Freeze Drying Knowledge

Freeze drying or lyophilization, is a low temperature dehydration process. Dry products in a solid state and is under vacuum environment. Typically use to preserve perishable materials or make the material more convenient for storage.

Vacuum freeze dry is a sublimation process. Freeze drying removes water by freezing the material, and then reduce its surrounding pressure to allow the frozen water in the material to sublime directly from solid phase to gas.

Lyophilization and freeze drying are synonymous. People call freeze drying in food industry, and call it lyophilization in bio and pharma industry. Depends on customary or the industry it taking place.

Freeze drying is a low temperature dehydration method. During the process, most time, materials are keeping in minus temperature. So, freeze drying has less impact on product original properties, no ruin the biological activity, vitamin, flavor, taste and appearance. By adding water or other solvents, they can be reconstituted easily and quickly. And freeze dried material is considered as next to fresh material.

Freezing Stage. Materials completely frozen is the first step also is the insurance of a success lyophilization.

Primary Drying Stage. Remove physical water, as know, >90% water in raws are physical water, this stage takes quite long time.

Secondary Drying Stage. Remove bound water, bound water is hard to remove, this stage need ultra vacuum and higher Temp.

Freeze drying technology costly. The freeze drying equipment matters only 10% of its overall cost, 90% is its operation. A poor machine designing and a lack of productivity due to machine maintenance is going to cost you continuously.

Based on production capacity, they can be divided into lab scale and production scale.

Based on application fields, they can be divided into pharmaceutical lyophilizers, food freeze dryers and general purpose freeze dryers.

Purchase of a freeze dryer need consider: Application Feasibility, Supporting Facilities, Freeze Drying Batch Duration, Consumptions Of Water and Electric, Total Investment and Future Necessary Maintain/Labor Cost etc. Which need a comprehensive investigate, to guarantee your freeze drying business is profitable.

Products Can be Freeze Dried

• Food, Fruits, Vegetables, Meats, Dairy, Eggs, Meals, Coffee
• Pharmaceutical, Vaccines, Injectable Formulations, Serum, Penicillin
• Biological, Lactic acid bacteria, Probiotics, Plant Extracts.
• Chemical, Graphene, Earth

Products Can not be Freeze Dried

• High fat, sugar and oil contain products not suit freeze drying. Like syrup, pure chocolate, pure honey and butter etc. is not easy to dry.

The main difference between them is the water remove theory: Vacuum drying based on water boiling point, and vacuum freeze drying based on water melting point.