The manufacturing of HDPE (High-Density Polyethylene) containers and bottles is a highly automated, efficient process. The dominant method is Blow Molding, with Extrusion Blow Molding Machine and Injection Blow Molding Machine being the two primary techniques.

HDPE Material Advantages:

HDPE is chosen for its chemical resistance, stiffness, good moisture barrier, and relatively low cost. HDPE can be naturally translucent/white or colored with masterbatch pigments added during processing.

Manufacturing Processes of Blow Molding Machine:

Extrusion Blow Molding Machine (EBM):

This is the most common method for making larger, asymmetrical, or handleware containers (like detergent bottles, jerry cans, drums).

• Plasticizing & Extrusion: HDPE pellets are fed into an extruder—a heated barrel with a rotating screw. The pellets are melted (plasticized) into a homogeneous, viscous melt.
• Parison Forming: The molten plastic is forced through a die head to form a hollow, continuous tube called a parison.
• Mold Closure: A two-part mold, shaped like the final bottle, closes around the parison, pinching and sealing the bottom.
• Blowing: A blow pin is inserted into the neck of the parison. High-pressure air (often 80-100 psi) is injected, inflating the soft parison like a balloon to take the exact shape of the cold mold cavity.
• Cooling & Solidification: The mold is water-cooled. The HDPE solidifies almost instantly against the cold mold walls.
• Mold Opening & Ejection: The mold opens, and the finished container is ejected. Excess plastic (flash) at the seams is trimmed off and recycled.

Injection Blow Molding Machine (IBM):

Common for smaller, precise, symmetrical bottles with excellent neck finish (like pharmaceutical, cosmetic, or single-serve food bottles).

• Injection: Molten HDPE is injection molded around a core rod (also called a mandrel) to form a precise, thick-walled test-tube shape called a preform. The neck and thread details are fully formed at this stage.
• Blowing: The core rod with the preform rotates into a blow mold. High-pressure air is introduced through the core rod, inflating the preform into the final bottle shape.
• Ejection: The finished bottle is stripped off the core rod. There is little to no flash, as the neck was already perfect.

About Suzhou Bestar Blow Molding Machinery Co., Ltd:

Beier Group and Bestar company are same owner And Bestar has been established for more than 19years. Bestar provides customers high efficiency, innovative, energy saving blow molding machinery solutions. Bestar blow molding machines sold to more than 60 countries.

Series blow molding machine is used for blowing 100ml-1250L HDPE PE PP products like milk bottles, daily chemical packaging bottles, jerry cans, pesticide bottles / medicine bottles and stacking barrels.

Please write your machine inquire Email, Phone Number and Company Name here, we will respond within 12h. Or you can directly contact us: Email: sales@bestarmachinery.com or at Whatsapp/Wechat +86 18862609888.