Electrically-driven hot runner targets automotive applications
By Stephen Moore | October 15, 2013
Dusseldorf, Germany - Italian hot runner system vendor HRSflow (San Polo di Piave) is participating in this year’s K Show with its new FLEXflow product taking center stage with a live demo.
FLEXflow is an electrically driven system that accurately adjusts valve pins in large surface applications such as bumpers, instrument panels, door panels, and in general any large part that requires sequential cascade molding as well as quality optical parts whatever the size.
FLEXflow reportedly guarantees completely independent management of each pin during the opening and closing stages by precisely controlling each valve pin’s position, acceleration, velocity, and stroke. The result is optimal control of both the filling and packing time with a direct benefit on the part warpage too. The new electrical cylinder meets the requirements for high aesthetic quality, removing major defects such as flow marks, weld lines and flash on injection points.
Multicavity molds, where the dimensions of parts are significantly different in shot weight, can benefit from the new FLEXflow cylinder. It represents the ideal solution for the fine tuning of weld line position and when a complex filling pattern balance is required, even involving glass fiber materials where structural problems could arise. Moreover it meets the requirements of molding applications where the processing window is narrow, as well as of engineered materials. Furthermore, the total absence of oil makes FLEXflow suitable for clean rooms.
The new electrical cylinder reportedly has several benefits compared to conventional air/oil cylinders:
• class “A” aesthetic part quality;
• improved part-to-part consistency thanks to stable process repeatability;
• optimized balancing, reducing over-packing and clamping force;
• hydraulic connections are eliminated (no more oil leakage);
• maximum flexibility in multicavity/family tool design;
• reduced energy consumption;
• accurate process control;
• easy to use and easy maintenance.
The new HRSflow electrical cylinder is available for the supplier’s M, G and A series (5, 7, 10 mm pin diameter) hot runner systems and it can work up to a maximum pressure of 2000bar.
The nozzle is positioned on the side of the nozzle axis, reducing the height over the hot runner system package. The electrical cylinder can be easily fitted and replaced with a hydraulic cylinder considering FLEXflow has the same size as a hydraulic cylinder with side layout. Moreover three installation positions are possible, allowing the user full freedom over mold design.
Absolute control over the pin position provides processors with the ability to adjust the filling pressure to reduce the “pressure jump” phenomenon. Controlling the opening pin speed profile enables elimination of this pressure jump, thereby reducing the risk of flow marks on the part.
The new FLEXflow is adjusted, controlled and monitored by the FLEXflow advanced controller that can set the valve pin position with accuracy of up to 0.01 mm. The control unit is available in 8, 12 and 16 zone configurations. Full monitoring of the process makes it possible to adjust all parameters, resulting in optimal gate quality and part filling with the consequent elimination of flow marks and weld lines.
Challenging automotive applications are often the result of close collaboration with customers. At K, HRSflow hot runner systems will be mounted on George Kaufmann /GK molds and running live on an Arburg injection molding machine (Hall 13 Stand A13) and on an Engel machine (Hall 15 Stand B42/C58), both demonstrating automotive applications.