First, a UR5e picks up bottles supplied from a feeder and places them on a turntable. After the bottles are filled with liquid, the UR5e inserts liners into the bottles. At this stage, the robot’s built-in force sensor is used to insert the liner straight and confirm that it is properly seated.
For products without liners, such as pump bottles, this process performs provisional tightening.
Next, a UR3e supplies and tightens the caps. The UR3e’s infinite rotation wrist is effectively utilized for the cap-tightening operation.
“If the cap is tightened too much, it becomes difficult to open. If it is too loose, liquid leakage can occur. To prevent this, we control the tightening torque using the UR3e’s built-in force/torque sensor to achieve the optimal condition,” says Junki Ueda, Group Leader, Production Engineering Section, Production Engineering Division, Mandom Co., Ltd.
Sensors attached to the turntable detect whether the cap is properly installed, and the UR5e transfers acceptable bottles to the next process. After weight measurement, the UR5e performs inkjet printing and then places the inspected products into containers.
Peripheral devices such as feeders and turntables are connected to the robots via PLC I/O.
“We used the palletizing templates built into the UR robots to arrange products in the containers. You simply follow the instructions and input the stacking pattern, so programming was easy,” they explain.
The biggest challenge was reducing cycle time.
“To shorten takt time, we focused on simplifying robot motions and optimizing the layout while coordinating with peripheral equipment. As a result, we were able to achieve our target,” they say.
In this project, Robotiq electric grippers and Schmalz vacuum grippers were also used.
“Because these grippers can be operated directly from PolyScope, there was no need to design special gripper control, which was very convenient and helpful,” says Junki Ueda, Group Leader, Production Engineering Section, Production Engineering Division, Mandom Co., Ltd.
By designing, commissioning, and operating the line entirely in-house, the team deepened its understanding of robot characteristics and improved its utilization skills. This experience also enhanced their internal technical capabilities.
