Orbital Plastic Refabricator — 2D Batch Thermal Trace

A 2D cross-section counterpart to the orbital refabricator's 3D barrel view, focused entirely on the thermal batch process: heater power drives a first-order thermal model of the barrel, and each batch's starting temperature is whatever the previous batch's cooldown period left behind, not a reset to ambient. Run a sequence of batches back to back and watch the live temperature-vs-time trace — with adequate cooldown time every batch peaks inside the same safe melt window, but cut the cooldown too short and residual heat accumulates from batch to batch, pushing later peaks higher and higher until one crosses into the decomposition zone and chars the material instead of cleanly melting it. The same energy-balance trade-off that limits how quickly a real orbital recycler can be run back to back.