Have you experienced disappointment when the desired color you selected no longer looks the same after only a few years of sun exposure? The color may be fading to an unwanted shade, the gloss level may be changing significantly or there may now be unexpected chalky residue masking the original color.
Factors that affect the color retention of PVC fabrics over time include location, sunlight intensity and exposure frequency. The four PVC fabric qualities that help high-quality, vinyl-coated fabrics retain color are the UV resistance of the pigments used in the color, the performance level of the plasticizer, the complexity of the vinyl formulation and the filler content used in the coated fabric.
Pigments: For most UV-stable pigments in between carbon black and titanium dioxide, the quality and quantity of these pigments are critical to the long-term UV stability of colors. Some pigments absorb UV radiation while others reflect them. Others are inexpensive with poor UV stability while others cost more due to their long-term UV stability. Utilizing the correct pigment combination in a color formulation is key to achieving the expected life span of the color in your fabric requirement.
Plasticizers: The main function of plasticizers is to provide flexibility to the vinyl fabric by working together with hard PVC resins to form a flexible, solid solution that doesn't technically chemically bond. Diffusion or migration is when the plasticizers move over time to the surface of the fabric. This chemical residue alters the gloss level of the fabric and its color perception. To counteract and slow migration, high-quality plasticizers should be used, oftentimes in conjunction with protective clear topcoats.
Vinyl Formulation: Most pigments on the color wheel are only partially UV stable and need aid from other additives to help them retain their vivid colors outdoors. In addition to the PVC resin and plasticizer, there's a cocktail of UV stabilizers and additives to protect the color pigments and PVC coatings from UV degradation.
Filler Content: One way many manufacturers reduce the price of their vinyl-coated fabrics is to use varying degrees of inert fillers such as calcium carbonate in their PVC formulation. In addition to lowering the abrasion resistance and stiffening the working cold temperature hand of the coated fabric, fillers break down over time, creating the chalky surface residue that's highly visible on darker colors such as black or blue.
Eventually, most colors will shift over time due to UV degradation. However, by identifying and understanding a consumer’s expectations of color retention, a properly formulated vinyl fabric can last years or even decades when exposed to sunlight long term. If you have outdoor applications (e.g., tents, fabric structures or athletic field padding) and have questions regarding the colorfastness of PVC fabrics, please contact our technical team for advice on your outdoor fabric requirements.