PVC Processing AIDS and PVC additives are needed for PVC materials used in the medical field
PVC products have the advantages of high softness, good pressure resistance, high transparency, easy processing, non-toxic effect, disinfection use, etc., are widely used in the field of medical devices, and the gradual expansion of the market for disposable PVC medical products has also given PVC products greater space for development.
Statistics show that the use of PVC and polyethylene (PE) products in the domestic medical plastic market is the largest, of which medical products made of PVC as raw materials rank first in the market consumption ratio. Including blood transfusion bag, infusion bag, disposable intravenous infusion tube, peritoneal dialysis bag, all kinds of medical cannula, disposable identification bracelet, disposable nasal oxygen tube, etc.
Properties of medical PVC material:
1. With good chemical stability, will not react with drugs, blood, body fluids, etc.
2. With a high safety, the human body will not cause rejection or cause other inflammation, or teratogenic cancer.
3. With good physical, chemical and mechanical properties.
4. The properties of PVC materials cannot be changed after sterilization and disinfection.
5. With good processability.
Commonly used Processing AIDS and additives in Medical PVC :
1. X-ray opaque filler for PVC
X-ray opaque fillers commonly used in medical plastics include BiO3, BaSO4, bismuth subcarbonate, tantalum oxide, tungsten oxychloride and bismuth oxychloride. In order to facilitate the use of X-ray tracking and detection of the specific position of the interventional catheter during surgery, the interventional catheter commonly used in medical treatment must contain X-ray opaque lines.
2: Paint for PVC materails
Some medical devices need to use colored materials manufacturing, need to add specific dyes or pigments in PVC materials, plastic as raw materials to prepare medical devices, the amount of pigment added should be within 1%, the pigment commonly used in medical PVC is TiO2, when the amount is 1%, you can give the material to avoid light, uniform white. Both phthalocyanine green and phthalocyanine blue are made of organic pigments with strong coloring, and the material can be adjusted to a medium tone by adding 0.1% of the pigment.
3.PVC Stabilizer
In order to improve the stability of PVC, it is necessary to add a stabilizer in the production and processing process, which needs to have thermal stability, non-toxicity, oil resistance, chemical resistance and other characteristics, and the initial transparency and coloring of the stabilizer is good. The stabilizers often used in the preparation of medical devices using PVC are Zn, Mg, Ca composite stabilizers, etc., and need to add an appropriate amount of epoxy soybean oil or phosphite and other auxiliary stabilizers.
4: Lubricant Processing Aids fpr PVC
According to the role of lubricants, the commonly used lubricants in medical PVC materials can be divided into three categories, internal lubricants, external lubricants and internal and external lubricants. The internal lubricant needs to have good compatibility with PVC, and the internal lubricant is added to reduce the shear and friction between melt molecules; The external lubricant has a low melting point and poor compatibility with PVC. The addition of external lubricant is to reduce the shear and friction between the melt and the screw and barrel of the plastic extruder. Internal and external lubricants can be compatible with PVC materials, both internal lubricants and external lubricants.
5. Plasticizer
Initially, medical devices made of glass and natural rubber were mainly replaced by PVC with plasticizers. The main reason is that plasticized PVC is more transparent, easier to sterilization, low cost, and has good chemical stability. In addition, medical devices made of PVC have good elasticity and softness, which can avoid discomfort for patients.
The application of PVC materials in the field of medical devices is more and more extensive, and the market demand for polymer materials with excellent performance will continue to increase. Although medical PVC material is not universal, and there are still some safety problems, but through the relevant scholars research and design of new synthetic processing path, the synthesis of ideal materials with excellent biomedical properties can be expected soon.