Evaluating Robot Integrators in China for a Palletizing Cell

Project Overview

An anonymized food-products manufacturer was evaluating Chinese robot integrators for an end-of-line palletizing project.

The production line handled six carton sizes ranging from 4 to 17 kilograms.

Target output ranged from five to nine cartons per minute, depending on the SKU.

The plant wanted to reduce manual lifting and improve stack consistency.

The Initial Quotations

Early supplier proposals focused heavily on:

• Robot brand
• Payload
• Reach
• Robot price
• Cell footprint

However, several quotations did not clearly include:

• Carton accumulation
• Conveyor controls
• Pallet presentation
• Pallet removal
• Slip sheets
• Multiple pallet patterns
• Safety access
• Product changeover
• Stretch-wrapper interface
• Overseas commissioning

The lowest quotation appeared attractive but covered mainly the robot, pedestal, and gripper.

It was not a complete palletizing cell.

The Main Risks Were Defined

The buyer and project team identified five main risks.

1. Product Handling

Some cartons had:

• Flexible top surfaces
• Inconsistent tape position
• Glossy labels
• Minor deformation
• Different weights

A gripper selected only from drawings might not work across the full range.

2. Stack Stability

The buyer required several pallet patterns.

Some products needed interlocking layers.

Others required careful edge alignment to avoid collapse during transport.

3. Line Flow

The robot needed to communicate with:

• Upstream case sealer
• Infeed conveyor
• Accumulation zone
• Pallet conveyor
• Stretch wrapper

The cell had to manage blocked downstream equipment without losing cartons.

4. Changeover

Operators needed to select product recipes without calling an engineer.

The buyer also wanted future pallet patterns to be added without rewriting the full robot program.

5. FAT

A short robot demonstration would not prove:

• Carton handling
• Stack stability
• Conveyor accumulation
• Recipe change
• Recovery from blocked flow
• Operator access

Evidence Requested From Suppliers

Product Handling

Suppliers were asked to:

• Test real cartons
• Demonstrate the full weight range
• Explain vacuum or mechanical gripping
• Show behavior with deformed cartons
• Confirm label-contact risk
• Estimate gripper maintenance requirements

Pallet Patterns

Suppliers were asked to provide:

• Pattern drawings
• Stack simulation
• Maximum stack height
• Layer sequence
• Changeover method
• Slip-sheet approach
• Recipe management

Conveyor Integration

Suppliers were asked to provide:

• Cell layout
• Conveyor heights
• Accumulation logic
• Sensor positions
• Upstream and downstream signals
• Blockage recovery
• Reject procedure

Safety

Suppliers were asked to explain:

• Guarding
• Light curtains
• Pallet-access doors
• Operator entry
• Maintenance mode
• Safe restart
• Required installation-country standards

FAT

Suppliers were asked to define:

• Real carton quantity
• Runtime
• Product formats
• Target output
• Pallet patterns
• Fault tests
• Changeovers
• Pass-and-fail criteria

The Supplier Shortlist Changed

One supplier had a strong robot partnership and competitive price but weak conveyor capability.

Another supplier built packaging lines but outsourced robot programming.

A third supplier had a smaller sales presence but could show:

• Several comparable palletizing cells
• Real-carton gripper tests
• Pallet pattern software
• Conveyor logic
• A documented FAT process
• Overseas commissioning experience

The third supplier became the strongest candidate even though its robot brand was not the buyer’s initial preference.

The RFQ Became Cell-Level

The revised RFQ covered:

• Carton dimensions
• Carton weights
• Carton surface conditions
• Pallet dimensions
• Pallet quality
• Stack height
• Pallet patterns
• Slip sheets
• Cases per minute
• Conveyor interfaces
• Empty-pallet supply
• Full-pallet removal
• Guarding
• Safety access
• PLC and HMI
• Recipe management
• Spare parts
• Installation
• FAT

This forced each supplier to quote the complete operating cell rather than a robot package.

Proposed FAT

The recommended FAT included:

• Real cartons from all major SKUs
• Two complete pallet patterns
• Four hours of cumulative runtime
• At least one product changeover
• Conveyor-blockage recovery
• Missing-carton handling
• Emergency-stop and restart
• Full-pallet change
• Stack-dimension verification
• PLC, HMI, and robot backup handover

Case Study Takeaway

When sourcing palletizing equipment in China, compare complete cell ownership, not robot-arm prices.

The strongest supplier is the one that can prove product handling, line flow, stack stability, recovery, and FAT under real operating conditions.