Hot Runner Coil Heater Direction Of Development
At present, the main trends of hot runner molds at home and abroad can be summarized as the following aspects.
Components are miniaturized to enable multi-cavity and multi-gate multi-gate filling of small parts. By reducing the nozzle space, more cavities can be placed on the mold to increase product throughput and injection machine utilization. In the 90s, Master developed the smallest nozzle to 15.875mm; Husky developed multi-gate nozzles, each nozzle has four gates, the gate distance can be as close as 9.067mm; Osco developed composite nozzle, 12 sprue tips per nozzle for molding of 48-cavity molds. MoldMaters, Inc. targets space constraints for small parts. In 2001, a nozzle for small parts was developed that included integral heaters, needle tips and melt channels with a volume diameter of less than 9 mm and a gate pitch of only 10 mm. Moldable weights were 1 ~ 30g products; third hot runner company developed mini hot runner system, gate distance can be as close as 8.00mm, especially for smaller electronic products.
Currently, the user requirements for mold design and manufacturing cycle shorter and shorter, the standardization of hot runner components will not only help reduce duplication of design work and reduce the cost of the mold, and very easy to replace and repair fragile parts. It is reported that Polyshot company has developed a quick hot runner mold system, especially for injection pressure of 70kN small injection machine. Husky, Presto and Moldmasters and other companies are the nozzle, stem and manifold as a standard to facilitate the rapid replacement and delivery of molds, foreign only 4 weeks to deliver the mold, mold production in the country as fast as 2 weeks to deliver hot runner mold .
Hot runner mold design overall reliability. Nowadays, the major mold companies at home and abroad attach great importance to the research and development of the design of the hot runner plate and the pressure distribution, temperature distribution and sealing of the connection part of the hot nozzle. Laminated hot runner injection mold development and utilization is also a hot spot. Stack mold can effectively increase the number of cavities, injection mold clamping force requirements only need to increase 10% to 15%. Stacked hot runner mold in some developed countries have been used for industrialization. Stacked hot runner mold injection molding industry in the country has been widely used, such as disposable tableware, bottle caps, caps and anti-theft handle and other small pieces of high-volume Products such as domestic third-party hot runner company in the hot runner stack design and use has accumulated rich experience.
The purpose of improving hot runner component materials is to increase the wear resistance of nozzles and hot runners and to shape sensitive materials. Such as the use of molybdenum titanium and other toughness alloy material nozzle, metal powder injection molding sintered hot runner components have become possible.
Develop accurate temperature control system. In the hot runner mold molding, the development of more precise temperature control device, control the temperature of the molten resin in the hot runner plate and the gate is an effective measure to prevent the resin from overheating degradation and product performance reduction.
Use hot runner for co-injection. Through the effective combination design of the branch pipe and the hot nozzle element, the co-injection molding can be combined with the hot-runner technology to form composite plastic products of 3, 5 or more layers. For example, Kortec has developed melt delivery systems and co-injection nozzles; Incoe's multi-outlet, multi-cavity co-injection branch line can be used for multicomponent multi-component co-injection.
