" Hi, I'm Steve Easley here at Bob Vila's EnergyWise House. And on this project, we're gonna be using some special windows with some special glass. This glass is specially selective [unk]. This glowy coating helps reduce heat gain through the glass from the sun, in fact, as much as 60%. Well, today, we get a rare opportunity to go to Guardian Glass, the maker of this glass and see how glasses made. I'm in Carleton Michigan at Guardian Glass and with me is Tim Singel who is the marketing manager for Guardian. Tim, how is this glass made and how are the coatings applied?"

" Well, the first step in the manufacturing process for glass is to bring all the raw materials together. Primary raw material to make glass is actually silica sand about 70% of the batch, which is referred to is actually sand. Once you bring that back up to about 3000 degrees, you can begin the process of mixing and flowing or floating down the manufacturing line. In order to keep the glass moving down the line, you have to introduce the glass or flow in onto a bed of molten tin, and we used tin because it provides a very pristine, contaminant-free environment for the glass to travel along until it becomes firm or rigid enough to resist out external contamination. Once you moved through the tin bath [unk] referred to, we start to begin gradually cooling the glass. The first technique that we used is actually to introduce water through long wand, metal wand that extends over the top of the glass. So, you're introducing cooling that way. Further down the line we used very heavy blowing technique, air blowing to cool the glass even further. Now, once you have cool the glass enough that you're in a position to begin cutting, you have to inspect before you cut and certainly you wanna make sure that you remove any potential defect from the process from the product before you cut it up and send it along its way. So, we used 2 techniques. The first thing is the human eye. It's a very effective tool for identifying defects in the glass, but we take it a bit further and introduce a laser vision system so that we can identify defect from the glass that might be smaller than human eye could pick up, but still meaningful enough to warrant removal. So, once it's marked defects, you then begin the cutting process. We can actually cut around defect on the ply. The first thing we have to do is score the glass vertically. We don't cut glass like you would use a saw. We have to use a scoring line then you bump the glass, it actually separate the pieces into the final unit of sale, but the horizontal scores [unk] because if the glass is moving you can't simply cut straight across or scores right across. You have to score on an angle that compensate to the movement of the glass. Once you've actually finished your cutting process, we have to remove the glass from the line. And again, this is a little bit tricky because it still continually moving. We used robotics to minimize the amount of human involvement. It minimize the potential certainly toward for accident, we wanna avoid that, but we also wanna make sure that we minimize the potential from any defects being introduce through the unload or packing process. So, we used robotics to remove the glass from the line. At that point, we're ready to move over to the offline coating operation. Well, to start the manufacturing process for coating, we introduced the glass to the manufacturing process through the use of automation. Glass then moves through a very aggressive washing process because pristine surface is very important to the durable applications of the coating. At that point, we moved into the coater where we applied the sequential layers of material that ultimately form below the coating. There are number of different layers that we put down. The primary operative layer is to"

" operation. Truly difficult to actually see what goes on inside of the vacuum chamber, but if you look inside, what you'd see is the effect of plasma beam created [unk] electricity as well as some deposition material or target material. So you introduce the electricity from the plasma environment any material falls down under the glass. Now, they don't just rain down on the glass. They actually go down in a very, very smooth continuous layer so you have full system integrity when the layer structure is finished"

" Now, we never have to really worry about differences in shades or colors because this is such a fine tune high tech process."

" That's a very important point. Color uniformity is really critical. Well, I said earlier that you really don't see much color when you look at it you certainly would see variations in that color so it's important and it's one of our primary quality control measures to make sure that we are laying down that you have extremely uniform layer of each material so that we have continuity in the appearance of the glass."

" So what happens after the glass comes out of the coater?"

" Well, after its comes out of the coater, we packed the glass onto rack using a separator kind of hard material to stop the glass from scratching while we pack it and ship it to a window manufacturer who then fabricate the window."

" Are there any issues associated with how that glass is handled? It seems to me like it looks like a more durable product than you might think."

" Well, it's actually similar in mechanical durability or scratch resistance the clear glass. There are techniques that can be utilized to improve that scratch resistant that we are always focused on as a company. But, it does fabricate in a very similar fashion to clear glass."

" Well, Tim thanks a lot for joining us. It was a fascinating process."

" My pleasure. Thanks for coming by"

" Glowy coatings on glass do a lot of things for us. They help make your home more comfortable, a lot more energy efficient, and can also help prevent fading of fabrics and furniture. Now if you're looking for windows, shopping for windows can be pretty easy if you just look for the NFRC label. This label has 2 important numbers on it. One is U-factor and the Solar Heat Gain coefficient. Always shop for a product has the U-factor of 0.4 or lower and a Solar Heat Gain coefficient of 0.4 or lower and you'll be getting a window that will make your home a lot more energy efficient and a lot more comfortable living."