Greg: I am always looking for people with interesting and enlightening application experience to feature in this column. I was fortunate to have Jim Cahill, Emerson social media manager, point me to Francisco Campa, director of manufacturing operations for Mohawk Home, a division of Mohawk Industries. Even when the economy was hurting, Mohawk Home was breaking sales records. At Mohawk, Francisco has demonstrated considerable success in applying technologies such as robots in manufacturing operations for home products that are outside the areas of expertise and the process industry applications of my career. One of the great benefits of this column is the opportunity to develop an understanding of innovative automation accomplishments that are the result of extensive effort and expertise in an hour of conversation. This knowledge and recognition of achievement leads to the advancement of the automation profession. This is my main motivation.
Stan: Francisco, as a previous configuration engineer and director of technology addresses both the technical and business aspects important for maximizing benefits, what is your general approach?
Francisco: Everybody agrees to automate, but how do we pay for it? I develop and justify automation based on whether it makes good business sense. I seek the business case in terms of contributions to the bottom line. I develop the scope, architecture and technology. During my career I have done tens of millions of dollars of highly successful automation projects using this approach.
Greg: What was your most recent project?
Francisco: I was looking at using robotics to help bring manufacturing back from overseas. In this particular plant for reprocessing rubber tires into floor mats, the labor costs and human safety risks were excessive. The process is very labor-intensive and hazardous with many recordable incidents a year. I took the difficult and dangerous operations out of the hands of the operators. The result during this first year of operation is no recordable incidents, a 70% reduction in labor, 60% increase in productivity and an 80% improvement in quality. Consequently, we were able to reduce the number of production machines required, which reduced capital costs.
Stan: What are some of the details of the manufacturing process?
Francisco: In the key part of the process, molds are filled with recycled crumb rubber and then put into a high-temperature press. All of this was previously done manually. A robot now handles the molds by tending the press. The robot grabs a completed mold and empties the product onto a conveyor, then presents it to a filling station to be reloaded with material. After a set number of molds are ready, the robot puts them into the press. The down time between pressings was reduced by 85%, significantly increasing equipment utilization.
Our original project only considered a robot to just grab finished goods and put them on a pallet, but very quickly we realized that most of labor, quality opportunities and safety concerns were in the main molding department.
Past attempts to automate this manufacturing process showed limited success; I envisioned a robot as providing a flexible solution that could help us achieve our goals.
Greg: How did it work out?
Francisco: The robotics portion of the project was easy, but everything else was problematic. Robots have very high uptime numbers and are very reliable; tasks are easily programmable and for the most part, robots will carry out their tasks with no issues. However, the equipment around the robot is not as reliable and will show lower performance numbers.
Our initial productivity was only 10% of expected; by successively addressing these support processes we increased productivity to 60%, then 100%, and finally to the incredible level it is today.
Stan: Even a great solution can be for naught unless the whole process is addressed. Problems upstream or downstream can result in failure. How did you solve these problems?
Francisco: It is important to evaluate the complete value stream for the manufacturing process and not only that portion to be automated. Prior and subsequent process will have a significant effect on the automation's success and the performance. In our case, we included all supporting processes including press retooling and raw material properties. By doing this, we also were able to almost completely eliminate the downtime required for product and process changes and improved product performance while allowing for increased throughput.
The crumb rubber, once mixed and prepared to be used in a mold, has a very short shelf life. You only have so many minutes to get the mix into the mold and into a press. We also required the use of supplemental additives to aid in product extraction from inside the molds, which, if not properly used, could create quality issues downstream and buildup around equipment.