Understand Plastic Blow Molding Machines in One Article: Definition, Classification, and Core Components

The plastic hollow molding blow machine (commonly referred to as a blow machine) is a critical piece of equipment used to prepare hollow containers by heating and softening plastic materials, then using compressed air to inflate and shape them. It is widely applied in packaging fields such as food & beverage, daily chemicals, and pharmaceuticals. At its core, the machine transforms plastic pellets or preforms into hollow products of specific shapes, and it is primarily categorized into three main types:

Extrusion Blow Molding Machine: Composed of an extruder, parison die head, clamping mechanism, and more, this machine continuously produces tubular parisons via the extruder, which are then inflated and cooled to form the final product. It is suitable for manufacturing a wide range of hollow products from 2.5 ml up to 10,000 liters, particularly excelling in producing large, complex-shaped containers. While the equipment requires relatively low investment, its dimensional accuracy is somewhat limited compared to other methods.

Injection blow molding machine: Combines injection and blow molding functions—first injecting molten plastic to form a preform with a base, then transferring it to a blow mold for final shaping. Commonly available in three-station (preforming, blow molding, demolding) or four-station models, this equipment ensures precise product dimensions and superior bottle-mouth quality, making it the preferred choice for producing high-precision containers like PET beverage bottles. However, it comes with relatively higher mold costs.

Specialized blow molding machines: Designed for producing items with unique shapes—such as custom-shaped tool boxes or large storage tanks—using materials like sheets and preforms. The machine’s structure is tailored precisely to meet the specific requirements of each product.

Regardless of the type, blow molding machines all feature five core modules: a plasticizing system, clamping mechanism, blowing system, cooling system, and electrical control system. Key components such as the screw central shaft and die head are often made from wear- and corrosion-resistant materials like the 38CrMoAlA alloy.