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?
–Ralph