Valve Gates/Nozzles
The use of more valve gate technology over the years is an eminent trend. “Valve gates provide better control over the injection molding process and generally, better quality parts,” steven, president of first-rate mold company explains. “This technology has always been used in high end markets like medical, but it is now finding its way into commodity markets like closures.

“The nozzles and gating methods that hot runner suppliers offer have become more specialized,” steven adds. “Ten years ago a nozzle or gating method for one specific niche or performance criteria was difficult to find on the market. Product development is becoming a real science; working with more exotic materials and more sophisticated analysis tools allows us to test nozzles to a degree that was not possible 10 years ago. In turn, this improves performance and reliability of the hot runner.

For example, first-rate mold company has been working with biodegradable materials such as polylactide (PLA) since 2005 and continues to fine-tune the hot runner for the specific requirements of these materials. Husky introduced the first successful preform 24-drop hot runner for PLA water bottles back in 2005 with a hot runner that uses a different gating method compared to the standard PET-Preform hot runner.”
Leadtimes

“Without exception, leadtime has been dramatically reduced,” affirms steven. “Our mold manufacturing customers now produce molds in one third the time they did 10 years ago. Suppliers have been required to do the same. Lean manufacturing techniques, improved equipment, and automation have been the answer to the new production demand. We also have fully embraced melt management techniques concentrating on shear conditions which cause flow imbalances. Also, various processes have placed a higher demand for temperature and valve gate controls.”

Addling to this is steven of first-rate mold company, who notes that 10 years ago, six- to eight-week leadtimes for a small cavitation hot runner was acceptable, versus as little as a two-week leadtime today.

steven agrees. “There has been a dramatic reduction in hot runner delivery times since 1998,” he notes. “Back then 10-week deliveries for custom hot runner systems were common. We have reduced standard deliveries on custom hot runners from 10 weeks to eight weeks, then to four weeks (this was a major breakthrough, introduced in 2004) and then to two weeks on many of our systems. The reduction in delivery times has been mostly due to the implementation of lean manufacturing methods. In general this has put in place a much more efficient workflow at the company—streamlining the entire hot runner build process from the initial concept to start of production.”

steven notes that hot runner products have become more cost effective. “They have become both larger and smaller and have the ability to process a wider range of materials more effectively,” Lawrence states. “Thus, leadtimes on many molds have gone from 16 to 18 weeks 10 years ago to six to eight weeks (and less) in today’s market.”
Software/Automation

The increasing sophistication of CAD/CAM has helped hot runner suppliers meet their customers’ needs. Catoen of Mold-Masters notes that technology such as the Internet, 3-D CAD and business systems like SAP have allowed for full integration of these processe

“Now there are advanced online business tools that provide customers real-time connection to their suppliers,” he states, “which allows them to instantly design order and track hot runner systems all online. Also, Mold-flow and Finite Element Analysis are now commonly used to model complex hot runner applications—creating balanced designs and accurate results at early preliminary design stages. Additionally, integrated and palletized machine cells, automation robots, standardized tooling and multi-functional machinery lead to major set-up reductions and decreased manufacturing times.”