Mikell Knights, senior correspondent at Plastics Machinery Magazine
Suppliers of hot runners are adding more capabilities to their systems to help molders optimize their processes. New hot runners configured for a specific end market and new devices that enhance such systems mark the latest design developments. Several suppliers previously reported their news regarding complete hot runner and manifold systems.
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Milacron’s TempMaster hot-runner temperature controller. |
Milacron
Milacron LLC, Cincinnati, has launched a Mold-Masters-brand Adaptive Process System (APS), a self-adjusting process-control method that optimizes melt quality by automatically tuning the operating and temperature control parameters of a hot-runner system and other aspects of the molding cycle.
“Injection molders are being pressured by their clients to make parts even faster and better in order for that client to remain competitive. To achieve it, molders need an even higher level of control, where every single action that occurs in the molding process becomes a control point toward optimizing melt quality,” says Bruce Catoen, chief technology officer at Milacron.
APS controls hot-runner temperature, valve-gate or pin motion and other aspects of the molding cycle automatically. “Ten years ago, no one would think you need to profile the opening and closing stroke of a valve gate, but today that parameter is considered a critical aspect for melt control. It relates directly to part quality,” says Catoen.
APS is compatible with Milacron’s entire line of melt-delivery products, including its Temp-Master series hot-runner temperature controllers and M2-SVG valve-gate controller. APS also controls a range of hot-runner and tooling components, including Milacron’s E-Drive electric valve-gate system, servo-electric valve gate and sequential valve-gate technology, as well as its E-Multi add-on injection unit. APS maintains melt temperature to within 0.1 degree Fahrenheit of set point.
APS helps molders working with difficult engineering or high-viscosity resins, high melt pressures and small shot sizes. With it, they can gain control in a process where molding conditions are dynamic.
A number of algorithms provide short-circuit protection, hot-runner leak detection and automatic, even heating to ensure proper thermal expansion of the manifold and nozzles. The unit also features automatic soft start and continuous ground fault detection, an autopurge feature and automatic slaving of a thermocouple to another when failure occurs. APS monitors the flow, temperature and pressure of the water system, and signals when operations fall outside of parameters. It also monitors valve-pin position and speed for sequential valve-gate systems.
Husky
Husky Injection Molding Systems Ltd., Bolton, Ontario, is launching Lucent, a manifold line for automotive lenses and lighting. The entire hot- runner system is made from special steel, with a special coating that prevents PC degradation and the formation of black spots in lenses and window panels.
Lucent is a unified, pre-assembled, drop-in manifold available with an angled configuration for parts with optical or very high aesthetic requirements. “Lucent is a single- piece system that the molder removes from the shipping crate ready to assemble and install as is. Previous systems designed for automotive lens applications were multipiece systems that required some additional work and assembly before they could be used,” says Craig Reynolds, director of business development. “A significant difference here is the Lucent system is wired and ready to go out of the crate.” Lucent can produce a wide range of lens and lighting products, and handle a range of shot sizes. The system uses Husky’s Ultra line of nozzles, says Reynolds.
Usually, an angled manifold carries a higher risk of leaking in the hot runner due to the combined thermal expansion between the manifold and nozzles. Also, an angled seat in the mold is difficult to machine, which can make designing flow paths a challenge. To solve these challenges, Husky uses its UltraSeal technology, which prevents hot-runner leaks even at startup.
With UltraSeal, the nozzles are preloaded to the manifold to provide leak-proof operation in cold conditions. The preload ensures leak-proof operation that covers a wide processing window. An UltraSeal spring pack offers protection against overheating, and spring forces are optimized to minimize plate bowing, reducing mold wear.
Lucent incorporates other new features that improve processing performance and ease installation and maintenance. They include a nozzle shoulder designed to minimize thermal loss by 30 percent, compared to a standard solid skirt design, and an easily removable actuator. Lucent also has jacketed heaters and a valve-gate tip configured from three materials for a high level of thermal performance and high wear resistance.
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Synventive’s new SynCool3 system draws heat from a manifold away from the actuator. |
Synventive Molding Solutions
Synventive Molding Solutions, Peabody, Mass., added a new cooling technology to its line of valve gate technologies that makes it possible to eliminate water cooling lines from hot runner tooling for low to medium temperature molding applications.
“Actuators that drive valve pins are often bolted onto the hot manifold. The actuators have water cooled cooling plates which prevent the hydraulic fluid and seals in the actuator from overheating. When molding is completed, the cooling system and the heaters are turned off and the tool is pulled but the manifold is still very hot. The manifold can take hours to cool down and in that time the hydraulic fluid or seals in an actuator can overheat,” says Bill Rousseau, chief engineer.
Synventive introduced SynCool3, a new spring-loaded device that bolts onto actuation cylinders and is designed to perform as a heat sink to draw heat away from the actuator. It pulls heat by touching the top plate, says Rousseau. The cooling effect of SynCool3 is strong enough that molders processing commodity-type resins may be able eliminate cooling lines for the actuators, negating issues associated with clogged cooling circuits. By removing the cooling plate, the manifold temperature uniformity also improves. “Eliminating the need for cooling lines can be a huge time and maintenance saver that can boost productivity,” says Rousseau.
Synventive says SynCool3 has been available since January.
Osco Inc.
Osco Inc., Rochester Hills, Mich., calls its new Quickset Valve Gate System (QSS) a simplified, prewired, plumbed and tested valve-gate manifold for producing co-injected products.
QSS is designed as a complete manifold system that installs easily into a mold, says Peter Rebholz, VP of sales. In terms of design and configuration, QSS is positioned between a unitized system and a hot-half construction, he says.
“It provides the value and benefits of a complete hot half but at a much lower price,” says Rebholz.
QSS is furnished with a standard Osco manifold, Osco PIC and MTC-type mold connectors. The nozzles are installed into the mounting plate, unlike threaded nozzles that go into the manifold. The benefit is that the nozzles can be installed with a centerline distance of 2 inches compared to centerline distances of 5-7 inches with screw-in manifold drops, says Rebholz.
The wiring arm and all connectors of QSS are secured to the manifold, and the system features a wiring schematic plaque fastened to the terminal box for easy in-press zone identification. The wiring zones are clearly labeled, reducing installation and disassembly time while ensuring reliable and accurate connections. QSS uses a system mounting plate the same size and shape as the manifold. Osco bores holes into the plate for the drops, adding the nozzles into the system plate. Then the manifold is joined to it, says Rebholz. Users then add their own mold plates to complete the mold hot-half. A range of nozzle styles in various sizes can be incorporated into a QSS.
Hasco America
Hasco America Inc., Fletcher, N.C., extended its Multi Shot series with a new compact hot-runner system dubbed the H4070, designed to handle engineering plastics that have a narrow processing window.
A complete, ready-to-install, prewired system is designed with four or eight modified Techni Shot 20 nozzles with a fixed spacing of about 5 inches. The nozzles connect to a naturally balanced manifold with single-sided heating that provides a uniform temperature profile. Nozzle
and manifold temperatures are individually controlled.
Users can select from variable nozzle tips. The nozzle tips can be mounted from the parting plane, which simplifies removal of the nozzle tips and heating unit for maintenance. Options include a hot half designed with outside dimensions of about 7.7 square inches as a low-cost, high-cavitation solution.
