Comments of the PET/Aluminum/PET/PE

A couple of postings ago I commented on a question about the presence of a second PET layer in a lamination for a tomato sauce. My comment was perhaps it is for corrosion resistance. We got two very good comments on the use of adding the chemical resistance to a primer for the aluminum for bonding PE to the foil (use of an EAA primer suggested as well as adding the chemical resistance to the PE or Primer). These are both good suggestions but raise a couple of further points about the original lamination of PET/Foil/PET/PE sealant.

First there may be ways to replace the original lamination with a more cost competitive alternative as the suggestions recommend. This requires that the laminator be physically capable of applying the primer. Second we don’t really know the purpose of the extra PET, just my supposition as to its potential use in the lamination. If as I suggest it is simply for chemical resistance then the suggestions for replacement could result in a lower cost structure and perhaps a competitive replacement. If however, there are other attributes which the PET supplies, then it may not be so easily replaced.

So to replace the existing lamination with a cost effective alternative we really need to interview the end user to determine what the application really needs, I call this the “Fitness for Use” (FFU) Interview. In this process we ask the customer what the package needs to do for him, in his language. I.e. it has to run at 100 packs/min on a pouch machine holding X oz of sauce place into the pouch at Y degrees C and then has to be dropped 3 feet into a box without bursting. It has to allow superior print quality and supply a shelf life of Z months without a loss of color, or nutritional value. From this description we can begin to develop a packaging structure for the end use.