Corrugated Fiber Board Boxes

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/

Flute Height

Flutes Per Meter

(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 delamination 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

Center

Special

Regular Slotted Container

Slotted 123 Bottom Tuck Top

Full Overlap Container

123 Bottom RSC Top

Container

Glue in Divider

Telescope Top or Bottom

Half Slotted Container with Telescope Top

One Piece Folder

Five Panel Folder

2 Sided Rollover Tray with Auto Bottom RSC Top Flaps and Ears

Applications of C.F.B Ω Backing boards and folders

2 Sided Rollover Tray

Infold Clamshell

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 CFB Paper 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 Single Wall and Double Wall

Double and Triple Wall

Maximum Mass Contents 5 8 10 15 20 30 40 15 20 30 40 55 75

Maximum Combined Internal Dimensions (L + W + D) 635 750 1025 1275 1525 1650 1775 1275 1525 1650 1775 1900 2150 *****

Maximum Bursting Strength of the Board (Kgf./cm2 ) 6 8 10 12 13 15 21 10 12 14 17 24 29