Box compression test
Encyclopedia
The container compression test measures the compressive strength
of packages such as boxes, drums, and cans. It usually provides a plot of deformation vs compressive force
.
It is commonly used to evaluate shipping container
s made of corrugated fiberboard as well as wooden box
es and crate
s. Industrial and consumer packages other than boxes can also be subjected to compression testing: drum, pail, bottle, etc.
It is usually a laboratory test involving a special machine, a compression tester, to apply controlled compression on a test specimen
. A universal testing machine
is sometimes configured to perform a package compression test. Compression testing can also involve a superimposed dead load to a test package.
s, is to compress a box at a constant rate of 1/2 inch (12.5 mm) per minute between two rigid platens. The platens can be fixed so that they remain parallel or one can be pivoted or "floating". The test can be conducted on empty or filled boxes, with or without a box closure. Conditioning to standard temperature and humidity is important.
The results of the constant rate of compression test can be:
The dynamic loads have some relationship with expected field loads.: often factors of 4 or 5 are used to estimate the allowable working load on boxes.
A test can also be conducted with platens that are not mechanically driven but are free to move with a fixed mass (or fixed force) loaded upon them. The results of static load testing can be:
As with any laboratory testing field validation
is necessary to determine suitability.
(ECT). There have been efforts to estimate the peak compression strength of a box (usually empty, regular singelwall slotted containers, top-to-bottom) based on various board properties. Some have involved finite element analysis. One of the commonly referenced empirical
estimations was puplished by McKee
in 1963. This used the board ECT, the MD and CD flexural stiffness, the box perimeter, and the box depth. Simplifications have used a formula involving the board ECT, the board thickness, and the box perimeter. Most estimations do not relate well to other box orientations, box styles, or to filled boxes. Physical test
ing of filled and closed boxes remains necessary.
methods are available to evaluate these compression dynamics.
Compressive strength
Compressive strength is the capacity of a material or structure to withstand axially directed pushing forces. When the limit of compressive strength is reached, materials are crushed. Concrete can be made to have high compressive strength, e.g...
of packages such as boxes, drums, and cans. It usually provides a plot of deformation vs compressive force
Force
In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity , i.e., to accelerate, or which can cause a flexible object to deform...
.
It is commonly used to evaluate shipping container
Shipping container
A shipping container is a container with strength suitable to withstand shipment, storage, and handling. Shipping containers range from large reusable steel boxes used for intermodal shipments to the ubiquitous corrugated boxes...
s made of corrugated fiberboard as well as wooden box
Wooden box
A wooden box is a container made of wood for storage or as a shipping container.Construction may include several types of wood; lumber , plywood, engineered woods, etc...
es and crate
Crate
A crate is a large shipping container, often made of wood, typically used to transport large, heavy or awkward items. A crate has a self-supporting structure, with or without sheathing. For a wooden container to be a crate, all six of its sides must be put in place to result in the rated strength...
s. Industrial and consumer packages other than boxes can also be subjected to compression testing: drum, pail, bottle, etc.
It is usually a laboratory test involving a special machine, a compression tester, to apply controlled compression on a test specimen
Specimen
A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...
. A universal testing machine
Universal Testing Machine
A universal testing machine, also known as a universal tester, materials testing machine or materials test frame, is used to test the tensile stress and compressive strength of materials...
is sometimes configured to perform a package compression test. Compression testing can also involve a superimposed dead load to a test package.
Test Procedures
A common method of conducting the test, as described in several published standard test methodTest method
A test method is a definitive procedure that produces a test result.A test can be considered as technical operation that consists of determination of one or more characteristics of a given product, process or service according to a specified procedure. Often a test is part of an experiment.The test...
s, is to compress a box at a constant rate of 1/2 inch (12.5 mm) per minute between two rigid platens. The platens can be fixed so that they remain parallel or one can be pivoted or "floating". The test can be conducted on empty or filled boxes, with or without a box closure. Conditioning to standard temperature and humidity is important.
The results of the constant rate of compression test can be:
- The peak load
- The deformation at peak load
- The load at a critical deformation (head space, etc)
- The ability of a box to protect the contents from compression damage
- etc
The dynamic loads have some relationship with expected field loads.: often factors of 4 or 5 are used to estimate the allowable working load on boxes.
A test can also be conducted with platens that are not mechanically driven but are free to move with a fixed mass (or fixed force) loaded upon them. The results of static load testing can be:
- The time to failure
- The time to a critical deformation
- The ability of a box to protect the contents from compression damage
- etc
As with any laboratory testing field validation
Verification and Validation
In software project management, software testing, and software engineering, verification and validation is the process of checking that a software system meets specifications and that it fulfills its intended purpose...
is necessary to determine suitability.
Factors potentially affecting test results
- Size and construction of the specific shipping container under test
- Grade and flute structure of corrugated fiberboard
- moisture content of the corrugated board (based on relative humidityRelative humidityRelative humidity is a term used to describe the amount of water vapor in a mixture of air and water vapor. It is defined as the partial pressure of water vapor in the air-water mixture, given as a percentage of the saturated vapor pressure under those conditions...
) - Orientation of the box during the test
- Inner supports, if used during testing (wood, corrugated board, cushioning)
- Contents (when box is tested with contents)
- Box closure
- Whether the compression machine has "fixed" or "floating" (swiveled) platens.
- Previous handling or testing of box
- etc
Estimations
Corrugated fiberboard can be evaluated by many material test methods including an Edge Crush TestEdge crush test
The edge crush test is a laboratory test method that is used to measure the cross-direction crushing of a sample of corrugated board. It gives information on the ability of a particular board construction to resist crushing...
(ECT). There have been efforts to estimate the peak compression strength of a box (usually empty, regular singelwall slotted containers, top-to-bottom) based on various board properties. Some have involved finite element analysis. One of the commonly referenced empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
estimations was puplished by McKee
Edge crush test
The edge crush test is a laboratory test method that is used to measure the cross-direction crushing of a sample of corrugated board. It gives information on the ability of a particular board construction to resist crushing...
in 1963. This used the board ECT, the MD and CD flexural stiffness, the box perimeter, and the box depth. Simplifications have used a formula involving the board ECT, the board thickness, and the box perimeter. Most estimations do not relate well to other box orientations, box styles, or to filled boxes. Physical test
Physical test
A physical test is a qualitative or quantitative procedure that consists of determination of one or more characteristics of a given product, process or service according to a specified procedure...
ing of filled and closed boxes remains necessary.
Dynamic Compression
Containers can be subjected to compression forces that involve distribution dynamics. For example, a package may be impacted by an object being dropped onto it (vertical load) or impacted by freight sliding into it (horizontal load). Vehicle vibration can involve a stack of containers and create dynamic compression responses. Package testingPackage testing
Package testing or packaging testing involves the measurement of a characteristic or property involved with packaging. This includes packaging materials, packaging components, primary packages, shipping containers, and unit loads, as well as the associated processes.Testing measures the effects...
methods are available to evaluate these compression dynamics.
Relevant Standards
- ASTM Standard D642 Test Method for Determining Compressive Resistance of Shipping Containers, Components, and Unit Loads.
- ASTM Standard D4577 Test Method for Compression Resistance of a Container Under Constant Load
- ASTM Standard D7030 Test Method for Short Term Creep Performance of Corrrugated Fiberboard Containers Under Constant Load Using a Compression Test Machine
- German Standard DINDeutsches Institut für Normungis the German national organization for standardization and is that country's ISO member body. DIN is a Registered German Association headquartered in Berlin...
55440-1 Packaging Test; compression test; test with a constant conveyance-speed - ISO 12048 Packaging -- Complete, filled transport packages -- Compression and stacking tests using a compression tester
Further reading
- Brody, A. L., and Marsh, K, S., "Encyclopedia of Packaging Technology", John Wiley & Sons, 1997, ISBN 0-471-06397-5
- Soroka, W, "Fundamentals of Packaging Technology", IoPP, 2002, ISBN 1-930268-25-4
- Urbanik, T. J, and Frank, B, "Box Compression Analysis of World Wide Data", Wood and Fiber Science, 2006, http://www.fpl.fs.fed.us/documnts/pdf2006/fpl_2006_urbanik002.pdf
See also
- Corrugated box designCorrugated box designCorrugated box design is the process of matching design factors for corrugated fiberboard boxes with the functional physical, processing and end-use requirements...
- Corrugated fiberboard
- Package testingPackage testingPackage testing or packaging testing involves the measurement of a characteristic or property involved with packaging. This includes packaging materials, packaging components, primary packages, shipping containers, and unit loads, as well as the associated processes.Testing measures the effects...