what is difference b/w PVC and PVDC foil blisters?
Polyvinylidene chloride or PVDC can be coated onto a PVC film to obtain very high moisture and oxygen barrier properties depending on the coating weight.
Morpholine test is applicable to PVDC blister reel, while for PVC not needed.
what is morpholine test?
Morpholine is a type of you can say identification test for PVC/PVDC, OR PVC/PE/PVDC,
if you apply morpholine(few Drop) on the film, the PVDC side will turns yellowish to brownish after few seconds of application, it has strong pungent smell.
is it give different color with PVC?
No. The test is applicable while you change rolls for different lots or after slice detection , and generally the PVDC side should be facing aluminium foil sealing face or as per procedure and agreement.
physically what is is diff b/w PVC n PVDC?
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.
pvc or pvdc which one most used in the packing department