Mainly, shelves and trays are fabricated from Aluminum alloy or stainless steel material. Due to the heat conductivity of different material, the liofilization drying time a bit different.
It has been proven that liofilizador/lyophilizer come with aluminum alloy shelves&trays, drying speed is much faster than stainless steel unit. Since aluminum alloy heat conductivity about 14 times higher than stainless steel.
Thus, lyophilization equipment to dehydrate normal fruit, herbs, vegetables or snacks, aluminum alloy shelves/trays are recommended, to short the drying period, save energy and maximum your profit. For pharmaceutical, biological or chemical materials, inert material (stainless steel or with coated surface) is needed, to avoid raw product pollution by ingredient reaction.
The drying chamber shape also influence the cycle time.