Project Name: Automated Taping Fixture for Rotary Die-Cutting
Team Members: Armand Ali, Mikolaj Matyjazek, and Dexter Loh
Programs: Solidworks and ABAQUS
Year: Fall 2019 - Spring 2020
Over the course of this project, all of us worked on every aspect of the product to a certain extent. Even though we all had a particular role, each of us has worked on each section. The main areas where I put the most work in were the research, conceptual designs, drawings, part selection, and preliminary testing. The first aspect done for the project was the market research. Where I did research for machines and patents that related to our particular design to better understand what was used on the market already to get a sense of what we would be designing for. I also created the preliminary conceptual designs at the start of the project. Along the same lines, most of the drawings that are not CAD were made by myself since I have a lot of experience in Adobe Photoshop. I also had the responsibility of part selection, FEA Simulation of Cutting Mechanism, and the Arduino Flowchart . My last contribution was testing the taping and cutting methods using cardboard prototypes to simulate the motions as well as helping my teammates with their CAD models as needed.
Purpose:
The Frank Lowe Rubber company wants to improve the efficiency of their factories by speeding up the manufacturing of their product. Rubber squares are cut out of long strips of rubber in a machine. New rolls of rubber must often be attached to previous ones in order to continue production. Currently workers manually tape the rubber together. Our fixture aims to automate the taping process for the workers. This will decrease taping time from 30-40 seconds to 10-15 seconds
Design Requirements:
●Must work for all materials the company processes
●Must be compact enough to fit onto the machines without major modification
●Must reduce taping time to about 10 seconds
●Must be safe to use and comply with all factory safety standards
●Must tape the rubber together properly every time
●Must not get in the way of the other processes on the machine
●Must not require maintenance often
Conceptual Designs:
The conceptual designs have been split up into three different components for the main mechanisms needed in the product. These being the material cutter component that cuts the raw end of the input roll of rubber material to be straight, the material mover, which moves the input rubber material to the correct location for taping, and the taping component, which tapes the input and existing rubber material together then cuts the tape to length, the rubber mover, which moves the input rubber material to the correct location for taping. Below are my conceptual designs for the previous described mechanisms.
Taping Mechanism
The tape will be stationary on one side of the material and a “grabber” will hold the piece of tape and drag it across the width of the material. The grabber is on a rail and moved using a motor. Then, a flat headed piston will come down and press the tape onto the material to ensure it is adhered to the surface. Finally, a blade will cut the tape at the base of the tape roll. This design would also be flipped to do the same operation on the bottom side of the material to tape both sides.
The tape roll is attached to a rail, but is able to rotate freely. The tape roll would start at one edge of the material and a grabber/holder would hold the tape edge and the tape would move across the width of the material until it gets to the end. After which the tape would be cut. While it is taping, the scraper that is attached to the tape roll is pressing the tape onto the surface of the tape to ensure it is adhered properly.
Similar to the previous design, but instead of a scraper there is a roller attached to a spring that would press the tape onto the material surface.
Moving Mechanism
The rollers would rotate on both the top and the bottom of the material and that would move the material forward. This would move the input material to the correct place so it can be cut as well as to be taped.
Our chosen method for moving the rubber was a rotary actuator and a free roller attached to a spring-like mechanism pinching the material to increased contact area as well as friction. The “free rollers” on the left of the drawing act to support the material in a way that the material is fed cleanly through the rollers. These free rollers will resemble the ones that can be found at most cashier checkout set ups in supermarkets
Cutting Mechanism
The blade would be pushed down with a piston cutting the raw end off of the input material. Guides will ensure that the material stays stationary while the material is being cut. The blade is also slanted to allow for better cutting.
Prototyping:
This prototype is a proof of concept for the taping mechanism we have designed in CAD. The goal of this prototype was to figure out the viability of this mechanism, and if so, the location of tape and output roll, and testing the tape cutting design. After constructing this prototype, it became clear that it was going to work, but we would need to make sure all the speeds of the motors and pistons are timed in order to ensure the tape does not rip causing the fixture to be shut off and fixed. Which would cause more downtime then if the fixture was not there in the first place. For the best results we found that moving both the tape roll and the output roll resulted in the least force on the tape so our design change from one stepper motor on the output roll to one on both. Another solution found was the location and addition of rollers in the mechanism to ensure the tape is flat when pulled across the material surface and the design is more compact then before. Lastly, testing the tape cutting mechanism with the adhesion piston traveling on the inside of the cutting piston, worked very well and allowed for the tape to be cut and not the material below it. Overall, even though it was not a fully working prototype with the actual parts, a lot was learned and we were able to fix many problems that we have not seen otherwise from the CAD models.
Tape Mechanism Roll Orientation
Full Taping Mechanism
Tape Cutter and Adhesion Piston [Side View]
Tape Cutter and Adhesion Piston [Front View]
Final Mechanisms:
After several design iterations and adjustments, the following mechanisms were created.
Taping Mechanism
Isometric View
Front View
Moving Mechanism
Isometric View
Side View
Cutting Mechanism
Isometric View
Side View
Full Design:
The final design was chosen because it would satisfy all the PDS. Early on we determined this design was the optimal choice for our project, but we were wary of the taping mechanism. We worried that stamping a smaller piece of tape out of the larger piece would cause the tape to tear. However, our worries were put to rest after some testing proved that it was possible as long as we are careful with the cut. A real-world model would most likely need to have the razor blades replaced fairly often to ensure the tape cut is a clean cut.
As we can see by the video, the full process takes about 5 seconds to complete. This along with placing the input roll into the mechanism will probably take the employees about 10 seconds to complete. The main goal of this project was to reduce the time of taping to less than 10 seconds to speed up the factories process. With this in mind we can consider this design to be a huge success. Some things to consider are the replacement of the blades and the tape. These things will take away from factory time but should be infrequent. The rubber cutting blade would most likely not need to be replaced for many years. In other machines at the factory the same exact cutting mechanism cuts rubber hundreds of times a minute and doesn't need to be replaced often. With our design, the cutter only cuts once every minute. It is hard to estimate how often the tape or razors would need to be replaced since we would need extensive testing on a physical prototype. However, it is a safe estimate that the tape would need to be replaced less than once a day and the razors most likely less than once a month.
Our design also satisfies the size constraints placed by the factory. There was limited space for this fixture to be mounted but we did not have issues encapsulating the mechanism within the constraints laid out. In addition, the fixture is surrounded by a thick box of durable plastic. This would both protect the mechanism and the workers, keeping our design in line with the safety standards of the factory. In addition, the box will be see-through to allow workers to observe the process while it is in action and potentially stop it in case of an accident. We also believe this box would protect the mechanism in a drop test, but this cannot be stated as fact without a prototype. Our design is also capable of supporting any of the types of rubber described to us. No changes will have to be made to change the type of rubber being fed into the machine allowing for the workers to have an easy time.
Full Fixture in Case
Top of Case
![Isometric View [Inside]](https://images.squarespace-cdn.com/content/v1/5f624c0e3eca1c34b5a3017b/bbc9c9f0-b817-45d7-9bd2-ba02910eee82/Screen+Shot+2021-07-04+at+5.21.42+PM.png)
Isometric View [Inside]
![Isometric Back View [Inside]](https://images.squarespace-cdn.com/content/v1/5f624c0e3eca1c34b5a3017b/26cc7c78-0bc4-4ebc-b243-d968c1543a16/Screen+Shot+2021-07-04+at+5.17.40+PM.png)
Isometric Back View [Inside]
Side View
Front View
FEA Simulation of Cutting Mechanism:
Due to the limitation of the student edition of ABAQUS the material was not able to be simulated breaking apart.
Arduino Flowchart:
The program is constructed to work based on sensors and timing. The sensors are in place to make sure the material is in the correct location during each portion of the fixture’s operation and as a safety feature for the operator. The program is initiated by a button that is located on the fixture. Without this, the program will not run and the operation will not occur. After this, it checks that the door on the front of the fixture is shut. It also does this after each operation and if it is not shut a red LED is turned on signaling too the operator the problem. Since the mechanisms within the fixture comprise of several sharp blades and motors, it would be very dangerous if the fixture were open at any point during the fixture’s processes. Next, it starts the cutting phase signified be a yellow light. During this phase, the first motor moves the input roll of the material into place. It then waits for the operator to insert the output material into place. The program then recognizes this and continues the process. The valve operating the cutting piston is opened, cutting the material. Then the motor moves the material in place based on time. Another check is done to ensure the material is in the correct locations for the taping process. Once it is, the valve operating the tape cutting is opened to cut the tape and then the adhesion piston is opened very close after in order to press the tape onto the material on the top and bottom. After this a green light is turned on signaling to the operator that the process is complete. The program then begins to rotate the motors holding the tape slowly to put a new piece of tape above the material for the next process. It then waits for the operator to insert a new material roll and press the on button.