Being Proactive about Hot Runner Maintenance

Hot runner systems are not new, but their use in toolrooms across original equipment manufacturers (OEMs), molding and mold building facilities grows every year as the technology behind these systems reduces molding costs and improves design capabilities. Cost reduction comes from advancements in venting, valve-gating, nozzle design, serviceability, temperature control, monitoring, melt delivery and maintenance and repair.

The whole mold supply chain can benefit from the right hot runner system. OEMs get better part quality and fewer part failures. Molders get faster cycles, less resin waste and decreased energy consumption. Moldmakers, many of whom are adding presses for sampling and production, get higher productivity from their molds. These benefits make the matter of better educating mold designers, moldmakers, molders, maintenance technicians and mold owners on hot runner system selection, integration and maintenance essential.

Therefore, MoldMaking Technology and Plastics Technology magazines have collaborated to bring you this special hot runner supplement. When developing the content, we set out to find answers to common hot runner system challenges that our readers share with us.
When it comes to design and engineering, for example, molders and mold builders encounter problems with the balance between drops, especially on high-cavitation molds that have smaller, tight-tolerance parts. Some attempt to artificially correct the problem with temperature variation between zones, which is not an ideal solution. Other shops struggle with determining the proper type of gate or determining how to cool the temperature near the tips.

When it comes to maintenance, the mechanical nature of these systems becomes a real challenge. Technicians need proper training to keep these molds in good shape and to execute repairs when the systems wear out or break. For example, many molders and mold builders fail to identify the root cause of degradation and contamination in the manifold. 
As a result of these needs, we decided against presenting articles on the latest in hot runner systems and components (some of which can be found in the products sections of MoldMaking Technology magazine and Plastics Technology magazine). Instead, we opted to highlight stories on making better system decisions, on improving hot runner integration and on keeping those systems up and running. 

The real lesson in all of this is getting every-one involved early—the hot runner system supplier, the moldmaker, the molder and the end customer. Everyone suffers the impact of bad decisions about any part of the melt delivery system, and that suffering can last for years.