Noctua is a well-respected manufacturer of PC case fans and similarly unromantic cooling components. But unromantic does not mean uninteresting, as demonstrated by a lengthy article the company published explaining why it takes so long to release any given fan in black after the company's house tan. At the tolerances involved, injection molding "is less like making ice cubes and more like baking a complex soufflé where every degree of temperature and milligram of ingredients matters." Even pigments change all the calculations.
Achieving such small tip clearances is essentially at the absolute limit of what injection moulding can consistently reproduce. … Colour pigments impact the injection moulding of these high-precision fans because the pigment particles behave like tiny solid fillers inside the melt. Their size, surface area, and thermal behaviour directly influence how the polymer flows into the mould, as well as how it cools and solidifies. Black pigments, which are typically carbon black, behave very differently from the beige or brown metal-oxide pigments used in our standard fans. Carbon black particles are much smaller and have a significantly higher total surface area, resulting in stronger interactions with the polymer melt. While beige and brown metal-oxide pigments are larger and have a weaker effect, carbon black alters the melt viscosity, heat absorption, and crystallisation behaviour more significantly.
It took them 10 months to get to releasing the coveted NF-A12x25 G2 in black, but the day is finally upon us. 2.28 watts, 24.8 decibels, a progressive-bend impeller with winglets, centrifugal turbulator, and flow acceleration channels, made with the company's custom liquid-crystal polymer for "less creep."
Previously:
• Inside an injection molding factory producing gaming miniatures
• Modeling with plastic sprues
