single layer)
- Number of prints on the poly bag (print can be any text, logo and warnings)
- Polymer rate (can be PP, PE and LDPE etc.)
For better understanding, we will measure poly bag consumption with examples;
Poly bag consumption formula (for 1000 pcs):
(Length of Poly bag + ½ flap of poly bag) x Width of Poly bag x gauge of poly bag / 3300
Buyer H&M, a basic T-shirt project quantity 250,000 pcs, garment has chest rubber print and we need to calculate polybag consumption and costing. Now we need single poly for this order. As per garment, we have below information;
Poly bag length is 28 cm,
Poly bag width is 25 cm,
Thickness of poly bag is 160 gauge,
½ flap of poly bag is 5 cm.
Rate of polymer is $0.40 per pound
Total consumption of poly bag (for 1000 pcs);
(Length of Poly bag + ½ flap of poly bag) x Width of Poly bag x gauge of poly bag / 3300
= (28 + 5) x 25 x 160 / 3300
= 40 kg
So, we need 40 kg polymer for 1000 pcs poly bag.
As per above garments quantity, we need polymer = 250000 / 1000 x 40 = 250 x 40 = 10,000 kg
And for 1 pcs poly bag, we need polymer;
= (40/ 1000) kg
=0.04 kg
We need to convert kg to lbs, because our price of polymer on th lbs. So, as per above result;
= (0.04 x 2.2) lbs [ we know, 1kg = 2.2 lbs.]
= 0.088 lbs
So, the cost of 1 pcs poly is;
= Polymer needed for 1 pcs poly x rate of polymer per pound (lbs.)
= 0.088 x $0.40
= $ 0.035 / per pcs poly
We already know the calculation process of poly bag consumption and cost of per pcs poly bag. As per above formula, we can make one shortcut formula;
(length of poly bag + ½ flap) x width of poly bag x gauge / 3300 / 1000 x rate of polymer in pound (lbs.)
So, the cost of poly bag for 250000 pcs is;
(length of poly bag + ½ flap) x width of poly bag x gauge / 3300 / 1000 x rate of polymer in pound (lbs.)
= (28 + 5) x 25 x 160 / 3300 / 1000 x 2.2 x $0.40 [ convert kg to lbs, 1 kg = 2.2 lbs]
= $0.035 x 250,000 pcs
= $8,800
So, the total cost of poly bag for 250,000 pcs is $8,800
Note: If you want to calculate per pcs poly costing then stop your calculation in second line or you can divide the total cost by total quantity (like, $8,800 / 250000 = $0.0352 per pcs).