Plastic Extrusion machine PLC replacement

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The  PLC based control system for a plastic extrusion machine failed and the customer did not have any backup files. Given the age of the PLC system it was decided that the best course of action was to replace and redesign the system using the Siemens S7-1200 platform. 

The machine control consisted of several elements. Some of which were

- 9" HMI for operator settings changes

- 8 heating zones controlled by PID loops using thermocouple measurement 

- analog speed control for the main drive. 

- Alarms and interlocks

Ink Automation was engaged to design and build the control system for a pallet dispensing machine. The machine is designed to automatically dispense pallets for use in a packing warehouse. The PLC selected for this was a Siemens S7-1214FC PLC with integrated safety and a Siemens 7inch HMI. The machine safety incorporated the following hardware:

- Type 4 safety light curtains to detect access to the front of the machine; 

- Emergency stop buttons x 3 dual channel with dynamic pulse;

- Hydraulic double block and bleed valve with spool monitoring to isolate stored hydraulic pressure;

- Dual safety contactors for hydraulic motor control; and

- Gate switch with OSSD output to detect side access. 

A complete set of engineering drawings and software was supplied as standard. 

Ink Automation was contracted to replace a faulty touch screen on a waste baling machine. Due to the lack of any backup files we were required to create a new HMI project working with the existing Allenbradley Micrologix PLC. The following steps were taken.

- Map out existing setpoints and control tags in PLC program

- Create HMI display pages to replicate the original screen. The operation manual was used for this.

- Install and verify operation of the machine. 

Ink Automation was engaged to replace a set of drive gears on a Gidue flexographic printing press. Nine print units were overhauled with a total of 72 gears and sets of bearings being replaced. The result was improved accuracy of the print registration and this eliminated the issues the customer was experiencing with print movement during the run.