Comparison of VCI & NON VCI Packaging

vci
Pdf

 


VCI Stands for Volatile Corrosion Inhibitors. A VCI packaging contains chemicals within the polymer matrix that can evaporate and protect corrosion on metal parts. This is done in 3 ways.

  1. evaporation and condensation of active molecules and forming a multimolecular layer on the surface of the metal

  2. evaporation and attachment of VCI molecules with water vapors and when these settle on the metal parts, the corrosion action is inhibited by the vci molecules

  3. Alteration of the pH of the inside atmosphere which in effect reduces the corrosion forward reaction.


A normal plastic bag doesnot contain VCI molecules and hence cannot reduce the corrosion rate and hence doesnot increase the shelf life of a packed metallic component.


Property Comparison of VCI & NON VCI

Property

VCI

Non VCI

Moisture Barrier Properties

Good

Poor

Vapor Corrosion Inhibitors

Present

None

pH of the film

8-9

No effect

Vapors Neutralise the moisture

Yes

No

Vapors condense on metal parts and form barrier

Yes

No

Increases shelf life of metal parts

Yes

No

Puncture Resistance

Very High

Average

Tensile Strength

Very High

Average


Specifications of a VCI FIlm

Tensile Strength (kPa)

ASTM D 882

MD 26000  TD 24000

Puncture Resistance

 

0.060

Elongation at Break

 

MD 600 TD 400

Heat Seal Strength

ASTM F 88

2.6 – 3.5

Water Vapor Transmission Rate

ASTM 1249

<0.001

Oxygen Transmission Rate

ASTM D 3985

<0.001

Corrosion Test

ASTM 1748

Pass 500 hrs

German Vapor Inhibiting Ability Test

 

Grade 3 (Best)

Colour Availability

 

Blue, Green, Yellow, Transaprent