A complete peristaltic pump system usually includes 3 parts: the main engine, the pump head and the hose.
At present, the most common peristaltic pump tubing in China includes silicone tubing, composite rubber tubing, PVC tubing and so on.

The occasions where the silicone pump tube is used are generally related to the biological or pharmaceutical industry, such as the filtration of culture fluid, cell perfusion, fermentation tank, and water for injection transportation. In the industrial process, platinum vulcanized silicone tube with high manufacturing process is generally used. Its inner wall is smooth, which can meet the requirements of the corresponding regulations of FDA, USP, EU, NSF-51 and other standards.

When the silicone tube is used as a peristaltic pump, the service life is not long. Generally, the service life is 50-75 hours when it is 600rpm, 3 roller pump head, 23℃, and the test sample is pure water. However, platinum vulcanized silicone elastomer is an excellent material. Under the premise of excellent production process, platinum vulcanized silicone tube has a hydrophobic and smooth inner surface, which hardly brings eddy current dead angle, which is a complete change control; at the same time, the silicone tube can be 121 degrees damp heat**, so in biological and In pharmaceutical related fields, the application of silicone tubing is quite extensive.

In addition, the resistance of silica gel to organic samples is poor, and the transportation of polar organic solvents can easily cause the life of the pump tube to be greatly reduced, increase the number of shutdowns and tube changes; more importantly, after the silica gel is dissolved, its silicon content enters the next process Cause pollution.
The chemical compatibility of hoses with materials can be divided into 4 categories: excellent (E: Excellent), good (G: Good), unqualified, poor (F: Fail), and X (not recommended). In principle, if the compatibility is F or X, other pipes must be replaced. Example: platinum silicon sulfide

The resistance of the glue to ethanol is F, the resistance to acetone is X, the resistance to ethanol is E, and the resistance to weakly polar substances such as acetic acid and fatty acids is G. For ethanol and acetone, other pipes with resistance of G or E must be used, which is ignored by most users. However, in some experiments, the dissolution of silicone tubes by such organic substances has already affected the experimental results.

What caused the weakness of the silicone tube in the face of organic materials?

From a microscopic point of view, silica gel is a porous cellular Si-C chain polymer, and the hydrophobic groups on its surface can prevent the passage of most polar molecules.
At the same time, because of this, polar molecules are similarly compatible. When transporting polar organics, the silicone tube itself is constantly eroded and dissolved. After a period of use (the length of time varies depending on the nature of the organic matter), the silicone tube absorbs water like a sponge, filled with organic solvents, and molecules constantly volatilize from its surface.
These organic molecules exist in the form of gas or steam, soaking the pump head of the peristaltic pump for a long time. If the pump head itself is made of poorly chemically resistant materials such as PESU, it will generally accelerate the deterioration of the pump head and even cause cracking