What are the differences in thermal conductivity between black and white plastic cans?

The thermal conductivity differences between black and white plastic cans primarily stem from color-based radiation absorption rather than inherent material changes. Both typically use identical polymer materials like HDPE or PP, meaning their fundamental thermal conductivity remains equal (approximately 0.15-0.24 W/m·K). The critical difference emerges in solar radiation absorption: black pigments absorb up to 90% of visible and infrared radiation, converting it to heat that spreads through the material, while white pigments reflect 80-90% of radiation. This creates a surface temperature variance of 10-20°C under sunlight, making black cans feel hotter despite identical conduction properties. Applications vary significantly - white cans excel for temperature-sensitive storage (e.g., food, chemicals) by minimizing heat gain, whereas black cans benefit applications requiring heat retention. Manufacturers sometimes incorporate additives like carbon black or titanium dioxide, but these minimally alter bulk conductivity. The perceived "faster heating" of black cans results from radiative heat transfer initiation, not enhanced conductivity. Proper thermal design must consider both color-induced radiation effects and material thickness to optimize performance for specific environmental conditions.