Can Seaming

From Can Networks in our Multi-Grain Filler Case Study to Can Seaming in this one, here's another example of Machine Upgrading in the Powder Industry to preserve Raw Materials and Uplift Functionality. Once again, the client wish was to maintain the mechanics of the machine as the Machine was Mechanically Sound.

This is a very reasonable client request, not least from a perspective of respecting nature and preserving both fit for purpose Raw Materials and Workmanship.

What was unfit for purpose was the System, so the Specification was to negate the need for a new machine with a robust upgrade on a site producing nutritional powder for post-surgery patients.

Can seaming is the process wherein the lid of a can is joined to the body of a can to create an airtight seal.

As such, this process is used to maintain contaminant-free environments for products. Here is the Specification outline:

• Increase productivity from 30 cans per minute to 50 

• Simplify maintenance by increasing the diagnostics on the machine 

• Ensure that the machine meets the latest safety standards 

• Increase reliability and therefore machine availability by reducing downtime 

• Prevent the main seaming motor from over-heating 

• Detect the level of oxygen in the can before sealing to increase product shelf life. 

To overcome the problem of product shelf-life, the product is filled with nitrogen to remove oxygen from the system.

However, the client had no way of knowing how much oxygen was in the can before seaming.

We therefore introduced an oxygen measurement system with a transmitter that was then connected to the PLC.

Previously the operator was able to open the guard doors while the machine was running. Even though this would stop the process, the system did not account for the ramp down time of the motors. This presented a risk of injury to the operator. At 2M we proposed the following: 

• Increase the robustness of the doors by increasing the thickness of the Perspex doors from 3mm to 10mm 

• Introduce a magnetic safety gate system with a holding force of 500N 
• Introduce a safety dump valve to dump the air in the system when the guard doors are open 

Ramp Down Time means the duration (measured in minutes) the flexibility asset (or pool of flexibility assets) take(s) to change output from the instructed output (demand or generation) to normal operating output at the end of service delivery.

The best production speed we could achieve with this method was approximately 40 cans per minute. Higher speeds were observed to reduce the seaming quality.

2M proposed to change the Seaming Motor from a standard AC Motor to a Servomotor to deliver the speed and quality the client desires. 

In summary, an existing machine was upgraded to increase speed from 30 to 40 CPM, meet SIL3 safety levels and EU Machine Directives, be accessed remotely by engineers to diagnose faults, and seam all cans to contain the right amount of Nitrogen for a guaranteed shelf life. 

This was also yet another Reverse Engineering project for 2M as there was no machine software back-up. Therefore, a Solution was designed by observing the machine and collating information from Operators and Maintenance Engineers.