Productivity is the relationship between utility and effort. Reduced cycle times mean increased productivity and reduced costs because a greater number of parts (utility) can be produced within the same time frame (effort). Of course this is only holds true if the process is reliable and scrap rates do not increase. Reduced cycle times — together with other cost reduction measures — should always be the primary focus for injection molders. For various reasons, however, this is often not the case. Paradoxically, not having enough time is the reason most manufacturers give for not investing more effort in optimizing cycle times.
Partnering for Success
Our applications team, in collaboration with our partners, can help with cycle time reduction. With each project, we generally follow these steps:
- Analysis of the actual and potential cycle times for the whole system (injection molding machine, mold, automation technology, auxiliary equipment and material)
- Definition of measures and creation of a cycle time prognosis
- Recommendations and implementation plan
- Implementation and assessment of recommended measures
- On site production support
- Review of results following a pre-agreed period of time
Cut cycle times in half
The production of faceplates for Siemens C45mobile telephones demonstrates just one successful project. Initial analysis showed a cycle time of 18.2 sec. including 6.8 sec. of non-productive, 1.6 sec. for part removal, and a cooling time of 9.8 seconds. By implementing parallel machine functions Ferromatik engineers calculated that non-productive time could be reduced to 3.5 sec. By using a lighter robot arm, a new part removal time of 0.8 sec. was projected. By changing the position of the cooling channels and using impulse cooling the mold cooling could be optimized to 3.0 seconds. Since not all the mold cooling optimization measures could be implemented with the existing mold, the actual process time could “only” be reduced to 3.5 sec. Altogether after implementation of all these optimizations a cycle time of 7.8 sec. was attained with no loss of part quality. This is a total cycle time improvement of 10.4 sec. – or 57%!
