Container compression test: Difference between revisions

Revision as of 14:24, 21 November 2013

Revision as of 06:36, 4 February 2014

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* The ability of a container to protect the contents from compression damage

* etc.

The dynamic loads have some relationship with expected field loads.:<ref>{{cite journal |last=Burgess |first=G|authorlink= |coauthors=Singh, Srinagyam |yeardate=July 2005 |month=July |title=Predicting Collapse Times for Corrugated Boxes Under Top Load|journal=Astm Jte|volume=33 |issue=4 |pages= |id=|url= |accessdate= |quote= }}</ref> 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:

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* 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 humidity]])<ref>{{cite journal |last=Miltz |first=J|authorlink= |coauthors=Rosen-Doody |yeardate=February 1981 |month=February |title=Effect of atmospheric environment on the performance of corrugated|journal=Packaging Technology|volume= |issue= |pages=19–23 |id=|url= |accessdate= |quote= }}</ref>

* Orientation of the box during the test

* Inner supports, if used during testing (wood, corrugated board, cushioning)

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| accessdate = }}</ref>

* Whether the compression machine has "fixed" or "floating" (swiveled) platens.

* Previous handling or testing of box<ref>{{cite journal |last=Singh |first=S. P.|authorlink= |coauthors=Pratheepthinthong |yeardate=July 2000 |month=July |title=Loss of Compression Strength in Corrugated Shipping Containers Shipped in the Single Parcel Environment|journal=J. Testing and Evaluation|volume=28 |issue=4 |pages= |id=|url= |accessdate= |quote= }}</ref>

* etc.

===Estimations===

Corrugated fiberboard can be evaluated by many material test methods including an [[Edge crush test|Edge Crush Test]] (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]].<ref>{{cite journal |last=Urbanik|first=T J|authorlink= |coauthors= |yeardate=July 1981 |month=July |title=Effect of paperboard stress strain characteristics on strength of singlewall corrugated boxes|journal=US Forest Products Laboratory Report|volume=401 |issue= |series=FPL|pages= |id=|url= |accessdate= |quote= }}</ref> One of the commonly referenced [[empirical]] estimations was published by [[Edge crush test|McKee]] in 1963.<ref>{{cite journal |last=McKee|first=R C|authorlink= |coauthors=Gander, Wachuta |yeardate=August 1963 |month=August |title=Compression strength formula for corrugated boxes|journal=Paperboard Packaging |volume=48 |issue=8 |pages= |id=|url= |accessdate= |quote= }}</ref> 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.

==Dynamic Compression==