Packaging Analysis Improves Design
Tetra Pak is a food processing and packaging company that pioneered aseptic processing methods in the 1960s. It involves the ultra-high-temperature (UHT) treatment of milk and other liquid foods so that they are kept safe, fresh, and flavorful for at least six months without refrigeration.
Tetra Pak is a food processing and packaging company that pioneered aseptic processing methods in the 1960s. It involves the ultra-high-temperature (UHT) treatment of milk and other liquid foods so that they are kept safe, fresh, and flavorful for at least six months without refrigeration.
But the next step can present some problems: Gravity drives the liquid down, however, the folding step and the resulting tube deformation force the liquid backward. A pressure flange reduces the amount of backflow but the tube can still deform. It needs to retain its structural integrity without breaking or crimping.
- The composite packaging
- The packaged fluid including its flow and pressure properties
- The flotation device that rests on top of the fluid surface
- The system that folds the packaging material
- The pressure flange that controls pressure waves inside the tube
The combination of methods helped the engineers model the interaction of the packaging tube and the fluid in a single analysis. Because the packaging process is axially symmetric, the engineers modeled one-half of the system to substantially reduce processing time. The model involved approximately 220,000 elements with about 700,000 variables.
Engineers were able to model and define a variety of design parameters including:
- Sequencing the folding system action, including the deformation of the material
- Determining the choice and suitability of the packaging material
- Establishing the correlation between fluid injection rate and formed packaging volume
- Defining the tensile load applied to the material so as to prevent breakage or crimping