Poly bag: Poly bags, usually known as polythene bags, have a variety of uses in many industries. This is a plastic
packet (pouch) used to contain garments destined for export or to merchandise
so that apparels remain intact and they could not obtain dust, dirt or
moisture.
Garments
in a poly bag usually look smart and safe. Different type of materials used to
produce poly bags such as PP, LD, HD, LLDP, LDPE, OPP and VINYL etc.
PP,
LD, VINYL, LDPE & VINYL mainly used for special purposes. It is popular due
to its glossy finish and excellent strength. Before PP and LD poly bags used
for garments packing but now buyer like to use LLDP, LDPE for environmental
friendly issues.
Because
both are a recyclable item but others cannot be recycled easily. LDPE is little
bit expensive than LLDP. Thus, some producer uses both elements proportionally
while producing poly bag. Besides, a mixture of both items helps to make
transparent poly bag. Thicknesses of a poly bag for general purpose are between
100-450 gauges. In addition to materials of poly bags, there may be different
construction of poly bags:
1) Plain poly bags
2) Poly bags with flap
3) Lip and Gazette bags
4) Poly bag with button
5) Hanger Bags
6) Poly tubing/Heat Sealed
7) Adhesive Poly or self-sealing bags
8) Slider zip lock poly
9) Zip lock ploy
Thickness: Usually,
three different ways can be used to count poly bag thickness.
1) Mil
2) Microns
3) Gauge
Mil: Mil is recognized as thousands of an
inch. One mil means the thickness is of 1/1000 of an inch.
Micron: Micron is 1/1000 of an M.M
Gauge: It is globally recognized system for
counting poly bag thickness. One gauge is equal to 1/100000 of an inch. So, one
mil is equal to 100 Gauge.
Conversion: 1 mil = 25 microns = 100 Gauge.
Poly
bags need to be treated if they are required to be printed. If poly bags
undergo special treatment before printing, printing does not wash away.
Generally flexo printing, griever printing, roto or screen printing are done in
poly bags.
Garment industries
require massive quantities of poly bags for export or merchandise their
products.
Merchandiser
needs to procure poly bag during dispatch the finish goods. There are no exact
principles for costing poly bags. The cost of these items mainly depend on the
number of quantity; style provided, design to be printed and the type of
sealing mechanism etc.
We can follow below
formula to find out poly bag costing.
Poly
Bag Costing Calculation Method in Garments Industry:
1.
Poly
bag length in inch or centimeter, [ If length is CM, convert CM to Inch )
2.
Poly
bag Width in inch
or centimeter, [ If Width is CM, convert
CM to Inch )
3.
Poly
bag thickness in ( gauge < Micron < Mil ), 1 mil > 1 microns > 1 gauges
4.
½
flap of poly bag (Here we take 1/2 length because the flap is single) (width of poly bag is double
layer),
5.
Numbers
of print on the poly bag (Print can be any types of logo, text, warning etc.),
6.
Rate
of polymer per pounds (It can be PP (polypropylene),
PE (polyethylene) and LDPE (low-density polyethylene), HDPE (high density polyethylene) etc.).
Q.1: Suppose, Poly bags having length is 29 cm, Half flap 5 cm, Width 26 cm
& poly thickness 160 gauge. Now find out weight of 1000 pcs poly bags?
Solution: Poly bags in KGs = {(Length
(inch) + Half flap (Inch)) X Width (Inch) X Gauge / 3300}
= {(29÷2.54 + 2.5÷2.54)
X 26÷2.54 X 160 / 3300}
= {(11.41 + 0.98)
X 10.24 X 160 / 3300}
= 6.15 KGs for
1000 pcs
Note: We used half flap during calculation because
flap is single layer & length, width of poly bag is double layer.
Q.2: Suppose, per pcs poly weight is 0.0397 KGs, polymer price 1 lbs (pound)
is $0.35. Now find out the price of per pcs poly?
Solution: Per pcs
poly weight X Polymer price
= 39.709 / 1000 X $0.35
= 0.0397 X 2.2 X $0.35
[1 kg = 2.2 lbs]
= $0.03056 /pcs
Q.3: Suppose, Poly bags having length is 30 inch, half flap 5 inch, width 25 inch
& poly thickness 150 gauge, 1 lbs polymer price is $0.35. Now find out the
cost 1 pcs poly bag?
Solution:
Poly bag cost = {(Length + Half flap) X Width X Gauge / 3300 / 1000 X
Price}
=
{(30 + 2.5) X 25 X 150 / 3300 / 1000 X $0.35}
= {32.5 X 25 X 150 / 3300 / 1000 X $0.35}
= 0.0369 KGs X $0.35
= 0.0369 X 2.2 X $0.35
[1 kg = 2.2 lbs]
= $0.0284 / pcs
Suppose,
A
LDPE poly bag having 28” length, 3” flap, 14” width, 140 gauge thickness with
self-adhesive facility and if cost of polymer is $.50 per lb. Polymer is the
main ingredients to produce poly bag. Let’s find out cost of 1 PC poly bag.
So,
weight of material =
(28+3x14x140)/3300
= 60760/3300
= 18.412 kg/1000 pieces
Cost of Material = 18.412 kgx$.50 per lb
= 18.41 x $1.1/Kg (as we know 1
kg=2.20 lb)
= $20.253/1000 pieces
= $0.020 (cost of 1pc poly bag)
Cost of Adhesive tape =
28”x$.002
= $.056
So, final cost of 1
piece poly bag will be = ($0.020+$.056)
= $0.076
If
exist print, please include that cost with this poly bag costing. Please be
noted that poly bag factory may not take under 1000 units for LDPE, PP bags
order due to consideration of their raw materials wastage and production
smoothness. But for gazette type of poly bags, it has to be over 5000 units.
MOQ could be negotiable depends on supplier’s wiliness.
Else Example:
Suppose, the buyer “ZARA” suggests the below information about
the poly bag of a garment export order.
Poly bag length – 28”,
Poly bag width- 24”,
Poly bag thickness – 160 gauge,
½ flap of poly bag- 5”,
Rate of LDPE polymer- $0.40 per pound.
Now,
calculate the poly bag costing for the above order.
Solution:
At first, we have to calculate poly consumption according to
given data.
Poly bag consumption (for
1000pcs in kg),
= {(Poly bag length + ½ Flap) × Poly bag width
× thickness of poly bag} ÷ 3300
= {(28+5) ×24×160} ÷3300
= 38.4 kg per 1000pcs ply bag.
So, for 1000pcs poly bag, LDPE
polymer needed 38.4kg.
And,
For 1pc poly bag, LDPE polymer
needed,
=
(38.4/1000) kg= 0.04kg= (0.04 × 2.20) lbs= 0.08lbs
So, cost of LDPE polymer for
1pc poly bag ($),
= LDPE
polymer needed for 1pc poly bag × LDPE polymer cost per pound (lb)
= 0.08 × 0.40
= 0.03
So, cost of LDPE polymer or cost for 1pc poly bag is $0.03
And,
Cost of 1000pcs poly bag,
=
$(1000 × 0.03) = $30
Example-2
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).
