Blow molding is a manufacturing custom plastic process used to manufacture hollow plastic parts by inflating a heated plastic tube until it fills the mold and forms the desired shape. In this process, the raw material is a thermoplastic in the form of small particles or small particles, which is first melted and shaped into a hollow tube, called a parison. There are various methods for forming the parison, as described below. Then the parison is sandwiched between the two mold halves and inflated with compressed air until it conforms to the internal shape of the cavity. Typical pressure is 25 to 150 psi, which is much lower than injection molding pressure. Finally, after the part has cooled, separate the mold halves and eject the part.
hollow and thin-walled, such as bottles and containers, and they have various shapes and sizes. Smaller products may include bottles for water, hand sanitizer, shampoo, motor oil, and milk, while larger containers include plastic buckets, buckets, and storage tanks.
Low density polyethylene (LDPE)
High density polyethylene (HDPE)
Polyethylene terephthalate (PET)
Polyvinyl chloride (PVC)
Extrusion Blow Molding-An extruder uses a rotating screw to force molten plastic through a die that forms a parison around the blow pin. The parison is extruded vertically between two half-open dies, so they can be closed on the parison and the blow pin. Compressed air flows through the blow pin to expand the parison. This is the most common type of blow molding and is used to manufacture a large number of relatively simple parts.
Injection Blow Molding-The molten plastic is injected around the core in the parison mold to form a hollow parison. When the parison mold is opened, both the parison and core are transferred to the blow mold and clamped firmly. The core is then opened and compressed air expands the parison. This is the least commonly used method because of its low productivity but the ability to form more complex parts with higher accuracy. For small, complex bottles (such as bottles in medical applications), injection blow molding is usually preferred.
Stretch blow molding-parison formation is the same as injection blow molding. However, once transferred to the blow mold, it is heated and stretched down by the core before being inflated. This stretching provides greater strength to the plastic. Stretch blow molding is commonly used to manufacture parts that must withstand certain internal pressures or are very durable, such as soda bottles.
In 2010, with the approval of the Municipal Science and Technology Bureau, the "Changzhou Hollow Blow Molding Products Engineering Technology Research Center" was established to increase the company's innovation capability in the research and development of new materials and varieties, and is also the only engineering center in the industry.