Reduction of unscheduled maintenance of bulk carpet fiber texturizing equipment
This project involved the measurement and reduction of unscheduled equipment maintenance in the final stage of a nylon-6 bulk continuous filament process. The SINTEX operation was selected because the cost of poor quality (COPQ) was estimated to be higher here than elsewhere in the process. An accurate measure of the time lost was obtained by measuring the time spent on unscheduled maintenance for a typical machine for forty-eight days. Area personnel ranked potential causes for the most frequent baseline repairs in a Failure Modes and Effects Analysis (FMEA.) Using the causes listed in the FMEA, an experiment was designed with three treatments; cleaning the draw and separator rolls, checking and adjusting threadpath, and maintaining a vibration standard. Results from the experiment showed that the combination of adherence to a vibration standard and weekly inspection and repair of the threadpath reduced unscheduled maintenance by 69 percent over the baseline.
Maintaining the demonstrated gains would involve monitoring the amount of unscheduled maintenance downtime and require entering the data recorded at each of fourteen lines daily into a database. This would require hundreds of hours per year. Therefore, an automated maintenance reporting system is recommended to allow a timely response to the unscheduled maintenance system possible.