How should I choose between a short path molecular distillation system and a wiped film evaporator?

It depends on how much heat stress your material tolerates and how much throughput you need. Short path molecular distillation operates at the highest vacuum with the condenser only centimetres from the evaporating surface, giving the shortest possible residence time — the right choice for heat-sensitive, high-boiling compounds such as APIs, essential oil fractions and vitamin esters. A wiped film evaporator handles higher feed rates and more viscous or solids-containing streams, because the wiper blade continuously renews the film and prevents fouling.

As a rule of thumb: highest purity on delicate material → molecular distillation; continuous throughput on tough or viscous material → wiped film. Glass models suit laboratory and visual process development, stainless steel models suit pilot and production scale.