Finishing is the final step of the production process, as well as the last stage of our journey through the 2022 Xylexpo Innovation Awards, which started with the nominations by the jury, the selection of winners, and the detailed presentation of the five award-winning solutions, one in each category, one in each Xylon issue in 2023.
The 2022 Xylexpo Innovation Award in the finishing and coating category was given to “Excellent CM80”, presented by Makor from Sinalunga (Siena). It’s a high-end oscillating spraying machine for high production volumes, which can also operate in continuous mode, mainly designed to paint doors and furniture doors.
Having redesigned most of the key components of the machine, all functions have been optimized to achieve a near-total recovery of overspray, i.e. the paint not deposited on the workpiece, and a significant reduction of ordinary and extraordinary maintenance and cleaning actions, with consequent economic and environmental benefits.
While the quantity of paint atomized in a second may seem low, you can easily understand how much paint can be accumulated with these machines that can spray more than 150 kilos per hour. This explains the constant search for tricks to reduce overspray and the time for paint removal.
Let’s review the design features that have led to such innovations, starting from state-of-the-art of spraying machines to see the difference. Normally, in flow-through machines, the working width of parts is 1,300 millimeters, and the spraying machines manufactured so far with this size have a two-meter-wide belt to support and feed the parts, running between protection side bands to avoid paint from staining the lower face of the belt.
The key concept of “Excellent CM80“ is a 2.5-meter-wide belt. In addition, the booth was designed using complex simulation techniques, to optimize air pressurization and suction: it is divided into three areas, including an inlet and outlet pressurization chambers, and a painting chamber with prismatic ceiling to optimize the airflows. This configuration ensures the best painting quality with minimum waste and excellent cleaning of the spraying arms and the entire booth.
Through the combination of wide belt and optimized airflows, virtually all the sprayed paint falls onto the belt, including the finest drops, with only a minimum portion reaching the filters. As a result, the filters last up to 70 percent longer, with an equally strong reduction of replacement costs and times; furthermore, the protection side bands were eliminated, together with the corresponding cleaning process and the disposal of polluting materials.
The filters are placed in a lower position, to restrict the “dirty” area under the worktable, avoiding dust being blown onto the part by the turbulence generated inside the booth. The four boxes where the filters are lodged, two on each side of the machine, are provided with wheels for easier maintenance and faster replacement, and with safety sensors. Filtration is a dual-stage process, as each box contains two filters at different levels through which the air flows in sequence, each with a surface of one square meter.
So, the total filtering surface is eight square meters, ensuring long filter life and cleaner air, as mentioned above.
Conventional spraying machines normally have two belts, one going in and one going out, besides the main belt of the painting booth. This means that the fresh paint on the panel edges stains the outlet belt. To avoid this, “Excellent CM80” has one single belt from the entrance to the outlet section. This single belt, 2,500 millimeter wide, and the absence of side bands are patented concepts.
The belt cleaning system, mounted onto the side extraction carriage, is equipped with a motor-driven scraping unit for the chute, much more reliable than the conventional pneumatic cylinder, and polyester protections for the chute that can be easily dismantled for quick maintenance. A second carriage for quick color change can be supplied upon request. Obviously, the recycled paint, both basecoat and topcoat, can be mixed back into the fresh product sent to the guns.
For the transmission of motion to the axes that drive the guns, the conventional belts have been replace with pinion racks, independent for each arm. This means smoother motion, which translates into no dust on the parts to the benefit of painting quality, and longer life of all kinematic systems, as well as a 50% reduction of motor power requirements, with consequently lower energy consumption.
Other noteworthy specifications include: a reading barrier for incoming parts with 120 photodiodes; the paint flow adjustment on two independent circuits; airflow control for paint atomization in the guns; spark control system in the booth; suction flow control with automatic signaling and adjustment via inverter; and finally, a clear and ergonomic interface for easy operation.
“Excellent CM80” was previewed at Xylexpo in October 2022, and it is currently the Makor’s best-selling high-end machine.
