for optimum absorption of moisture. Extruder speed control, die open-area management and various mixing elements also may be beneficial.

Note: Do not overlook what effects the added moisture will have on your drying efficiency and capacity. Each dryer is designed to remove a specific amount of water (depending on rate, bed depth, temperature, etc.). If the incoming feed moisture changes, the drying process must be reviewed to ensure proper operation and delivery of quality and in-spec product.

Mixing ingredient

Since the typical meat slurry is high in moisture, an aggressive and efficient mixing configuration is required in the preconditioner and, with some formulations, also may be required in the extruder barrel. A poor mix of the meat with raw materials will render a final feed product of poor appearance, homogeneity and overall quality. As detailed in the September 2007 Preconditioning issue of The Extru-Technician, through proper preconditioning a final homogenous product mixture of dissimilar raw materials is achieved. This hydrates that mix to specific moistures while maximizing pre-cook of the mix prior to extrusion to reduce extruder component wear and facilitate uniform raw material feed to the extruder. Once again, appropriate preconditioning of raw materials helps resolve another processing issue.

The key is to verify the equipment limitations within your specific process with your equipment manufacturer. Not all extruders are created equal, and some specific models offer more flexibility than others. ■

Coming next issue:

GREEN

In these times of high energy costs and increasing concern about the environment, every company needs to be as proactive as possible about energy efficiency. The Extru-Tech Model E975 Extrusion System is just one example of the type of innovation and engineering Extru-Tech, Inc. is employing to help petfood manufacturers go green.

The E975 combines high capacity production with lower horsepower (HP), thus lowering energy requirements. For example, the E975 comes standard with a 150 HP drive motor, yet has the production capacity of extruders that require 200 HP to achieve the same capacity.

Plus, Extru-Tech’s advanced setup using our dual conditioning cylinder allows for better efficiencies at lower energy requirements. These are just a few of the innovations and new products Extru-Tech, Inc. is releasing on the market to go for the green!

Find out more in the next issue of The Extru-Techician.

September 2008 Extru-Technician 8