HDPE Plastic Bottle Manufacturing Process (Extrusion Blow Molding)
Step 1: Raw Material Preparation
HDPE resin in granular form serves as the primary material. Additives like color masterbatches or UV stabilizers are mixed in to ensure color uniformity and specific properties.
Step 2: Plasticizing & Parison Extrusion
The material is fed into an extruder, where it is heated and melted (typically at 180-230°C). The molten HDPE is then forced through a circular die head to form a hollow, continuous tube called a parison.
Step 3: Mold Clamping & Parison Capture
The mold, which defines the final bottle shape, closes around the parison once it reaches the desired length, simultaneously cutting it. A blow pin is positioned at the top or bottom of the captured parison.
Step 4: Blow Molding
High-pressure air is injected through the blow pin, inflating the soft parison to conform exactly to the inner contours of the cold mold cavity. This shapes the bottle body and finishes the neck formation.
Step 5: Cooling & Solidification
The mold, equipped with cooling channels, rapidly chills the HDPE, causing it to solidify into its final rigid shape. Cooling time is critical for both quality and production cycle efficiency.
Step 6: Demolding & Ejection
After sufficient cooling, the mold opens, and the finished bottle is automatically ejected.
Step 7: Post-Processing
Trimming: Excess plastic flash, especially around the neck and bottom, is removed.
In order to meet the demand for higher efficiency and greater output, Zhenghao added three new extrusion blow molding machines in August. Currently, Zhenghao has over 12 automated extrusion blow molding machines, achieving a daily supply demand of 100,000 pieces.
For a professional plastic packaging manufacturer like Zhenghao, through advanced extrusion blow molding equipment, precise molds and mature process parameter control, it is possible to achieve large-scale production of HDPE plastic bottles with high efficiency, high quality and low cost, meeting the high requirements of customers for packaging containers in many fields such as personal care, cosmetics, food and medicine.
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