1. Pigments Mixing Binders Driers Milling Thinning or Mixing Solvents Plasticizer Finishing Sludge Storage Packaging Labelling Screening Filling Eco – Friendly Paint Formulation AadityaKulkarni, Muhammad NasirFarooq, Sanjay Goplani. PratapGade, NileshPatil School of School, University of Greenwich at Medway, Central Avenue, Chatham Maritime, Kent ME4 4TB UK Alternative Options Introduction For eco-friendly paint, alternate options are: Clay paint: paint made from essential oils, clay and natural pigments of plant or mineral origin. Milk paint: contain casein, water, limestone, clay and natural plant pigments. Lime wash: mixture of calcium carbonate and water. Conventional solvent based paints contain organic solvents, pigments and additives that pose serious health and environment problems, the most important of which is depletion of ozone causing global warming. Need of hour is an eco friendly paint formulation that do not contain any harmful ingredient and uses natural materials like water, inorganic pigments and additives, making the formulation safe for living system and environment friendly. Preferred Solution An aqueous emulsion paint formulation containing water and inorganic pigments is the most suitable choice for a commercial grade eco friendly paint. Such a formulation follow the three E’s: effective, ecological, economical. Paint Production Mixing of different components is done in a commercial grade mixer followed by grinding in grinding mills to break down solid particles in required size. Additives life surface active agents, Anti-foaming Agent, dispersing agents are added. Solvent is then added and along with thickener and plasticizers and final product undergo filtration to give finish product which is then filled, labeled, and stored. Paint Components An aqueous paint compromises of an oil in water emulsion system in which suitable pigment is suspended along with other additives. The major components of this paint formulation are binder, solvents, pigment and additives. Binders By-products of crude oil e.g. acrylic or poly vinyl acetate can be utilize as binder for commercial synthetic aqueous paint. The binder will form a binder-pigment suspension before drying and provide a solid coat of paint after exposure to air. In water based aqueous emulsion systems the binder forms a binder emulsion with a stabilizing agent to improve dispersion and a surface active agent to promote wetting and incorporation of binder and stabilizer. The most common used stabilizer with poly vinyl acetate is methyl cellulose or starch. Challenges during Manufacturing Process SolventsSolvent is the liquid portion of paint formulation that gives it the desired fluidity and act as a dissolving medium for other components. Commercial solvents are organic solvents like turpentine oil, which are not eco-friendly as they emit VOC and reduces air quality. Aqueous emulsion paint utilizes water as solvent that is safe and non-toxic in nature. PigmentsPigment is suspended in a binder emulsion as pigments are insoluble solids. The physical and chemical aspects that are considered in pigment selection are chemical composition, particle size, density, rigidity, and weather light and chemical resistance, gloss retention, anti corrosive properties, and compatibility with binder. Pigment Volume Concentration For good quality paint, concentration of binder and pigment should be 30%-45% by volume whereas the liquid and additives make the rest of volume. The relationship of pigment with binder can be determined by following formula: The effect of PVC concentration on paint film is described in Figure. (a) below the CPVC (b) at the CPVC (c) above the CPVC Apart from fulfilling the requirements for low VOC content, biodegradable product and waste certain in-process difficulties also arise during production. Additives Additives are different chemical substances added in paint formulation to impart specific characteristics to paint and help to improve quality and stability of in-process and finished product. The average additive content in paint is between 0.01%-1.0percent. Results Conclusions The finished product is an eco friendly formulation and is effective, ecological and economical. It does not generate any hazardous waste and has low voc content and odor. It also provides a durable and widely applicable semi-gloss paint with variety of colors. The proposed formulation results in a green paint with VOC content <5g/L and low pigment concentration (30-35%) and is preferred over the alternate options because of commercial and consumer benefits. Paint Formulations References A proposed formulation for semi-gloss aqueous emulsion paint is given below and consists of two parts: Binder Emulsion Semi-Gloss Paint 01. Scribd.com (2005), “Industrial Inorganic Pigments (Third Edition) by Gunter Buxbaum and Gerhard Pfaff” available online at http://www.scribd.com/doc/23581925/Industrial-Inorganic-Pigments-Third-Edition; date accessed [Apr 11 2011] 02. Scribd.com (2008), "Paint Production Process Diagram" available online at http://www.scribd.com/doc/18751253/Paint-Production-Process-Diagram- ; date accessed [Apr 25 2011] 03. Books.google.co.uk (2004), "The Science and Art of Paint Formulation" available online at http://books.google.co.uk/books?id=Iz0RQK0oMWUC&pg=PA317&lpg=PA317&dq=paint+formulation+process&source=bl&ots=Kh5ewB8D7a&sig=4DCpzIf4cMjOfCGqJ86zWtUoIMo&hl=en&ei=rOm2TY9Ecms8QOGg807&sa=X&oi=book_result&ct=result&resnum=6&ved=0CFAQ6AEwBQ#v=onepage&q=paint%20formulation%20process&f=false ; date accessed [Apr 25 2011] Acknowledgements Sincere thanks to our supervisors Dr. Bruce Alexander & Dr. VivekTrivedifor extended support and guidance and to all colleagues of MSc. Formulation Science group . www.gre.ac.uk