A small amount of products in the laboratory freeze dryer are generally pre-frozen in the cold trap cylinder. The flask needs to be equipped with a cold bath with a freezing device to pre-freeze into a shell structure. The ampoule can be pre-frozen in the refrigerator or pre-frozen with a centrifugal attachment. The vials are generally pre-frozen in a low-box refrigerator....

When producing a product using a production freeze dryer, the material needs to be pre-frozen. The purpose of pre-freezing is to sublimate the product under vacuum. If not frozen. ...