Inkjet Printing Visual Inspection Machine

PET Bottle Vision Inspection System

Cap, Tamper-Evident Ring, Liquid Level & Inkjet Printing Inspection

I. Equipment Overview

1. Project Name:
   PET Bottle Vision Inspection System for Cap, Tamper-Evident Ring, Liquid Level, and Inkjet Printing Inspection

2. System Description:
   The inspection system is designed to perform automated quality checks on PET bottles, including cap position and integrity, tamper-evident ring condition, liquid level, and inkjet printing quality. Bottles that fail to meet the predefined inspection criteria are automatically identified and removed from the production line.

3. Maximum Line Speed:
   Up to 60,000 bottles per hour (BPH)

4. Applicable Container:
   PET bottles

5. Applicable Volume:
   200 mL to 2 L

II. Environmental and Installation Conditions

1. Applicable Installation Altitude:
   5–3,000 meters above sea level

2. Ambient Operating Temperature:
   5°C–40°C

3. Relative Humidity:
   50%–65% RH

4. Site Requirements:
   The installation area shall have sufficient floor flatness, structural stability, and load-bearing capacity and shall comply with applicable national standards to ensure safe, reliable, and stable equipment operation.

5. Storage Conditions:
   Prior to installation, the equipment and its components shall be stored in an environment that meets applicable national standards. During the storage period, appropriate lubrication, protection, and routine maintenance shall be carried out to prevent corrosion, surface damage, deformation, or other conditions that may affect subsequent installation, commissioning, and normal operation.

III. Utility Requirements

1. Power Supply:
   220 VAC, 50 Hz, single-phase.

   The electrical supply shall be provided by the customer. Any special or non-standard voltage requirements must be confirmed before equipment design and production, as they may result in changes to the equipment configuration, manufacturing lead time, and project cost.

2. Total Power Consumption:
   Approximately 2.4 kW

3. Control Voltage:
   24 VDC

4. Compressed Air Supply:
   4–12 Pa

   The customer shall provide the compressed-air connection and pipeline from the air supply source to the main equipment unit.

Technical Note: It is recommended to reconfirm the compressed-air specification. 4–12 Pa is an extremely low pressure for industrial pneumatic equipment; if the intended specification is 4–12 bar or 0.4–1.2 MPa, the unit should be corrected in the final technical document.

IV. System Functions and Inspection Method

1. Installation Position

The inspection system shall be installed and integrated into the PET bottle production line at a suitable position according to the overall line layout, bottle conveying direction, and production process requirements.

2. Inspection Items

The vision inspection system is configured to identify the following defects:

• Missing cap

• Excessively raised cap

• Incorrectly positioned or misaligned cap

• Damaged or broken tamper-evident ring

• Insufficient liquid level

• Missing inkjet marking

• Excessive or abnormal inkjet printing

3. Inspection and Rejection Process

Step 1 – Bottle Detection and Identification

When a PET bottle enters the inspection area, the positioning sensor detects the bottle and sends a trigger signal to the control system.

The system assigns a unique identification number (ID) to the bottle and associates this ID with the encoder's real-time position signal. This provides continuous and accurate tracking of each bottle as it moves through the inspection section.

Step 2 – Image Acquisition and Vision Analysis

Based on the bottle position and encoder feedback, the control system triggers the cameras to acquire images at three designated inspection areas:

1. Bottle cap

2. Liquid level

3. Inkjet marking

The captured images are transmitted to the vision processing system for analysis. The inspection results are displayed in real time on the HMI (Human-Machine Interface) and simultaneously communicated to the PLC (Programmable Logic Controller) for subsequent defect handling and rejection control.

Step 3 – Defective Bottle Rejection

When an abnormality is identified, the control system links the inspection result to the corresponding bottle ID and continuously tracks its position through the encoder signal.

Once the defective bottle reaches the designated rejection position, the PLC sends a command to the automatic reject mechanism. The rejector then removes the corresponding non-conforming bottle from the production line.

This process creates a closed-loop inspection and rejection system, enabling accurate product tracking, automated defect detection, and reliable removal of defective PET bottles while maintaining continuous high-speed production.