Can you imagine a fully-automated painting line, with nearly 30% reduction in length compared to traditional processes, highly flexible and with capacity of more than 50 units per hour? A dream? No, it’s reality. Such a line already is in operation and combines an automation concept with an integrated application process.
Short booth lengths save money, first in capital cost and then on operating costs. Cost is one of the most important considerations when planning for a new paint shop. The most dramatic factor in booth length is a compact painting process that features a solvent-based, three-wet process along with a fully automated exterior and interior robotic application process. Its advantages include low costs per unit achieved through high transfer efficiency, low color change losses, reduced energy consumption, and related carbon dioxide emissions. Customers benefit from the particularly consistent film uniformity and high quality level finishes.
Process stability also is an important consideration. Contemporary painting robots have high uptimes, but what happens if a failure occurs? The simplest and most frequently practiced response is the manual backup zone. Manual operators, however, come with some disadvantages including additional booth length, quality problems resulting from the sensitivity of modern paint materials, narrow process windows, and limited painter experience.
Traditionally, adding booth length and application equipment avoids these pitfalls. Another way to compensate for robot downtime is to reassign the painting scopes in the affected station to the remaining robots. This degrade concept might cause a temporary reduction in system throughput and can be managed with the number of robots required for normal production. If temporary production loss isn’t allowed, redundancy must be part of the robot station design.
Figure 1. A comparison of two concepts for a solvent-based, three-wet process. The capacity in both lines is 50 units per hour. Waterborne lines can achieve similar reductions, but have longer flash zones.
|Figure 6. Painting robot with handling functionality: Between hand axis and atomizer, a tool is mounted that can open and close hoods and doors.|
It’s no longer necessary to have different applicators for different painting zones. Processes can be optimized. Modular or integrated concepts in which a vehicle can be painted completely in a fully automated manner in one station are within reach. This means much better cycle utilization, lower paint losses during color change, as well as high system flexibility. It’s possible to react to market demands considerably better by switching individual modules on or off.