Pinturas Tropical in Santo Domingo, Dominican Republic, used to counteract its imprecise, PLC-based dosing and batching system for producing acrylic paint by requesting less additives than needed, and supplementing them manually. The legacy process also lacked automated reporting, which along with the manual adjustments, made it impossible to analyze production efficiency and identify needed improvements.
Fortunately, system integrator Maximo Logo and his company, RMS Industrial Tech, were located just down the road, and he proposed implementing Opto 22's groov EPIC system. It would address PinturasTropical’s precision issues by using time-proportional output (TPO) to control its dosing valves. TPO is a form of pulse width modulation (PWM) that controls how long a dosing valve is open, and uses fixed timing cycles to precisely control flow rate from the dosing pump.
These TPO functions are enabled by groov EPIC’s GRV-ODCSRC-24 discrete, DC, output module and Opto 22’s PAC Control flowchart-based programming software. PAC Control includes a free Modbus/TCP integration kit to communicate in real time with Pinturas Tropical’s custom-built weigh scales. Each scale had a Modbus/TCP enabled transmitter outfitted with four load cells. Using high-speed Ethernet communications provides real-time feedback on the amount of additives delivered.
In addition, groov EPIC comes with web-based visualization software, groov View, which lets any user on the network with appropriate credentials view the system’s current and historical status. Lugo also used groov View to let operators enter batch parameters, and signal the system to start or stop batching operations.
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Because each groov EPIC also comes preloaded with Node-RED, a flowchart-based programming environment for IIoT applications, RMS used the open-source platform to write batch data to a PostgreSQL database. “At the end of each batch, a PAC Control variable is toggled true, which signals Node-RED to read a string table that contains all the batch information, including batch number, requested amounts, delivered amounts, target time, date/time, etc,” explains Lugo. “From there, we use a Node-RED PostgreSQL node to move those values into a database.”
RMS’s approach ensures that exact additives amounts are injected into the paint batches, eliminating waste, and maintaining Pinturas Tropical’s stringent quality standards. Better visualization and recordkeeping enable tighter control over its dosing and batching system, as well as better ability to analyze production and any issues that may arise.
Pinturas Tropical reports that RMS’s customized paint batching system is a hands-down success. The paint producer’s operations team happily report they now have a zero-error paint batching system. Encouraged by the project’s success, the company is exploring its next project, a resin dosing system for batching oil-based paints. They add groov EPIC’s scalability and flexibility make it an ideal choice for future projects and expansions.
