Fully Automatic PET Bottle Blowing Machine Stretching Mechanism
The fully automatic PET bottle blowing machine stretching mechanism is the core component that determines PET bottle molding quality and production stability. Installed inside the machine, this mechanism works with the blowing system to achieve uniform and accurate PET bottle forming in the stretch blow molding process.
The fully automatic PET bottle blowing machine stretching mechanism is the core component that determines PET bottle molding quality and production stability. Installed inside the machine, this mechanism works with the blowing system to achieve uniform and accurate PET bottle forming in the stretch blow molding process.
Structure of the Fully Automatic PET Bottle Blowing Machine Stretching Mechanism
The stretching system of a fully automatic PET bottle blowing machine mainly consists of three key parts: the stretching unit, sealing unit and blowing unit.
• The stretching unit uses a stretching cylinder or servo motor to drive the stretching rod up and down quickly and precisely.
• The sealing unit keeps stable pressure inside and outside the preform mouth to avoid mouth deformation during stretch blow molding.
• The blowing unit injects low-pressure air for pre-blowing when the stretching rod rises, then switches to high-pressure air to complete bottle forming.
The direct acting part is the equally spaced stretching rods. At the original state, the stretching rods stay below the preform holder axis and align with the mold cavity center. During blowing, the stretching rod quickly enters the preform and pushes the top to stretch, helping the preform expand evenly under high-pressure air.
Stretching Rod Replacement for Fully Automatic PET Bottle Blowing Machine Stretching Mechanism
The stretching rod of the fully automatic PET bottle blowing machine needs replacement in three cases: change of preform mouth size, change of preform inner diameter, and change of bottle shape or size.
Disassembly and Assembly Steps for Fully Automatic PET Bottle Blowing Machine Stretching Rod
1.Operate the HMI to move the stretching rod to a proper position.
2. Rotate the bolt to unscrew the stretching rod from the connector.
3. Remove the bottom screw of the connector and take off the connector.
4. Take out the stretching rod from top to bottom. Installation is in reverse order.
Installation and Adjustment Standards for Fully Automatic PET Bottle Blowing Machine Stretching Rod
The stretching rod must be vertically centered with the mold mouth. Keep a 1mm gap between the rod head and the mold bottom. All stretching rods must be level with no height difference. The rod head should fall into the center of the mold bottom, and the cylinder sealing head should insert into the preform mouth smoothly.
Cycle Motion Flow of the Fully Automatic PET Bottle Blowing Machine Stretching Mechanism
The fully automatic PET bottle blowing machine stretching mechanism runs in a fixed cycle to ensure continuous stretch blow molding production.
1.Initial State: Mold open, sealing and stretching parts at the lower position.
2. Mold Closing and Sealing: After preform positioning, the mold closes; the sealing cylinder moves up to press the preform axis and complete sealing.
3. Stretching and Blowing: High-pressure air is supplied, the stretching servo starts, and the stretching rod rises to the set height to form the bottle. Pressure is maintained until the bottle solidifies.
4. Opening and Resetting: Exhaust valve releases air, sealing and stretching mechanisms reset, mold opens, finished bottles are moved out, and new preforms are sent in for the next cycle.
The fully automatic PET bottle blowing machine stretching mechanism requires fast action, accurate positioning, low noise and low vibration. Its stroke and speed can be precisely adjusted for different bottle types, making it essential for efficient and stable PET bottle production. Whether it is a 10L, 15L or 20L fully automatic bottle blowing machine, the stretching mechanism is the core guarantee of product quality. We provide customized solutions for the stretching mechanism according to different materials and production requirements, helping customers achieve more efficient and stable production and create greater value.
