Polyethylene terephthalate (PET) plastic is a durable lightweight plastic that is usually used to make containers in the food and beverage, pharmaceutical and personal care industries. Therefore, it has producedPlastic Lotion Pump Bottle , PET Shampoo Bottle, etc. Various containers. A version of polyester plastics has appeared since 1833, when they were first developed as liquid varnishes. In 1941, DuPont chemists developed PET, but it was not until the 1970s that plastic bottles became popular.
After years of experimentation, Nathaniel C. Wyeth developed the first plastic bottle. He discovered the blow molding method still in use today. Wyeth has solved long-standing problems such as uneven wall thickness and irregular neck size by blowing plastic, and consolidated the process of manufacturing a well-structured, durable plastic bottle.
Since then, billions of bottles have been produced each year, leading to an increase in community recycling programs across the United States to curb the growth of landfills and increase the reuse of materials. Manufacturers are now looking for new ways to recycle PET and make it well utilized in the market.
Production of plastic bottles
PET is a form of polyester. It is a polymer mainly derived from petroleum hydrocarbons and is the result of the reaction between the monomers ethylene glycol and terephthalic acid.
In the manufacture of PET plastic, terephthalic acid is mixed with methanol to produce dimethyl terephthalate and water. This product is then mixed with ethylene glycol at a temperature of 305 degrees Fahrenheit to produce another substance called bis(2-hydroxyethyl) terephthalate and methanol.
In the last step, a polymer is formed and at the same time another molecule is released. This polycondensation process of bis(2-hydroxyethyl) terephthalate occurs at 530 degrees Fahrenheit in a vacuum, producing chains of PET and ethylene glycol, which are continuously removed during the polymerization process and used to make other PET.
When the PET mixture reaches a suitable thickness, it will quickly cool to prevent discoloration and degradation. It can be reheated later for other purposes.
Bottle making process
PET Shampoo Bottle are usually manufactured using one of the following three blow molding processes.
The blow molding process is very suitable for smaller plastic bottles and can be used to mold a variety of polymers, including PET and HDPE. Break down this step and learn about one method of plastic from pellets to containers in this short video.
Extrusion blow molding
The extrusion blow molding process involves extruding molten plastic polymer (usually HDPE or LDPE) into a hollow tube or "Parion". In the extrusion reciprocating blow molding process, the two dies move back and forth to capture the continuously extruded parison. Learn how to do it in this short video.
Injection stretch blow molding process
A wide variety of bottles, jars and other containers can be molded using the general injection stretch blow molding process. The preform can be immediately formed into the final container by the 1-step method, or it can be saved as a stock for later use in the 2-step method. In this quick video, we will decompose the 1-step process from pellets to containers.
Before packaging, strict testing of PET bottles is the last step of the production line to ensure that they meet industry standards. Testing can include:
Impact resistance test
Manufacturers must also conduct tests to ensure that the size, shape, and finishing process of the final product are consistent before packaging and shipping to the final destination.