Wolfpak Recycling was created from the need to efficiently recycle 1500 pounds of cardboard a day. In the ever expanding industries of processing and manufacturing, waste disposal has become a pertinent issue in maintaining a strong business strategy. A local packaging company, Worldpak LLC, chose the team to turn their cardboard waste stream into a profit generating center.
The most profitable solution for Worldpak is to compress the cardboard into functional and high quality archery targets. In order to manufacture the targets, the team designed and built an adapter to use in the existing baler at the company. The produced targets feature a modular design that allows the target to meet consumer needs for durability and weight. Wolfpak Recycling was able to successfully meet their design objectives and create a highly profitable solution for Worldpak to implement. A video overview of the project can be found below.
Wolfpak Recycling created an initial design concept for both the archery target and baler adapter. The archery target was designed to be 24 x 24 x 18-inches with the target shell encasing three individual modules. The modular design prolongs the lifespan of the target in addition to providing easier transportation of the target. The archery target design can be found in the figure below.
The initial baler adapter design consisted of a metal frame capable of producing six modules per cycle. The concept featured enhanced structural support to ensure that the adapter would not buckle or yield due to the baler platen force. Additionally, the adapter had strategically placed risers at the bottom to allow standard forklifts to transport the baler adapter. As a result, the original functionality of the baler would be preserved since the adapter would not be permanently fixed. The baler adapter design can be found below.
Proof of Concept
A proof of concept (POC) was manufactured to test the feasibility of the archery target and baler adapter designs. The POC consisted of a single compaction chamber which allowed the team to check various design questions and assumptions in order to create the best possible design. The initial testing results confirmed the feasibility of both designs and allowed the team to optimize the designs prior to manufacturing the baler adapter. Overall, the team was pleased with the performance of the POC and the creation of the first module. A photo of the POC can be found below.
Detailed Design Overview
The team finalized the design of the baler adapter prototype moving into production. The six chamber design was reduced to a single chamber that reused the POC to save on labor and material costs. The final baler adapter features reinforced walls fixed to the originally fabricated POC. In order to withstand the platen force of the baler, a 4-inch solid rod which is not shown was added to prevent buckling. The baler adapter features 2-inch guides for the compactor insert which stabilize and align the vertical movement while ensuring no lateral displacement in order to compact the cardboard consistently across cycles. Removable stabilizing supports were added to the rear and sides of the chamber which maintains the vertical position of the adapter throughout the manufacturing process. Additionally, a torsion rod was used on one side to tighten the adapter into a secure position which reduced the necessary fabrication tolerances.
The compaction insert features a 0.5-inch gap between each wall of the chamber and the compactor plate which provides clearance for a high-strength double-thickness B and C flute cardboard module shell to be inserted into the chamber prior to compaction. By compacting the shredded cardboard inside the module shell, the manufacturing process is drastically simplified as the operator can simply remove the finished module and close the box completing the manufacturing process of the module. The detailed design of the baler adapter and compactor insert can be found below.
Due to the detailed design modifying the existing POC, the final archery target module dimensions are 24-in x 24-in x 6-in. A single module was proven to effectively stop an arrow from a 60-lb compound bow after testing the POC. As a result, the triple module design has enhanced durability and brings the final archery target dimensions to 24 x 24 x 18-inches as proposed in the initial concept. The detailed design of the archery target can be found below.
At the request of Worldpak, the final design was fabricated by a local company, Remarc Manucturing, Inc. Utilizing an external manufacturer allowed the team to ensure that the baler adapter was built to the designed specifications. Additionally, Remarc’s fabrication expertise led to the timely creation of the baler adapter at the end of the semester. Overall, the fabrication process was straightforward although the team needed to prepare highly detailed assembly drawings in order to guarantee that the adapter was created as designed. In the fabrication process, the team elected to add removable pins to the guide tracks in order to improve the usability of the adapter in repeating cycles. The completed compaction chamber, supports, and solid rod can be found below.
The adapter was specifically placed to fit as close to center on the floor beams while remaining between the teeth on the baler door. The compactor insert and baler door teeth are shown below.
The team successfully created a single target module for additional comprehensive testing at the end of the semester. The module was able to stop both field point and broadhead arrows indicating a successful design. Since a single module could effectively stop both arrows, the team concluded that the full target with three modules would also be highly effective at stopping a variety of arrows. To test the performance of the target, the team shot 10 field point arrows into the module which penetration depth ranging from 5 to 9-inches. An additional 10 broadhead arrows were tested with penetration ranging from 4 to 7-inches. Additionally, the module exhibited a regenerative effect due to the compression of the shredded cardboard which extended the life of the module significantly. At the end of the semester, the team elected to create a custom graphic for the target face that allowed the team to shoot at our rival school’s logo. A picture of the completed module can be found below.
Meet The Team
Jeff Mitchell is team leader and will graduate from the University of Nevada, Reno in Spring of 2015 with a degree in Mechanical Engineering and a minor in Business Administration. Jeff enjoys an active lifestyle and a passion for music production. He intends to pursue a graduate degree in engineering or business administration.
Dylan Lane is a senior mechanical engineering student expecting to graduate in Spring 2015 with an emphasis in robotics and computer science. He is looking to pursue a graduate degree in one of those fields and conduct research on mechatronic systems.
Cameron Corson is a senior mechanical engineering student at UNR, and is expecting to graduate Spring of 2015 with an emphasis in thermal sciences. In his spare time, Cameron enjoys improving his firearm marksmanship, reloading ammunition, and competing in local martial arts tournaments. He hopes to pursue careers in the energy and weapon industries.
William Gomolka is a senior at the University of Nevada, Reno planning to graduate in May of 2015 with a degree in mechanical engineering and a minor in statistics. He shoots competitive archery and is looking to persue engineering in the archery field.
Josh Wang is a senior at the University of Nevada expecting to graduate with a major in mechanical engineering and minor in unmanned autonomous systems. He is looking to conduct graduate research on active seismic isolation systems.