“Bridge Breaker” Allows Accurate Dosing

The pneumatically operated device that is deployed inside one of the hoppers in a gravimetric blender makes possible accurate dosing of regrind, recycled plastics, and other ingredients that tend to agglomerate or “bridge”.

USA-based Maguire Products, Inc. has introduced the new “bridge breaker” for its three largest blender series, those with maximum throughput capacities of 5,000 kilograms/hour, (11,000 pounds/hour) and the capability of blending up to twelve ingredients. The device consists of 1) a hopper insert that directs material straight down onto the dispensing valve, and 2) a rotary device that operates automatically while the dispense valve is open. The device rapidly pulses between clockwise and counter-clockwise movement, enhancing material flow through the dispense valve, the provider gave account. The hopper insert, which provides a vertical alternative to the sloping wall of the hopper, could be retrofitted in any blender currently in operation , the provider explained. “To make up for the space occupied by the insert, the complete hopper assembly includes an extension to accommodate the desired quantity of material”.

Hopper insert with
bridge breaker (Photo: Maguire Products, Inc.)

According to Frank Kavanagh, vice president of sales and marketing, the new “bridge breaker” addresses the growing demand for recycled content in plastic products and the increasing use of regrind as a means of reducing production costs. “More and more processors have been finding it a challenge to keep such materials flowing consistently. In fact, we developed the bridge breaker to help one of our customers solve a problem with trim scrap.”

The large-capacity Maguire blender families – the 1200, 2400 and 3000 series – blend up to twelve ingredients, using a wide range of removable hopper and feeder configurations and numerous dispensing devices. The blenders handle raw materials in a variety of forms, including regular pellets and regrind, bulk powders, flake and ingredients that are especially bridge-prone, such as wood flour. As with other Maguire weigh scale blenders, once all ingredients are dosed into the weigh chamber, the batch falls into a mixing chamber. A microprocessor makes corrections from batch to batch, including adjustments to compensate for variations in extrusion rate or bulk density, maintaining overall batch accuracy to within + / – 0.1 percent, the American manufacturer informed.

Maguire Products, Inc., headquartered in Aston (Pennsylvania), is – in its own estimation – the world’s largest supplier of gravimetric blenders, liquid color pumps and vacuum dryers. The company also manufactures loading systems, auger feeders, granulators and related equipment and software. Founded in 1977, Maguire operates six manufacturing facilities in Aston. The producer maintains a network of distributors in the Americas and overseas and has six sales and service subsidiaries that stock, sell and service auxiliary equipment systems from Maguire and its affiliate, Novatec, Inc.: Maguire Canada, Maguire Europe, Maguire Asia, Maguire China, Maguire IMEA and Maguire Taiwan.


(Published in GLOBAL RECYCLING Magazine 2/2021, Page 52, Photo: Maguire Products, Inc.)