How to Select the Right Robot for Your Injection Molding Machine
Selecting the correct injection molding robot is a critical engineering decision that directly impacts production efficiency, part quality, and return on investment. This guide walks through the key technical parameters and selection criteria to help manufacturing engineers make informed decisions.
Step 1: Match Robot to Injection Molding Machine (IMM) Tonnage
The robot must be sized appropriately for the injection molding machine it will serve. Undersized robots risk mechanical failure and slow cycle times; oversized robots waste capital and consume excessive floor space.
| IMM Tonnage | Recommended Robot Series | Key Characteristics |
|---|---|---|
| 50-250 tons | BaoTa Series / BeiKe Series | High-speed 5-axis, telescopic arm, 3-5kg payload |
| 250-500 tons | TanKe Series / BP Series | Open-type or swing-arm, 5-8kg payload |
| 500-2000 tons | Anston Series | Heavy-duty 5-axis, reinforced structure, 10-30kg payload |
| Special Configurations | Side Vertical Series | Side-entry for vertical clamp IMMs |
Step 2: Calculate Required Stroke Lengths
Proper stroke calculation ensures the robot can reach all required positions within the mold area:
- Traverse Stroke (X): = Mold width + safety clearance (200-400mm). Must clear the mold area completely for safe operator access
- Vertical Stroke (Y): = Mold height + part drop height + gripper clearance (150-300mm). Telescopic arms can reduce Y-axis requirements
- Crosswise Stroke (Z): = Distance from robot mounting to mold centerline + reach into mold
- Take-Out Time Budget: = Available mold-open time minus safety margins. The robot must complete the entire in-mold sequence within this window
Step 3: Payload Calculation
The robot payload rating must account for both the part weight and the end-of-arm tooling weight. A common mistake is sizing only for part weight:
Total Payload = Part Weight + EOAT Weight + Safety Factor (20-30%)
Additionally, consider dynamic loads during acceleration. The robot wrist must handle moment loads caused by the part center of gravity offset from the wrist centerline, especially important for large automotive parts and furniture components.
Step 4: Wrist Configuration
The wrist configuration determines what movements the robot can perform at the mold:
- Standard Wrist (Flip 90°): Simple vertical-to-horizontal part reorientation. Suitable for most applications
- 3-Axis Wrist (Flip + Rotation): Adds wrist rotation for complex part orientation requirements, insert loading, and in-mold labeling
- 5-Axis Full Wrist: Maximum flexibility with flip, rotation, and tilt axes for the most demanding applications
Step 5: Control System Integration
The robot controller must communicate with the injection molding machine controller. EUROMAP 67 (basic interface) and EUROMAP 77 (advanced interface) are the industry standards. YUBAO robots support both protocols, plus SPI (Society of the Plastics Industry) standard for the North American market.
For technical assistance with robot selection for your specific application, contact YUBAO engineering team.
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