PET Bottle Mouth Inspection Machine

The Bottle Mouth Inspection Machine employs advanced machine vision technology to perform fully automated, non-contact online inspection of PET bottle mouths, detecting deformation and damage with high accuracy. It is designed for a rated capacity of 48,000 bottles per hour and is suitable for use 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 other site parameters must comply with national standards to ensure proper machine operation.

• Storage Requirements: After delivery, equipment and components must be stored in facilities that meet national standards. During storage, adequate lubrication and maintenance are required to prevent surface damage, corrosion, or deformation that may affect installation, commissioning, or operation.

Equipment Operating Conditions

• Noise Level: ≤85 dB (actual values may vary depending on container type, machine power, building acoustics, and other environmental factors).

• Electrical Connection: Between the customer’s main electrical cabinet and the equipment cabinet.

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

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

• Total Power Consumption: Approx. 1.0 kW

• Control Voltage: 24 VDC

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

Equipment Description

4.1 Bottle Finish Inspection Machine

• Equipment Name: Bottle Finish Inspection Machine

• Model: MT-PK021

• Quantity: 1 set

• Rated Speed: 48,000 bottles/hour

• Applicable Containers: PET / PE bottles

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

• Installation Position: Located inside the blow molding machine, either at the bottle discharge section or on the conveyor chain.

• Function: Inspects and rejects PET/PE bottles with deformation or damage on the 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 each bottle passes the positioning sensor, the sensor detects its presence and, through the control unit, records the bottle ID along with the current encoder value.

2. The positioning sensor then signals the camera to capture an image of the bottle mouth. Once the image is obtained, it is processed by the image processor. The processed data is transferred to the HMI for real-time display and simultaneously sent to the control unit in preparation for rejecting bottles with defective finishes.

3. When the control unit receives a rejection signal, it activates the rejector to remove the specific bottle corresponding to the stored ID.

4.3 Image Acquisition Components

• Light Source: An LED area light source with a service life of up to 30,000 hours is employed. By using front illumination, it ensures that the features of the inspected object 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 applied. The focus ring is adjusted to achieve maximum clarity on the CCD sensor surface, while the aperture ring is fine-tuned to ensure optimal image brightness.

• Camera: An area-array CCD analog camera is used, featuring a resolution of 640 × 480 pixels and capable of capturing up to 60 frames per second.

4.4 Bottle mouth detection module:

image processing process

4.5 Test Scope and Precision

4.5.1 Inspection Items
A. Through-holes
B. Internal chipping
C. External chipping
D. Spot chipping
E. Deformed or oval-shaped bottle neck

4.5.2 Detection Accuracy