Current Questions & Answers

MEMBER'S QUESTION:

At our corrugator and converting operations we know there are many TAPPI Test Methods that can be used to describe the properties of the linerboards and mediums we purchase.  What do you believe are the most important?

ASKRALPH! Responds:

Here are my thoughts on the most critical physical properties for each of the three major classes of containerboard that you purchase.  I believe that it is critical that you ask for actual reel positional data from each supplier.  As you buy narrow trim rolls from mills, you are more likely to obtain containerboards that are slit from the operator or drive sides of the paper machine.  Out on the edges of the paper machine, the physical properties are more likely to have higher variation indexes.

 

 

 Do not accept reel average specifications or physical property tests.  Push back on our upstream partners.  I can assist you in this effort and even lead the conversations with your mill reps.  There is a methodology for obtaining this infomation so that you can compare various product offerings.  Also seek out the upper and lower reject points for each of the physical properties.

Hi Ralph,
I've read some of your responses to the ASK Ralph service.  I'm a packaging engineer for a US based manufacturer of computers and preferrials.  Products we have build and packaged in China are having box compression failures.  We specify a minimum box compression strength on our drawings.  Test results performed by the supplier at the time of manufacture are passing.  We are using a safety factor of 4.5 to 5.5 that should account for all the environmental and conversion effects acting on the box to degrade it's performance.  However, after arrival at our distribution centers in Americas and Europe, the box is failing under load.

My research so far seems to point to the recycled material China uses in their box board paper.  This material looses it's bond strength after cyclic exposure to high heat and humidity.  BCS at time of manufacture is not the same after this type of exposure, and is much worse that industry experience with typical virgin or re-cycled softwood fiber.

If I could add a minimum stiffness requirement on my drawings (per TAPPI 836), do you think I would have a way to manage the use of recycled content board such that my expected box compression performance is not compromised over time?  If yes, how would I create a table of expected stiffness requirements?  Should it be related to board combo caliper, by flute size, by ECT or Mullen test values, etc?

Thank you for your advice,

ASK!Ralph Responds

Thank you for the inquiry and contacting the AICC.

Where have the boxes failed in the supply chain?  Do you have any pictures that you can share so I can offer an opinion on the type of box compression failure?

MEMBER'S QUESTION:

I was wondering if we had any idea of the average cost of ink per MSF .Not sure  if this the data would be collected from converters in Canada or the USA. ....just wondering... thanks in advance...

ASK!Ralph RESPONDS:

While I am still waiting fro input from other network associates here is what I have so far.

Typical ink costs are as follows:
    1) GCMI- lowest cost   range $0.60- 3.50/lbs.
    2) PMS- average cost  range $1.50- 6.00/lbs.
    3) Specialty ( fluorescents, metallics, etc.)-  range $7.00- 15.00/lbs.

We calculate 1lbs./1000 sq. ft. for high hold out surfaces and 2lbs./1000 sq. ft. for kraft or absorbent paper stocks. Many variables enter into an ink usage calculation depending of the substrates, drying mechanisms, anilox roll line screen, ink metering systems, plates and press speed. These numbers are averages.  You do the math!

MEMBER'S QUESTION;

Can you provide ten years' worth of prpicing history and when hte changes occured?

ASKRalph! Responds:

See the chart below.  These are the transaction prices published in Pulp and Paper Week and do not include and discounts as mentioned in the discussion part of the newsletter.

MEMBER'S QUESTION:

We are pursuing packaging options for a large volume of boxes that must comply to the DOT 49 CFR regulation.  In this day and age of ECT where board combinations can float as long as the performance of the corrugated box is quaranteed, why are we still required to keep the basis weight of the components with a range of plus/minus five percent of the original design?

ASK!Ralph Responds: