Automated Bottle Capping Machine 1. Machine Description Bottle capping machines are one of the last pieces of equipment a liquid-filled container will pass through prior to shipping. The bottles of liquid, in this particular application shampoo bottles, are passed via conveyor from the filling station to the capping station. At the capping station, a capping head is accelerated to match speed with the bottles on the conveyor. Once at matched speed with the bottle, an output fires which crimps the cap onto the bottle. The capping head then decelerates, and rapidly returns to the beginning of the cycle for the next bottle. To maintain high throughput, the conveyor is never stopped during the cycle. Occasionally in a capping application, the bottles on the conveyor feeding from the previous process may not be perfectly spaced. This results in caps not being placed properly on the bottles. This is a situation for which the machine must constantly monitor and correct. Galil’s DMC-2123 Ethernet controller will be used in this application to apply the bottle caps. The electronic cam mode (ECAM) will be used for the cyclical motion of the capping head. A special feature of the ECAM mode which allows the slave CAM table to be shifted on the fly will be used to insure caps are placed correctly on the bottles. This machine uses one axis to apply the bottle caps to the bottles. The conveyor is run by an open loop AC motor controlled by a PLC.
This motor has an encoder which is read by the Y-axis encoder input of the controller, and is used as the master for the ECAM. The X axis is a servo motor which moves the capping head horizontally. This axis is responsible for accelerating and matching speed with the bottles on the conveyor. Once they have matched speed, an output fires a solenoid, which crimps the caps onto the bottle tops.
After the caps are applied, the X axis retracts to its initial position, and the cycle repeats. A mechanical diagram of the machine follows: Figure 1. Bottle Capping Machine. 2. Requirements This section summarizes the requirements for the machine described above: (1) One servo axis (X) for capping head motion. (2) One axis (Y) to read the position of the bottle conveyor encoder. (3) Electronic CAM mode to simulate the motion of a mechanical cam. (4) Input position latch (Y) for homing and phase alignment correction. (5) Dynamic adjustment of capping head position with relation to the bottle conveyor. (6) Digital output (100 mA required) to apply cap to bottle. (7) Forward/Reverse limit inputs and index pulse on X axis. (8) 2 digital inputs for coordination with PLC; one to indicate conveyor is moving, another for cycle start signal. (9) Stand alone operation. 3. Components Selected This section describes the Galil hardware and software products chosen to implement the machine’s control system. Below is a complete bill of materials followed by a description of major components.
GalilMotionCode Solution: Automated Bottle Capping Machine Galil Motion Control, Inc. 3750 Atherton Road • Rocklin, CA 95765 USA • 800-377-6329 • Phone: 916-626-0101 • Fax: 916-626-0102 • www.galilmc.com 1 Part Number Description Unit Price (U.S.) Qty 1 / qty 100 DMC-2123-DC24-BOX Econo series 2-axis Ethernet motion controller $1095 / $810 ICM-20105 Opto-isolated interconnect module $195 / $145 WSDK Servo Tuning Software Servo Tuning and Analysis Software $195 (one time) Table 1. Bill of Materials