Pellet quality

Vervaet C, Baert L, Risha PA, Remon JP. The influence of the extrusion screen on pellet quality using an instrumented basket extruder. Int J Pharm 1994 107 29-39. 

In conventional feed manufacturing this by-product is regarded as a combination of bran and shorts and tends to be intermediate between the two in composition. It also may contain some wheat screenings (weed seeds or other foreign matter that is removed prior to milling). It is commonly included in commercial feeds as a source of nutrients and because of its beneficial influence on pellet quality. When middlings (or whole wheat) are included in pelleted feeds, the pellets are more cohesive and there is less breakage and fewer fines. 

However, whole soybeans may have adverse effects on the carcass fat of broilers. A standard recommendation is that the soybean product should be limited to supplying a dietary addition of 20g/kg soybean oil in order to ensure an acceptable carcass fat quality and good pellet quality. This may require that the incorporation rate of soybeans in the feed of finishing broilers should not exceed lOOg/kg. 

Pellet quality and capacity vary with properties of the feed such as... 

Soh JLP, Liew CV, Heng PWS. Torque rheological parameters to predict pellet quality on extrusion/spheronization. Int J Pharm 2006 315 99-109. 

Pellet quality and capacity vary with properties of the feed such as moisture, lubricating characteristics, particle size, and abrasiveness, as well as die characteristics and speed. A readily pelleted material will yield about 122 kg/kWh [200 lb/(hp h)] by using a die with 0.6-cm (V4-in) holes. Some characteristics of pellet mills are given in Table 21-33. 

It is a task of these studies to relate the equipment parameters and the material characteristics, both of feed and product as well as the binder data, such that the conditions in the balling apparatus and the pellet quality can be... 

Briggs, J.L., Maier, D.E., Watkins, B.A., Behnke, K.C. 1999. Effect of ingredients and processing parameters on pellet quality. Poultry Science 78 1464—1471. 

Cavalcanti, W.B., Behnke, K.C. 2005. Effect of composition of feed model systems on pellet quality A mixture experimental approach. I. Cereal Chemistry 82 455-461. 

However, to obtain uniform pellet quality, minimize pellet length variations, avoid uneven die wear, and ascertain constant power demand, it is necessary to distribute the feed evenly across the entire working width (= perforated area) of the die. Since the particulate feed can only enter the operational area of the machine from the open front of the die ring and, additionally, the interior is to a large extent occupied by the press rollers, this requirement is not easily met. 

The Influence of Ferrous Scrap Collocation on Cold Bonded Pellet Quality... 

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