Archive for the ‘Containerboard’ Category

Analyzing the cost of corrugated boxes

September 17, 2019

Amine asks,

I would like to analyze the spend I have to my corrugated box suppliers across more than 1000 type of references.

I got the specifications for the references ( type of box ( Fefco, RSC, etc),fluting, the dimensions, the different liners and their Gsm, MOQ, volumes, etc).

I have calculated the area of each reference and the weight of each box. Then, I have calculated the price per sqm and the price per gram.

From there I would like to understand the cost drivers that influence the prices and identify the references that are priced too high.

How would you proceed?

Ultimately every corrugated shipping container is made to a physical and graphic specification that can endure the distribution environment. Since you are an international company shipping from and through different systems your analysis becomes very difficult to evaluate. Universally we must look to the minimum compression strength necessary to survive transport. This is best determined by ISTA testing protocols.

What you really need is to determine cost to strength ratios. Containerboard is a global commodity and yet strength to gsm ratios vary greatly.

There are differences between virgin and recycled fibre costs. Secondary fibre prices have been falling, but both products are often traded in the same range. You would also have to look to the financial returns of publicly traded companies to ascertain their margins over time. It is considered a very supply and demand driven packaging system.

Of course, order size and frequency of order can play a large part in the final cost of a box as well. The finish of the box is another thing you need to take into consideration. Are they all one-color boxes, or are they two, three, four or more colors.

The manufacturing regions can affect the product price. Material prices and manufacturing costs can vary—sometimes significantly—from one region/market to another.

Here are links to a couple documents that you might also find helpful.

How Does One Relate ECT and Basis Weight2

Selecting Components to Engineer a 44# ECT Corrugated Structure Combining For Strength with the Least Cost Containerboards

—Ralph

 

UPDATE:

Vann comments,

Amine, I recommend that you have some performance testing of your boxes that relates to your various applications.  I think that this could help you rationalize your supply of boxes with the objective of reducing the very large number of different boxes but still cover the critical needs of each of the applications. In other words, find out what current boxes can handle multiple applications in order to reduce the number of different boxes.

Is Burst and Puncture Testing Performed on Triplewall?

August 30, 2019

Bobs asks,

Is burst testing and puncture testing done on triple-wall boards? I’m having trouble interpreting the minimum fiberboard requirements issued by NMFC Item 22 and UFC Rule 41. Specifically 1100 triple-wall, does the 1100 represent minimum burst strength of 1100 lbs. per square inch? Or does 1100 represent a puncture test value?

That’s a really good question. It is Mullen burst and not a Beach puncture. It is really based on the additive Mullen values of the liners. So if you were experimenting with low Mullen yet high SCT liner and strong mediums, it would be better to go to an ECT standard.

— Ralph

UPDATE

Miranda comments,

TAPPI T810 Section 1.2 states mullen burst is not applicable to triplewall board. If the test is being performed on triplewall it would not be clear what the results would mean.

Pin Adhesion Test (PAT)

August 30, 2019

Sam asks,

Do you have any formal reference of what the ideal pin adhesion test result should be.   For agro boxes (vegetables) we currently use values of 55 to 60  (pound/inch) and in industrial 40 and higher.

We have a particular customer that has experienced some delamination failures. The PAT test value is 27 (pound/inch) which we believe to be too low. However, we are lacking established information to back up our opinion.

I could not agree with you more.  I prefer a minimum, not average, of 45 for industrial application.  My technical associates at TAPPI like this 45 value while I would rather have 55 on all corrugated bonds.  It is most important to know where the failure is occurring: linerboard, medium, or in the starch itself.  Under ideal conditions we want 100% liner failure. As you can see in these photos a very low PAT value can have disastrous results. There is very little liner pull and very little glue with a poor bond.

A good reference for the PAT is the most recent version of TAPPI document TM 821 (TM 821-0M 17 at this writing), Pin adhesion of corrugated board by selective separation.

— Ralph

Pin Adhesion Test sample Pin Adhesion Test sample Pin Adhesion Test sample

Insulating Properties of Corrugated

August 15, 2019

Rich asks,

I have a question about the insulating properties of corrugated and the impact of vent holes in dairy applications. I have a dairy customer who is looking to pack sour cream in cartons. It is filled at 100 degrees F and put into 35 degree refrigeration. What is the difference in how long it will take to get down to 40 degrees if there are no vent or hand holes in an RSC against if there are some? Is there a formula that exists for the cooling time? This would be an ECT48 DW RSC. Thank you as always for your guidance.

Here is a link to a research paper (Overall Effective Thermal Resistance of Corrugated Fiberboard Containers) complied by the US Dept. of Agriculture and the Forest Products Laboratory. Pages 4 – 6 of this report contain information regarding the affect of vent holes.

The location and area of the vent holes as well as the velocity of the circulating air will also have an affect on the thermal transition time.

Would it be possible to perform an experiment using a grill or meat type thermometer to determine when the core of a loaded box with vents and a loaded box without vents reached the desired 40 degrees F?

— Ralph