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Plant design of inorganic zinc silicate paint 2014
A PROJECT REPORT ON
PLANT DESIGN OF INORGANIC ZINC
SILICATE PAINT
Submi...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 ii
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 iii
ABSTRACT
Successful synthesis of nanocr...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 iv
ACKNOWLEDGEMENT
It gives me a great plea...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 v
VISHWAKARMA INSTITUTE OF TECHNOLOGY
(An A...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 vi
Page
Abstract iii
Acknowledgements iv
Ce...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 vii
Chapter 1
INTRODUCTION
The zinc silicat...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 viii
1.1 PHYSICAL PROPERTIES OF INORGANIC Z...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 ix
1.2 Chemical properties of inorganic zin...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 x
1.2.1 Curing mechanism
These coatings cur...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xi
1.2.4 Mud Cracking
Mud cracking (Diagram...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xii
1.3 Methodology
Zinc silicate (Zn2SiO4)...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xiii
2 Zn(OH)2(s) + SiO2(s) Zn2SiO4 + H2O ...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xiv
1.4 ADVANTAGES AND DISADVANTAGES OF ZIN...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xv
1.5APPLICATIONS OF ZINC SILICATE PRIMERS...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xvi
1.5.2 Objects: New constructions / Main...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xvii
Chapter 2
Literature survey
2.1 Histor...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xviii
A still extant example of 17th-centur...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xix
In simple commercial context, the first...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xx
In contrast with the sales figures befor...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxi
2.2 components:
2.2.1 Binder, vehicle, ...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxii
The paint type known as Emulsion in th...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxiii
2.2.2 Diluent or Solvent
The main pur...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxiv
Hiding pigments, in making paint opaqu...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxv
like. Additives normally do not signifi...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxvi
Rollers generally have a handle that a...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxvii
Cracking
Cracking of paint film is du...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxviii
2.5 Dangers
Volatile organic compoun...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxix
2.6 Indian paint industry
2.6.1 Brief ...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxx
2.6.3 Total contribution to the economy...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxxi
 Indian per capita consumption of pai...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxxii
Chapter 3
Objectives and future plans...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxxiii
REFERENCES
[1] Alavi, S., Dexpert-Gh...
Plant design of inorganic zinc silicate paint 2014
Chemical Engineering – 2014 xxxiv
[7] Mai, M., Feldmann, & Claus. (2009...
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Plant design of inorganic zinc silicate paint (project report part 1)

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Plant design of inorganic zinc silicate paint (project report part 1)

  1. 1. Plant design of inorganic zinc silicate paint 2014 A PROJECT REPORT ON PLANT DESIGN OF INORGANIC ZINC SILICATE PAINT Submitted to the University of Pune, Pune in Partial Fulfillment of the Requirements For the Award of the Degree of BACHELOR OF ENGINEERING (CHEMICAL) BY Gajanan R. Hange (Gr. No. 111251) Pawan V. Jamadar (Gr. No.111330) Sandeep R. Bhagat (Gr. No. 111020) Department of Chemical Engineering BRACT’S Vishwakarma Institute of Technology, 666, Upper Indiranagar, Bibwewadi, Pune – 411 037
  2. 2. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 ii
  3. 3. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 iii ABSTRACT Successful synthesis of nanocrystalline Zn2SiO4 powders using solid state reaction of the ZnO powder precipitate and amorphous cristobalite SiO2 powders from processed rice hull ash at 800≤T≤1000oC is presented in this study. ZnO powders were grown by chemically reacting stoichiometric NaOH and ZnSO4. The solid state reacted powders were characterized using scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDX), Fourier transform Spectroscopy (FTIR) and x-ray diffraction (XRD). Microscopic analyses of the Annealed powders were consistent with reported morphological structures of Zn2SiO4. FTIR results indicate the presence of ZnO4 and SiO4 groups corresponding to Zn2SiO4. XRD results further revealed that Zn2SiO4 powders were synthesized at the reaction temperatures of 900 and 1000oC with onset growth at 800oC. The method used in this study shows that Zn2SiO4 can be grown at a much lower temperature (800≤T≤1000oC) compared to the reported temperature of synthesizing Zn2SiO4 through solid-state reaction. The Zn2SiO4powders exhibit dominant a-axis orientation and the average crystallite size for zinc silicate powders annealed at 1000oC is about 33 nm. The results suggest that the Zn2SiO4 powders are promising materials for phosphor applications. Using SiO2 from RHA in the synthesis of ZnSiO4 increases the value of rice hulls and as a result becomes beneficial to rice farmers and that RHA collection and utilization policies has to be incorporated in local governments.
  4. 4. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 iv ACKNOWLEDGEMENT It gives me a great pleasure to find an opportunity to express our deep and sincere gratitude to all those who have been directly or indirectly related to this project I specially thank our internal guide Prof. A. R. Gangwal for his tremendous support, timely guidance and for sharing his experience and knowledge, for the valuable direction that keeps us going and inspires to perform better Also, I cannot overlook the fact that without the support of our Head of Department Prof. Dr. D. S. Bhatkhande our work would not have been accomplished in its entirety Last but not the least we would like to convey our heartiest thanks to all our friends who time to time have helped us with their valuable suggestion during our project report SANDEEP BHAGAT GAJANAN HANGE PAWAN JAMADAR Bansilal Ramnath Agarwal Charitable Trust’s
  5. 5. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 v VISHWAKARMA INSTITUTE OF TECHNOLOGY (An Autonomous Institute Affiliated to University of Pune) 666, Upper Indiranagar, Bibwewadi, Pune – 411 037 APRIL 2014 CERTIFICATE It is certified that the project work entitled “PLANT DESIGN OF INORGANIC ZINC SILICATE PAINT” Submitted by Gajanan R. Hange Gr. No. 111251 Roll No.22 Pawan V. Jamadar Gr. No. 111330 Roll No.23 Sandeep R. Bhagat Gr. No. 111020 Roll No.06 is the original work carried out by them under the supervision of Mr.Prof. A. R. Gangwal and is approved for the partial fulfilment of the requirement of University of Pune, Pune for the award of the Degree of Bachelor of Engineering (Chemical) This Project Work has not been earlier submitted to any other Institute or University for the award of any degree or diploma. (Prof. A. R. Gangwal) (Prof. Dr. D. S. Bhatkhande) Guide, Head, Department of Chemical Department of Chemical Engineering Engineering TABLE OF CONTENTS
  6. 6. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 vi Page Abstract iii Acknowledgements iv Certificate v Table of Contents vi List of figures vii Chapter 1 INTRODUCTION 1 1.1 Physical properties of inorganic zinc silicate paint 2 1.2 Chemical properties of inorganic zinc silicate paint 1.2.1 Curing mechanism 1.2.2 Film cure 1.2.3 Bubbling/Pinholes 1.2.4 Mud cracking 3 4 4 5 1.3 Methodology 6 1.4 1.5 Advantages and disadvantages of inorganic zinc silicate Paint Applications of zinc silicate paint 1.5.1 Segments 1.5.2 Objects 8 9 9 10 Chapter 2 LITERATURE SURVEY 11 2.1 History of paint science and technology 11 2.2 Components 14 2.2.1 Binder, vehicle, or resins 14 2.2.2 Diluent or Solvent 15 2.2.3 Pigment and Filler 16 2.2.4 Additives 17 2.3 2.4 2.5 2.6 Application of paint Failure of paint Dangers Indian paint industry 2.6.1 Brief Introduction 2.6.2 Size of the Industry 2.6.3 Total contribution to the economy/ sales 2.6.4 Top leading Companies 2.6.5 Latest Development 18 19 21 22 22 22 23 23 23
  7. 7. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 vii Chapter 1 INTRODUCTION The zinc silicate primer has to it’s the name the promise of perfection for the long run. It is useful in highly corrosive areas like chemical factories and refineries etc. Zinc is a self sacrificial metal its gives full protection to the metal. Although inorganic coatings can be formulated with a variety of inorganic binders, they are generally made from polymers based on silicon chemistry. By the combination of metallic zinc powder and silicate binders, inorganic zinc silicate primers have been formulated. Since their introduction and use in the first part of this century, zinc silicates have been recognized as the most effective corrosion resistant primers in the protective industry. Inorganic topcoats are predominantly formulated with silicon based binders, such as silicone resins, water and solvent based silicates, silanes and mixtures of organic binders with silicate binders. Traditionally, long term corrosion protection has been obtained with inorganic zinc silicates. This is achieved by a combination of the cathodic protection properties of metallic zinc and the inert polymer matrix of the inorganic polysilicate binder. The polymeric structure of the silicate binder, which surrounds the metallic zinc as a matrix, is represented as a dense cross-linked inorganic polymer structure of - Si - O - Si - chains. The resulting inorganic zinc silicate coatings provide excellent resistance to numerous corrosive exposure environments. They exhibit excellent corrosion protection and adhesion to the metal substrate, inhibiting under-cutting and rust migration under the film.
  8. 8. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 viii 1.1 PHYSICAL PROPERTIES OF INORGANIC ZINC SILICATE PAINT  Inorganic zinc silicate act as an anticorrosive primer for protection of steel .  Inorganic zinc silicate paint is resistant to dry heat up to 4500 C .  Solid content by volume in inorganic zinc silicate paint is 69% .  Recommended dry film thickness for Inorganic zinc silicate coatings is u to 75microns  Estimated spreading rate of inorganic zinc silicate paint is up t the 9.2 sq m/l  One of the most important property of inorganic zinc silicate coating is that it gives cathodic protection to the metal  The paint is very sensible to application condition .  Drying time for top coating is about 24hrs.  Zinc rich coatings are abrasion resistant and rock hard
  9. 9. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 ix 1.2 Chemical properties of inorganic zinc silicate primer Inorganic zinc rich coatings afford superb corrosion resistance, they are also rock hard and very abrasion-resistant. They make some of the best anti-corrosive primers available. Ethyl silicate based inorganic zincs (Galvit ES600 & Galvit ES510) should be applied at 75 microns (dft). Because they have a tendency to grip unlike most other coatings, they may be applied to the faying surfaces of bolted steel joints. Inorganic zinc-rich primers have excellent resistance to temperatures up to the melting point of zinc (above 400oC). Inorganic zincs should not be exposed to acids and alkalis. However, their resistance to organic solvents and organic chemicals is excellent. The term “zinc-rich” refers to the percent by weight of metallic zinc in the cured coating film, which may range from 50% to 90%. The film is a hard, adherent coating composed of metallic zinc powder suspended in a silicate matrix Fig no 1.1 Zinc particles embedded in a silicate matrix
  10. 10. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 x 1.2.1 Curing mechanism These coatings cure by hydrolysis or reaction with moisture following the evaporation of solvent. These coatings are typically resistant to rain showers in one hour or less. High humidity conditions usually accelerate the cure of ethyl silicates. When the relative humidity is less than 40%, water may be sprayed on the coating surface to complete the curing process. 1.2.2 Film cure To determine if a film has cured a clean cloth soaked in methyl ethyl ketone (MEK) is rubbed over the coating. A properly cured film should have no zinc transfer onto the cloth. 1.2.3 Bubbling/Pinholes The zinc silicate matrix film is quite porous, which can result in bubbling or pinholes when a subsequent coating is applied. To overcome bubbling and/or pinholes excessive film builds and overspray should be avoided and/or removed prior to topcoating. For best control over the spray application conventional spray is preferred over airless equipment. When topcoating, apply a mist/tack coat of suitable product, thinned approximately 25% to seal off the zinc prior to application of a full coat.
  11. 11. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xi 1.2.4 Mud Cracking Mud cracking (Diagram 1.2) can occur due to a number of reasons, these include: Low blast profiles Excessive film build Poor ambient drying conditions Old Product Insufficient ventilation, which is pronounced in concave corners and cavities Fig 1.2 mud cracking
  12. 12. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xii 1.3 Methodology Zinc silicate (Zn2SiO4) is synthesized using equimolar concentrations of zinc sulphate (ZnSO4) and sodium hydroxide (NaOH) producing zinc hydroxide (Zn(OH)2). The addition of strong electrolyte (ZnSO4) and strong base (NaOH) in an aqueous solution results to the exchange of ions. The formation Zn(OH)2 and Na2SO4 is the product of ion exchange. Zn(OH)2 is insoluble in water thus it remains as solid in an aqueous solution. On the other hand, Na2SO4 is soluble in water hence it is in liquid phase. The reaction proceeds as follows ZnSO4 (aq) + 2NaOH (aq )  Zn(OH)2(s) + Na2SO4(l). The resulting solution is filtered and washed with distilled water. The precipitate is mixed with appropriate amount of silicon dioxide (SiO2) in water with constant stirring at an elevated temperature of 80o C. Neither Zn(OH)2 and SiO2 are soluble in water. Thus, no chemical reaction is expected in the mixing of Zn(OH)2 and SiO2. However, the water is used as an amalgamation medium to promote the adhesion of Zn(OH)2 particles on the surface of SiO2 creating a nucleation site where Zn(OH)2 particles coat SiO2. The reaction mechanism for this process is Zn(OH)2(s) + SiO2(s)  Zn(OH)2(s) + SiO2(s) + H2O(g). The precipitate is washed with distilled water and dried at 100o C. The dried precipitate is annealed at 800, 900 and 1000o C. Solid-solid diffusion is expected to occur at these temperatures. The mixing stage promote the adhesion of smaller particle Zn(OH)2 to the surface of SiO2 allowing the formation of Zn2SiO4 at lower temperature. Thus, the powders annealed at 800To 1000o C are expected to contain Zn2SiO4 following the process
  13. 13. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xiii 2 Zn(OH)2(s) + SiO2(s) Zn2SiO4 + H2O (g). The resulting powders are characterized using scanning electron microscopy (SEM) equipped with energy dispersive x-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD).
  14. 14. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xiv 1.4 ADVANTAGES AND DISADVANTAGES OF ZINC SILICATE PRIMER Some important advantages and disadvantages of inorganic zinc silicate paint are listed below. These factors are to be considered while its application to the industrial and on household equipments 1.4.1 ADVANTAGES OF ZINC SILICATE PRIMER  Inorganic zinc silicate paint primer are Very good corrosion protection  Inorganic zinc silicate paint primer are Very good solvent resistance  High heath resistance is offered by Inorganic zinc silicate paint primer (max 400o C)  Very high mechanical strength is the main advantage of Inorganic zinc silicate paint primer  Very good adhesion to blast cleaned steel is the useful property of Inorganic zinc silicate paint primer  Relatively good recoat ability is there for Inorganic zinc silicate paint primer 1.4.2 DISADVANTAGES OF ZINC SILICATE PRIMER  Alkyl enamels cannot be applied directly over Inorganic zinc silicate paint primer  Higher application skill required for the application of Inorganic zinc silicate paint primer  Inorganic zinc silicate paint primer takes long time to dry.  Inorganic zinc silicate paint primer recoat time is more.  Greater than recommended film thickness of Inorganic zinc silicate paint primer causes mud cracking
  15. 15. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xv 1.5APPLICATIONS OF ZINC SILICATE PRIMERS 1.5.1 Segments: 1) ships 2) offshore 3) Industry One of the most important application of Inorganic zinc silicate primer Is that it is used in marine areas where most of the equipments comes in to contact with corrosional substances. As zinc is the self sacrificial metal , it protects the equipments from corrosion . zinc provides the cathodic protection to the metal against the galvanic corrosion.
  16. 16. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xvi 1.5.2 Objects: New constructions / Maintenance Exterior and interior design , above and below water . Popular application of Inorganic zinc silicate primer is that it is used in building sections areas where most of the equipments comes in to contact with corrosional substances. As zinc is the self sacrificial metal , it protects the equipments from corrosion . zinc provides the cathodic protection to the metal against the galvanic corrosion. Inorganic zinc silicate paint have also found many applications in Maintenance Exterior and interior design.
  17. 17. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xvii Chapter 2 Literature survey 2.1 History of paint science and technology In 2011, South African archaeologists reported finding a 100,000-year- old human-made ochre-based mixture that could have been used like paint. Cave paintings drawn with red or yellow ochre, hematite, manganese oxide, and charcoal may have been made by early Homo sapiens as long as 40,000 years ago. Ancient colour walls at Dendera, Egypt, which were exposed for years to the elements, still possess their brilliant colour, as vivid as when they were painted about 2,000 years ago. The Egyptians mixed their colours with a gummy substance, and applied them separately from each other without any blending or mixture. They appear to have used six colours: white, black, blue, red, yellow, and green. They first covered the area entirely with white, then traced the design in black, leaving out the lights of the ground colour. They used minium for red, and generally of a dark tinge Pliny mentions some painted ceilings in his day in the town of Ardea, which had been done prior to the foundation of Rome. He expresses great surprise and admiration at their freshness, after the lapse of so many centuries. Paint was made with the yolk of eggs and therefore, the substance would harden and adhere to the surface it was applied to. Pigment was made from plants, sand, and different soils. Most paints used either oil or water as a base (the dilutant, solvent or vehicle for the pigment).
  18. 18. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xviii A still extant example of 17th-century house oil painting is Ham House in Surrey, England, where a primer was used along with several undercoats and an elaborate decorative overcoat; the pigment and oil mixture would have been ground into a paste with a mortar and pestle. The process was done by hand by the painters and exposed them to lead poisoning due to the white-lead powder. In 1718, Marshall Smith invented a "Machine or Engine for the Grinding of Colours" in England. It is not known precisely how it operated, but it was a device that increased the efficiency of pigment grinding dramatically. Soon, a company called Emerton and Manby was advertising exceptionally low-priced paints that had been ground with labour-saving technology:
  19. 19. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xix In simple commercial context, the first graph below shows how, in the US at least (from Census Bureau data), the paint industry continues to be important and grows with the economy and suffers with the economy. In fact, as long as one needs to control the appearance of useful or amusing things, or they need protection, we will always need paint. Even modern nano- or bio-materials are more often employed as coatings than any thing else
  20. 20. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xx In contrast with the sales figures before, the graph below places the rise of paint technology in the context of some of the external influences The last graph labels the rise in paint technology with events that were important from the point of view of alkyd paint
  21. 21. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxi 2.2 components: 2.2.1 Binder, vehicle, or resins The binder, commonly called the vehicle, is the film-forming component of paint. It is the only component that must be present. Components listed below are included optionally, depending on the desired properties of the cured film. The binder imparts adhesion and strongly influences properties such as gloss, durability, flexibility, and toughness. Binders include synthetic or natural resins such as alkyds, acrylics, vinyl- acrylics, vinyl acetate/ethylene (VAE), polyurethanes, polyesters, melamine resins, epoxy, or oils. Binders can be categorized according to the mechanisms for drying or curing. Although drying may refer to evaporation of the solvent or thinner, it usually refers to oxidative cross-linking of the binders and is indistinguishable from curing. Some paints form by solvent evaporation only, but most rely on cross-linking processes. Paints that dry by solvent evaporation and contain the solid binder dissolved in a solvent are known as lacquers. A solid film forms when the solvent evaporates, and because the film can re-dissolve in solvent, lacquers are unsuitable for applications where chemical resistance is important. Classic nitrocellulose lacquers fall into this category, as do non-grain raising stains composed of dyes dissolved in solvent and more modern acrylic-based coatings such as 5-ball Krylon aerosol. Performance varies by formulation, but lacquers generally tend to have better UV resistance and lower corrosion resistance than comparable systems that cure by polymerization or coalescence.
  22. 22. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxii The paint type known as Emulsion in the UK and Latex in the USA is a water-borne dispersion of sub-micrometer polymer particles. These terms in their respective countries cover all paints that use synthetic polymers such as acrylic, vinyl acrylic (PVA), styrene acrylic, etc. as binders. The term "latex" in the context of paint in the USA simply means an aqueous dispersion; latex rubber from the rubber tree is not an ingredient. These dispersions are prepared by emulsion polymerization. Such paints cure by a process called coalescence where first the water, and then the trace, or coalescing, solvent, evaporate and draw together and soften the binder particles and fuse them together into irreversibly bound networked structures, so that the paint cannot redissolve in the solvent/water that originally carried it. The residual surfactants in paint, as well as hydrolytic effects with some polymers cause the paint to remain susceptible to softening and, over time, degradation by water. The general term of latex paint is usually used in the USA, while the term emulsion paint is used for the same products in the UK and the term latex paint is not used at all. Paints that cure by oxidative cross linking are generally single package coatings. When applied, the exposure to oxygen in the air starts a process that cross links and polymerizes the binder component. Classic alkyd enamels would fall into this category. Oxidative cure coatings are catalysed by metal complex driers such as cobalt naphthenes. Paints that cure by polymerization are generally one or two package coatings that polymerize by way of a chemical reaction, and cure into a cross linked film. Depending on composition they may need to dry first, by evaporation of solvent. Classic two package epoxies or polyurethanes would fall into this category.
  23. 23. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxiii 2.2.2 Diluent or Solvent The main purposes of the diluent are to dissolve the polymer and adjust the viscosity of the paint. It is volatile and does not become part of the paint film. It also controls flow and application properties, and in some cases can affect the stability of the paint while in liquid state. Its main function is as the carrier for the non volatile components. To spread heavier oils (for example, linseed) as in oil-based interior house paint, thinner oil is required. These volatile substances impart their properties temporarily—once the solvent has evaporated, the remaining paint is fixed to the surface. This component is optional: some paints have no diluent. Water is the main diluent for water-borne paints, even the co- solvent types. Solvent-borne, also called oil-based, paints can have various combinations of organic solvents as the diluent, including aliphatics, aromatics, alcohols, ketones and white spirit. Specific examples are organic solvents such as petroleum distillate, esters, glycol ethers, and the like. Sometimes volatile low- molecular weight synthetic resins also serve as diluents. 2.2.3 Pigment and Filler Pigments are granular solids incorporated in the paint to contribute colour. Fillers are granular solids incorporate to impart toughness, texture, give the paint special properties, or to reduce the cost of the paint. Alternatively, some paints contain dyes instead of or in combination with pigments. Pigments can be classified as either natural or synthetic. Natural pigments include various clays, calcium carbonate, mica, silica’s, and talcs. Synthetics would include engineered molecules, calcined clays, blanc fixes, precipitated calcium carbonate, and synthetic pyrogenic silica.
  24. 24. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxiv Hiding pigments, in making paint opaque, also protect the substrate from the harmful effects of ultraviolet light. Hiding pigments include titanium dioxide, phthalo blue, red iron oxide, and many others. Fillers are a special type of pigment that serve to thicken the film, support its structure and increase the volume of the paint. Fillers are usually cheap and inert materials, such as diatomaceous earth, talc, lime, barytes, clay, etc. Floor paints that must resist abrasion may contain fine quartz sand as a filler. Not all paints include fillers. On the other hand, some paints contain large proportions of pigment/filler and binder. Some pigments are toxic, such as the lead pigments that are used in lead paint. Paint manufacturers began replacing white lead pigments with titanium white (titanium dioxide), before lead was banned in paint for residential use in 1978 by the US Consumer Product Safety Commission. The titanium dioxide used in most paints today is often coated with silica/alumina/zirconium for various reasons, such as better exterior durability, or better hiding performance (opacity) promoted by more optimal spacing within the paint film. 2.2.4 Additives Besides the three main categories of ingredients, paint can have a wide variety of miscellaneous additives, which are usually added in small amounts, yet provide a significant effect on the product. Some examples include additives to modify surface tension, improve flow properties, improve the finished appearance, increase wet edge, improve pigment stability, impart antifreeze properties, control foaming, control skinning, etc. Other types of additives include catalysts, thickeners, stabilizers, emulsifiers, texturizers, adhesion promoters, UV stabilizers, flatteners (de-glossing agents), biocides to fight bacterial growth, and the
  25. 25. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxv like. Additives normally do not significantly alter the percentages of individual components in a formulation. 2.3 Application of paint Paint can be applied as a solid, a gaseous suspension (aerosol) or a liquid. Techniques vary depending on the practical or artistic results desired. As a solid (usually used in industrial and automotive applications), the paint is applied as a very fine powder, and then baked at high temperature. This melts the powder and causes it to adhere to the surface. The reasons for doing this involve the chemistries of the paint, the surface itself, and perhaps even the chemistry of the substrate (the object being painted). This is called "powder coating" an object. As a gas or as a gaseous suspension, the paint is suspended in solid or liquid form in a gas that is sprayed on an object. The paint sticks to the object. This is called "spray painting" an object. The reasons for doing this include: 1) The application mechanism is air and thus no solid object touches the object being painted; 2) The distribution of the paint is uniform, so there are no sharp lines; 3) It is possible to deliver very small amounts of paint; 4) A chemical (typically a solvent) can be sprayed along with the paint to dissolve together both the delivered paint and the chemicals on the surface of the object being painted; 5) Some chemical reactions in paint involve the orientation of the paint molecules. In the liquid application, paint can be applied by direct application using brushes, paint rollers, blades, other instruments, or body parts such as fingers and thumbs.
  26. 26. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxvi Rollers generally have a handle that allows for different lengths of poles to be attached, allowing painting at different heights. Generally, roller application requires two coats for even colour. 2.4 Failure of paint The main reasons of paint failure after application on surface are the applicator and improper treatment of surface. Application Defects can be attributed to: Dilution This usually occurs when the dilution of the paint is not done as per manufacturer’s recommendation. There can be a case of over dilution and under dilution, as well as dilution with the incorrect diluent. Contamination Foreign contaminants added without the manufacturers consent can cause various film defects. Peeling/Blistering Most commonly due to improper surface treatment before application and inherent moisture/dampness being present in the substrate. Chalking Chalking is the progressive powdering of the paint film on the painted surface. The primary reason for the problem is polymer degradation of the paint matrix due to exposure of UV radiation in sunshine and condensation from dew. The degree of chalking varies as epoxies react quickly while acrylics and polyurethanes can remain unchanged for long periods. The degree of chalking can be assessed according to International Standard ISO 4628 Part 6 or 7 or American Society of Testing and Materials(ASTM) Method D4214 (Standard Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films).
  27. 27. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxvii Cracking Cracking of paint film is due to the unequal expansion or contraction of paint coats. It usually happens when the coats of the paint are not allowed to cure/dry completely before the next coat is applied. The degree of cracking can be assessed according to International Standard ISO 4628 Part 4 or ASTM Method D661 (Standard Test Method for Evaluating Degree of Cracking of Exterior Paints). Erosion Erosion is very quick chalking. It occurs due to external agents like air, water etc. It can be evaluated using ASTM Method ASTM D662 (Standard Test Method for Evaluating Degree of Erosion of Exterior Paints). Blistering Blistering is due to improper surface exposure of paint to strong sunshine. The degree of blistering can be assessed according to ISO 4628 Part 2 or ASTM Method D714 (Standard Test Method for Evaluating Degree of Blistering of Paints). Degradation The fungi Aureobasidium pullulans consumes wall paints.
  28. 28. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxviii 2.5 Dangers Volatile organic compounds (VOCs) in paint are considered harmful to the environment and especially for people who work with them on a regular basis. Exposure to VOCs has been related to organic solvent syndrome, although this relation has been somewhat controversial In the US, environmental regulations, consumer demand, and advances in technology led to the development of low-VOC and zero-VOC paints and finishes. These new paints are widely available and meet or exceed the old high-VOC products in performance and cost-effectiveness while having significantly less impact on human and environmental health.
  29. 29. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxix 2.6 Indian paint industry 2.6.1 Brief Introduction There is a phenomenal growth on the housing sector front with rapid urbanization and availability of easy to secure housing loans which have become the prime drivers of growth in the decorative paint segment, which comprises 70% of the $2 billion Indian Paint industry. An average increase of growth of about 10% in the automobile sector contributes to 50% of the revenues in the industrial paints segment. Paints can be classified as Decorative Paints & Industrial Paints. Decorative Paints are usually meant for the housing sector. Distemper is mostly affordable by all and used in the suburban and rural markets. Interestingly, 20% of all decorative paints in India are distempers. Indian Paint products are highly in demand in countries of United States, China, India, United Kingdom, Australia, Pakistan, Hong Kong, Canada, etc forming the turning points in the Paint Industry of India. 2.6.2 Size of the Industry A large number of Paint outlet or shops have automated/manual dealer tinting systems. Today India has more than 20,000 outlets in operation, probably the highest for any country. There are only approximately 7,000 tinting systems in China for a market two and half times of India's size. 30% to the paint industry revenue in India is accumulated from Industrial Paints. The size of the Paint Indian industry is around 940 million litres and is valued at approximately $2 billion. The organized sector comprises 54% of the total volume and 65% of the value. In the last ten years, the Indian Paint Industry has grown at a compounded annual growth rate (CAGR) of 12-13%.
  30. 30. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxx 2.6.3 Total contribution to the economy/ sales The market for paints in India is expected to grow at 1.5 times to 2 times GDP growth rate in the next five years. With GDP growth expected to be over and above 7% levels, the top three players are likely to clock above industry growth rates. There are high volumes of low cost distempers sold in India, which amounts to approximately 200,000 tons per annum at an average cost of Rs35 per kg ($0.88) at the present rate. 2.6.4 Top leading Companies  Asian Paints India  Nerolac India Paints  Berger  Dulux India Paints  Shalimar Paints 2.6.5 Latest Development  Indian Paint Industry today is about Rs 49 billion sector which has demands for paints which is relatively price-elastic but is linked to the industrial and economical growth.
  31. 31. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxxi  Indian per capita consumption of paints is at 0.5 kg per annum if compared with 4 kgs in the South East Asian nations and 22 kgs in developed countries.  Organized sector in India controls 70% of the total market with the remaining 30% being in the hands of nearly 2000 small-scale units.  In India 30% accounts for the industrial paint segment in paint Industry while the decorative paint segment accounts for 70 % of paints sold in India. Globally, Indian Industrial Paints segment accounts for a major share which indicates that this segment offers many opportunities for paint manufacturers. In June 2009 with a recovery in realty sector, the production volumes in the sector have substantially recovered. In the year 2009-2010 the Production of paints grew by a robust 25.2% during as compared to a 40 basis points drop in production in the corresponding year-ago period. As the production of passenger cars is expected to grow by 15.3% in 2010-11 the demand for automotive paints will continue to remain healthy as sales are expected to grow in double-digits. And with realty majors launching new projects, construction activity is expected to gain momentum and generate demand for decorative paints. Rise in demand is expected to be supported by higher supply as the industry is expected to commission additional capacity in 2010-11.
  32. 32. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxxii Chapter 3 Objectives and future plans  Process Flow Diagram.  Material and Energy Balance  Detail Equipment Design.  Piping and Instrumentation Diagram.  Plant Layout.  Costing and Economics.  Safety and Environmental Studies.
  33. 33. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxxiii REFERENCES [1] Alavi, S., Dexpert-Ghys, J., & Caussat, B. (2008). High temperature annealing of micrometric Zn2SiO4:Mn phosphor powders in fluidized bed. Materials Research Bulletin, 43, 2751-2762 [2] Catoire, L. & Naudet, V. (2004), A Unique Equation to Estimate Flash Points of Selected Pure Liquids Application to the Correction of Probably Erroneous Flash Point Values. Journal of Physical and Chemical Reference Data, 33, 1083-1111 [3] Chakradhar, R. S., Nagabhushana, B. M., Chandrappa, G. T., Ramesh, K. P., & Rao, J. L. (2004). Solution combustion derived nanocrystalline Zn2SiO4:Mn phosphors: A spectroscopic view. Journal of Chemical Physics, 121, 1025010259 El Mir, L., Amlouk, A., Barthou, C., & Alaya, S. (2007). [4] Synthesis and luminescence properties of ZnO/Zn2SiO4 /SiO2 composite based on nanosized zinc oxide- fi . : Condensed Matter, 68, 412417 [5] Inoue, Y., Toyoda, T., & Morimoto, J. (2008). Photoacoustic spectra on Mn-doped zinc silicate powders by evacuated sealed silica tube method. Journal of Materials Science, 43, 378-383 [6] Lee, B. I., & Lua, S. W. (2000). Synthesis of nanoparticles via surface modification for electronic applications. Journal of Ceramic Processing Research, 1 (1), 20-26
  34. 34. Plant design of inorganic zinc silicate paint 2014 Chemical Engineering – 2014 xxxiv [7] Mai, M., Feldmann, & Claus. (2009). Two-color emission of Zn2SiO4:Mn from ionic liquid mediated synthesis. Solid State Sciences, 11, 528-532 [8] Natarajan, V., Murthy, K., & Kumar, M. J. (2005). Photoluminescence investigations of Zn2SiO4 co-doped with Eu3+and Tb3+ ions. Solid State Communications, 134, 261-264 [9] Takesue, M., Hayashi, H., & Smith, R. L. (2009). Thermal and chemical methods for producing zinc silicate (willemite): A review. Progress in Crystal Growth and Characterization of Materials, 55, 98-124 [10 ] Tani, T., Takatori, K., & Pratsinis, S. E. (2004). Evolution of the Morphology of Zinc Oxide/Silica Particles by Spray Combustion. Journal of the American Ceramic Society, 87, 365-370

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