Setting Seven Performance Standards with Your Sheet Suppliers

August 4, 2014

For the last several years we have prepared you well with the Key Characteristics of Linerboard and Medium and Their Impact on Combined Corrugated Board-Second Edition, how to Get the Best Box, and Understanding Box Performance-Third Edition.  Make sure you have these brochures in your library. (available at the AICC Store)

Then at the third Science of Paper School we shifted the focus somewhat from what converters need to know about containerboards in general to combined board characteristics specifically.  Recently when compiling a list of sheet feeders for the Associations’ Board of Directors we were reminded to provide members with the key quantitative quality requirements one might want to establish with their internal or external suppliers.  Several years ago we publish a series of spreadsheets for singlewall and doublewall combinations listing a few physical properties categories so a converter could establish incoming sheet specifications with their supplies.

Let’s review those and explore a more comprehensive array of properties.

ECT: Yes, it is well know but not completely understood. While the already known losses of box compression will varying with supply chain elements, deterioration rates vary by actual amounts of board crush or flute degradation and the use of semichemical or recycled mediums.

Caliper: spring back or recovered thickness after crushing.  While fluting is a resilient material and recovers from much of the sever deformation that occurs during combining and/or converting, its inherent strength contribution to the corrugated may be significantly compromised.

Flat Crush: This measure of actual combined board crush verses the potential resistance to crushing as predicted from the Concora strength of the medium. This, however, is not a good predictor of actual board crush.

Pin Adhesion: Determines the strength of the bonds between the liner(s) and the medium(s).

Four Point Bending Stiffness: Measures the rigidity of the combined board and the sidewall wall robustness of the corrugated box.

Torsional Stiffness: Relatively new to the US, but known elsewhere.  This maybe the single best overall determinant of board strength.

Warp: Should have no more than 1/8 deviation from flatness per foot.

Look for more details in an upcoming issue of BoxScore

Settling the “Score” with Sheet Suppliers

July 18, 2014

Chuck asks,

How can we, as a sheet buyer, communicate to our sheet suppliers what we mean by ‘heavy scoring’. Is there a TAPPI industry standard for how much score pressure should be applied at the corrugator on the substrate…based on the flute configuration and weight of combined board? Does the corrugator have gages that indicate how much scoring pressure is being applied to the combined sheet at the slitter/scorer?

We have multiple vendors, we find that we’re having difficulty getting some of the suppliers to understand what we mean by ‘heavy scoring’. Hence my questions. We need a consistent means to communicate to our suppliers what we require when we ask for ‘heavy scoring’.

Every sheet plant must set quality and quantifiable specifications with their sheet suppliers. In regards to this latter point those measurable and reportable properties should be ECT, Flat Crush, caliper, four point bending, board performance index, and score bending. In a Corrugated Today article written by Dick Target, he discusses testing many aspects of corrugated board including score bending. (Raising Manufacturing Standards – Corrugated Today, March/April 2012, Page 22). You can and should set very specific values with your sheet supplier and establish a numerical target verses the very subjective term, “Heavy Scoring.”

Score bend testers available from the normal commercial testing machine manufacturers can be rather pricey. You may want order one from Dick Target, start to set standards for your sheets and hold your supplies accountable!

-Ralph

ECT Standard Differences

July 10, 2014

Michael asks,

Recently, we have been discussing ECT test methods with one of our partners plants. They are utilizing ‘X Brand’ testing equipment and using the Neckdown method (T 838 cm-12), which was revised as a ‘classic method’ in 2012. We have been using the ‘short column test’ (TAPPI/ANSI T 839 om-12), which has been an official test method since 2002.

The problem is that we have recently been getting different ECT values, where ours have better numbers than our partner plant. Assuming there is nothing happening to the material during transit, our feeling is that our different test methods could be the source of our conflicting data values.

I have heard that there are not many who still use the Neckdown method of testing. I have also been informed that supposedly there have been studies that indicate that ‘X Brand’ of equipment may not be giving consistent data.
Is there any information or perspective you can share regarding all of this? Specifically, how probable is it that any significant difference in our data is because of our different testing methods or equipment?

As I recall from my last visit, you are also using ‘X Brand’. All testing machines and tools can get out of calibration and need regular and often costly maintenance.

There should not be a significant difference between test methods. The quality of the cutting knives is critical. Are you using gloves? You might consider preconditioning and then conditioning the samples before testing until you discover the root cause of the differences. What is the two sigma range for the two testing methodologies? Have you exchanged samples? How about considering a third party testing facility to validate your tests? Perhaps you would want to send samples directly from your partner plant and then equivalent samples, from the same batch, that you have received from the partner plant.

Please don’t assume that there is no damage in transit! One study shows an ECT loss of 7% depending on the roads.

Sometimes operator variability and preference comes into the picture.

These are a few things you can look at and if you have any additional information, or follow up results to share, please do.

If anyone else ahs any comments, we’ll be happy to listen.

— Ralph

Educating the Community about Environmentally Friendly Corrugated

May 20, 2014

Joe ask,

We are having some issues with the community surrounding our plant, they seem to feel that we are creating hazardous waste which they say is causing illnesses. We have obtained and maintain all required permits and are always in compliance. My question to you, does AICC have any documentation that would cover how environmentally friendly the corrugated industry is?

Joe it sounds like you’re looking for materials to help educate your community and I think that is a very good first step. Human nature makes us leery of things we don’t understand. Those outside of the industry don’t realize that most of the materials used in corrugated packaging are natural such as paper, starch and soy. Nor do they realize that industries and industrial sites are typically held to a much higher level of compliance. When you add up the communities individual contributions to the environment (cars, barbecues, furnaces that are probably older and very inefficient and the biggest offenders of all gas powered lawn tools) you may find the plant is not the largest threat to the neighborhood.

But we’re not looking to shift blame, just to be good neighbors. I’ll check our resources here and touch base with TAPPI and FBA to see what they may have.

Let’s also open this up for comment from other members and followers who may have or are facing the same issues. Does anyone want to share their experiences on how they have addressed similar issues?

In the mean time, just some ‘good neighbor’ things to consider.

  • How is your boiler fueled and how is the exhaust handled?
  • How long will you allow trucks to idle, are there oil spills under cars and tractors, and what hours do they operate?
  • Are night lights and truck headlights shining into neighbors homes?
  • Where is water discharged and what is known about your roof and hard surface runoff?
    How is your waste water stored or disposed? Drums being hauled away from an industrial site can look much more menacing than they really are.
  • How modern is your dust collection system?
  • What’s the decibel level at the property lines?
  • When are your dumpsters emptied and how is your rodent control?

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