Safety Precautions for Laboratory Freeze Dryers(Lyophilizers)
Time：
2026-01-27 15:14
A freeze dryer operates on the principle of vacuum freeze-drying technology, which rapidly freezes the material at low temperatures and then subjects it to a suitable vacuum environment, allowing the frozen water molecules to sublimate directly into vapor and escape. After freeze-drying, the original biological and chemical properties of the material remain largely unchanged, making it suitable for long-term storage. The material can be restored to its pre-freeze-dried state by rehydration while retaining its original biochemical characteristics. Vacuum freeze-drying technology is widely used not only in pharmaceuticals, biological products, food, blood products, and active substances but also in various other fields.
Laboratory freeze dryers are available in both benchtop and vertical configurations, including standard types, top-press types, and manifold types. Benchtop freeze dryers feature an integrated compact design with a freeze-drying area typically ranging from 0.1 to 0.12 square meters and are equipped with four material trays. The cold trap temperature is generally around -50°C. Most models use transparent acrylic cylinders with a bell-jar design, allowing observation of tray-loaded materials. Vertical freeze dryers have a split design and can handle medium-sized sample batches. They support ultra-low temperature pre-freezing down to -80°C, offer excellent heat dissipation, and exhibit slower aging rates for components such as compressors and control circuits.
Safe and standardized operation of a freeze dryer must be maintained throughout the entire process - before, during, and after operation - to ensure experimental accuracy, prolong equipment lifespan, and guarantee personnel safety.
Pre-Operation Preparation
Ensure the equipment is in good condition. Check that the vacuum pump oil level is between the marked lines and the oil is clear. Inspect the refrigeration system for any signs of leakage (such as uneven frosting or oil stains), and confirm that door seals show no signs of aging or cracks. Samples require pre-treatment: liquid samples should be maintained at a thickness of 5–15 mm, solid samples should have side lengths no greater than 10 mm, and samples prone to oxidation or moisture absorption should be handled under inert gas protection.
Operation Control
During the pre-freezing stage, the temperature must be lowered to 5–10°C below the sample’s eutectic point. For heat-sensitive samples, a cooling rate of 1–2°C/min is recommended, while conventional samples can be cooled at 3–5°C/min. After pre-freezing, maintain the temperature for 1–2 hours. During the sublimation drying stage, after starting the vacuum pump, the vacuum level must drop to ≤10 Pa within 30 minutes. If this target is not met, stop the machine and check for sealing issues. Heating must not be initiated if the vacuum level is insufficient.
Post-Operation Procedures
Before sampling, introduce inert gas to slowly break the vacuum and avoid airflow impact. After removal, immediately seal the samples, label them with relevant information, and store them in a cool, dry place. Perform regular cleaning of the equipment to prevent “use-and-leave” negligence.
Special Scenario Handling
When handling flammable or explosive samples, operations must be conducted inside a fume hood. Open flames are strictly prohibited in the drying chamber, and the vacuum level must be kept within a safe range. Fire extinguishers should be available on-site. In case of alarms from the refrigeration system or vacuum pump failure, stop the machine immediately for troubleshooting. In the event of electrical leakage, disconnect the main power supply first.
News
CONTACT US
LICHEN Scientific Group
LACHOI Scientific Instrument (Shaoxing) Co., Ltd.
WhatsApp: To expedite your request, we recommend using our message form or Email
Add: Room 102, 1st Floor, Lianhe factory, No. 1423, Renmin East Road, Gaobu Street, Yuecheng District, Shaoxing City, Zhejiang Province, China
右侧在线客服样式 1,2,3 1
图片alt标题设置： lichen scientific
表单验证提示文本： Content cannot be empty!
循环体没有内容时： Sorry,no matching items were found.
CSS / JS 文件放置地