Tray Former

In modern logistics and packaging production lines, the folding tray machine (Tray Former) is a key piece of equipment for automated container forming. It automatically folds, bonds, or heat-seals flat sheets of paperboard or plastic into standardized trays, boxes, or packaging containers, providing uniform carriers for subsequent filling, stacking, and handling processes.

By converting flat sheets into three-dimensional containers through mechanical folding and fixing, the system significantly improves packaging efficiency, ensures dimensional consistency, and reduces manual labor costs.

Forming Principle and Folding Mechanism

The core of a folding tray machine lies in its precise control of the forming process.

The equipment typically uses a multi-station rotary arm or linear folding module to complete the folding sequence. Once the sheet material enters the forming station, it is first positioned and fixed by vacuum suction cups or locating pins. Then, folding guide rails or robotic arms execute controlled folding along predefined trajectories to form the container shape.

For glued containers, the system integrates adhesive units such as spray glue systems or hot melt glue guns, applying adhesive precisely during folding. For plastic sheets, thermal bonding is achieved using hot air or heated plates.

The folding accuracy directly determines the squareness and dimensional stability of the final tray. Therefore, servo-driven folding mechanisms are commonly used, ensuring angular accuracy within ±0.5°.

Sheet Feeding and Positioning System

Stable material feeding is essential for continuous operation.

The system usually adopts vacuum belt conveyors or chain push conveyors to ensure stable sheet transport without deviation at high speeds. Before the forming station, photoelectric sensor arrays continuously monitor sheet position and orientation.

If deviation is detected, an automatic correction system—such as side pushers or rotary alignment platforms—adjusts the sheet to ensure accurate positioning before folding.

For different sheet sizes, the machine supports quick changeover functions. Servo motors or pneumatic cylinders adjust positioning guides and folding rails, allowing format changes within approximately 5 minutes.

Bonding and Fixing Methods

Depending on material type and application requirements, different bonding technologies are used:

Cold Glue Bonding

Used mainly for paper-based packaging. Glue dosage and position are precisely controlled using gear pumps or screw pumps combined with solenoid valves to ensure consistent bonding strength.

Hot Melt Adhesive Bonding

Suitable for high-speed production lines. Hot melt glue solidifies quickly, improving throughput. A constant temperature control system ensures stable adhesive viscosity.

Thermal Sealing

Used for plastic sheets such as PET or PP. Heat and pressure are applied to fuse materials together. Key factors include temperature stability and uniform pressure distribution to avoid deformation or weak bonding.

Mechanical Locking

Used for simple or eco-friendly packaging where no adhesive is required. Structural tabs or slots are used for locking, suitable for disposable or recyclable packaging applications.

Electrical Control and Automation Integration

The folding tray machine is typically controlled by a PLC (Programmable Logic Controller), combined with an HMI (Human-Machine Interface) for parameter setting and system monitoring.

The system includes self-diagnostic functions. In case of abnormalities such as sheet jams, glue failure, or motor overload, the machine automatically stops and triggers alarms.

It also supports communication with higher-level systems via industrial protocols such as Profibus or Ethernet/IP, enabling real-time production data monitoring and remote diagnostics.

For high-speed lines, synchronization control ensures that forming speed matches upstream and downstream conveyors, preventing accumulation or starvation.

Typical Application: Food and Beverage Packaging

In the food and beverage industry, folding tray machines are widely used for producing trays, egg cartons, and beverage carriers.

For example, in egg packaging lines, the machine folds flat paperboard into structured egg trays with precise compartments, ensuring each egg is securely positioned and protected during transport.

In such applications, the equipment must comply with food-grade hygiene standards. All contact parts are made of stainless steel or food-grade plastics, and cleaning spray systems are often integrated for easy maintenance.

Maintenance and Service Requirements

Proper maintenance is essential for stable operation:

Folding Mechanism

Regular inspection of folding rails is required to ensure smooth operation and prevent wear-related misalignment.

Adhesive System

Hot melt or glue systems must be cleaned regularly to prevent nozzle clogging and ensure consistent bonding quality.

Transmission System

Chains, belts, and other transmission components require periodic tension adjustment and lubrication replacement.

Electrical System

Sensors must be checked for alignment and sensitivity, and wiring terminals inspected to prevent loose connections.

Safety Systems

Emergency stop buttons and safety light curtains should be tested monthly to ensure full operational safety.

System Value Summary

The folding tray machine plays a critical role in automated packaging lines. Its performance directly impacts overall production efficiency and packaging quality.

When selecting equipment, key factors such as production speed, container size range, bonding method, and system compatibility must be carefully evaluated to ensure it meets actual operational requirements and integrates seamlessly into the production line.