What is blow molding?
Blow Molding is a plastic processing technology used to manufacture hollow plastic products, such as bottles, containers, baby bottles, plastic buckets, toys, etc. This process typically involves heating, expanding, and forming the plastic into the desired shape. There are different variations of blow molding, including extrusion blow molding, injection blow molding, and stamp blow molding, but the basic principles are similar.
The following is the basic working principle of blow molding:
1. Melting plastic: First, solid plastic pellets or pellets are heated and melted. This is usually done in a special blow molding machine, where the molten plastic is pushed into a heated area by a screw or plunger.
2. Form the blow molding blank: Once the plastic reaches a sufficiently molten state, it is extruded or injected into the mold to form a hollow plastic blank that is similar in shape to the desired final product.
3. Blow molding: The formed blank is placed in a mold, which usually contains two halves. One mold half is held in place while the other mold half is pushed against the mold wall by injecting air or nitrogen into the blank. The blank conforms to the inner walls of the mold and takes on the desired shape.
4. Cooling and solidification: Once the plastic blank takes the desired shape, cooling air or nitrogen is used to cool the plastic and solidify it.
5. Mold separation: Once the plastic is completely cooled and solidified, the mold will separate, allowing the finished hollow plastic product to be removed.
Blow molding is generally divided into two main types:
1. Extrusion blow molding: In extrusion blow molding, the molten plastic is passed through an extruder to extrude the blank and then blown into the desired shape through a mold. This method is suitable for making hollow objects such as bottles.
2. Injection blow molding: Injection blow molding combines the principles of injection molding and blow molding. First, molten plastic is injected into a mold to form a blank, which is then blown into a hollow product.
Blow molding is an efficient production method suitable for high-volume production of hollow plastic products that are commonly used in applications such as packaging, containers and containers. Due to its high production efficiency and low cost, it is widely used in food and beverage, medical, household products and other industries.