Corrosion is a natural process where metals return back to its original state. Corrosion takes place in an electrochemical process where the electrolytes often found in
the form of humidity causes the electrons to flow from anode to cathode on the
unprotected metal surfaces.
Identification of Corrosion Case
– Identify metal types
– Identify metal grade
– Identify position and severity of corrosion
– Identify use or method of corrosion inhibitors
– Identify atmospheric conditions
According to NACE International (National Association of Corrosion Engineers), there are
17 different types of corrosion such as the uniform corrosion, pitting crevice corrosion, filiform corrosion, pack rust, galvanic corrosion, lamellar corrosion, erosion corrosion, cavitation, fretting corrosion, intergranular corrosion, exfoliation, dealloying, environmental cracking, stress corrosion cracking (SCC), corrosion fatigue,
hydrogen embrittlement, and etc.
What Causes Corrosion? – Volatility and Conditions for Corrosion
– Relative Humidity – in general, corrosion begins in RH levels of 70% with presence of agents
– Exposure to corrosion agents – NO2, chloride, fluoride, sulfides (electrolytes in general)
– Volatility of aforementioned conditions
What Are the Most Common Cases of Corrosion?
– Common Industries: Oil & Gas, Packaging, Equipment/Machinery, Circuit Boards
– With the presence of corrosion agents (i.e. within open loop or closed loop systems)
– With the presence of microbiological organisms
– When there’s human error in handling process
How Much Would Corrosion Cost?
According to WCO (World Corrosion Organization), NACE Interntational (National Association of Corrosion Engineers), CSSK (The Corrosion Science Society of Korea), (NDRC) National Development and Reform Commission, and CSCP (Chinese Society for Corrosion and Protection) the annual cost of corrosion worldwide is over 3% of the world’s GDP.
Corrosion Cost in USA: USD 276 billion
Corrosion Cost in China: USD 250 to 400 billion
Causes of Corrosion in Packaging
Humidity inside Container
Changes in temperature during shipment leads to sudden evaporation and condensation inside the container, increasing humidity levels of up to 200%. High temperatures and ocean humidity causes the build-up of acid levels increasing the rate of metal corrosion at an exponential rate.
Moisture Absorbent Boxes
Starch in boxes absorbs moisture present in the atmosphere to a tune of 15-60% of the weight of corrugation. At room temperature the moisture levels absorbed in corrugation always exceed 15% threatening the packaged goods.
Plastics are Water Permeable
LDPE, HDPE have porosity of water also termed as Moisture Vapor Transmission Rate (MVTR) to the extent of 4 gms/sqm/24hrs. In order to make packaging full proof, chemicals need to be present inside the packaging to continuously neutralize moisture and inhibit the breathing of the plastic.