Electric machines have significantly improved the electricity efficiency of your injection molding industry over the past 20 years. New strategies to save energy and maintain costs down in times of rising energy costs is the necessity of the hour. Melt-stream heating, particularly of the barrel, presents a solid prospect. Typically, 30-70% in the power consumed by mica heater is wasted by radiation and convection towards the surrounding environment. Eliminating these losses will reduce specific energy usage and let machines to get pre-heated faster utilizing the same power delivery infrastructure, thereby reducing downtime to boost productivity. Inherent characteristics of band-heaters also hamper temperature control response, limiting improvements to some extent-to-part quality uniformity and efforts to reduce change-over times. A band heater’s temperature must first rise above those of the barrel before the barrel may be heated, and conversely, a band-heater’s temperature must fall below that of the barrel prior to it being cooled. The thermal mass of band-heaters along with the thermal contact resistance between the two and the barrel, therefore significantly improve the thermal inertia in the melt stream. The current introduction of lower weight radiant heating elements provides a chance for improvement. Another new technology that provides significant advantages is noncontact induction. Barrel heating using helical induction coils has become considered for many years, but was poorly applied. Past efforts often used inefficient low-frequency power supplies and constantly position the coils in direct connection with the barrel, undermining the compelling benefits of induction. Heat generated in the barrel was still permitted to escape to ambient along with the coils’ thermal mass wasn’t pulled from the equation. Experience of the new barrel also increased the coil’s electrical resistance & reduced efficiency gains.
Xaloy nXheat™ induction barrel heating (patent pending) sharply cuts energy costs and improves temperature control for higher quality and fewer scrap in comparison with conventional heater bands. The nXheat ™ barrel heating solution (patent-pending) uses an optimized high-frequency power supply and a thermal insulating layer interposed involving the barrel and coils to handle the above issues and exploit the full potential of induction. Each of the heat is generated directly in the barrel and stays during this process. The coil’s thermal mass is likewise eliminated, and coil resistive losses are negligible hence the exterior surface is cool to the touch. Barrel heating efficiency approaches 100 % and temperature control response is quite a bit improved.
Energy savings for barrel heating as much as 70% in comparison with heater bands
• Additional energy savings – upto 35% more – because of reduced air-con load
• Additional energy cost reduction from reduced peak power demand
• Fewer heater failures to slice downtime and maintenance costs
• Immediate cooling and heating solution to improve quality and reduce scrap
• Quicker heat-up, typically 2X or more, to boost productivity
• More heating capacity- typically 3X higher wattage to the barrel- eliminates a bottleneck
• Higher barrel temperature power to mold high-temperature polymers, or metal
• Cool exposed surfaces for increased operator safety
The nXheat™ system relies on a high-frequency power supply and helical induction coils to produce heat directly inside the barrel wall. A thermal insulating layer is interposed between the coils and barrel to combat heat loss, increase efficiency and improve control response.
The system can be found in two forms:
1) all-zone nXheat™ where induction heating completely replaces conventional heater bands;
2) nXheat-Hybrid™ by which power-saving induction technology heats the barrel’s feed zone while conventional band heaters handle downstream zones.
All-zone nXheat™ delivers maximum savings in power consumption, about 50-70%. It is the ideal system for larger machines with over three heating zones as a result of high importance of the reduction in power consumption.
On smaller machines with several zones the nXheat-Hybrid™ system can deliver the majority of the savings of your all-zone system because induction can be used within the barrel’s feed zone in which the greatest amount of heat input is necessary to start the melting process. On such machines, which generally have barrels with inside diameters of 50 mm or less, the hybrid system will typically provide a 30 to 50% decline in power consumption.
Inside the hybrid system, downstream zones dexmpky42 use either insulated or uninsulated band heaters. Greater energy savings are achieved with the use of insulated band heaters. A similar sheet insulation which is used from the induction-heated feed zone enables you to wrap the downstream band heaters. The precision and fast response of induction heating inside the feed zone will also substantially reduce temperature overshoot issues that can occur with insulated band heaters.
The device will cover itself with power cost benefits along with other cost and quality benefits. These include reduced scrap stemming from less variation in melt temperature and faster solution to changes in target melt temperature. The payback period on investment costs of these systems is very dependent on electricity rates, machine size and production schedule (hours of operation annually). This sort of system typically costs about 25-50% of any all-zone system.