Box creep testing service

p e e r C x o B

s e c i v r e S g n Testi

New Orange Board service available: box creep testing

Test Procedure

We offer our customers and partners different creep testing

A typical cycle is a continuously variable relative humidity of 50% –

services that reveal the true load-carrying capability of a ma-

90% – 50% at 23 oC. The time until the sample collapses is recorded.

terial in variable climate conditions (creep = slow deformation of

The test provides information in a standard format about:

During the test, the sample is kept under load in variable humidity.

a material under load). The creep tests are offered by Orange

how many climate cycles a material can withstand

Board and conducted by Mondi Powerflute®. They are available

how long a material can carry a load

for boxes, corrugated board and, in limited amounts, for paper.

which weight a material can carry over a certain period of time

Variable humidity strains the paper to a great extent and acceler-

This information helps our customers to determine the true perfor-

ates creep significantly. It has been found in tests that BCT (box

mance of various materials (paper, corrugated boxes) and supports

compression test) and creep performance (long-term load-car-

box producers in choosing the right type of paper and corrugated

rying capability) of a box are not the same, and BCT does not

box designs for their applications.

necessarily guarantee long-term performance.

Testing creep of corrugated materials in variable conditions that

Testing can be done for corrugated boxes (recommended), ready-

simulate the daily climate changes a box encounters during its

cut ECT strips (edge crush test) and paper (both liners and flutings,

lifespan is the most advanced method to simulate reality. Box

in limited capacity).

producers can be confident that their boxes will carry the load as intended.

Test scheme

Benefits

Approximate testing time

Basic package

Lifetime of one product in variable humidity conditions and with preselected or another load For regular product comparison

2 weeks

10 corrugated boxes or 12 ready-cut ECT strips or 5 sheets A4 paper

Medium package

Lifetime comparison of two or more products in variable humidity conditions

2 weeks

12 corrugated boxes or 12 ready-cut ECT strips or 5 sheets A4 paper

Full package

Load that one product can carry and estimation of lifetime for any load in variable humidity conditions Based on test for preselected time (ten and/or 20 days)

1–2 months

24 corrugated boxes or 20 ready-cut ECT strips

Sustainable by Design

Minimum material requirement

mondigroup.com

Test scheme

Typical product comparison

The material requirement and testing time depends greatly on the chosen test scheme. Simple single load tests/comparisons typical-

Comparison of load-carrying time

ly take two weeks, the full analysis (which measures the capability

relative to best tested sample

for a period of ten and/or 20 days) takes one to two months. The test time is dependent on the number and duration of individual tests needed for a reliable result.

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

1st class fluting

good highrecycled option performance fluting

The product comparison test provides information about which product performs better. It can be carried out more quickly than the full analysis, and it is often all that is needed. The test can be done for corrugated boxes and paper alike. Moreover, it gives an estimation about how long a material can carry its designated load and how many climate cycles it will sustain.

Left: Paper and ECT creep tests are conducted by using specific instruments in controlled climate conditions. Testing can also be done in reduced and elevated temperatures.

Contact and further information

Right: Example of loaded box pile in test room. Every box was loaded to its nominal capacity. The boxes quickly collapsed after exposure to light loads in variable humidity.

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Regular BCT test can be misleading Typical box test result, full analysis

BCT / Creep kg/10 d 60

Creep kg/10 d

55 50 45 40 35 30 25

300

350

400

450

500

550

600

BCT [kg] Higher BCT test results do not necessarily mean longer box lifetime under load. On the graph above, we compared BCT test results of two sets of boxes with the maximum load which boxes can hold for ten days. Boxes from set 1 can hold different loads despite having similar BCT values around 350 kg. On the contrary, the boxes from set 2 show different BCT values, but in reality they can hold similar loads. Without testing box lifetime in the creep test, we can easily overdesign packaging or select inferior box types from a few boxes having similar BCT values.

Mondi Marxergasse 4a | 1030 Vienna | Austria T +43 (0)1 790 13 - 0 F +43 (0)1 790 13 - 960 info.cb@mondigroup.com mondigroup.com/containerboard

Explore the full Orange Board service package here: Please contact your local Mondi sales representative for further details and arrangements.