Covered mold — often called silicone duplication molding — solves one specific sourcing problem: you need parts, but all you have is a physical sample and no drawings.
How it works: a master (the sample, or a 3D-printed replica refined from it) is suspended in a frame; liquid silicone is poured around it and cured into a flexible mold; polyurethane or silicone resin is then cast or pressed in the cavity. The cycle repeats dozens of times before the silicone mold fatigues.
Where it fits: legacy parts with lost tooling; bridge production while a steel tool is being cut; gaskets and pads with simple but irregular geometry; 10-100 piece needs where steel tooling cannot amortize.
Honest limits: dimensional fidelity about ±0.2mm (a silicone mold copies but also breathes); limited material choice — properties approximate, never equal, production-grade rubber compounds; surface quality inherits the master; not suitable for seals with tight compression requirements.
Economics at Rubbrother: duplication molds cost a fraction of steel tooling and run in days, ideal for validation batches. When volumes justify it, we reverse-engineer the sample into a proper drawing and cut a steel tool — the duplication parts serve as the dimensional reference. Mold fee refund policy applies on volume orders as usual.