Decolorization

Discoloration and surface roughness are the characteristic degradation features of UV exposure of NFPC. In one of the research through Sharma et al. (2006), surfaces of coir/PP laminates confirmed a moderate change in surface roughness after 10h of UV exposure; but, with improved publicity time of 20h, the surfaces started out to show white and after 200h of publicity, the surfaces have become very tough and chalky with clearly visible fibers. Stark (2005) studied the coloration change in injection molded and extruded wood flour/HDPE composites beneath UV publicity and UV exposure with water spray. A Minolta CR-two hundred Chroma Meter was used to measure shade the usage of the CIELAB colour gadget. In the CIELAB color system, the L* cost is considered as lightness component wherein L* represents reflectance of a pattern. If L* = 0, the sample does no longer mirror mild and if L* = a hundred, the sample displays one hundred% mild. An increase in L* (+ΔL*) represents fading or lightening of the pattern and reduce in L* (−ΔL*) represents darkening of the pattern. In this colour machine, a* and b* are chromacity coordinates and represent red–green and yellow–blue coordinates. A high quality Δa* price represents a shade shift in the direction of crimson while a poor Δa* price represents a shift closer to green. Similarly, a superb Δb* values represents a colour shift toward yellow even as a poor Δb* price represents a shift closer to blue. The resultant shade exchange ΔE become calculated in line with ASTM D 2244 (Muller et al., 2003) as visible in Equation