Simulation and analysis, or Computer Aided Engineering (CAE), enables engineers and organizations to analyze and explore new packaging processes and methods in a virtual environment, reducing the time and cost requirements associated with physical and experimental testing.
For over 40 years, product manufacturers in transportation industries have relied on computer simulations as a means to accelerate innovation and significantly reduce the risk and cost of product development. Take for instance the automotive industry which on a daily basis utilizes simulation and virtual test for early system-level performance studies ranging from vehicle dynamics and ride and handling to Noise, Vibration and Harshness (NVH), durability, and crash and safety. The aerospace industry has established and deeply engrained virtual test methods for aeroelasticity, flight loads, and a broad range of additional structural analysis studies on the airframe and its components and sub-systems, for instance. One can imagine the positive impact that these tests have on product development. Through virtual testing, new insights or potential design flaws are now identified much earlier in the development stages rather than having to wait for physical test results. Now packaging equipment manufacturers can achieve the same benefits by expanding their investment and utilization of virtual testing to determine how best to fully utilize their equipment and maximize efficiency.
According to I.D. Images, the packaging industry has seen several changes over the past few years. There is consolidation at every level including suppliers, distributors, and customers which has led to an increasingly competitive market. This presents a challenge for packaging equipment companies to differentiate themselves in the fierce marketplace and deliver unique value to their customers. Because solid margins have begun to decline for some companies, investing in new research and development methods becomes one means of differentiation and payoff for firms in the long-run. The more efficient and innovative packaging equipment and processes become, the more customers will rely on brands and continue being loyal advocates.
We have witnessed several companies who are continually developing innovative packaging methods. The highly competitive nature of this industry requires faster development times and lower costs. Machines must operate faster and more reliably than their predecessors. Increasing the speed of machines raises inertial loads, creating the potential for vibration and resonances that could substantially reduce the life of the machines and cause breakdowns.
This article discusses two examples of how packaging equipment companies are successfully implementing modeling and analysis methods to increase competitiveness and establish differentiation in their markets.
Kosme, a customer of MSC Software’s, manufacturers a full range of packaging and beverage lines, providing custom solutions based on the philosophy: high performance, highly reliable, simple to use. In the past, Kosme engineers used hand calculations to estimate the performance of components and built physical prototypes to evaluate system performance. Problems were being discovered during the prototype stage. These problems often required many iterations of revisiting the design and modifying and re-testing the prototype. The company began using structural finite element analysis and multibody dynamics to model and assess the performance of their systems.
One application in particular involved a customer in Argentina who had asked Kosme to build a bottle-boxing machine capable of processing 36,000 bottles per hour. This represented a substantial increase over the previous generation of machines which were only capable of processing 24,000 bottles per hour. The primary limiting factor on the performance of the machine was the ability to move bottles at high speeds without incurring vibration that will damage the machine in a relatively short period of time, according to the Technical Director at Kosme. To increase machine speed, they needed to increase the strength of critical mechanism components while keeping their weight low to reduce the strain on motors, drive systems and structural members.
The simulation model they created behaved nearly the same as the previous generation machine, making it possible to begin evaluating alternative solutions for the new generation by modifying the model and measuring the impact on machine speed and vibration. As an example, the finite element model revealed the stress in components under actual machine operating conditions. This made it possible to improve component design by reducing mass in low-stress areas and adding mass in high-stress areas. Using this process, the mass of critical moving components was reduced by 20% to 30% while reducing stress levels.
The multibody dynamic simulation was used to evaluate the performance of the complete machine at various speeds including potential vibrations. Each design iteration took between one and two days and didn’t require any hardware, which meant that the design process moved much more quickly than would have been possible using the old build-and-test approach. The simulations also provided much more information than could be gained from physical testing, such as displacement, acceleration, loads and torques of every node in the model throughout the time period of the simulation.
Kosme’s ability to quickly and thoroughly evaluate many design alternatives using simulation made it possible to increase the processing speed of the machine by 50% while reducing vibration levels below the previous generation of machines. The first prototype provided the performance and functionality predicted by the simulation so it became the final product. The new machine was completely designed in one and a half months, faster than any similar machine.
Simulation makes it possible to design, optimize and visualize packaging machines prior to the prototype stage. The result is that the company was able to engineer substantial performance improvements while getting the design right the first time. To see the full case study, please visit: http://bit.ly/1QOtyJn
The second case study example is the Italian Institute of Technology (IIT) who used engineering simulation to test a complex folding machinery. Packaging plays a particularly important role in the high-quality confectionary market where producers produce elaborate cartons with complicated folding procedures that can be compared to origami. Most of these packages are not secured by glue, but rather with complicated tuck-in operations, requiring that the carton be constructed with flaps and slots that mate to each other during the folding operation. Complex packages are traditionally built by human operators, because of the difficulty in developing automated machinery that can manage the complicated folding operations and also be readily adapted to new packaging styles as they are developed.
The industry is working on developing flexible automation systems based on programmable robots that can handle complicated packages and can accommodate new designs with software changes alone.
One of the greatest challenges involved in the design of the carton and packaging equipment is understanding the behavior of the carton during the folding process. The cardboard consists of a multiply laminate with each ply providing high tensile stiffness and low compression stiffness. When the adjacent panels rotate around a crease, the outer plies are stretched and the inner plies are compressed.
As one example, the tuck-in operation, where the end flap of the lid is secured by inserting it into a slot, is the most complicated task of carton folding. The tuck-in operation is complicated by the fact that the lid is divided into three links whose kinematics must be well understood to insert the end plate into the small slit. This complex operation can be completed without difficulty by a skilled person, however, it much more challenging to automate the process so it can completed at a high rate of speed while maintaining perfect quality.
IIT engineers produced a multibody dynamics simulation model of both the carton and robot to demonstrate how the folding operation could be performed. The carton folding sequence of the folding model matched up perfectly to the actual robot. With the multibody dynamics simulation model being validated against the physical test, researchers are now able to evaluate different folding methods and new package designs with the simulation model as opposed to having to use the actual robot. One of the best results is that they computed the contact forces that were impossible to measure on the physical prototype, because the contact points were too small to install a pressure/force sensor and the motor typology was not suitable for this feature. Researchers are now working on incorporating flexible materials into the model which will increase the accuracy of the simulation and make it possible to accurately simulate even more complicated folding operations. To see the full case study, please visit: http://bit.ly/1PRlebG
In summary, we anticipate the continued growth and application of simulation methods in the packaging industry over the coming years as the technology is now mainstream and instrumental in decision making processes within product design teams and throughout all stages of development. Business leaders will see positive results that impact the bottom line. Their companies will design stronger, innovative brands that lead to unique differentiation in the marketplace.