The basic building blocks of PET are ethylene glycol and terephthalic acid, which are combined to form pellets of PET. These resin pellets are then heated to a molten liquid that can be easily extruded or molded into items of practically any shape.
PET is created by combining ethylene glycol and terephthalic acid, which forms pellets of the PET polymer.More specifically, when the two raw materials of PET are combined under high temperatures and low vacuum pressure, long chains of the polymer are formed. As the mixture becomes thicker, the chains grow longer. Once the appropriate chain length is achieved, the reaction is stopped. The resulting spaghetti-like strands of PET are then extruded, quickly cooled, and cut into small pellets.
When the resin pellets are reheated to a molten liquid stage, the polymer chains can be stretched in one direction (for fibers) or in two directions (for bottles and films). If the polymer is cooled quickly while it is stretched, the chains are frozen with their orientation intact. Once set in stretched form, the material is extremely tough.
If PET is held in the stretched form at elevated temperatures, it slowly crystallizes and starts to become opaque, more rigid and less flexible. This crystalline form PET is often used for take-home and prepared-food containers and trays that can be reheated in the oven or microwave.
The basic building blocks of PET are ethylene glycol and terephthalic acid, which are combined to form pellets of PET. These resin pellets are then heated to a molten liquid that can be easily extruded or molded into items of practically any shape. PET is created by combining ethylene glycol and terephthalic acid, which forms pellets of the PET polymer.More specifically, when the two raw materials of PET are combined under high temperatures and low vacuum pressure, long chains of the polymer are formed. As the mixture becomes thicker, the chains grow longer. Once the appropriate chain length is achieved, the reaction is stopped. The resulting spaghetti-like strands of PET are then extruded, quickly cooled, and cut into small pellets. When the resin pellets are reheated to a molten liquid stage, the polymer chains can be stretched in one direction (for fibers) or in two directions (for bottles and films). If the polymer is cooled quickly while it is stretched, the chains are frozen with their orientation intact. Once set in stretched form, the material is extremely tough.If PET is held in the stretched form at elevated temperatures, it slowly crystallizes and starts to become opaque, more rigid and less flexible. This crystalline form PET is often used for take-home and prepared-food containers and trays that can be reheated in the oven or microwave.
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