Flexible PVC is an inherently weather resistant material. Like all thermoplastics, however, it can be affected by weathering - a general term used to cover a wide range of outdoor environmental conditions.
Various additives are available to improve a compound's weather resistance. Before selecting a compound and additives, it is important to fully consider the environment that will be surrounding the end product and the other desired physical properties of your application.
Factors Influencing Weathering of Flexible PVC
The following environmental factors should be considered when selecting a flexible PVC compound for your weather resistant application.
Sunlight
Temperature
Moisture
Wind
Gases
Location
Sunlight
The suns rays contain a significant amount of ultraviolet radiation. When the material absorbs ultraviolet, a degrading chemical reaction occurs as well as the formation of heat.
Temperature
Daily ranges in temperature can vary drastically between seasons and from location to location. Heat resulting from solar radiation can increase the temperature of the material by up to 60° depending on the color. Such extremes of temperature over an extended period can cause physical damage to the polymer. Therefore, heat stabilizers must be incorporated into the compounding ingredients in order to offset the negative effects of high temperatures. In addition, it should be remembered that chemical reaction rates increase exponentially as the temperature increases.
