Container compression test: Difference between revisions

Revision as of 20:21, 20 September 2020

Revision as of 17:06, 23 November 2020

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==Test procedures==

A common method of conducting the test, as described in several published standard [[test method]]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:

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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= |author2=Singh, Srinagyam |date=July 2005 |title=Predicting Collapse Times for Corrugated Boxes Under Top Load|journal=Journal of Testing and Evaluation |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= |author2=Rosen-Doody |date=February 1981 |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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}}</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= |author2=Pratheepthinthong |date=July 2000 |title=Loss of Compression Strength in Corrugated Shipping Containers Shipped in the Single Parcel Environment|journal=Journal of Testing and Evaluation|volume=28 |issue=4 |pages= |id=|url= |accessdate= |quote= }}</ref>

*Vent and [[package handle|hand holes]]<ref>{{Citation

| last =Fadiji

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| volume =14

| issue =

| pages =194-201194–201

| date =2018

| url =https://d1wqtxts1xzle7.cloudfront.net/58363337/AZOJETE-CIGR_19_194-201.pdf?1549687286=&response-content-disposition=inline%3B+filename%3DTHE_ROLE_OF_HORTICULTURAL_PACKAGE_VENT_H.pdf&Expires=1600537321&Signature=aikwpcP68LIvJexSUqyf9mWiLUgLdMWQxSEB4MPixHGmQ5sXUdLWEXVfmfKgZl62LxdAbjCnfVoXtsv5elZYS-sVEPye7hIYaAP2ttOw6-qW94zNegP1qXmsjI0Hb3iirvcz7O2dsHAscnDHusoV5-Xzy-XCM17xOjLf7c5qx2dwQauDYrEZm4CoQuFoxvmTRfT55tf0CrIIRcC~w8EmX9zY9B4OgFT1CDIlj9RSdSXsclVUqLkfCxhBT0b37oN0qypBzbQzPVN7xHVzg3LoIEl0-Lc8ukr-0sEmL-vis-zDbPW2Pv3OTKDSqIUnGBv375Xxl9LdAw1icwwa7rFpHQ__&Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA

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| pages =227–238

| year =2008

| month =

| url =http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1000&amp=&context=it_fac&amp=&sei-redir=1&referer=https%253A%252F%252Fscholar.google.com%252Fscholar%253Fhl%253Den%2526as_sdt%253D0%252C24%2526qsp%253D3%2526q%253Dcorrugated%252Bboxes%252Bhand%252Bholes#search=%22corrugated%20boxes%20hand%20holes%22

| access-date = 2 April 2018}}</ref>

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===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= |date=July 1981 |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= |author2=Gander, Wachuta |date=August 1963 |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.

===Calculating compression requirement===