DFM Optimization for Food Packaging Machinery Frame Welding Assembly
Summary
Tetra Pak reduced welding operations by 61% and achieved 99.2% weld quality compliance for packaging machine structural frames through integrated weldment design optimization. The project eliminated post-weld machining and integrated sanitary design features meeting FDA food contact requirements.
The Challenge
Initial Need:
Tetra Pak's Denton, Texas manufacturing facility faced escalating costs and quality challenges in their structural welding operations for aseptic packaging machine frames, requiring complex multi-joint assemblies and extensive post-weld machining to achieve precise dimensional tolerances essential for high-speed packaging line performance. The original design comprised 94 individual steel components requiring 187 separate weld joints.
Pain Points:
Complex welding sequences: 187 separate weld joints requiring 67 hours of skilled welding labor per frame assembly
Post-weld machining requirements: 78% of assemblies requiring precision machining after welding for dimensional recovery
Weld quality defects: 11.8% of critical structural welds failing ultrasonic testing per AWS D1.1 acceptance criteria
Dimensional distortion issues: 23% of frames exceeding ±1.0mm flatness tolerances due to welding thermal effects
Our Solution
Our Approach:
The DFM optimization strategy focused on weldment consolidation through strategic joint elimination, optimized weld joint design minimizing distortion and stress concentrations, and integrated sanitary features eliminating secondary finishing operations required for food contact compliance. The engineering team implemented comprehensive welding simulation using SYSWELD finite element software.
Methodology:
Engineers utilized SYSWELD welding simulation software to analyze thermal cycles, distortion predictions, and residual stress patterns across 15 different weldment design iterations. Advanced fixturing design incorporated spring-loaded clamps and thermal expansion compensation, enabling consistent dimensional control throughout welding sequences.
Final Summary:
The optimized frame design consolidated 94 components into 41 major weldments, reduced weld joint count from 187 to 73 through strategic assembly redesign, and achieved ±0.5mm dimensional accuracy directly from welding operations eliminating 89% of post-weld machining requirements. Welding cycle time decreased from 67 to 26 hours.
Execution
Process Description:
Implementation required extensive structural validation including finite element analysis per AISC 360 steel design standards, dynamic load testing exceeding 15-ton capacity with vibration analysis up to 2,500 packages per minute operating frequency, and comprehensive sanitary design verification per FDA Food Code Section 4-1 equipment requirements.
Outcome
Value Comparison:
The DFM optimization delivered exceptional improvements in manufacturing efficiency and product quality, generating $5.2M annual savings through reduced welding operations and eliminated secondary processes. Direct labor cost reduction of $1,890 per frame through cycle time optimization contributed $3.4M annually based on 1,800-unit production volume.
Client Testimonial:
"This comprehensive DFM optimization transformed our packaging machine frame manufacturing from a complex, labor-intensive welding operation into a streamlined, highly automated process that consistently delivers superior quality and dimensional accuracy. The 61% reduction in welding operations combined with integrated sanitary design features fundamentally improved our manufacturing competitiveness."
- Erik Johannsen, Senior Manufacturing Engineering Director, Tetra Pak Denton Manufacturing Center