1 / 27

Product development for green productivity a case study Development of algae resistant surface coating for building fac

Product development for green productivity a case study Development of algae resistant surface coating for building facades in the humid tropics. 2 nd APO World Conference on GP Manila 9-12 Dec 2002 LOH Wah Sing Institute of High Performance Computing Singapore. Outline of presentation.

nemo
Download Presentation

Product development for green productivity a case study Development of algae resistant surface coating for building fac

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Product development for green productivity a case studyDevelopment of algae resistant surface coating for building facades in the humid tropics 2nd APO World Conference on GP Manila 9-12 Dec 2002 LOH Wah Sing Institute of High Performance Computing Singapore

  2. Outline of presentation • Paint failure on painted building facades with respect to microbial fouling – site survey - pattern of fouling - algae vs. fungus • Causes of paint failure • Climate of tropics vs. sub-tropics • New paint quality attributes + environmental consideration • Screening of algal resistance in field • Full field test • New product standardisation • Implication of project to green productivity

  3. About Singapore • Urban island nation near the equator • Area : 660 sq km • Population : 4 million; 6000 people/sq km • 860,000 public apartments (Ave 70 sqm/unit) housing 3 million population • Mass construction of public housing by Housing and Development Board started from early 1960s

  4. General microbial fouling on building facades

  5. Finishing on building facades • Paint finish widely used on residential buildings • Problem of unsightly disfigurement of paint by microbial fouling became serious from 1970s • Microbial fouling on facades was caused by algae, not by fungus – latter advocated by paint manufacturers • Main fouling algal species : Trentepohlia odorata • Conventional emulsion paint short lived – 3 yrs • Frequent repainting caused social disruption for urban living • HDB tried solvent-based paint for repainting fobs from early 1980s – emission of 900 tons of solvent per year

  6. Fouling on porous surface (right)

  7. Microbial growth along cracks

  8. Algae - Growth on both inorganic and organic substrate - Photosynthesis capability, presence of chlorophyll Fungus - Live on organic substrate as source of food

  9. Causes of paint failure • Climatic stress – temperature, humidity, rainfall, UV radiation • Detailing of buildings – consider tropical features? • Quality of substrate – porosity • Quality of paint • Painting specification • Painting workmanship

  10. Climate - Singapore vs. MiamiSingapore: 103 oE, 1 oNMiami : 80 oW, 26 oN

  11. Climate - Singapore vs. MiamiSingapore: 103 oE, 1 oNMiami : 80 oW, 26 oN

  12. Climate - Singapore vs. MiamiSingapore: 103 oE, 1 oNMiami : 80 oW, 26 oN

  13. Climate – solar radiation • A Davis & D Sims, “Weathering of polymers” (1983), Applied Science Publishers • L.R. Koller, “Ultraviolet radiation”(1965), Wiley • Total solar radiation shows maximum intensity at latitude 15 deg • Solar UV radiation shows * max intensity at equator, decreases with increasing latitude * max intensity at noon of day * max intensity in summer of year • Combination of UV and moisture (humidity) accelerates degradation (S.P. Pappas, “Weathering of coatings – formulation and evaluation” (1989), Prog in Organic Coatings, vol 17, No.2, pg89)

  14. Product development – attributes considered • Cost effectiveness • Service life of 6 years or more under humid tropical climate • Environmental consideration – water-based paint to be developed • Rule 66, smog, VOCs, fire & health hazards etc • Formulation for weather durability – binder/pigment ratio, type of binder, biocides, additives * High pigmentation level causes chalking/erosion * Binder susceptible to moisture and alkali will not last * Hygroscopic additives will affect moisture sensitivity of paint * Low pigmentation characterised by appearance of sheen on dry paint surface

  15. Weathering test – crack-present and crack-free quality

  16. Screening test against algal resistance at field

  17. Screening against algal resistance at field

  18. Field test on 8 buildings for 8 yrs; Example – Changi Telecoms Building

  19. Field test – algal growth on glass window due to condensation

  20. Product standardisation – for purchasing specification NR: not required

  21. Life cycle costing

  22. Impacts and benefits • Product commercialisation * 11(14) paint manufacturers in S’pore * Adopted in Brunei and Hong Kong • Changing marketing concept of paint * Partnership of paint manufacturers and painters * Sell paint (semi-product)  sell paintwork (finished product) • Cost effectiveness * Extended service life  longer repainting cycle * Life cycle costing  savings of S$2 million/year • Green productivity * Waste reduction  savings of labour (paint production and painting), scaffolding, water, paint materials, logistics and administration…. * VOCs elimination  savings of 900 tons solvent/year * Reduced ESH impact

  23. Thank you

More Related