Posted 21 May 2011 - 02:24 PM
I work for a Stained Glass manufacturer. I have been assigned a project seeking to be able to measure the thickness of the glass, flowing down a 300ft lehr, closer to our Hotend. Our glass flows from a furnace, down a forehearth, through a set of forming rolls, and down the lehr. Our glass thickness ranges from 0.500" down to 0.075". The hotend lehr zones are typically 990 deg F. Right now the way we measure the thickness of the glass is we wait for the glass to come out of the lehr, at the coldend, and cut a piece out and measure using a micrometer (the glass being around 30" wide and 300ft long, continous flow). If the glass is not in the target range then the coldend operators call it up to the hotend and they adjust. It takes around 15 min for the glass to get from the hotend to the coldend any adjustments made, that may or may not have been correct, will not be seen for another 15 min. Being able to measure the thickness of the glass closer to the hotend will greatly improve productivity and save the company time and money. Contact sensors don't seem to be the logical solution since roll wraps in our forming rolls or last glass from an end of a run will typically lose the flatness and could damage a contact sensor. I have been looking at displacement lasers to see if this is the avenue to go down. My concern is the temperture and reflectivity of the environment. I am asking if anyone out there has had any information I could use to find the best solution. Maybe some companies I could call to ask what they are using or if you know of a company marketing a device that I might wanna try. Thanks.