POLYMERS – PS – COLOUR CHANGE AND REDUCTION OF TRANSIT TIME BETWEEN PRODUCTION CHARGES

REPORTED PROBLEM

During a colour change at the production line, a transition from dark to bright colour used to take about 80% more than a reverse transition, from bright to dark. Additionally, an off spec product was a result, thus subject to recycling as a waste product.

ACTIONS

The production process as well as raw materials, equipment and technologies being used were all analysed. A source of this problem was determined as one of the equipment’s component, a worn end nozzle where a dark polymer mixture has deposited. Due to the fact the company could not afford a new nozzle, as we initially suggested, we developed an alternative method for such colour change.

EFFECT

  • The transit time between colour changes in manufactured products was reduced by 50%
  • The off spec product ratio, being a waste product, was reduced
  • The company managed to generate savings (waste reduction) and to increase production efficiency (shorter transit time between production charges); the process was used for 18 month after this project, and it has been since used on an ad hoc basis for acceleration of colour change during production