|
#1631
Author: Eldridge M. Mount III, EMMOUNT Technologies
Email:
Subject: Solvent retention during dry bond lamination
Solvent retention is influenced by the chemical resistance of the materials. Remember the adage, "like dissolves like." Oriented polypropylene (OPP) is nonpolar and polyester terephthalate (PET) is polar so OPP absorbs more organic chemicals than does PET. PET will absorb more polar molecules such as water and alcohols, whereas OPP is more water resistant because it is nonpolar. PET is more resistant to many chemicals and as a consequence is a better aroma barrier than OPP. OPP is not very chemical resistant especially for the organic materials used for solvents and will absorb some from the process. Consequently, you will need to dry the OPP more completely to remove all traces of solvents. Since OPP should not be exposed to temperatures exceeding 160 F, it usually will need a longer oven or must be run at a slower speed. Alternatively, you can improve the mass transfer coefficient of the oven through design changes.
Back to top
|
