When sourcing PC machinery, you must prioritize screw design and material, as Polycarbonate is highly viscous and heat-sensitive. Look for bimetallic screws and barrels to resist wear and corrosion. Ensure the machine features high-precision temperature control systems (within ±1°C) to prevent material yellowing or degradation. For sheet production, verify the T-die chrome plating thickness and the cooling roller diameter, which directly impact the optical clarity and surface finish of the final product.