Flexible PVC for Roll Goods and Strip Doors
Poly Vinyl Chloride compounds - or PVC as it is known in the industry - is converted to its end product by a number of in-line processing techniques. Together, the series of steps that we use to convert the raw material into a finished product is simply referred to as our Extrusion Line. The process that we utilize is used for making continuous lengths of profiles which, in our case, are the long PVC rolls. A "profile" varies only in two dimensions, as opposed to our roto-molded products which vary in three.
For the flexible PVC that we manufacture in our Oregon facility, we have a single screw extruder which consists of a very large metal barrel with a closefitting internal screw that is connected to a an electric motor drive mechanism with a means for applying heat to the barrel in multiple zones. A pelletized compound is used, typically containing a large percentage of PVC, with the remainder being plasticizers that determine the stiffness for normal use or softness needed in low temperature applications, pigments for the variety of transparent or opaque colors we offer, and stabilizers to reduce Ultra Violet (UV) degradation from certain types of lighting or natural sunlight.
After melting the pelletized compound, a continuous stream of hot PVC plastic is pushed through a specially designed die by the turning action of the screw. Sheet products, like our roll goods are manufactured by the slit-die extrusion technique. The next step, called calendaring, is then used. In this next process, the material from the die is passed between a series of large heated revolving rollers which squeeze the material into sheet or film. The thickness of the finished material is controlled by the space between the final rolls. The surface of the film or sheeting may be smooth, matted, embossed with loc-ribs or imbedded with reinforcing string depending on the surface of the final rollers. As the material comes off these rolls, adjustable knives trim the edges and cut the material to specific widths before it is immersed in a cold water bath which quickly cools the material. As it emerges from the water bath, "squeegees" and fans are used to dry the material before it is wrapped on rolls by an automatic tensioning winder. The calendaring technique is capable of producing high-quality material at very high rates of output but requires constant attention to a number of time and temperature variables to maintain consistency. We use the material we produce for the manufacture our own strip doors and flexible traffic doors, and sell bulk PVC roll goods to plastics distributors and manufacturers around the world.
Because of our in-house capabilities, expertise and experience with extruding we can assure our customers are getting the high quality and most cost-effective strip curtain or pvc roll on the market.