In a land not so far away, many weeks ago, five mechanical engineering students on a quest to graduate were given one final task to complete. These students identified only by the name WRAPR are nearing the completion of this task. You may be asking yourself what are they wrapping? Gifts? That would be convenient for the holiday season. But no. It’s even better.
The task is wrapping a filter. Porvair filtration challenged the team to create a machine that can wrap a filter with minimal human interaction with the possibility of it being automated in the future. These filters have to be wrapped in two different types of films and heat sealed to hold them in place. To break the processes down into required steps I will show a component by component view of what will become the wrapper tool.
The first assembly and the heart of the tool is a rotational assembly. The assembly consists of a stepper motor, a backing plate to interface with the filter, a filter that is represented by a cylinder to protect intellectual property, and the assembly that has been nicknamed the pinball mechanism. The pinball mechanism allows for different sizes of filter to be placed in the rotational assembly and they can be loaded by pulling back the plunger loading the tube side of the filter onto the cone-shaped plug and sliding it forward to interface with the backing plate to ensure correct alignment. The stepper motor allows for precise rotation of the filter so that the heat seals can occur in the correct locations.
Next are the two heat sealing assemblies. These allow for a radial seal around the filter on the top and bottom of the core and a longitudinal seal along the length of the core to hold the thin films in place. All heating elements are adjustable temperature soldering irons that are attached to adjustable mounting plates to allow for precise placement of the heating elements.
The longitudinal seal is done first to attach the film and again for the final seal. This heating element can be seen on the left side of the picture pointing upwards. The radial seals are done while the stepper motor is rotating the core. Those two soldering irons can be seen on the right side of the picture facing downwards.
Last but certainly not least is the loading and cutting assembly nicknamed the duckbill. The duckbill is a clamping mechanism that allows for the film to be loaded to the face of the cylindrical core and the first longitudinal seal to be completed. It also has a small l-shaped plate that can be added to the top to allow for precise cuts to be made on the thin film when needed. This clamp can also have cut out for smaller size filters if needed.
These sub assemblies are all held together by 80 20 aluminum extrusions. These aluminum extrusions make up the frame. When it’s fully assembled it’ll look like this.
Here’s a video showing the wrapping of one core. You see the core is currently being loaded. The film is being pulled forward. The longitudinal seal is occurring. The clamp is being removed. The radial seal is now occurring. Now the tape would be cut and the core is being removed.
If you wish to learn more about this tool please attend the WRAPR team’s showcase breakout room on December 9th 2020 at 4 to 4 30 p.m. And we want to give a heartfelt thank you to Porvair filtration and the Boise State College of Engineering for providing us with this opportunity to build this tool. Thank you for listening and we hope to see you there you.