How to determine the specification & maximum stacking allowed for your box ?

The main point of this articles is how to calculate maximum BCT ( Box Compression Test ) value of Box that we must develop and determine maximum stacking allowed for the Box. What is BCT ? BCT is a value that indicating maximum load allowed through the box that can not causing damage for the box. If we fail to calculate it, you will found that any damage happen to your box and any cost will be spent out to solve this problem. By the way, in this articles. we solve it !

Just for information, commonly substance used to packed product like Food & Beverages, Pharmacy, Soap product, Candle product, Tools, etc today is :

Type of single wall :

150K/125M/150K in fact, giving BCT value around 200 kgf

150K/150M/150K

200K/125M/200K

200K/150M/200K in fact, giving BCT value around 220 kgf

Type of double wall :

150K/125Mx3/150K in fact, giving BCT value around 280 kgf

150K/150Mx3/150K

200K/125Mx3/200K

200K/150Mx3/200K in fact, giving BCT value around 330 kgf

and using safety factor like this :

Grade Persentage

More save 50%

Save 45%

Enough save 40%

Risk 30%

High Risk 20% and below

Note : Recommended to use safety factor more than 40% to minimize risk from damage.

What is the main factor that we must prepare to develop Box ?

1. Maximum BCT allowed must be calculated
2. Maximum height of stacking on pallet :

• Depend on the stability of pallet during handling the box
• Maximum height and weight of racking. Commonly max height = 1200 - 1300 mm. Commonly max weight per rack = 1000 kgs / racks for 6 racks in height.

3. Maximum stacking on container, Maximum 2370 mm for either 20 and 40 feets.

Type of joint, commonly used is either gluing, stitching, or combination both of them, giving the similar performance of BCT value. ( Rarely, type of joint from glue stitching increasing the value not more than 25% rather than previous joint like glue or stitching ). The difficulty is to ensure consistency of gluing performance during process making. If You not sure about it, recommended to use type of joint from stitching or glue-stitching ( combination both of them ).

TIPS for YOU !

1. Create a different dimension specially for length and width of your box, so you can LOCK the configuration of your box on pallet that you can maintain your box stable ( not moving ) when handling your product on pallet.
2. Never use type of joint from stitching for packed product like liquid ( Oil, Shampoo, Detergent liquid, etc ). Leakage of the product packed will be happen when metal of stitching opened ( must be closed in normal condition ). Survey said, more than 70 % leakage problem from liquid product happen when we use type of joint from stitching and the metal stitch can not perform in right condition.

For an example : We already develop a new soaps 100g/pcs for packed 100 pcs/box. The inner dimension is 350 x 250 x 150 mm. How to determine the specification of your box ? How to determine the maximum stacking allowed for your box ?

OK,...follow this steps to solve it !

Steps.1 Calculate the weight of product for 100 pcs packed in single box. Note : In this calculation, the weight of packaging box not more significantly rather than weight of product. In this calculation, we assume weight of packaging box below 1000 g, commonly 200 - 400 g/Box. If said, in this case we choose 300 g/Box, then the total weight of box and product is [ (100 x 100 ) + 300 ] = 10,300 g = 10.3 kgs.

Steps.2 If the max height of container 20 & 40 feets is 2370 mm, for this box ( we assume the total height for double wall is height of inner dimension + 13 mm = 150 + 13 = 163 mm ) we can place them up to 14 boxes in height. ( Devide 2370 mm with 163 mm, result is 14.5 .. )

Steps.3 Calculate total weight accumulated for the first layer box.

[ ( 14-1 ) x Total weight of Box and product ]

[ 13 x 10.3 ] = 133.9 kgs.

For safety factor, we choose Grade " Save " 45%, then max bursting strength allowed is total weight accumulated for the first layer box / ( 100% - safety factor )

= 133.9 / ( 100% - 45 % ) = 243.45 = 245 kgf

Steps.4 So, in this case, we choose the specification of box that giving BCT value more than 245 kgf is : 150K/125Mx3/150K ( min 280 kgf ). We can not choose the spect of box from 150K/125M/150K because the value of BCT is around 200 kgf, below 245 kgf.

Steps.5 Maxmum stacking of box on pallet. Commonly, the distance of racking in range 1200 - 1300 mm. If we said for 1200 mm, assume the thickness of pallet = 110 mm, 6 Box maximum with the total height = ( 6 x 163 ) + 110 = 1088 <>

So, the specification of the box for this product is :

Inner dimension : 350 x 250 x 150 mm

Substance : 150K/125Mx3/150K

Gramature : 778.7 gsm ( will be explained more detail on next articles )

Type of joint : Stitching ( Not for Liquid Product )

Flute : BC ( Commonly )

BCT : min 245 kgf.