MODUK - DEF STAN 81-147
Water-vapour Resistant Material and Bags for Packaging
|Publication Date:||14 February 2017|
This annex specifies the requirements for three types of heat- sealable, flexible, aluminum foil laminates suitable for use in packaging where low water-vapor transmission rates (WVTR) are required. They are;
a) Type 1 Non-woven plastics film backing
b) Type 2 Kraft paper backing
c) Type 3 Woven natural or synthetic fibre backing
Type 1 is divided into two grades, A and B. Type 1B has greater tear and stiffness properties and lower WVTR when flexed and is used where a more robust material is required than Type 1A.
The use of Type 2 is not recommended when the application involves twisting or flexing the foil laminate (as distinct from creasing) during either the packaging make-up procedure or service use.