What is preform injection?
Preform injection is an injection molding process used to produce intermediate products for bottles and containers called preforms. These preforms are typically made from polyethylene terephthalate (PET) material and have the shape and basic structure of the final product, but require secondary blow molding to create the final product.
Preform injection process steps:
Raw material preparation: First, the PET resin pellets are dried to remove moisture from them. This step is very important because moisture can affect the physical properties of the material and the quality of the final product.
Plasticizing and injection: The dried PET pellets are fed into the hopper of the injection molding machine and melted in the heating barrel through the screw. When the set temperature and viscosity are reached, the molten plastic is injected into the preform mold.
Cooling and solidification: After the molten plastic is injected into the mold, it is rapidly cooled by the cooling system to solidify the plastic and form the shape of the preform.
Removal and inspection: The cooled and solidified preform is removed from the mold and quality inspected. Qualified preforms will enter the next production stage, while unqualified ones will be recycled.
Secondary blow molding: The preform is heated to the appropriate temperature and then placed in the blow mold. It is expanded by air pressure and pressed against the inner wall of the mold to form the final bottle or container.
Advantages of preform injection:
Efficient production: Preform injection combined with blow molding can achieve efficient large-scale production, especially suitable for products with large demand such as beverage bottles and cosmetic bottles.
Quality Control: By precisely controlling the injection and blow molding processes, preform injection ensures consistent quality and appearance for each product.
Material saving: PET material has good recycling characteristics, and waste materials can be reprocessed and used, reducing material waste.
Cost-Effectiveness: Preform injection is a very cost-effective production method due to high production efficiency and low scrap rates.
Applications of preform injection:
Preform injection is widely used in the manufacturing of various types of plastic containers that require high transparency, high strength and lightweight, including:
Beverage bottles (such as mineral water bottles, carbonated drink bottles)
Food containers (such as soy sauce bottles, cooking oil bottles)
Cosmetic bottles (such as perfume bottles, shampoo bottles)
Medical containers (such as medicine bottles)
Preform injection is an efficient and precise injection molding process particularly suitable for manufacturing preforms for a variety of plastic bottles and containers. This process combines the advantages of injection molding and blow molding, making product production highly efficient, stable, and low-cost. It is widely used in food, beverage, cosmetics, pharmaceutical and other industries.
