The Elements of Neutec® Flowlogic® Technology

Learn the details of the six elements that define Neutec® Flowlogic® technology in this article from Rio Grande.

Last edited: 10/4/2018
Crucible chamber of Flowlogic Casting Machine

The Elements of Neutec® Flowlogic® Technology

Flowlogic® technology from Neutec® represents an evolution in approach and design that emerged from Neutec engineers pursuing an answer to their own questions around whether a pressure-only casting system might yield casting results superior to those produced by the existing pressure-over-vacuum (POV) technology of the J-zP Autocast machine. Their findings became the basis for Flowlogic. Flowlogic technology encompasses a collection of elements—some intrinsic to the casting machine itself and some intrinsic to the supplies and consumables designed for these machines—that work together to deliver exceptional castings through reliable, repeatable, intuitive and cost-effective casting processes.

As is true of casting itself, the work that produced Flowlogic® is a combination of science, experience and motivation to achieve optimum results. While there are a number of process and component improvements in the Neutec Flowlogic casting machines, six main elements define the Flowlogic difference.

1 – Pressure Differential System

Neute® 610 Casting Machine

In investigating why vacuum pumps were seemingly effective in providing crisp, detailed castings, we learned that the benefit is not so much the differential in pressure between the outside of the flask and the top of the poured metal but rather the flow of gas through the chamber and flask; it is this flow that moves the metal quickly into the flask cavity. The pressure-only design of the Flowlogic® system effectively and efficiently directs the flow of gas from the upper chamber, down through and around the crucible, past the pour nozzle and into the flask; the process fills the flask cavity in less time and with less heat dissipation than can be accomplished with a pressure-over-vacuum system. Because of this technology, the Flowlogic machines eliminate the need to purchase, maintain, repair and replace vacuum pumps.

2 – Closed, Inert-Gas Environment

In any casting process, exposure of hot metal to oxygen can cause a variety of defects in the castings that, in turn, cause rework, wasting time, money and materials; preventing this exposure is critical to success. In Flowlogic® machines, controlled access for introducing the casting grain to the crucible chamber and a closed environment during the melt and pour stages, along with a continuous, positive flow of inert shielding gas into the crucible chamber, drastically reduce the presence of oxygen around the metal and prevent its intrusion into the process. A hopper accepts the grain load; a mechanical lever, attached to a spring-loaded gate at the bottom of the hopper, releases the grain into the crucible at the proper time without having to open the machine. The spring-loaded gate forms an additional barrier to oxygen infiltration. During this time, the flow of inert gas carries oxygen out of the crucible chamber, preventing oxidation of the metal in the crucible.

Flowlogic machines are designed to use either nitrogen or argon. Argon is considered a true noble gas and will not react with any metal; however, it can be considerably more expensive than nitrogen. Nitrogen, though not a noble gas, does not react with the metals typically used in jewelry manufacturing (gold, silver, brass or bronze) and, over years of testing and observation, Neutec engineers have not found a benefit to using Argon.

3 – Type-A Crucible

The innovative Flowlogic® Type-A crucible design creates a significantly more stable (low-turbulence) flow pattern, both inside the crucible and at the pour hole.

  • At the crucible bottom, a tapered profile presents a smoothly and continuously changing inlet radius that minimizes internal flow resistance while increasing the flow velocity and stability.
  • At the pour hole, a sharp, squared-off edge minimizes 1) the uneven effects on the exit flow (and the flow disturbances that result) and 2) the characteristic bulbous shape generated on the front of the exiting flow (that is thought to be caused by surface tension and tends to inhibit flow into the mold).
  • Beneath the crucible, a specially designed graphite pour nozzle nests into a recess designed into the crucible bottom to guide and align the flow of metal from the crucible into the flask throughout the pour.

These features contribute to a smoother, more stable, maximized flow, ensuring that all molten metal transfers to the mold. Crucibles fabricated with this design produce better mold fill characteristics with consistently higher fill percentages and faster pour times.

4 – Flask Alignment Design

The base of the crucible chamber of the Flowlogic® casting machine features an exclusively designed centering plate that creates a seamless and airtight seal against the base of the invested flask to position and hold the flask and crucible chambers in a perfect alignment. In addition, the plate aligns itself with the flask and flask adapter to ensure a perfectly vertical pathway for the molten metal—the metal pours in a straight line directly from the crucible into the bottom of the flask, filling the mold cavities quickly and effectively with almost no turbulence or heat loss. In addition, with the centering plate in position over the button, the pressure is focused more directly at the button during the pour rather than distributed across the entire upper surface of the invested flask.

5 – NeuSprue® Sprue & Base System

Patented NeuSprue® wax sprue and base systems eliminate many of the defects common with old-style sprue and base designs and delivers close control over the metal in process, reducing costs and saving time and money. The NeuSprue base does not have a button structure; instead, each NeuSprue wax sprue features its own built-in button at the end of the sprue. The interior of button is threaded, allowing it to be secured onto the specially designed base by a threaded plastic holder inserted through a small hole in the base. The base, sprue and holder form a fresh, airtight seal with every single tree. This system streamlines the treeing, investing and casting processes to support better patterns, smoother surfaces, significantly improved fill rates, reduced reject rates, and to virtually eliminate the incidence of floating trees.

  • The two-piece screw-on base assembly, securing the threaded sprue to the base, eliminates the risk of floating trees in the investment process, prevents air from getting trapped between sprue and base, and creates a perfect, one-use connection for every tree, every time. And, because the base is simply unscrewed to remove it from the invested tree, there is no stress inflicted on the wax tree and patterns and no chipping or crumbling of reservoir area that can result in debris falling into the patterns.
  • A built-in, funnel-shaped button, part of the sprue itself and not part of the base, provides a smoothly angled slope (instead of the traditional bowl-shaped button) that significantly dampens turbulence as the metal enters the mold cavity, ensuring a quicker fill, minimizing the amount of metal in process, and allowing you to control the amount of metal in process because the button is weighed along with the tree and patterns in calculating the metal needed for casting. Minimizing the metal in process reduces costs—both of new metal going into each casting cycle and of recycling unused metal following each casting cycle.
  • A specially designed tip has a rounded interior surface sets up a swirling action, minimizing turbulence and preventing the splashback that a flat, squared-off tip causes. This starts the pour with less turbulence, helping produce superior casting results.
  • A tapered sprue body provides a continuously angled slope that helps smooth away turbulence throughout the fill. This tapering width enhances the progressive solidification of metal during and after pouring.
  • The proprietary wax formula of NeuSprue reliably holds its shape through the stresses and demands of the treeing process, then burns out cleanly and completely, and resists absorption into the surrounding investment—ensuring cleaner surfaces and higher quality castings.

6 – SuperPerf Flasks

SuperPerf perforated flasks, available with or without flanges, are solidly constructed of heavy #304 (3mm thick) rolled stainless steel that is stress-tested for optimal performance and minimal flange warpage when heated, and manufactured to precise tolerances for roundness, flange size/position and perforation locations.

  • The flasks are specially engineered with larger-diameter perforations that cover approximately 50% more of the flask surface area than traditional flasks, providing a significantly improved vacuum draw during investing and more effective outgassing under pressure during the pour.
  • Clean, uniform submarine welds ensure a vacuum seal between the flask and the steel flange; the 5/16"-thick stainless steel flanges are welded on both sides for optimum seal; both welds are precision machined for flatness to enable faster cleanup and smoother removal of cold investment.
  • Double cross-bar supports a true, round flask shape and investment, even through high-pressure casting.

In Closing

These six elements represent the most prominent of the collection of improvements that define the exclusive Flowlogic® technology. After the basic concept was realized, Neutec engineers worked with a variety of mechanical and casting parameters under controlled conditions and carefully observed the results. Once optimum results were obtained, the Flowlogic design was finalized and a control program created to allow reliably repeatable results. The design yields low heat loss with low turbulence, but most importantly, the fastest cycle times, highest fill rates and highest product quality in the industry today.

Flowlogic® machines are manufactured with the highest quality materials. These machines are manufactured in the U.S. at the Rio Grande facility in Albuquerque, New Mexico, USA, where each one is fabricated and assembled by quality-focused associates with years of experience behind them. Every Flowlogic machine is supported world-wide with service provided by a dedicated Neutec Field Service Engineer (FSE) team and by distributors around the world who have been trained and certified by Neutec.

Find out more about Neutec, its history, products and drive to innovate.

 

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