Inkjet Printing and Inspection Machine

I. Project Equipment Overview

1. Project Name: PET Bottle Cap, Anti-theft Ring, Liquid Level, and Inkjet Printing Inspection System

2. Project Description: The system performs online inspection and automatic rejection of PET bottles with defects in caps, anti-theft rings, liquid levels, and inkjet printing.

3. Maximum Capacity: 60,000 bottles/hour

4. Bottle Type: PET bottles

5. Product Volume Range: 200 mL – 2 L

II. Environmental Conditions

1. Installation Altitude: 5–3000 meters above sea level

2. Operating Temperature: 5°C–40°C

3. Relative Humidity: 50%–65% RH

4. Factory Infrastructure: Floor flatness, load-bearing capacity, and related parameters must comply with national standards to ensure reliable operation.

5. Storage Conditions: Upon arrival, equipment and parts must be stored in accordance with relevant standards. During storage, proper lubrication and maintenance must be carried out to prevent damage, corrosion, or deformation that could affect installation, commissioning, or operation.

III. Equipment Operating Requirements

1. Power Supply: 220V, 50Hz, single-phase (to be provided by the customer; special voltage requirements must be communicated in advance, as they may affect specifications, delivery, and cost).

2. Total Power: Approx. 2.4 kW

3. Control Voltage: 24V DC

4. Compressed Air: 4–12 Pa (customer provides the pipeline connection from the compressed air source to the main equipment).

IV. Equipment Introduction

1. Installation Location
   To be installed directly on the production line at the designated inspection point.

2. Inspection Items

• Missing cap

• High cap

• Tilted cap

• Broken anti-theft ring

• Low liquid level

• Missing inkjet code

• Excessive inkjet printing

• Step 1: As each PET bottle passes through the positioning sensor, the system records the bottle’s unique ID along with the encoder signal.

• Step 2: The sensor then triggers the camera to capture images of three inspection points: the bottle cap, the internal liquid level, and the inkjet marking (note: this refers to the printed content, not the printer itself). The image processor analyzes the captured data and transmits results both to the HMI (for real-time display) and to the PLC (to prepare for rejection of defective bottles).

• Step 3: If a defect is detected, the control unit sends a rejection command to the rejector, which accurately removes the defective bottle corresponding to the recorded ID.

4. Equipment mechanical components

5. Electrical composition of the equipment

6. Testing cabinet structure diagram

Capping liquid level detection (capping liquid level detection at stations one and three)

Inkjet printing inspection (station 2, single-camera inkjet printing inspection)

7. Cap Inspection

This module is equipped with three CCD cameras positioned at different angles to capture comprehensive images of each bottle, minimizing blind spots during inspection. Specialized optical lenses are employed to filter ambient light from all directions, ensuring clear and accurate image acquisition. The system is designed to identify cap-related defects, including missing caps, raised caps, misaligned caps, and damaged caps.

8. Liquid Level Detection

This module employs a CCD camera to capture frontal images of the bottle’s liquid level. It ensures that the liquid surface remains nearly horizontal when the bottle is stationary. Through advanced image processing, the portion of the image below the liquid surface is displayed as black, while the area above, representing the empty section of the bottle, appears white. A specialized algorithm is then applied to accurately distinguish whether the liquid level falls below or exceeds the preset threshold.

9. Inkjet Printing Inspection

This module uses a CCD camera to capture images of the inkjet printing on bottles and caps from the front. It then digitally analyzes the captured images and automatically and accurately rejects bottles with unqualified inkjet printing. It is compatible with both yellow caps with black ink and black caps with white ink.

10. Detection accuracy