Storage of Exceval™ solutions!
How can possible foaming of Exceval ™ solutions be prevented during solving and application?
What total solid content can I prepare?
At what temperature do I need to dry?
How much material is required to achieve a high gas barrier level?
How do I improve the barrier properties?
How to improve the water resistance?
Exceval™ should be dispersed in cold water with agitation and then be heated to 95°C inner temperature and kept there for 2 hours. The solution should then be cooled down slowly.
Upon storage at low temperature an Exceval™ solution may increase viscosity and become gel depending on the concentration. Storage at elevated temperature as well as addition of hydrogen bond inhibitors such as isopropanol (IPA) will improve the storage stability.
There are some way to prevent the foaming, such as addition of alcohol (IPA etc.) / defoamer, controlling agitation condition and reducing solution viscosity.
Typically a 10-15% solution should be made.
No specific temperature is needed as Exceval™ solutions are forming a film upon drying.
A dry weight of 1-2μm is enough to achieve a high gas barrier level (permeation less than 1 cm³·m¯²·day¯¹·atm¯¹).
Crystallisation is the driving force behind the barrier performance of Exceval™. Any temperature treatment will improve the barrier performance. Storage of the coated film at elevated temperatures (50°C for several days) will allow the improvement of the gas barrier level.
In general, crosslinking and heat-treatment will improve the water resistance; however, the crosslinking ratio will reduce the barrier performance. A metal binding complex is preferred in order to combine good water resistance while maintaining the excellent barrier level.
Yes, it has a very good affinity printing inks.
To estimate the flexibility of the packaging film, the barrier properties are evaluated before and after mechanical torsion (Gelbo Flex test). Even after 20 torsions Exceval™ barriers demonstrate outstanding performance.
Increasing the coating temperature will reduce the viscosity. Depending on the coating temperature the total solid content can be adjusted. By increasing the solid content the drying time can be reduced.
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