What viscosity is best choice for PET resin for water bottles?
What viscosity is best choice for PET resin for water bottles?
The viscosity of PET resin used in water bottles is usually around 0.800±0.02dl/g.
PET resins with different viscosities have the following different characteristics in the manufacture of water bottles:
In terms of processing performance: It has better fluidity. During processing such as injection molding and blow - molding, it can more easily fill the mold cavity, reducing processing difficulty and improving production efficiency. For example, in the blow - molding process, the PET resin with lower viscosity can be blown into shape more quickly, reducing the molding time.
In terms of product quality: The transparency of the water bottle produced may be slightly higher. However, due to the relatively lower molecular weight, its mechanical strength may be slightly inferior. For instance, the impact resistance and compression resistance of the water bottle may be slightly worse, and it is more likely to be damaged during transportation and use.
In terms of processing performance: Its fluidity is relatively poor. During the processing, higher pressure and temperature are required to ensure the flow and molding of the resin, which places higher demands on processing equipment and technology. For example, in the injection - molding process, a greater injection pressure may be needed to make the resin fill the mold.
In terms of product quality: The water bottle produced has higher mechanical strength, better impact resistance and compression resistance, and can withstand greater external forces. It is less likely to deform and break during transportation and storage. However, due to the longer molecular chains and their entanglement, the transparency may slightly decrease.
