Myths About PVC
I hear myths about PVC all the time. I have been in the industry for just over 20 years and have run across many different polymers, but none as flexible and diverse in use as PVC -- otherwise known as polyvinyl chloride. PVC was first discovered in the 1800’s, and then rediscovered and patented in 1913 by a German inventor Friedrich Heinrich August Klatt. BF Goodrich then worked on commercializing it in the 1920’s in order to replace the natural rubber in applications, primarily because of the rising prices of rubber. During WW2 it began to replace other materials, like wire insulation in military vehicles. It soon gained traction in other applications, such as a coating on fabrics for inflatables, and found new uses in transporting water in pipes and other products.
Myth Number 1: PVC and vinyl are not the same. This might be more of a misconception than a myth. But many people I speak with don’t know that vinyl and PVC are in fact one and the same. Many people think of PVC in only its rigid state. Which is understandable since at least 66% of all PVC produced in the world is used in PVC pipe applications. Other rigid type applications include vinyl siding, fencing and decking. But PVC can be made flexible as well. Applications for flexible PVC (vinyl) could be roofing, shower curtains, pond liners and upholstery.
I still recall, when I first got into this market place, the stories about Naugahyde that one of my mentors in the industry would tell me. Naugahyde® is a synthetic leather brand product produced by Uniroyal®. My mentor used to kid people about how many baby “Naugas” had to perish for that one couch to be produced.
There are very few plastics that have such diverse applications and different textures than PVC. The ability to be able to formulate PVC so that it can be used in a wide spectrum of industries and products sets this polymer apart from other commodity resins, such as polypropylene and polyethylene. Which is exactly why PVC is the third most widely used resin today.
Myth Number 2: PVC is brittle and will crack in cold applications. EPT/RMA supply a variety of industries with above grade and below grade waterproofing applications. When formulated correctly vinyl formulations can pass cold crack tests at -400F. We have a roofing product line called XTRM Ply® RV Roofing. When we entered the market, all of our competitors said that our product would never work. The most common reason given was that it would not stand up to the cold fluctuations typical seen in RV roofing applications. This proved to be completely false, and is proven by many applications already in use. Flexible vinyl is an amorphous thermoplastic so as the temperature fluctuates so does the flexibility of the product. In short, when it gets cold it gets stiffer and when it gets warm it gets softer. This does not mean it will crack. To date our XTRM Ply has tripled its use over the last 3 years and competitors that knocked our product for the first few years are now coming out with their own. I guess imitation is the best form of flattery.
Myth 3: Vinyl is not recyclable. Vinyl is recyclable. As we mentioned before, vinyl is a thermoplastic. Thermoplastic also means that the product can be re-melted. If it can be re-melted, it can be reprocessed. Which means it can be reformed into other products, unlike thermosets like rubber that need to be repurposed in their original form. The recycle rates of PVC come in much lower than the recycle rates of other plastics. Why? Many PVC applications are durable applications. The service life is generally long. For instance, most PVC pipe is used in buried applications. There are studies available that state the useful life of PVC pipe is over 50 years; some manufacturers state over 100 years. All of this is fairly hard to prove, because PVC pipe has only had widespread use since the 1970’s. We are just coming up on the 50-year mark. Most flexible PVC applications are durable as well. Our PVC roofing products in the market place are warrantied for over 15 years. Geomembrane pond liners can be buried for at least this amount of time. My point being is if 66% of the PVC market for resin is PVC pipe than much of the production that has been made is still in use. The CFFA and the vinyl industry has been looking into how to collect and recycle PVC products at the end of life, most of which is coming from old structures that are being remodeled or demolished http://www.cffaperformanceproducts.org/cffa-includes/pdfs/FOCUS03_Sustainability.pdf).
Myth 4: When vinyl burns it releases harmful fumes: That is correct. But you don’t want to be around anything when it burns. This is not really a myth, but it is not the whole story either. When you are in a burning building what you really need is time to get out. PVC is slow to burn and used in many building applications for these exact fire-retardant properties. Many other polymers when burning, such as TPO, PE, or EPDM burn more like a wax, releasing fire droplets that can cause a fire to spread (https://www.youtube.com/watch?v=GgZH0JX2pHI). As PVC burns it tends to char and not drip. As it burns further it begins to unzip and release hydrogen chloride gas, which helps to slow down the burning process. Hydrogen chloride gas has an extremely unpleasant, pungent smell thus allowing for early detection. Since most PVC is very fire retardant it is used in many exterior and interior applications such as siding and wall paper. While a burning building that contains PVC will release hydrochloric gas, it will give you time to exit the building and survive the fire.
PVC is a polymer that is used in our daily lives whether it’s being surrounded by it in our homes, drinking water that has come in contact with it via pipe, or receiving or giving a blood transfusion through a PVC blood bag. Its economics and versatility make it a good choice for years to come.