Chemically PVC is Polyvinyl chloride which have very good heat sealing capacity, moisture barrier i.e.2.4 to 4.0 g/m2/day . PVC sheet thickness is chosen between 200µ to 300µ depending on the cavity size and shape.
Chemically PVdC is ** Polyvinylidene chloride** which have very good heat sealing capacity, higher moisture barrier i.e.0.16 to 0.70 g/m2/day . PVdC lamination over PVC sheet thickness is chosen for better sealability & high moisture barrier .Typical coating weights used include 40, 60, 90 and 120g/m2 over PVC laminate.
We can differentiate the PVC & PVC/PVdC laminates by morpholine test as PVdC gives us yellowish to brownish after few seconds of application of Morpholine. However PVC does not give any colour changes. In other word ,PVC is mono layer laminate and PVC/PVDC lamiate is bi -layer laminate which have base material is PVC and specified GSM of coated PVdC available for high moisture barrier.