Soft Coat Glass


Soft Coat Glass, otherwise known as vacuum coated or off-line coated glasses, are manufactured by a process which is entirely different from hard coat glass (discussed in last post). The name soft coat is given because of the susceptible nature of the coating to get peeled off (in single glazing/ monolithic application) when compared to hard coat. However, soft coat glasses can offer a very low solar factor when compared to hard coat glasses.

Manufacturing process involves metal particles being deposited on the glass surface inside a vacuum chamber. The process, otherwise known as Magnetron Sputtering Vapor Deposition (MSVD) is sometimes referred to as Cathodic Vapor Deposition. Some glass manufacturers mention it as CVD coating, just to create a confusion with actual Atmospheric Pressure Chemical Vapor Deposition, mis-interpret it and mis-sell it as hard coat.

During the process, the material to be sputtered is loaded in a high voltage electric circuit, which is followed by the feeding of process gas into vacuum chamber, where plasma is formed. An ion discharge takes place inside the chamber, these positive charged ions gets attracted and collide with the material to be sputtered. This process happens at a very high speed and atoms of the material sputtered gets ejected, which gets accumulated on the glass below. Most widely used metals for sputtering are Silver and Titanium.

Soft coat glasses are generally used in double glazed units, with the coated surface at position 2 or 3, so that the coating is kept protected from peeling off. With the advance in technology, soft coat glasses are now made which can also be used in monolithic form (single glazed) with much improved life for the coating, but still the life of the coating cannot match with that of hard coat glass in monolithic applications.

Soft coat glass also has problems while tempering when compared to hard coat glass. It tends to show up a problem called lensing, which happens because the coated surface of the glass reflects Infra Red radiation and heats up differently than the lower surface (which is heated).

 

Reference:

http://www.pilkington.com/the+americas/usa/english/building+products/for+architects/faqs/default.htm

http://glassmanual.com/article.php?aid=171

http://www.glassonweb.com/forum/view.php?mID=5397&gSearch=soft%20coat%20glass

http://arcon-glas.de/var/plain_site/storage/original/application/8276eb9e8f92e47dcb82f9da74472322.pdf

News on Glass & Refractory World, week# 08


° Jushi USA / Gibson Fiberglass announced to have developed ViPro™, a high strength, high modules fiber for reinforcement for composite applications with improved corrosion resistance and physical properties; this product will be fully marketed by end of Q1-2011 and is manufactured by Jushi Fiberglass, Tongxiang Economic Development Zone, Zhejiang, PRC. With three production bases in Tongxiang, Jiujiang, and Chengdu, they have a capacity for 900,000 TPY of fiberglass.

° Guardian Industries Corp. following extensive analysis and strategic planning announces plans to build a float glass manufacturing plant in Krasny Sulin (Rostov region), Russia, with 900 TPD capacity and downstream treatment facilities. The plant is expected to begin operations in mid 2012.

° Saint-Gobain SEFPRO has announced the forthcoming opening of its new manufacturing facility for sintered refractories at its existing production site, SEPR India, in Palakkad. The product range will include sillimanite, andalusite, mullite, high alumina, bonded AZS and zircon for the glass industry and will be made under Savoie Refractaires standards.

° Owens Corning announced that will sell its glass fiber reinforcements plant in Capivari, Brazil to China’s Chongqing Polycomp International Corp. Terms were not disclosed, but the sale is expected to close in Q2-2011. This will not affect OC’s ownership of its fiber reinforcements and fabrics facilities in Rio Claro, Brazil.

° Saudi Advanced Industries Company (SAIC) announced that has begun the float glass operation at its subsidiary Obeikan Glass Company. The plant is located at Yanbu el Bahr, Saudi Arabia, some 350 km north of Jeddah. When fully operational, the plant will produce 800 TPD, under Fives Stein technology.

° Resco of Pittsburgh, PN, on Jan. 20, has announced 2011 products prices increases from 5-15%, up to 20-25% for some specific item, mostly due to raw materials (bauxite, magnesite, graphite, dolomite, etc) price inflation but also freight and labor costs, not anymore absorbable through cost savings. Increases will become effective on March 1st.

Guardian expanding presence in Russia


http://www.prnewswire.com/news-releases/guardian-to-build-second-float-glass-plant-in-russia-116806968.html

News on Glass & Refractory World: week# 07


° Corning predicts for 2011 increased demand for special glass installed in tablet computers and smartphones, which employ scratch-resistant Gorilla Glass for touch screen devices. This will also drive increased utilization of platinum components used in these glasses specialties production.

° Cabot Corporation/US and China National Bluestar (Group) Corporation have initiated expansion of fumed silica production capacity Jiangxi Province, PRC. It will be a USD 43 million investment at Cabot Bluestar Chemical (Jiangxi) Co. Ltd. First phase will increase capacity from 5000 to 20000 TPY, second phase is aimed to a final 20000 TPY capacity.

° Guangdong Orient Zirconic Ind. Sci. and Tech. and DCM DECO Metal (DCM) won the approval of Australia authorities to jointly acquire Australia Zircon NL; in May 2010, the Chinese company announced it would invest 40 million Australian dollars to set up the joint venture with DCM, giving itself a 51-percent stake in the scheme to acquire all of Australia Zircon NL’s assets. This is a significant move to control Australian zircon sources, made by Chinese entities.

Hard Coated Reflective Glass


Espace rolin fortis, Brussels- Stopsol Silverlight

Hard coated or pyrolytic coated reflective glasses are those in which the coating is applied when the glass is manufactured,i.e. it is an online coating process. In this process of coating, the glass is fused into the glass at 650-700 degree celcius, and on cooling, the coating becomes a part of the glass.

Primary advantage of hard coated glass is the durability, it could also be handled like normal/annealed glass, could be easily heat strengthened, toughened, laminated or curved. These glasses could also be used in single glazing without any fear of losing the coating. Soft coat glasses (to be discussed in the next post) are susceptible to scratch and degradation over time, and requires special handling, hard coated glasses were invented just to counter this problem. Only disadvantage is the variety of colors available when compared to off line coating. Continue reading

What is a Green Building ?

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For all “Green-illiterates” (pardon my word usage)- A Green Building is not a green colored building, nor does it look different from any other building, then what is a green building?

A green building is basically distinguished with the approach, which involves the sincere care for the life of natural resources, providing human comfort, safety, as well as productivity. In a green building,

  • There would be minimum disturbance to the landscape and site condition.
  • Eco-friendly and recycled building materials are used.
  • Materials used are non-toxic and recyclable.
  • Equipments used are energy efficient and eco-friendly
  • Renewable energy is used

Even though the benefits of a green building are infinite, both tangible and intangible, an immediate tangible aspect could be readily observed once the green building starts operating, which is the significant reduction in operating cost and water costs (up to 40% savings !). Another tangible aspect would be the enhanced asset value. Intangible aspects would include increased productivity, health and safety, and much more.

Non-Solar Heat Control Glasses

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Solar and Non-solar heat transfer- IGU

In the previous post, types of heat entering a building was discussed, of which solar heat comprises around 80% and the rest is non-solar heat. It becomes very important to control non-solar heat as well even though it contribute to only 20% heat entering a building, especially in buildings where there is 24 x 7 operations and households, so as to bring down the energy consumption during night time. In this post, non-solar heat and how all to control it will be discussed in detail.

Non-solar heat is mainly transferred in three ways- conduction, convection and radiation, and is measured in terms of U-value (W/m2.K). Continue reading

Solar and Heat Control Glasses

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solar and non-solar heat

Glass is used in a building to harvest natural light inside it and there by reducing the internal artificial lighting requirements, in turn saving energy. The two major sources for heat entering the building is solar heat and non-solar heat; solar heat is nothing but the direct solar heat entering the building through visible light, non solar heat is caused by various factors like conduction, convection and radiation. Out of the heat sources, solar heat is the major one and requires more attention, even though the effects of non-solar heat could not be ignored as well, as it plays a major role in certain structures. Continue reading