- 6 February 2008 -
New loading device boosts feeder performance

Maguire Products Inc. has developed an advanced method of loading material into a gravimetric feeder, which the company claims makes it possible to meter colorant or additive into a plastics processing machine with a degree of accuracy far exceeding that achieved with a volumetric feeder.

Even with the addition of an advanced loading system, Maguire® MGF feeders cost no more than comparable volumetric feeders, says the company, and they provide the superior precision, consistency, and data generation characteristic of gravimetric systems. Maguire adds that the enhanced accuracy of MGF Series gravimetric feeders enables moulders and extrusion processors to reduce colour and additive consumption, increase control over product quality, and document colour usage for each production run.

The feeders are available with throughput capacity of up to 16 kg (35 lbs) per hour and can be mounted directly to the throat of most moulding machines or extruders. The company says that the new loading device, a direct descendant of venturi loaders that Maguire has manufactured for many years, transports material to the feeder from a gaylord, drum or other container. Rather than load continuously or intermittently, however, the loader rapidly and completely fills the feeder just once, upon a signal from the feeder controller that the level of colour or additive has fallen to precisely 10% of feeder hopper capacity. In this way the loss-in-weight measuring function of the feeder, which is what makes a gravimetric system so accurate, continually tracks and adjusts for dosing errors without interference or distortion from the addition of new material. As a result, the feeder maintains dosage within tight tolerances from moulding shot to moulding shot and does so for hours as hopper material levels steadily decrease.

Maguire Products; www.maguire.com