A melt system that includes a melt unit. The melt unit includes a reservoir and a melt grid disposed above the reservoir. The melt grid is configured to expose solid polymer to a temperature sufficient to form a molten polymer and to deposit the molten polymer into the reservoir. The melt unit includes at least one hopper for holding a supply of the solid polymer. The melt unit includes a thermal isolation region disposed below the hopper to thermally isolate the hopper from the molten polymer in the reservoir.