Medical equipment involves multiple sectors pharmaceuticals, machinery, electronics, plastics, etc., in which the rapid development of plastic medical devices. Since the 1930s, people first used synthetic polymer materials. Since celluloid film is made as an artificial kidney dialysis membrane used in clinical success. Polymer materials are gradually replacing traditional inorganic materials such as metals, glass, ceramics, phosphorus gray stone for the preparation of medical devices.
This is because:
(a) A polymer material with good mechanical properties and chemical stability, more suitable for medical use;
(2) A rich source of polymer materials, inexpensive, disposable medical supplies for made to avoid the traditional material products due to high prices. And had to repeatedly use disinfection and problems caused by secondary infections;
(3) Or more easily modified plastics have been good tissue compatibility, blood compatibility of products;
(4) Made of plastic low cost, suitable for a variety of molding methods, ease of processing into complex shapes. And the development of new medical products.
Compared with ordinary plastics, medical plastics require higher:
(1) Since most toxic monomers and oligomers, so medical plastics are strictly limited to the residual of the foregoing;
(2) plastic in the polymerization process inevitably comes into contact with the reactor, metal catalysts. Which often contain trace metal ions, according to the medical plastics GB requirement for zinc, lead, cadmium, copper, barium, tin, and other metal ions residual cases are clearly defined;
(3) Resin requirements for medical plastics with high purity, narrow molecular weight distribution;
(4) Plastic processing or modified in the process need to add various additives. Such as the amount of plasticizer in PVC medical products often as high as 30-60%, thus requiring to maximize the use of toxic chemicals. To prevent long-term use or reduce the precipitation of additives to affect product performance and treatment;
(5) In accordance with the requirements of medical plastic, often need to make products with surface hydrophilicity, anti-radiation sterilization, and other functions.