Introduction

Vacuum freeze drying is the removal of water or other solvents from the frozen samples. During the whole drying process, the sample is in liquid state and the temperature is generally lower than -10. The purpose of vacuum freeze drying is to restore the original characteristics of the sample after rehydration.
Because the drying process is carried out at low temperature, it can be used for some materials such as proteins, which are easy to be denatured at high temperature, and can ensure that the properties of other compounds will not change.
Most of the biological products, such as tissues, tissue extracts, bacteria, vaccines and serum, were changed into dry samples by vacuum freeze-drying. Vacuum freeze drying is the most gentle process to preserve the biochemical properties of sensitive tissue or other tissues. It is also the best method for drying inorganic materials, such as nano particles, because the surface area of particles is almost unchanged.

Application

HFD-6 vacuum freeze dryer is a kind of freeze-drying machine widely used in high performance laboratory. Freeze dry glass flask and serum bottle of solid and liquid samples. A variety of containers can be carried out on the same freeze dryer:
The pre freeze shelf surface temperature control
The samples of freeze-dried can be carried out in the user defined temperature
Dry in the limit temperature of freezing - user defined samples, high vacuum drying, and can remove capillary bound water molecules.
HFD-6 series machine is applicable to the bacteria, virus, plasma, serum extract, antibody, vaccine and drug products: such as chloramphenicol, streptomycin, vitamins, enzymes and biological test of the plant extracts.

Main features

1.Vacuum Freeze Dryer adopts Tecumseh or Secop, rapid cooling, LCD control system, easy operation, powerful function, stable performance, easy operation, and low noise.
2.The dry room door is made of colorless transparent organic glass, with programmable heating and temperature control functions, you can view the freeze-drying curve and the freeze-drying process can be observed.
3.Matching vacuum pump for pumping vacuum, an international standard KF quick connector connects the vacuum pump.
4.A variety of containers can be carried out on the same freeze dryer: The pre-freeze shelf surface temperature control, The samples freeze-dried can be carried out in the user-defined temperature in the limited temperature of freezing - user-defined samples, high vacuum drying, and can remove capillary bound water molecules.
5.Applicable to the Freeze drying suitable for seafood, wild vegetables, dehydrated vegetables, food, and fruit, also applies to plasma, serum extract, antibodies, etc.
6.Stable performance, easy operation and low noise.

General operation process of freeze drying

（1）Connecting the freeze dryer correctly;
（2）Adding sample into disc (liquid sample is poured directly, solid sample or bottled sample is distributed );
（3）Putting disc on the tray, to ensure they are completely coincided.  Closing the door and locking the handle;
（4）Turning on the switch and getting in main interface;
（5）In control interface, touching main interface button and getting in;
（6）In main interface, touching user parameters button and getting in;
（7）In user parameters interface, could setting drying process, including stage number, temperature and time for each stage;
（8）Touching back to control interface.  Touching button to start temperature control and freeze system to ensure the sample’s temperature is changed following setting values.  In drying process, stage one is pre freezing stage.  The sample will be frozen to below Eutectic point, and make sure the sample has been frozen totally;
（9）When pre freezing stage finished, the process getting into drying stages(stage two and later stages).  Open vacuum pump, making vacuum condition in chamber, to dry the sample.  Make sure all the vent valves had been closed;
（10）When all stages finished, it means the drying process is over.*
Open the vent valve at first, then close vacuum pump, close temperature control and freeze system.  Finally, turn off the power and take off the power plug.  While the pressure balance between chamber inside and outside, open the door, take out sample.
（11）Defrosting the ice by heater.  After all the ice removed, clean the dryer.**
*Note: Due to the specific characteristics of the material, and the thickness of the material is different, the user should be tested to determine the appropriate freeze drying process to ensure that the material is completely dry.
**The outlet of the vacuum pump should be cover to avoid dust entering.

Below operations are prohibited

（1）The freeze dryer is not properly installed
（2）It’s not allowed or authorized
（3）The tray is not fixed
（4）It is not possible to freeze dry corrosive substances without special safety measures. Even in the case of protection, it is necessary to ensure that no corrosion to reduce the mechanical strength of the trap, door panels, and other accessories.
（5）Not allowed to add attachments. Do not use container with poor quality. Because it is very dangerous with burst risk.
（6）Do not use freeze dryers in areas where there is a risk of explosion.
（7）Do not move or compact the freeze dryer, do not lean on or rest on it when working.
（8）Do not place potentially dangerous objects, such as liquid bottles, in the vicinity of a freeze dryer.
（9）Do not dry the samples which will react when freeze dry.
（10）Do not freeze dry explosive or flammable samples.