Florida exposure

Lightfastness is measured by exposing pigmented film to an artificial or natural, eg, Florida exposure, light for a predetermined time. It is a relative term where the color of a sample exposed to a known light source is compared to its original color values. To make it meaningful, aH conditions of the exposure have to be weH defined. 

Thus, the compulsory requirement for automotive coatings of a two-year Florida exposure can be reduced to a period of less than 6 months. This is advantageous for the developmental process. 

Figure 7.11. Color changes of various white coatings after Florida exposure (-) PVDF (- ) silicone polyester (- -) acryUc ( ) polyurethane (—) vinyl plastisol.

Figure I. Illustration of the non-hiocidal activity of the hindered amine light stabilizer LS I and the benzotriazole UFabsorber LS II on a modified styrenic terpolymer. Key left, unaged and right, Florida exposure for 500,000 langleys (approx. 4 years).

Table 5. Florida Exposure of HDPE Tapes KLY to 50% Retention of Tensile Strength...

Figure 15. Light stability of HDPE plaques (Ziegler). Florida exposure, KLY to 50% retention of tensile impact strength.

Table 6. Influence of Fillers on Light Stability of LDPE Blown Film Florida Exposure KLY to 507, Retention of Elongation...

Figure 6. Gloss retention vs. months Florida exposure. Key A, acrylic B, vinyl C, fluoropolymer D, silicone polyester ---, chalking.

Figure 5. High-density polyethylene (2% rutile Ti02, 0.5% LS). Elongation retention as a function of 45° south direct Florida exposure for high density polyethylene stabilized with 0.50% of various light stabilizers. Pigmented rutile TiOt.

Natural weathering in Florida is often used as a means of forecasting more rapidly effects that will occur in temperate climates. For example, one year s exposure in Florida has been said to be roughly equivalent to 4-5 years in central Europe. Such comparisons are necessarily highly approximate and could cause materials to be rejected that would, in fact, be satisfactory. Nevertheless, Florida exposure often forms part of the specifications for weather resistance throughout the rest of the world. 

Tsbie E. Comparison of Film Formulations in Florida Exposure Tests (4 Mil Unbacked Film)... 

The net effect of these factors is illustrated in Figure 10.1, which compares the loss in extensibility of polyethylene samples exposed floating in seawater to that exposed in air at the same location in Biscayne Bay, Florida. Exposure over an approximately 2-month period was negligible for samples exposed floating on water, while those exposed in air nearly embrittled over the same period. Observations were not continued until embrittlement was obtained for the sample... 

Figure 4.30 Tensile strength retention of 1296 denier/72 strand polypropylene fiber having 0,2%wt HALS Lowilite 62, Chimassorb 944, or Uvasil 299 under Florida exposure conditions (45° South). Base stabilization includes 0.16%wt Anox TB311 and 0.1 %wt calcium stearate. The control has no HALS. kLy is a unit for outdoor exposure for which 1 year equals 110-140 kLys.

Fig. 20. Depth distribution of CYASORB UV-1164L and Tinuvin 900 in clear coat/base coat films after cure and after three years of florida exposure.

Results of exposure 82% tensile strength retention after 6 years of Florida exposure ... 

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