Technical Information about VCI flexible poly Products:
sealrust® VCI Poly Products : Technical Information
The Term VCI stands for volatile corrosion inhibitor. When metal items are packed in VCI packaging material, the chemicals volatilise in the surrounding environment and forms a protective invisible molecular layer on the surface of the metal. This protective layer works as a barrier between metal surface and corrosion causing materials like moisture, oxygen, dirt, salt etc; and thus prevent them from depositing on the metal to cause rust and corrosion.
While Selecting VCI Poly Packaging Material, it is advisable to get technical information about VCI plastics packaging material. Number of technical issues in respect of VCI poly packaging material: suitability of VCI flexible poly material over VCI paper, its life span, effect of thickness of plastic material etc have been highlighted:
VCI Poly Products to be Used for Primary Packaging
For optimum protection from Corrosion, VCI Poly Material should be used for Primary Packaging at the time of production and it should not be used in combination with any other option of corrosion protection.
VCI molecules evaporate to settle on the metal surface to form an invisible thin film to protect the same from corrosive substances. If VCI material is combined with any other type of rust preventive material, VCI active agent may not fully cover the object material by forming invisible film on it, thereby making such area vulnerable to corrosion.
Similarly VCI active chemicals will not have any opportunity to from invisible protective micro film on metal surface if VCI material is used as secondary packaging material and other types of protective methods used for primer packaging.
However, for maximum and long term protection under worst climatic conditions, same VCI material should be used for primary as well as secondary packaging.
Advantages of VCI Poly Products over VCI Paper
VCI Poly material has many advantages over Traditional VCI paper products used as packaging medium for protection of metal surface from corrosion and rust. Some of the main Advantages are :
Difference between VCI Poly and VCI Paper Products
There are many benefits of using VCI poly Material compared to use of VCI paper Products. VCI paper is manufactured by coating of VCI chemical on paper while VCI Poly products are produced by extrusion process using VCI ingredients and master batch.
Thus in poly material there is uniform distribution of VCI chemical thereby giving more effective performance compared to VCI Paper.
Poly Products can be sealed to form a safe and protective enclosure around the object. Paper Bags have to sealed using some adhesive which itself may become source of corrosion due to presence of moisture in paper.
Paper absorbs moisture and humidity and thus becomes non effective in course of time which is not possible with plastics.
Poly film have much more superior tear strength than Paper.
Life span of sealrust® VCI Poly Bags & Wrappers
Life span and effectiveness of VCI Products depends upon many factors such as packaging methods, transit & shipping conditions, material to be protected and to what extent Guidelines for using VCI Products are followed.
However life of sealrust® Poly Products is considered to be three years in an ambient temperature.
This estimation is based on Salt Spray Test conducted in the laboratory as per ASTM B-117 for 1,000 Hours.
Effect of thickness of sealrust® Plastics Products
Effectiveness of VCI Plastics Bags & Wrappers remains almost same irrespective of the thickness of Poly Products. However thicker plastic film offers greater resistance to moisture transmission compared to thinner films.
Hence for better protection against corrosion, the thickness of the film should be selected from 400 to 800 gauge depending upon duration of protection required.
Can VCI active agent be seen, smelt or felt?
VCI agents are neither visible nor capable being felt. As far as smell is concerned, it will, by and large, depend upon the nature of active agents used in VCI product formulation by the individual manufacturer.
Nature of smell or its intensity does not give any indication about the presence of active agent or its effectiveness in any VCI Product.
Effect of colour variation in VCI material?
Colour variation inherent in the VCI Poly material in no way affects its quality, performance or effectiveness. Similarly nature of smell or its intensity does not give any indication about the presence of more or less dose of active agents or its effectiveness in any particular VCI Product.
In fact VCI poly material is manufactured in standard light yellow tint color and also in custom colours depending upon individual packaging requirements based on products identification.
Appropriate Method of closing VCI Poly Bags
Normally VCI packaging products do not require airtight packing to work effectively. However VCI products must be enclosed properly so that air or moisture do not enter in VCI Bag from the opened side of the bag.
Due to packaging constrains if VCI poly bags are not sealed, parts or material should be completely wrapped or enclosed with VCI packaging material.
Difference between Mono extruded VCI Film & co-extruded Film
Co-extruded VCI Film contains VCI formulation, which is chemical blend of several ingredients, only on one side of poly material where as Mono extruded VCI film contain VCI formulation on both the sides of the plastics. That is why studies have indicated that VCI film made by mono extrusion process shows better corrosion protection ability and longer protection life cycle as compared to co-extruded material.
Sealrust Poly Film is manufactured by mono extrusion process by using superior VCI Technology and formulation for long term protection from corrosion.
Effectiveness of Salt Spray Test?
Salt Spray Tests and Humidity tests provide only guidelines about effectiveness of VCI products. Performance of VCI products depends upon many factors such as storage, transportation and shipping conditions, surrounding temperature; humidity, presence of salt, sulphur in the atmosphere. It is, therefore, necessary to conduct field testing of VCI products before deciding about its effectiveness and performance.
Recycling of sealrust® Poly Products
Scrap of sealrust Poly material can be reprocessed without any difficulty into commercial (second) grade film like reprocessing of any other PE material. However such reprocessed bags or sheets should not be used again for VCI applications under any circumstances. The additives and master batch used during VCI Plastic material can not be recovered from the scrap of vci material during recycling process.
Sealrust Poly Products are meant for Industrial use
sealrust® VCI Poly Products manufactured and sold by us is meant for Industrial use Only.
More information about VCI Products:
Range of our Products for anti Corrosion Application :
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Our Contact Information:
Modi Polyfab Pvt Ltd
Phone : +91 - 93231 51828