Tuesday, October 16, 2018

How to Measure Sewing Button Size and Quantity in Garments Factory

In garments factory, sewing button size is calculated by three units e.g. in mm (millimeter), inch and ligne in accordance with buyer's instructions.




For finding out Button Size in mm and inch, we need measure the dia of button with measurement tape. To find out Button Size in ligne, we need divide button's mm dia by 0.635.




Button's Dia
Button's Dia


Button size calculation : 
1 inches = 40 ligne = 2.54 cm, 

1 ligne = 0.635 mm

Now find out ligne of a button with 10mm Dia?

Answer: 10 ÷ 0.635 = 15.75 ligne or 16 L (L refers to ligne or ligner) 

(Formula: button dia in mm ÷ 0.635= button ligne)


Sewing Buttons
Sewing Buttons


Button quantity calculation:

12 pcs = 1 dozen, 

12 dozen = 1 gross, 

12 gross = 1 GG 

1 GG = 1728 pcs (GG means Great Gross)

Suppose: 

A shirt has 6 buttons, total order quantity 3456 pcs, find out total button quantity for the order.

Answer: 6 × 3456 ÷ 1728 = 12 GG. 

(Formula: number of buttons per product × order quantity ÷ 1728)
(1 GG = 1728 pcs)

Note: Extra quantity (minimum 3%) is added while counting buttons for an order to save garments from risk in case of shortage due to defective & damaged.




Poly Bags Consumption & Costing in Apparel Industries

Most used poly bags in garments industries are PP (polypropylene) poly bags, PE (polyethylene) & LDPE (low density polyethylene), HDPE (high density polyethylene) etc. Basically there’re three different ways to measure poly bags thickness. These are:

(1) Mil (1 mil = 1/1000 of an inch)

(2) Microns (1 microns = 1/1000 of a mm)

(3) Gauge (1 gauge = 1/100000 of an inch)

Conversion, 1 mil = 25 microns = 100 gauge.

Note: Gauge is the most used system of counting poly bags’ thickness worldwide.




Poly Bag
Poly Bag

A poly bags having length 30 inches, flap 3 inches, width 16 inches, poly thickness 150 gauge. Now find out weight of 1000 pcs poly bags? Answer: {(30 + 1.5) x 16 x 150 / 3300} = 22.91 KGs for 1000 pcs 

Formula: KGs needed for 1000 pcs poly bags = {(length + half flap) X width X gauge / 3300}

Now, if we want to find out weight of 1 pcs poly bag, then we need divide the outcome with 1000. 

Answer:
 22.91 / 1000 = 0.023 KGs. (1 pcs poly bag weight)

Note: You see, I count flap measurement in half (1.5 inches) during calculation because flap is single layer. And length, width of a poly bag is double layer.

Now the question is 1 lbs. polymer price is 0.40 USD, find out cost of 22.91 KGs polymer?Answer: 22.91 x 2.2 x 0.40 = 20.16 USD. (1 KG = 2.2 lbs.) 

A poly bags having length 30 inches, flap 3 inches, width 16 inches, poly thickness 150 gauge. 1 lbs. polymer price is BDT 40. Now find out cost of 1 pcs poly bag? Answer: {(30 + 1.5) x 16 x 150 / 3300 / 1000 x 2.2 x 40} = 2.01 BDT. (Bangladeshi Taka). 

An Overview of Poly Bag Used in Apparel Industry

In the standard format for describing a bag:
  • the width of the bag is always taken to be the side that opens, so this is normally, but not necessarily, the shorter side.
  • the width of the bag is given before the length.
  • the thickness of the bag is given last and is usually expressed in 'gauge' (100 gauge = 1/1000 of an inch).
  • hence the size of a bag is given as: Width (inches) x Length (inches) x Thickness (Gauge).
Flat BagsFlat Bags
Ziplock BagsZiplock Bags
For example: if a bag is said to be 4" x 6" x 150 gauge then the bag is 4" wide by 6" long with 150 gauge thickness and the bag will open on the 4" width.

How thick is thick?

100 gauge - a 1/1000 of an inch.
120 gauge - 'light duty' - good for protective covering.
250 gauge - 'medium duty' - good for holding light materials.
500 gauge - 'heavy duty' - where strength is required.

Metric and Imperial - a complication!

Most measurements are given in imperial (inches and gauge) but some of us prefer to use metric scales and the conversions are as follows:
1" = 25.4 mm
400 gauge = 100 micron
For example: a 4"x 6" x 150 gauge bag is the same as a 102mm x 152mm x 37.5 micron bag.

Gussets - a complication!

Some bags have a gusset at the sides to help the bag open out more and enable a greater volume of items to be put in - a good example is a refuse sack. Others have a gusset at the bottom to enable a wide product to fit in - a good example is a carrier bag.
Gussted BagsGusseted Bags
  • A side gusset is expressed as a bag being x" wide opening to y" wide. For example: if a refuse sack is 16 x 25" x 39" this means it is 16" wide opening to 25" wide when the gusset is opened, with a bag length of 39"
  • A bottom gusset is expressed as + x". For example: if a carrier bag is 15" x 18" + 3" then the carrier is 15" wide by 18" long with a bottom gusset of 3".
D - Total depth
L - Length
W - Width
We very much hope this helps but if you require any help or have any questions please call 01749373738 and talk to one of our experts!