Preform mouth defect detection machine

The Bottle Mouth Inspection Machine employs state-of-the-art machine vision technology to perform online, fully automated, and non-contact detection of deformation and defects on PET bottle mouths. It is designed for a rated capacity of 48,000 bottles per hour and is compatible with both PET and PE bottles.

Environmental Conditions

• Operating Altitude: 5–3000 meters above sea level

• Ambient Temperature: 5°C – 40°C

• Relative Humidity: 50% – 65% RH

• Factory Requirements: Floor flatness, load-bearing strength, and related conditions must comply with national standards to ensure stable machine performance.

• Storage Requirements: Upon delivery, equipment and components must be stored in facilities that meet national standards. During storage, proper lubrication and maintenance must be carried out to prevent surface damage, corrosion, or deformation that could impact installation, commissioning, or operation.

Equipment Operating Conditions

• Noise Level: ≤85 dB (actual levels may vary depending on the type of container/package, equipment power, acoustic properties of the facility, and other factors).

• Electrical Supply Connection: From the customer’s main electrical cabinet to the equipment control cabinet.

• Main Power Supply: 3 × 380V AC ±10%, 50 Hz, 3PH + N + PE

• Lighting Power: 220V AC, 50 Hz, single-phase
  (Special voltage requirements must be confirmed in advance, as they may affect specifications, delivery times, and pricing.)

• Total Power Consumption: Approx. 1.0 kW

• Control Voltage: 24 VDC

• Compressed Air: 4–6 bar (customer is responsible for providing the air pipeline connection between the air source and the main equipment unit).

Equipment Description

4.1 Bottle Finish Inspection Machine

• Equipment Name: Bottle Finish Inspection Machine

• Model: MT-PK021

• Quantity: 1 set

• Rated Capacity: 48,000 bottles/hour

• Applicable Containers: PET / PE bottles

• Compatible Production Line: 48,000 bottles/hour PET/PE bottle packaging line

• Installation Location: Installed inside the blow molding machine, either at the bottle discharge point or on the conveyor chain.

• Function: Detects and rejects PET/PE bottles with deformations or defects on the top sealing surface of the bottle finish.

4.2 System working principle and process

Figure 4: System working principle and flow chart

System Operating Principle and Process

1. As a bottle passes the positioning sensor, the sensor detects its presence and, via the control unit, records the bottle ID together with the current encoder value.

2. The positioning sensor then activates the camera to capture an image of the bottle mouth. Once the image is acquired, it is processed by the image processor. The processed data is transmitted to the HMI for real-time visualization and simultaneously to the control unit to prepare for the rejection of bottles with defective finishes.

3. When the control unit receives a defect signal, it instructs the rejection mechanism to remove the corresponding bottle identified by its recorded ID.

4.3 Image Acquisition Components

• Light Source: An LED area light source with a service life of up to 30,000 hours is used. Through front illumination, it ensures that the measured features are clearly visible. In the captured image, the bottle mouth appears as a continuous bright ring. A fixed-focus lens with manual aperture adjustment is employed; the focus ring is adjusted for maximum sharpness on the CCD sensor surface, while the aperture ring is fine-tuned to achieve optimal brightness.

• Camera: An area-array CCD analog camera is employed, with a resolution of 640 × 480 pixels and a frame capture rate of up to 60 frames per second.

4.4 Bottle mouth detection module:

image processing process

4.5 Inspection Items and Accuracy

4.5.1 Inspection Scope
A. Presence of through-holes
B. Chipping on the inner surface
C. Chipping on the outer surface
D. Localized spot chipping
E. Neck deformation (oval shape)

4.5.2 Detection Accuracy