Cohesive Inc. has chosen to pursue the project “Structural Adhesive Dispensing System” and has been sponsored by local engineering company, HG Adhesive Dispensing. The goal of the project is to design and build a system that is capable of dispensing a highly viscous, syntactic material adhesive into hexagonal cells that measure 4-7 cm deep and .75 cm2. The system will dispense the one component adhesive from a one gallon steel can. Cohesive Inc. is designing the custom system for one of HG’s customers who use aluminum, honeycomb structure sandwich panels to manufacture aircraft wings. The structural adhesive will need to be dispensed into a group of 10 hexagonal cells in order to create a fastening point for exterior fixtures on the aircraft wings. The goal of the project is to increase the efficiency of a process that currently has to be performed by hand with a syringe. The system must be precise and minimize waste since the adhesive that will be used in the industry sells for approximately $8,000 per gallon.
The industry in which the one gallon structural adhesive dispensing pump belongs is the aerospace sealant industry. The main competitors are Graco Pumps and Nordson Sealant equipment. These are also the companies that build structural adhesive dispensing systems. As a team, Cohesive Inc. has spent time designing more efficient ways to dispense structural adhesives, hopefully giving them the opportunity to enter the industry. The competition and buying patterns are based on the reputation of each company. Cohesive Inc. and HG Adhesive Dispensing are competing with the competitors to have a higher reputation in the airline industry. The goal is to reach a high reputation in order to increase the buying patterns by the airline industry. The distribution pattern for the two competitors is that they are able to reach a high number of countries around the world.
Proof of Concept
Team Cohesive has come up with a solution to dispense a structural adhesive into ten honeycomb cells. This will increase productivity by filling more than one cell and a time. The undisclosed company are currently filling these honeycomb cells one by one with a syringe. Our design has a plunger screw to force the adhesive out of an adhesive tank. Then the adhesive will be forced thru piping to a dispensing gun with ten nozzles. This gun will fill each cell evenly without air pockets. In the designing stages of the product, team Cohesive has carefully considered the Project Specifications, Hazardous Identifications, Market Research, Surveys, Engineering, and Risk Management to come up with the best solution for our sponsor. This solution will be used in real world applications to effectively fill honeycomb structures to help increase productivity.
The product design specifications include designing a structural adhesive dispenser that is able to reliably and precisely dispense structural adhesive from a one gallon canister into ten separate honeycomb chambers. The structural adhesive is impregnated with glass beads and has a high viscosity between the ranges of 100,000-500,000 poise which cause failures in common adhesive dispensers. The honeycombs being filled have a cross sectional area of 0.75 cm2 and will be placed in a sandwich panel of an aircraft wing. After the structural adhesive dispenser is used, it should be able to be cleaned so the structural adhesive does not cure within the machine. The purpose of this project is to provide customers with a structural adhesive dispenser that will be able to be more efficient at filling honeycombs than the current method of using a syringe. This will allow customers to be able to work more fluently, saving time and money.
Fabrication: Brief Description
To start the assembly of the structural adhesive dispensing system, screw both supporting rods into the aluminum plunger lid. Next, screw in the two-way threaded bolts to the supporting rods. Push the opposite end of the two-way threaded bolts through the cross beam and connect it by screwing on the two lock washers and nuts. Next, connect the cross beam to the frame with the larger set of lock washers and nuts (the plunger lid should be aimed down towards the base of the frame). Attach the control fixture plate to the upper metal tubing of the frame with the two allen bolts. Connect both of the black air tubing to the attachment points located on the frame. Connect the pressure release valve and one-way air valve to the aluminum plunger lid by threading them in. Connect the yellow tubing from the control fixture plate to the one-way air valve located on the aluminum plunger lid. Thread in the blue adhesive tubing into the aluminum adhesive canister. Place the aluminum adhesive canister directly under the aluminum plunger lid. Lastly, connect the control fixture to an air compressor. The fabrication of the project involved using CNC equipment, a manual mill machine, an electric powered hand drill, and a tube cutter/crimper. All of the fabrication equipment was provided by the sponsor HG Adhesive Dispensing LLC.
Testing and Results
The testing procedure that will be executed in order to determine if the product will work properly for the future user are: elevator lift functionality, flow rate, and cleanability. These test were executed 4 times each in order to determine the product is functioning properly.
Elevator Functionality Test
This test will determine if the elevator bars are properly aligned. This is a very important test because the plunger lid must match the base can in order to push down on the adhesive. If this is not aligned the system cannot function properly and may cause the system to fail or be destroyed. This test was performed 5 times by turing the pneumatic control up and down to lift and push the plunger lid in and out of the can. This test worked every time and was perfectly aligned.
Flow Rate Test
This test will determine if the pressure and the speed of the auger screw are calibrated correctly to give the user a steady flow rate. This test needs to happen at least three times to find a medium for how fast the system has to flow. This test will be executed with joint compound to see if the system will dispense a viscous material. Joint compound will be used to simulate the viscous material because the adhesive runs roughly eight thousand dollars per gallon. During testing, the system failed to dispense the joint compound because some of the threads were cross threaded and leaked out. This prevented the team to get a proper flow rate, but these threads will be fixed and tested again.
Flow Rate: test failure due to cross thread on parts
This test will determine if the system is cleanable for the user so they won’t be wasting much material because of the high cost of materials. This test is important because wasting material and allowing material to cure within the system will cost the user money. If the system is not cleaned properly the adhesive will cure and part will need to be replace in order for the system to function properly. With our design the system can be easily dismantled and cleaned. This system will be performed each time the flow rate test is ran. Using protective gear to scoop out the adhesive must be worn at all time. For this test the materials will be scooped out of the base can and the auger screw will be taken off in order to clean. The hose will be capped and stored in the freezer to preserve the adhesive and piping. This test was ran and was found to be 95% efficient with saving materials. This was calculated by the weight of material put in and taken out of the system.
Meet the Team
Mark Adams is a senior Mechanical Engineering student at the University of Nevada, Reno. He was born and raised in the state of Virginia and moved out to Reno, Nevada his senior year of high school. His biggest academic accomplishments involve graduating with two associate’s degrees, one in mathematics and the other in engineering from Cuesta College in San Luis Obispo, California. The most challenging project Mark has worked on involved working on a research team at UNR in the Howard Medical Building in the pharmacology department. Mark was tasked with designing and 3D printing a head stage relay shell that would house a small electrical circuit. Over the course of his academic career, Mark has developed 3D modeling and technical drafting skills that have assisted him throughout his schooling and everyday life. An example when Mark used his drafting skills outside of school would be when he designed a smartphone/tablet holder for his Etsy shop where he sells woodworking products. Mark’s current goals are to find an internship for the Summer of 2018. Mark plans to graduate from UNR with his Bachelors in Mechanical Engineering by December 2018. After graduation, he plans to find a job at an engineering firm in the Sparks/Reno, Nevada area where he can continue growing as an engineer.
Barry Bow is a senior Mechanical Engineering student at the University of Nevada, Reno. He was born and raised in the Reno area. The most complex engineering project that Barry has been involved in is the project associated with his Mechanical Engineering Capstone course; designing and building a system that is capable of dispensing a highly viscous, one component adhesive into a precise location. Outside of school, Barry has mainly enjoyed working with his hands, working on projects such as performing a complete renovation of the house he currently lives in. He also recently attained his CSWA certification and has begun delving into 3D modeling and printing. Barry has utilized the design knowledge he has gained from Mechanical Engineering school to design and build multiple carnival games that have remained functional for 3+ years. Barry is on track to graduate in May of 2018 and is committed to applying himself in his Capstone course in order to create a functional system by his graduation date. After graduation, Barry hopes to seek out employment at a local engineering firm and continue developing his skills as a Mechanical Engineer.
Jason Maxim is a senior mechanical engineering student that is from the Carson City, Nevada area. He is currently working for a local engineering firm as a mechanical designer/draftsman. At this job he has used many analytical techniques to come up with the best possible solution to design mechanical and plumbing systems with various projects. Some of the engineering skills he has developed with these projects include: working cohesively with others, paying attention to detail, developing excellent communication skills, and the desire to expand his knowledge base. One of his goals after graduation is to pursue a career in aerospace engineering and one day pursue his pilot’s license.
Alexander Numberi is a senior Mechanical Engineering student at University of Nevada, Reno. He is an International Student from Indonesia. He is also a transfer student from Green River College. In UNR, Alex has been working as the grader for Heat Transfer class for two consecutive semesters. In Fall 2016, Alex was one of the names in the Dean’s List for Mechanical Engineering department. The most challenging engineering project that Alex has been involved in is the capstone course project; designing a structural adhesives dispensing pump for a high viscosity material. His goal right now is to develop his knowledge of science, engineering, mathematics and technology as much as he could. Alex intends to graduate in May 2018. His goal after graduating is to go back to his home country and to help developing his home country with his knowledge of Mechanical Engineering that he has developed.
Farhanki Sawor is a senior undergraduate student who is majoring in Mechanical Engineering at the University of Nevada, Reno. He is in an international student from Papua Province, Indonesia. Farhanki has received an outstanding academic accomplishment such as full scholarship from his local government to study in USA. During his academic years at University of Nevada, Reno, Farhanki has learned many engineering skills, for example; using 3D modeling and numerical programming softwares, working as a team, improving communication skills, and giving professional presentations either verbal or written. The most challenging engineering project that Farhanki has been involved, is senior project for capstone class. In this project, he and his team are tasked to design and manufacture a structural adhesive dispensing system. Outside of school, Farhanki is engaged into sports especially soccer. In 2015, Farhanki and his team won the tournament of intramural soccer at UNR, and he was awarded as top goal scorer in the tournament. His current objective is to graduate in May 2018. After the graduation, Farhanki is planning to go back to his home country, and applying for a job. He is motivated to help his community to grow by applying his mechanical engineering knowledges.
Our team would like to thank HG Adhesive Dispensing LLC for all of their help with sponsoring, mentoring and allowing us to use our engineering skill to develop a product with them. We would like to thank Paul Gossi who was our generous sponsors who made this all happen. Jesus (Master Machinist) who helped mentor us through the development of our system by teaching, guiding and challenging use along the way. Kevin (Marketing Director) who help will ordering and expedite the shipping process of our parts. Chris (Machinist) who helped mentor the team through teaching us how to properly operate machinery around the machine shop. Also we would like to thank the Capstone teachers for their help by showing us the proper step that must be taken in order to successfully develop a product and introduce it to the market. Without out these people being there for us through this process nothing would have been possible without them. Each person played a significant role in helping our team achieve our goals.