ㆍProduct: Coffee capsule machine
ㆍAnalysis Goal: Increase capacity by 25% without increasing overall costs and energy efficiency
Capacity is one of the most important features of an automatic packaging machine. OPEM’s designers are constantly looking for new design solutions that will allow the company to remain competitive. This project deals with the optimization of a machine for the production of coffee capsules. The main objective was to increase the capacity by 25%, without affecting the general architecture, the size of parts and the energetic efficiency of the machine. The objectives were achieved by optimizing the motion laws of all actuators. A large number of Multi-Flexible Body Dynamics simulations were performed in RecurDyn to check the effects of the optimized laws on the system behavior.
① Motion laws are applied to all ideal motors equipping the machine. Motion laws are designed and optimized to guarantee continuity and lowest possible accelerations, while achieving the desired displacements at the desired instants.
② The rigid multi-body model of the entire machine is used to check that the motion laws are properly synchronized. The same model is also used to measure the power demand which becomes the main information used to choose proper motors.
③ This model includes a Full Flex representation of the thin film that is used to seal the capsules.
④ The multi-flexible body model of the entire machine is used to check if the positions of tools and capsules are guaranteed even when the structures deform in dynamic conditions.
⑤ This model is also used to calculate the dynamic reaction forces at the constraints that connect each machine sub-system to the main frame.
⑥ The loads obtained from the multi flexible body model are used for structural assessment (strength and fatigue) using other Finite Element programs.
Key Technologies for Analysis
ㆍ Rigid multi-body dynamics is used to optimize motion laws and calculate power demand since it is very fast. Multiple iterations take little time to perform.
ㆍ Multi flexible body dynamics is used to check that all bodies (tools, capsules, and film) are in the expected (and required) position in severe dynamic conditions.
ㆍ Hundreds of non-linear contacts are used to describe the interaction between tools, capsules, and film.
The Problems that Customers are Facing
• The market demands packaging machines with increased capacity, reliability, and small dimensions.
• Machines have to be competitive in terms of cost.
• Many contacts are used to represent the complex chain mechanism.
• Many numbers of simulations are required for optimization because optimization of motion laws (cams and controlled electric drivers) is the key to achieving higher capacity without increasing the power demand and the dynamic loads.
• Rigid multi-body simulation is the most suitable approach to check the correctness of the motion laws, as each simulation takes a very short time. Running multiple iterations to optimize the laws is easy and can be done at no cost.
• Flexible multi-body (reduced ex and full ex) is necessary to check the effectiveness of the proposed design solutions. Although some components of the machine are largely flexible, the relative positioning of the capsule, film and tools must also be guaranteed in severe dynamic conditions.
• RecurDyn Chain toolkit allows for the easy modeling of the chain mechanism and the large number of contacts can be calculated quickly.
• The capacity of the coffee capsule machine production has been increased by 25%.
• New motion laws have been designed and verified.
• The structure of the main frame has been simplified.
ㆍPaper feed application for adjusting paper edge alignment
ㆍRoller engagement time control is used with RecurDyn MFBD technology
ㆍChain assemblies consist of 128 links and contact