Insecticide Bottle Filling and Capping Machines in De La Salle University Arthur Pius Santiago 1 Manufacturing Engineering and Management Department De La Salle University Manila 2401 Taft Avenue, 1004 Manila, Philippines Email: arthur.santiago@dlsu.edu.ph 1 Abstract - Insecticide Bottle Filling and Capping Machines have been one of the industry related projects in the Manufacturing Engineering and Management Department of De La Salle University Manila. The initial attempt was supported by Mapecon Philippines, Inc., a private business entity which formulates its own insecticide. This paper presents machine prototypes to replace the manual process. The prototypes shown were able to consistently fill and cap 500ml bottles of Big R Insecticide. Experiments were conducted to determine the production rate of the prototypes as well as to test whether the volume of insecticide dispensed are within company specified limits. Keywords: Bottle Filling, Bottle Capping, Process Automation, Solenoid Applications, Pneumatics, Conveyor Systems 1. INTRODUCTION Mapecon Philippines, Inc. is a pest control products manufacturer. Its vision is to deliver better goods to customers, that is why it is continuously looking for better ways to make its products more effective and environmentally-friendly. In 2006, the company introduced a new product known as the Big R. This product is proven effective for both flying and crawling household, commercial and industrial pests. It has both flush-out and knock-down effects and it is also an insect growth regulator (IGR). This product does not contain LPG propellants which give off cancer-causing Nitrogen Dioxide. Rather, it has organic contents that are similar to the ones found in soaps. These characteristics make this product better than the leading insecticide brands available in the Philippine market. However, due to these organic contents, problems in production arise. Currently, the filling and capping processes are done manually (refer to figure 1). An operator fills the six bottles at a time. The filling process produces a great number of bubbles which may affect the actual volume of the solution inside the container. To ensure that the correct amount is inside the bottles, the operators continually fill the bottles until all the bubbles are spilled out. The bottles are then transferred to the capping section where workers manually force-fit the caps onto the bottles. The excess solution is collected through a basin which is located underneath the bottles. Once the basin is nearly filled, the workers manually carry it back to the dispenser s solution container. This cycle takes a lot of time and effort. Figure 1: Manual Process Flowchart : Corresponding Author
The current manual process is observed to be inefficient and tedious. For the filling process, a great number of bubbles are generated which affect the volume of insecticide loaded into the bottles. The solution to ensure that the proper amount of solution is put in is unproductive. As for the capping process, it entails much effort since workers are asked to force-fit caps onto the bottles manually. position pushes the filling nozzle against the mouth of the bottle allowing insecticide to flow while a retracted position pulls the nozzle away from the bottle stopping the flow of liquid. 2. DESIGN SOLUTIONS In order to eliminate the problems encountered by manual processing of the bottle filling and capping, the following solutions have been developed: 2.1 Prototype 1 Prototype 1 can be broken down into (A) Mechanical components, (B) Electronic components and, (C) Software. The mechanical components can be further divided into three parts: (1) the transfer system, (2) the filling system, and (3) the capping system. The transfer system is a commercially available conveyor. It is composed of a belt, a motor and rollers. A pair of guide railings was also designed and installed onto the conveyor to prevent any misalignment and unnecessary movement by the bottles. The conveyor, with a length of 6ft and width of 1ft, is used to position the bottles at different stations at designated intervals, depending on the current process being done. The speed at which it moves is 8 ft/min. This speed was determined through experimentation. If in case minor changes need to be done, conveyor speed can be adjusted using a controller knob. The filling system makes use of a liquid pump, a specialized filling nozzle and pneumatic cylinders. The liquid pump in conjunction with pressure tanks and a storage tank ensure the steady supply of insecticide solution into the system. In order to ensure that the correct amount of insecticide is put in the bottles, uniform flow of liquid must be kept. This is maintained by controlling the pressure at a constant 10 psi for three seconds. The filling nozzle (figure 2) houses two sub-nozzles one for the incoming solution (from pressure tank) and one for the outgoing solution (to excess storage tank). When in a relaxed position, the solution will continually flow from the inflow nozzle to the outflow nozzle. When pressed, the solution will flow out to the bottle. Once the solution reaches the fill level, excess solution and bubbles formed will be pumped out through the outflow nozzle to the excess storage tank. In order to bring the filling nozzle to the brim of the bottle, pneumatic cylinders are used. The extended Figure 2: Specialized Filling Nozzle The capping system is responsible for capping the bottles after they are filled with the insecticide solution. A cap slide is used to release a bottle cap onto the brim of the bottle. A pneumatic cylinder pounds the cap in place. The electronic components may be lumped into (1) the control system, (2) the sensors, and (3) the actuators. At the heart of the control system is a microcontroller. A PIC16F877A was used to implement the design. It is responsible for controlling the flow of operation for the whole filling and capping process. It reads inputs from sensors and commands the conveyor motor and solenoid valves as to when to activate or shutdown. The sensors in this system are comprised of lasers in tandem with light dependent resistors (LDRs) as well as limit switches. The LDRs are found in the filling and capping system and signal the presence of a bottle in these respective positions. A limit switch can be found in the cap slide and this indicates the release of a cap onto a bottle in the capping process. The actuators in the system consist of solenoid valves and relays. The solenoid valves control the extension and retraction of the pneumatic cylinders. The relays on the other hand control the activation of the conveyor motor and the release of caps in the cap slide. In order to program the PIC microcontroller, C- language was used. The behavior of the program follows the flowchart illustrated in figure 3. As for the input and output ports, pin assignments are outlined in Table 1. Table 1: Input and Output Pins of PIC Microcontroller Input Pins Output Pins RA0 Capping Sensor RB7 Conveyor Activation RA1 Filling Sensor RB6 Cap Release Motor RA2 Capping Release RB5 Capping Solenoid Sensor RB4 Filling Solenoid RC LED Indicators
Figure 3: Process Flowchart for Prototype 1 2.2 Prototype 2 Prototype 2 is broken down into (A) Mechanical components, (B) Electronic components and, (C) PLC ladder logic. The mechanical components can be further divided into three parts: (1) the transfer system, (2) the filling system, (3) the capping system, and (4) the motion inhibitors. The transfer system is a custom-made conveyor using a steel top chain instead of a rubberized belt. This allows the bottles to stay upright when they are forced to stop at the filling and capping stations. The conveyor is driven by a ½ horsepower motor with a gear ratio of 80:1 used in tandem with a 220 volt, 3-phase inverter that controls the speed of the motor and turns the motor on and off. The total length of the conveyor is eleven (11) feet with a total width of one (1) foot. Guide rails are incorporated into the conveyor to provide stability. The filling system is composed of the solution reservoir, pressurized distributor and the solution dispenser. A 47-gallon storage tank is used as a reservoir to guarantee enough of the raw material is available for filling. It feeds into a pressure tank which ensures the correct pressure for filling is achieved. Two solenoid activated valves dispense the insecticide into two waiting bottles for a specific amount of time. The capping system consists of a cap slide and two pneumatic cylinders that places and force fits the pluggers onto the bottles. After filling, the bottles are transferred onto the capping station where the bottles are capped and then released from the station. The pluggers are released from the slide then a pneumatic cylinder force fits them onto the bottle. The motion inhibitors allow the system to simultaneously process bottles. Pneumatic cylinders are placed strategically below each station to allow or prevent the bottles from entering or leaving the station. The filling and capping stations both have two cylinders that act as stoppers. For each station, the two cylinders are placed at a specified distance from each other depending on the number of bottles that can fit into the station; two bottles for filling and one bottle for the capping section. The electronic components may be classified into (1) the control system, (2) the sensors, and (3) the actuators. The control system is made up of a Programmable Logic Controller (PLC). For this prototype, an FC20 PLC from FESTO was used. It is equipped with 12 inputs, 8 outputs, a 24V supply and a common port. The sensors used in this prototype are all proximity sensors. Two are placed in the filling station to determine if there are bottles under the dispenser nozzles. A third proximity sensor can be found in the capping section to ascertain if a bottle is available for capping. In actuating the solenoids, direct drive from the PLC was not possible. This is due to the fact that the solenoid actuated valves needed was 220V. Relays were then used to convert the PLC signal of 24V into the required 220V. As established, the PLC controls the whole operation of the machine. This is done through a ladder logic program embedded into the PLC. Inputs and outputs, which are considered for proper machine behavior, are presented in table 2. The actual operation is outlined in figure 4 following the conventions in table 2.
1 2 3 Table 2: Input and Output Pins of PLC Input Pins Filling Sensor 1 Filling Sensor 2 Capping Sensor A B C D E F G Output Pins Filling Motion Inhibitor Out Filling Motion Inhibitor In Solenoid Activated Valves Capping Motion Inhibitor In Capping Motion Inhibitor Out Capping Pneumatic Cylinder Cap Release Cylinder per 8 work hour day. Comparing this to the current manual production rate of 600 bottles per day, it is an improvement of 480%. For Prototype 2, it can be seen that on average the machine can fill and cap 6 bottles in 31.83 seconds (figure 6). This roughly translates to a production rate of 5,429 bottles per 8 work hour day. Comparing this to the production rate of prototype 1, it is a further improvement of about 186%, or 904% improvement from the manual process. Figure 5: Prototype 1 Production Rate Experiment Results Figure 4: Process Flowchart for Prototype 2 3. PROTOTYPE TESTING AND DISCUSSION The effectiveness of the machine prototype in conjunction with the objectives of the study was tested using the following experiments: (A) Production Rate, (B) Volume of Insecticide Solution. 3.1 Production Rate The objective of this experiment is to verify that the machine can fill and cap six insecticide bottles in one minute. A time lapse test will begin at the start of the filling of the first bottle. End time will be recorded at the start of filling of the seventh bottle. The total time elapsed is then recorded. The experiment is done on both prototypes 1 and 2. Based on figure 5 it can be seen that on average, prototype 1 can fill and cap 6 bottles in 57.89 seconds. This roughly translates to a production rate of 2,880 bottles Figure 6: Prototype 2 Production Rate Experiment Results Analyzing the results for both prototypes, it will be noted that the increase in productivity for prototype 1 can be attributed to the efficiency of the process as compared to that of the manual process. Bottle filling was optimized to reduce bubbling of the insecticide solution which causes overflow. Prototype 2 builds on the gains established by prototype 1 and further improves productivity by enabling parallel processing of the filling and capping systems. 3.2 Volume of Insecticide Solution The objective of this experiment is to verify that the amount of insecticide solution dispensed by the machine
into the bottle is within the specified tolerance 475 ml to 525ml. The experiment starts by loading empty 500ml bottles on the conveyor. The machine is then turned on. Wait until all bottles are filled and capped. Measure the actual volume dispensed into the bottles using a beaker and record. can be seen that the former performs better in terms of volume of insecticide dispensed. This can be attributed to prototype 1 s specialized filling nozzle. This feature was not included in prototype 2 since its design called for two nozzles filling two bottles simultaneously. To keep costs down, solenoid controlled valves were used as filling nozzles. 4. CONCLUSION Figure 7: Prototype 1 Volume Experiment Results This paper presented two prototypes for the automation of the filling and capping processes Mapecon Philippines, Inc. For both prototypes, significant increase in production rate was seen. It was also observed that volume dispensed for prototype 1 and 2 are within the 500ml ± 5% tolerance. The advantage of prototype 1 is that it performs better in terms of volume dispensed. However, there are other drawbacks in utilizing this machine. The first is that it employs a specially fabricated filling nozzle which is expensive. Next is that bottles have to be manually spaced so that it does not crowd the filling station. The positive points for prototype 2 is that it has a very high production rate. It can produce 9 times more filled and capped insecticide bottles as compared to the manual process. It achieved this by building on the improvements made in prototype 1 as well as incorporating parallel processing in the filling and capping systems. But it also has to improve on volume dispensed by the machine. Even though it is still within specifications, an average volume of 492.7ml might draw the ire of consumers since it is less than 500ml. ACKNOWLEDGEMENT The author would like to thank Ramon Barcelon, Mark Apelario-Ong, Berjoy Grajera, Sarah Sy, Darell Tan, Charmagne Untalan for their contributions for the completion of this paper. Figure 8: Prototype 2 Volume Experiment Results Analyzing the data in figure 7, we can see that all data samples are within the tolerance limits. On average, we can also see that the average volume dispensed of 500.44ml is very near the ideal of 500 ml. This result will be beneficial to both the company and consumer; consumers get their money s worth while the company does not lose profit due to overfilling of insecticide bottles. Looking at the results in figure 8, we can see that all data samples are within the tolerance limits. On average, we can also see that the volume of dispensed insecticide is 492.7 ml. Comparing the results for prototype 1 and 2, it REFERENCES Barcelon, R., Santiago, A. P., (2010) Modified Insecticide Bottle Filling and Capping Machine. Proceedings of the 15th OU-DLSU Academic Research Symposium, Manila, Philippines. Apelario-Ong, M. A., Grajera, B., Sy, S. K., Tan, D. M., Untalan, C. A., Santiago, A. P., (2008) Insecticide Bottle Filling and Capping Machine. Proceedings of the 1st Regional Conference in Manufacturing Engineering, Manila, Philippines.
Mott, R. (1999) Machine Elements in Mechanical Design, 3 rd edition, Prentice-Hall, New Jersey. M. Purification, et. al (2003) Automated Sachet Case Packing Machine. Thesis, Manufacturing Engineering and Management Department, De La Salle University, Manila, Philippines. Uy, N., et. al (2004) 2T Oil Packaging and Handling Machine. Thesis, Manufacturing Engineering and Management Department, De La Salle University, Manila, Philippines. Uy, S., et. al (2006) Semi Automated Bottle Processing Machine. Thesis, Manufacturing Engineering and Management Department, De La Salle University, Manila, Philippines. AUTHOR BIOGRAPHY Arthur Pius P. Santiago is an Assistant Professor at the Manufacturing Engineering and Management Department, College of Engineering, De La Salle University, Manila, Philippines. He received his Master of Science degree in Manufacturing Engineering and Bachelor s Degree in Manufacturing Engineering and Management also from De La Salle University. He is currently working on his Doctoral degree in Electronics and Communications Engineering from the same university. His teaching and research interests include automated systems, robotics, electronics systems and computer aided design. He can be reached at arthur.santiago@dlsu.edu.ph.