Need for making Antimicrobial Paint:
Paints & Coatings are vulnerable to microbial attack in the wet as well as in dry stage after its application on substrate. The growth of microbes in the form of fungus, yeast & bacteria etc degrades the quality of paints in terms of viscosity, change in colour, bad smell, gas generation etc even during storage. Microbial can enter in the paint by air, water, raw material used or by poor hygienic condition of plant. Sometimes it results in heavy losses both tangible & intangible because of quality complaint, product recall & downtime. The addition of antimicrobial as an additive is essential to protect paints from millions of microbes.
Need for using Antimicrobial Paint:
Even after drying both water or solvent based paint coatings, are susceptible to growth of fungus & bacteria. A small quantity of microbes can grow exponentially in few hours. The bath rooms & kitchen are more vulnerable to microorganism growth because of high humidity & temperature. The interior walls of hospital & doctor’s clinic are home for bacteria & viruses introduced by various patients acting as microbe carrier because of illness. Even the ceramic water tanks can contaminate people using water. Bacterial growth can be very harmful to human health as they deteriorate indoor air quality & can make work place highly toxic.
Factors responsible for Growth of Microbes:
pH: Most of the microorganisms develop in wide range of pH varying from 3.5 to 9.5. Fungus develops in acidic pH while bacteria is in neutral to slightly alkaline pH.
Moisture: Moisture content of any object depends upon number of factors like rain fall, humidity & temperature of the environment. The surface under shade will definitely be having more moisture content.
Nutrients: The source of nutrient is present in coating itself in the form of polymers, thickeners etc. Even the dirt acts as source of food for microbes.
VAM (Versatile Antimicrobial Agent) is an excellent biocide because it dissolves completely in water base paints and also dispersed uniformly in solvent base paints because of its very small particle size. VAM is manufactured using latest nano technology.
The unique characteristics of VAM is as follows:
The particle size of silver in VAM is below 8 nano meters.
It is highly concentrated product and require very low dosages.
It is indigenously manufactured in India only.
Only 3 gm of VAM has to be dissolved in one Kg of paint. The lower dosage requirement is because of its small particle size in nano meter, high surface area, high reactivity along with highly concentrated product itself.
The cost of additive added in paint will not exceed Rs 9 per kg of paint.
Testing of Antimicrobial Characteristics of Paints Using VAM as an Additive:
The testing of antimicrobial paint can be done using ASTM E – 2315 – Suspension Time- Kill Test.