What's New » Low-Cost Device For Feeding Color Into Extruders Helps Cut Color Cost and Enhance Electrical Properties

Low-Cost Device For Feeding Color Into Extruders Helps Cut Color Cost and Enhance Electrical Properties

TAMWORTH, STAFFORDSHIRE, UK, March 01, 2009: The Maguire® MGF Series gravimetric device for feeding color masterbatch into extruders processing wire and cable compounds has a new modular design that increases production “uptime” while continuing to be more accurate and no more costly than conventional volumetric feeders, it was announced today by Maguire Europe.

“The superior accuracy of MGF feeders enables wire and cable manufacturers to avoid over-coloring and reduce color consumption, increase control over product quality, and document color usage for each production run,” said Paul Edmondson, general manager of Maguire Europe. “By employing the feeder to exert close control over color dosing, manufacturers can run ‘faster and thinner’ without compromising electrical properties.”

The improved design increases uptime (time spent in production rather than changing colors or jobs) by making it possible to remove all main feeder components separately. The basic concept of the MGF feeder is still the same: use of load cells to accurately monitor the loss in weight of colorant in the hopper as the material is fed into the processing machine by an auger. But now the only component mounted on the load cell is the hopper, and this is readily removable from the device, as are the auger, the auger tube, the motor, and the load cell bracket. As a result, it is easier and faster to access components for cleanout or servicing.

“While color is a necessity for visually coding wire and cable and, increasingly, for product identity, it is in some ways also a necessary evil,” said Edmondson. “The pigments in color masterbatch can interfere with or degrade electrical performance. In the downstream test of dielectric integrity commonly performed on wire-coating lines, insulation with too much colorant or erratic color dispersion will fail the test by ‘sparking-out.’ By increasing the accuracy and consistency of color dosing, the Maguire MGF feeder enables wire and cable manufacturers to reduce colorant levels, not only to save costs but to enhance the electrical performance of the product in the spark test and in subsequent end use.”

Feeder Offers Benefits of Gravimetric Dosing but Costs No More than Volumetric Units

Maguire introduced the original-design MGF feeder in the U.S. in 2007 as the first low-cost gravimetric feeder, costing no more than widely used volumetric feeders but providing a much higher degree of accuracy. Today this equipment still costs the same as volumetric feeders and 25 to 35% less than competing gravimetric ones, according to Edmondson.

Also retained is an important advantage in accuracy: “Volumetric feeders do not monitor the weight of colorant as it is fed to the processing machine and thus generate no data about how much of the material is actually consumed from moment to moment,” Edmondson said. “Because a gravimetric system generates a wealth of data on color consumption, it adjusts color metering far more accurately to account for process variations.”

The key to adjusting for process variations is Maguire’s Loss-in-Weight software in the feeder control. This proprietary system scans data on color consumption every half-second and automatically adjusts dispensing when a predetermined amount of accumulated error is detected. “By responding exclusively to accumulated error over a given period of time, Maguire’s proprietary software focuses on real changes in throughput, not transitory or anomalous changes caused by vibration, clumping, or surges,” Edmondson said. “Thus the system provides real-time control and absolutely smooth metering consistency.”

To enter settings for extrusion into the microprocessor controller of the MGF feeder, the operator simply selects the “Continuous” mode. The next entries are those of letdown ratio and throughput. Finally, the operator presses “On” and “Run.” As material is metered into the feed throat, the dual load cells under the loss-in-weight hopper detect material usage. The loss-in-weight is collected by the controller and continuously monitored so that metering accuracy is held to within +/- 0.2%


MAGUIRE EUROPE supports a network of distributors throughout Europe, as well as in Africa and the Middle East, with sales and technical support, customer service, and an extensive inventory of Maguire® equipment systems and parts. Maguire Italy, a Padova-based Maguire Europe business unit serving customers through sales agents in five regions of Italy, can be contacted by telephone at 39-049-970-5429 and by email at Robert@Maguire-Europe.com. Maguire Europe is headquartered at Vanguard, Tame Park, Tamworth, Staffordshire B77 5DY, United Kingdom. Tel: 44-1827-265-850. Fax: -855. Email: Paul@maguire-europe.com.

MAGUIRE PRODUCTS, INC., headquartered in Aston, Pennsylvania, U.S.A., is the world’s largest supplier of gravimetric blenders and liquid color pumps and also manufactures loading systems, granulators, dryers, auger feeders, and related equipment and software. Its customers include injection, blow, and rotational molders, extrusion processors, and compounders. Founded in 1977, Maguire operates five manufacturing facilities in Aston and Smithfield, Rhode Island, U.S.A. The company maintains a network of distributors in the Americas and overseas and has two sales and service subsidiaries: Maguire Europe, which supports customers throughout Europe and operates a distribution center in Tamworth, Staffordshire, United Kingdom; and Singapore-based Maguire Asia, serves customers throughout South Asia and the Pacific Rim. Visit the Maguire Products web site: www.maguire.com