MEMBER: I am searching for an industry standard for caliper of incoming sheets.
I have surveyed our main suppliers and checked resources such as TAPPI. With so many corrugators using their own paper combinations, flute profiles, and reducing the flutes per inch I am curious if an industry standard is still available. Also, older standards I have seen were a single target, but I have not found information on an acceptable range for incoming and post-process calipers. Thank you for any guidance.
 

MEMBER:  Will you share some of the knowledge you have gained about fluting, corrugating rolls, and the single face operation?  We believe we have developed technological improvements to the design of corrugating rolls which may offer users additional fibre savings and reduced cost.  Please recommend a design experiment so that we may document and quantify these statements.

RALPH YOUNG:  It will be our delight to assist you and others in demonstrating and defining improvements that will benefit the independent members.  If your technology sets a new standard in performance than we want to know.

We discussed the four major fluting properties of caliper, coefficient of friction, MD tensile and MD stretch. When you flute the range of mediums available in the North and Central America, these are four critical properties, along with others, that must be measured to ascertain the ability of your equipment to deliver combined board caliper, flat crush, and edge crush.

Join TAPPI and become a contributing member of the CORBOTEC committee which meets two or three times a years.  These are the experts that have taught me so much over the years and on which I still depend.

Three major documents you may want to acquire and study on this subject are: Single-face Runnability and Bonding by the IPST, Corrugator Bonding by TAPPI, and Corrugated Medium: Its Influence on Box Plant Operations and Combined Board Properties and Packaging Performance.

Member’s Question: We are experiencing a significant amount of waste as a result of “rolling edges” by running a labeled carton through our flexo-folder-gluer. The specific item is a 32 ECT RSC with a mottled white outside liner with two large spot labels that are placed in panels 1 & 2 and panels 3 & 4.Our current routing through our facility includes the placement of both labels at the same time through our EM model Automatan and then finished off with our 66” McKinley FFG. We have tried increasing score pressure, using “scores” on the print cylinder to score both the inside and outside and using a variety of speeds.  The interesting outcome was that we would cycle through say 5 to 10 good boxes and then 2 or 3 “bad” boxes. Also, we were told by two cutting die vendors that moving this to a full die cut on the FFG would not be of any help…

 

ASK Ralph Responds: