CORRUGATED FIBRE BOARD - (CFB) Packaging

Corrugated Fiber Board (C.F.B.) packaging is a versatile, economic, light, robust,

recyclable, practical and yet dynamic form of packaging. Corrugated fiber board

packaging offers almost unlimited possible combinations of board types, flute sizes,

paper weights, adhesive types, treatments and coatings. Corrugated fiber board is

routinely; custom designed to meet specific customer requirements. Corrugated Fiber

Board is made from papers made up from cellulose fibres, which are virgin or

recycled. This makes Corrugated Fiber Board a renewable natural resource.

Corrugated Board is made from a combination of two sheets of paper called liners

glued to a corrugated inner medium called the fluting. These three layers of paper are

assembled in a way which gives the overall structure a better strength than that of

each distinct layer.

Components of C.F.B.: C.F.B. has three components which are as follows:

Ω Liner

Ω Fluting Medium

Ω Adhesive

Liner: Kraft paper of above 80 gsm to 250 gsm is used for making liner. Preferably

outer most liner used for box should be of the maximum grammage.

Functions of Liner:

a. Resist hazards like puncture, burst, abrasion, tear etc.

b. Properly hold the fluting medium when once combined.

c. Resist moisture or water either outside or inside depending on the nature of

product packed.

d. Be amenable to printing.

Waterproof paper such as bitumen, sandwiched, poly-coated or wax coated are also

used for liner.

Types of Flutes: Flutes come in several standard shapes or flute profiles (A, B, C, E,

F etc.) A-flute was the first to be developed and is the largest common flute profile.

B-flute was next and is much smaller. C-flute followed and is between A and B in

size. E-flute is smaller than B and F-flute is smaller yet. Table (1) gives a comparison

of various flutes with respect to Flute height and corrugation per meter.

Table (1): Comparison between various Flutes

Flute Corrugations/

Flutes Per Meter

Flute Height

(Mm)

High - A Flute 30 +/- 2 5.6

Jumbo A Flute 20 7.00

A – Flute (Broad) 105 TO 125 4.5 TO 4.7

B – Flute (Narrow) 150 TO 185 2.1 TO 2.9

C – Flute (Medium) 120 TO 145 3.5 TO 3.7

E – Flute (Micro) 200 TO 320 1.1 TO 1.5

F – Flute 124 +/- 4 0.8

G - Flute 178 +/- 4 0.5

K - Flute 25 +/- 1 6.6

Characteristics of Various Flute:

A Flute:

Ω High top to bottom compression

Ω Good stacking strength

Ω Excellent cushioning for product protection

C Flute :

Ω Good printing surface

Ω Good top to bottom compression

Ω Good resistance to flat crush

B Flute:

Ω High resistance to flat crush

Ω Excellent printing surface

Ω Scores and slots easily

Ω Adapts well to automatic equipment

E Flute:

Ω High resistance to flat crush

Ω Outstanding printing surface

Ω Mostly used for consumer goods shelf packaging

F Flute:

Ω Good alternative to paperboard applications

Ω Superior printing surface

Ω High resistance to flat crush (Similar to E)

Ω Consumer goods shelf packaging (most applicable)

Functions of Fluting Medium

Ω Provides necessary cushioning desired.

Ω Provides rigidity to the board.

Ω Contributes to resistance to bending under stress particularly after converting

into a box.

Ω The grammage of fluting medium may be in the region of 80-250 gsm.

Adhesive

While kraft paper is the main raw material for corrugated packaging industries,

adhesive – as the second most important material has gained significance

importance. Usually starch based adhesives are used for joining the outer liner

(This has relation to printing) Sodium Silicate (near to natural) also is used. The

silicate can give a rigid board but they can render the box brittle or lend to de-

lamination depending upon the humidity.

Types of Corrugated Board

Corrugated board consists of one or two outer plies, the flutes and, in multi-ply types

of corrugated board, of 3 or more intermediate plies. Corrugated board is classified

as follows according to the number of outer/intermediate plies and flutes:

Single face/Two ply Corrugated Board

Single face corrugated board consists of one ply of fluted paper, onto which paper or

cardboard is glued.

Single Wall/3-Ply Corrugated Board

Single wall (double face/3-Ply) corrugated board consists of one ply of fluted paper

which is glued between two plies of paper or cardboard.

Double Wall /5-Ply Corrugated Board

Double wall/5-Ply corrugated board consists of two plies of fluted paper which are

glued together by one ply of un-fluted paper or cardboard and the exposed outer

surfaces of which are each covered with one ply of paper or cardboard.

7-Ply Corrugated Board

Tri-wall corrugated board consists of three plies of fluted paper which are glued

together by two plies of paper or cardboard and the outer surfaces of which are

likewise each covered with one ply of paper or cardboard.

Advantages of C.F.B

Ω Effective cushioning material

Ω Easy to fabricate

Ω Easy to storing

Ω Easy to disposal

Ω More pilfer proof

Ω No strapping necessary

Ω Safe for human handling

Ω Articles can be kept dust free after sealing

Ω Could be specially made water resistance

Ω Printing and advertising advantages

Ω No self generating fungus

Ω Desired in export market

Ω Suitable for self service store display

Disadvantages of C. F. B.

Ω The base kraft paper not of desired standards

Ω Road transport is not developed properly

Ω Lack of Mechanical and Technical knowledge

Ω Improper warehousing

Ω Cargo handler resistance due to fear of damage

Ω Failure to comply with dimensional specification

Ω Supply of moist and damp material when hurry

Ω De-lamination of layers

Ω Use of unspecified adhesive and water proofing agents

Box Manufacturing

There are three steps involved in manufacturing of C.F.B. box.

Slitting and Scoring: This operation trims the board to obtain proper dimension/size

and creases the board for flap folding.

Slotting: Slot is cut made in corrugated sheet usually to form flaps and thus permit

folding.

Position of Slot: End of slot +/- 3 mm from center of flap score. Center of slot +/- 2

mm from center of panel score.

Joining is done by

Ω Stitching (Staples)

Ω Gluing (usually plastic resin adhesive)

Ω Taping (Cloth or paper)

Strength obtained by gluing is good but stitching is common and less expensive.

Depending upon the dimension of box there may be one, two or four joints.

Types of Box: Several designs of CFB boxes are commonly used in Packaging for

Export goods. Some of the designs are as given below.

Half Slotted Container Regular Slotted Container Full Overlap Container

Center Special Slotted

Container

123 Bottom Tuck Top 123 Bottom RSC Top

Glue in Divider Telescope Top or Bottom Half Slotted Container with

Telescope Top

One Piece Folder Five Panel Folder 2 Sided Rollover Tray

2 Sided Rollover Tray with

Flaps and Ears

Auto Bottom RSC Top Infold Clamshell

Applications of C.F.B

Ω Backing boards and folders

Ω Support panels for conservation work & display

Ω Box tray and support fabrication

Ω Shelf lining, dividers etc.

Ω Cushioning material in container

New developments in CFBs for Export Packaging:

Ω Mixed Flute Board: Mixed Flute Board utilizes the advantage of better

printing and better cushioning by using two different types of flute and thus

reducing the cost of the box.

Ω Duo Arch Board: Gives better strength by combining two flutes.

Ω Paper IBC for Liquids made from CFBPaper IBC for Liquid are the ideal replacement for most drums, returnable totes

and bottle-in-cage IBC. Carrying up to 1000 liters of liquid, replaces metal or

plastic drums, reduces the filling and handling cost, provides efficient storage and

transportation.

Picture of Paper IBC for liquid is as shown below. These IBC’s are collapsible and

hence occupy very less volume during storage in the warehouses.

Paper IBC for liquid packaging for Exports in ocean freight container is as shown

in the picture below.

Failures in the CFB during Export:

Adhesive Failure: Adhesive failure in CFB during transport may result in

delamination of the Flute and the Liner, which may occur due to : -

Ω Lower solid content

Ω Lower GSM coating

Ω Poor Quality adhesive

Probable Solutions

Ω Stringent Quality for Adhesive

Ω Bond strength determination by pin adhesion test gives the bonding strength

of the adhesive

Joint Failure: Failure may occur at the joints due to following reasons.

1 Stitching (Staples): Failure may occur due to corrosion of stapler and poor

manufacturing practice.

2 Adhesive Tape Failure: Failure occurring due to poor shear properties of the

adhesive tapes, or poor tensile property of tape.

Box design

The Bureau of Indian Standards (BIS) has published a Standard (IS: 2771) for

Corrugate Boxes. This standard may be used as a guideline for the Packaging of

Export goods where no guidelines are available from the importing country.

Depending upon the nature of contents and the journey intended this can be modified

to achieve economics. The weight carrying capacity and strength requirements as

per the Standard are given in the Table (2) below.

Table 2: Requirements for Corrugated Fibre Board Boxes

Type of Board Maximum Mass

Contents

Maximum Combined Internal Dimensions

(L + W + D)

Maximum Bursting Strength of the

Board (Kgf./cm2 )Single Wall and Double Wall

5 635 68 750 810 1025 1015 1275 1220 1525 1330 1650 1540 1775 21

Double and Triple Wall

15 1275 1020 1525 1230 1650 1440 1775 1755 1900 2475 2150 29

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