Raw materials. All vinyl products are made from a combination of vinyl resin and various additives, which gives these products their particular properties. For more information on the vinyl resin process, see the general vinyl section. Most formulations are different, and most are proprietary. Most vinyl fencing formulations are made up of about 80 percent vinyl resin. Some of the additives commonly used in vinyl outdoor living products include the following.
•Stabilizers improve heat stability, minimizing the degradation of the vinyl during exposures to high temperatures in the extrusion process. They also add to the product's strength and help it resist cracking, splitting, pitting.
•Impact modifiers improve impact strength, or resistance of the profile to cracking or breaking during the fabrication processes (sawing, routing and punching). They also improve resistance to general abuse during transportation, storage and installation.
•UV inhibitors protect the finished product from damaging rays of the sun. Titanium dioxide is the most common material used.
•Pigments provide consistent color throughout the product and may screen or absorb UV radiation, which would otherwise cause rapid degradation of the product.
Processing/fabricating. Extrusion and co-extrusion are the manufacturing processes used to make vinyl outdoor living products. After proprietary compounds are made by combining additives with vinyl resin, the product is extruded through molds to form various shapes and is cut into various lengths. Extrusion uses the same vinyl formula (compounds with stabilizers, modifiers and inhibitors) throughout the entire manufacturing process. In a co-extrusion process, the UV inhibitor and other modifiers for weatherability are concentrated in an outer layer while stabilizers and modifiers for durability and strength are put in the inner core of the product.
•Fencing. Vinyl fencing is either extruded or co-extruded then shaped into various components by routing and cutting. The rails, pickets and posts are cut to specific lengths as required for style. The corner, gate and end posts are internally reinforced with metal or wood. Then the parts are assembled, shipped and installed at the job site.
•Decking. Planks are either extruded or co-extruded into various lengths depending on the customer's need. Support ribs are added for strength and impact resistance. Then a slip-resistant design is etched into the planks to provide safety and security underfoot.
•Railing. The vinyl railing manufacturing process is similar to that of vinyl fencing, with vinyl components being extruded and then reinforced with metal or wood.