Corrugated Box / Shipper Testing Procedure :
Corrugated fiberboard as a light weight structure composed of liners separated by the corrugating medium which give adequate protection for the product during the transportation, storage, distribution and handling. Corrugated fiberboard of middle layer called a corrugated medium a one and two flat papers called the liners which are glued at the tips of the medium. The flute comes in fours standard size. B flute which is most commonly used give better crush resistance, fold more easily. Printing of the corrugated board by flexography printing. Corrugated fiberboards are usually designed by the maximum mullen bursting test of board. Bursting strength is used to determine the amount of hydrostatics pressure in kg/cm2 required to obtain rapture of the material. The pressure is applied at a controlled increasing rate though a rubber diaphragm. If one each liner & fluting are used it is called as single face board or a 2 ply board. If two liner & one fluting medium are used it is called as double faced board or a 3-ply board. The combination of two medium and three liner is called as five ply. The combination of three medium & four liner is called as seven ply. Corrugated board is generally made in one of nine flute size which are named as A, B, C, E, F, N and k. The Grammage of Kraft paper is normally 100, 120, 150 GSM. The Corrugated fiberboard box strength depends upon paper quality, moisture content, number of plies, Types of flute. Corrugated fiberboard box defects are wrap, delimitation because of excess gluing, wash boarding, bubbles, cut flutes etc.
- Normal shipper: Corrugated Boxes are made up of corrugated paperboard. The surface colour of Kraft paper is brown, non bleached and not any kind of surface treatment is done. The Kraft paper on without any surface treatment so water absorption and cob value of Kraft paper in high. The normal shipper only one colour printing done by flexography printing process. The bursting strength and bursting factor poor compare to printed shipper. Corrugated Boxes are light weight and thus are very convenient to handle while packaging, loading and unloading.
- Printed shipper: The surface of printed shipper is single or multicoloured. The upper liner of shipper needed white paper with good bursting strength and bursting factor. These papers are china clay coated paper. Clay coating create good surface printing and multicolour ink adsorption is fine. They use wet offset printing process for printing of board. Corrugated cardboard boxes have better printing and graphics capabilities. As such, they can be used as effective marketing tools for brand awareness and promotion.
- Acceptance Criteria: __________ coloured/ Multicoloured _____ ply corrugated box.
- Acceptance criteria: _______ Ply corrugated box, rust free staples and no separation of layers.
- Dimension : Measure dimensions with calibrated measuring scale.
- Acceptance criteria:
- Tolerance for Length : _______ ± 2 mm
- Tolerance for Breadth : _______ ± 2 mm
- Tolerance for Height : _______ ± 2 mm
- Weight : Weigh the sample on weighing balance.
- Acceptance criteria: _______ ± 5%
- Grammage : Cut the sample in 10 cm x 10 cm piece or suitable measured scale, weigh it and calculate the Grammage with following formula,
Weight of 10 cm x 10 cm piece in gm
Grammage = ————————————————– x 10000
Total area of piece in cm2
- Acceptance criteria: Not less than 100 gsm