Blown Film and Radon

I attended a company sales meeting this past weekend. One of the vendors that spoke was Raven Industries. We sell their construction films. I learned about the blown film extrusion process of making plastic films. I have never heard of this process before and since I am an infinitely curious person, I wanted to find out more. I am not in the plastic film industry, so, if you read this and are, please excuse my ignorance. Basically, as I understand it, the plastic pellets get heated and go through a dye where air is blown out to help cool the film. It goes straight up in the air to the top and it is slit or folded and is sent back down through the rollers. It seemed really interesting to me. Raven Industries has an animated video of their process. I wanted to find a video of the process on the Internet and I found one that looks like it makes clear pallet bags. Click here if you would like to see the video. I was really hoping the video would show every facet of the process and with some sort of neat camera angle that could show the middle of the blown film, but no such luck. It was still interesting anyway. There is another way to make plastic film and I understand it is called cast film.

One of the products discussed was the Raven VaporBlock Plus. It is an underslab vapor retarder and gas barrier. Radon is a gas. As I understand it, the Vapor Block Plus 20 helps reduce the amount of Radon gas. If you read the data sheet on page 2 note 5, it states, "When VaporBlock Plus gas barrier is used as a part of an active control system for radon gas, a ventilation system will be required. When installed as a passive system, it is still recommended to include a ventilation system that could be converted to an active system later." I knew that radon had become a bigger issue over the past few years. I still know very little about it, but the EPA has some information about the radon gas issue. On http://www.radon.com/ , there is a map where you can check the radon levels by state. It is interesting to look over.