Corrugated Board and Container Tests
For box quality tests, a minimum of 5 boxes is recommended
4-Point Bending Stiffness (Tappi T836 pm-02)
This method is used to measure the bending stiffness of corrugated board and heavy
paperboard in the machine or cross machine direction. The bending stiffness measurements,
when used with the edge crush test (ECT), can be used to predict the top-to-bottom compression strength of a box.
- Box compression strength
Caliper (Tappi T411 om-97)
Caliper is used to measure the thickness of corrugated board, reported in millimeters (mm) or thousandths of an inch
- crushed flutes
- soft board
This method is used to determine the weight of liners and mediums used in
the manufacture of corrugated board. The type of adhesive and the presence of
any coatings is also reported. - Verify board made to spec (Rule 41)
- Quoting Purpose
Compression (Tappi T804 om-02)
This is used to measure the ability of corrugated or solid fiber
shipping containers to resist external compressive force. This test
can be conducted on empty container of container loaded with its contents
and all inner packing. Reported as kilogram force (kgf) or pounds (lb)
- Stacking strength of box
- Box quality
ECT (Tappi T839 pm-95)
ECT is used to determine the edgewise compression strength parallel to the
flutes, of a short column of single, double or triple wall corrugated fiberboard.
- Verify board met spec. (Rule 41)
- Board strength
Flat Crush (Tappi T825 om-96)
This is used to measure stiffness of the board in the “Z” direction.
The value is dependent on the flute, medium weight, medium Concora and the
degree of crushing that the board experienced.
- Soft board
MBR (Tappi UM807)
This is used to measure the water resistant adhesive quality used in waxed board
- WRA quality (waxed board only)
Pin Adhesion (Tappi T821 om-96)
This is used to measure the force necessary to separate the facing
from the flute tips indicating the quality of the medium/liner bond.
Results are reported in kg/m of glue line
- Board delamination between liner and medium
Ply Separation (Tappi T812 om-97)
This is used to determine if water resistant or regular starch
adhesive has been used in the manufacture of corrugated board.
Sample is immersed in water for 24 hours and the resistance to ply separation is evaluated
- WRA Quality
- CGSB requirement
This method is used to determine the average difference in overall thickness
of un-printed and printed areas of combined board, measured in millimeters
(mm) or thousandths of an inch
- Soft Board
- Box compression strength
This is used to determine if starch application is adequate.
Indicated incorrect machine settings and poor bond quality.
- Delamination Problem
- Glue application
- Fingerlines - Soft board
Wax Weight Determination
This is used to determine the amount of wax used in cascaded, curtain coated or wax impregnated board. Was weights are reported as a percentage of the dry board when Cascaders are involved, and as pounds per 1000 square feet when corrugator impregnation and curtain coatings are involved.