Does 200# board require Mullen instead of ECT?

November 7, 2016

John asks,

If I order 200# C flute board with a 40# medium can I properly perform an ECT test on the board or do I have to stick with the Mullen test? We are trying to achieve 44 ECT by ordering a 42 – 40 – 42 liner combination. It is my understanding that if you order 200 flute board with any kind of medium it still requires a Mullen Test. Is that correct? Do you have to order an ECT liner combination such as 57 – 26 – 57 to properly test for an ECT value? Sometimes we do get the 44# ECT value but not always. Any suggestions would be helpful.

If I am being too complicated here, let me know. When you are considering that Mullen combination your incoming ECT levels will range from 45 to 60. That assumes that the corrugator has perfectly combined the liners to the fluted medium. This is not the real world. A good sheet supplier will know the strength characteristics of their containerboards and know what ECT levels they can achieve.

Have you ever considered EB double wall with even lighter and less fibre expensive that can still meet your needs?


Glue Flap Sizes and Types

October 10, 2016

Eugineo asks –

Is there a difference on the performance of the box if it’s used the normal, half extended or full extended glue flap?

Typically a normal glue flap running the full depth of the box body and 1-1/4 to 1-1/2 wide with 95 to 100 percent glue coverage creates a manufacturers joint sufficiently strong enough to hold the contents of the box.

Extended glue flaps are longer than normal flaps and usually extend 1-1/2 to 2 inches beyond the depth (body) and onto both the top and bottom closing flaps of the box.  Extended glue flaps are typically used on shorter (lower depth) boxes to provide more gluing surface for a stronger box, but may be used anytime a designer feels a stronger glue joint is needed.

On Half Extended glue flaps the glue flap it extended 1-1/2 to 2 inches beyond the depth (body) but only on one of the closing flaps of the box, usually the bottom flap.

It’s also very important to ensure the proper amount of glue is being applied to the flap. Certainly, insufficient glue application can cause a weak manufacturers joint and result in failure of the box. Over gluing uses more material than is necessary, can make a mess of the equipment as well as cause quality issues with the finished box. In some cases over application can also weaken the glue joint. If you have questions about application, your gluing equipment manufacturer or your glue supplier should be able to provide necessary and helpful information.

Warp standards for micro boards and S-warp

August 25, 2016

Rick asks,

I am seeking written accepted warp standards for corrugated. I’m looking primarily for standards on C, B and E flutes.

I seem to recall 1/4″ per running foot as acceptable for B and C.

1. Is the same true for E Flute and other “micro”
2. Is there anything for “S” warp, as that seems to be issue with lower profile flutes.

I have not been able to locate “written” warp standards for E flute and finer corrugated board. And S warp is just a matter of compound warp in both the MD and CD directions.

Yes, the Fibre Box Handbook recommends that warp of corrugated board should not exceed 1/4” (6mm) over 12 lineal inches (305mm) of the material’s surface. However, there does not seem to be anything specifically relating to micro or finer flute board. I would think due to the nature of material and its uses that the warp standards would be different than that of larger flute board.

One has to look to setting standards on paper moisture variations, glue application rates, and corrugator process controls. It’s these input variables that a paper buyer, corrugator supervisor, and control system need to establish. Without getting the front end communicated there is not much chance of flat board.

Hey followers… We’re always open to your input. Please share your knowledge and experience on this subject with us.

— Ralph

Corrugated Safety Data Sheets

August 19, 2016

Kim asks,

Recently a customer asked us to provide a Safety Data Sheet (SDS) for corrugated sheets. Have you ever heard this request before and do you know if anyone has a standard SDS or a template for and SDS?

Yes Kim, it’s a more common request than you might think. Click here for a Corrugated Safety Data Sheet example provided by the FBA. This should help you craft your SDS.
— Ralph