Flat Door Transfer Hatch

The Flat Door Transfer Hatch is a stainless pass box whose two doors are flat, flush panels rather than framed or dished doors. The flat face opens and closes smoothly and presents a simple, unbroken surface on both sides of the wall. The two doors are tied by an interlock - mechanical or electronic - so they cannot be opened together, which stops conditioned clean air from flowing across the aperture while an item is passed through. Each face carries a double-sided glass viewing window so the receiving operator can see the contents before opening, and a built-in UV disinfection lamp can be added. The cabinet is built in 201 or 304 stainless steel, with standard outer sizes from the 400-type to the 1200-type. Each flat panel mates against a continuous gasket around the frame, so when both doors are shut the opening seals around the whole perimeter rather than at two corners, and the viewing glass sits flush with the door face instead of in a raised bezel.

The flat door is chosen for hygiene and wear, not looks. A framed or dished door has raised edges and recessed corners that catch lint and dust and have to be wiped by hand corner to corner; the flush panel has no ledge to collect particles and can be wiped in one pass, which matters in a transfer point that gets opened dozens of times an hour. The smooth, low-friction movement also puts less load on the interlock mechanism over a high number of daily cycles, so the latch stays reliable where a heavier framed door would loosen sooner. We match the door finish and interlock type to how often the hatch is actually used, and the flush panel removes the protruding handles and finger traps that a framed door exposes on a busy boundary.