Jan. 20, 2021
There are currently three main raw materials for vaccine bottles, namely polyethylene, polypropylene and polyester. Each of the three materials has its own characteristics, which are described in detail below.
First, high-density polyethylene (HDPE) is a highly crystalline, non-polar thermoplastic resin. The appearance of the original HDPE is milky white, and the thin section is translucent to a certain extent. PE has excellent resistance to most domestic and industrial chemicals. It is light in weight, non-toxic, colorless, odorless, and ignorant. It has a melting point of about 130°C. It has good chemical stability and is not affected by strong acids, strong alkalis and most fluxes. It has better abrasion resistance, cold resistance and moisture resistance. Good, with sufficient strength, rigidity and impact resistance, and easy to process. It is suitable for blow molding hollow products. A certain amount of low-density polyethylene and linear polyethylene can be added to adjust the processing and use performance. At room temperature, it is insoluble in any organic solvents, resistant to corrosion by acids, alkalis and various salts; the film has low permeability to water vapor and air, and has low water absorption; poor aging resistance, and environmental cracking resistance is not as good as low density poly Ethylene, especially thermal oxidation will reduce its performance, so antioxidants and ultraviolet absorbers must be added to improve this deficiency.
Polypropylene (PP) is a thermoplastic resin made by polymerizing propylene. It is non-toxic, ignorant, odorless, and colorless. It has a melting point of 164~170℃. It is one of the lightest plastics. It is extremely difficult to dissolve in water. Due to its high crystallinity, this material has surface stiffness and scratch resistance. The characteristics are very good. It has excellent mechanical properties, yield strength, high tensile strength, high hardness, superior elasticity and stress crack resistance, good chemical stability, resistance to strong acids, strong alkalis and most organic substances, excellent air tightness and water vapor barrier. The melting point is as high as 170℃, which is especially suitable for high temperature disinfection and sterilization. It is an excellent plastic material for manufacturing oral liquid bottles. It can also be blended with polyethylene to meet requirements.
Polyester (PET) is a high polymer, derived from the dehydration condensation reaction of ethylene terephthalate. Ethylene terephthalate is obtained by the esterification reaction of terephthalic acid and ethylene glycol. PET is a milky white or light yellow, highly crystalline polymer with a smooth and shiny surface. It has excellent physical and mechanical properties in a wide temperature range. The long-term use temperature can reach 120℃. The electrical insulation is excellent. Even at high temperature and high frequency, its electrical performance is still good, but the corona resistance is poor. Creep resistance, fatigue resistance, friction resistance and dimensional stability are all very good. PET is colorless, transparent, non-toxic, odorless, tasteless, has good chemical stability, good barrier to oxygen and water vapor, good barrier to odor, and has high tensile strength and good low temperature resistance. It is used for medicine Excellent material for plastic bottles.
The medicinal plastic bottles made of the above three types of plastic raw materials can basically meet the requirements of most veterinary drugs packaging. Other plastic materials, such as polycarbonate and polystyrene, also have unique properties, which are comparable to the above three types of plastic raw materials. Compared with that, it is not so widely used. At present, most of the oral liquid bottles on the market are made of the above three types of plastics, which have been recognized by the market.