Determination of an Extrusion Machine Performance Based on the Working Field of the Extruder Die

Some inventions along with theoretical and experimental research made it possible to increase the output of a thermally homogeneous melt provided by the screw. However, the quality of the extruded product depends on some specific features of the extrusion die and to a large extent on the rheological behavior (viscous and elastic) of the polymer melt. The mismatch between the design of the screw-cylinder subassembly and the design of the extrusion die results in products with relatively short service life. The present paper has drawn up the working field of the extruder die and adjusted it based on the limitations imposed by the screw-cylinder subassembly, namely: - the maximum output rate that ensures the required thermal homogeneity of the melt; - the maximum output at which the heating system on the barrel (and possibly the screw) ensures the extrusion temperature; - the minimum economic output corresponding to the diameter of the screw. The working field of some extrusion dies for blown films of the following polymers have been plotted: polypropylene, low density polyethylene, high density polyethylene and ethylene vinyl acetate.

Study of the kinetic regularities of the grain extrusion process in the production of highly digestible feed with protected protein for cattle

The problem of developing of highly digestible compound feeds with protected protein for cattle is due to the specifics of the gastric tract of cows and the peculiarities of protein assimilation. Due to the importance of preliminary moisture-heat treatment of grain for the subsequent course of the extrusion process, it was carried out by steam at a pressure of 0.6 МРа before moistening the feed to a humidity of 17–20% and heating to a temperature of 70–80° C. It is established that heat treatment has a significant effect on the carbohydrate complex of grain: heating it at high temperatures causes the destruction of starch, accompanied by the formation of easily soluble carbohydrates, which has a positive effect on the digestibility of feed. The kinetic regularities of the processes of moisture-heat treatment, grinding and extrusion of grain in the production of highly digestible feed with protected protein for cattle were studied. The degree of dextrinization and the digestibility of starch increased with the heating temperature of corn and its mixtures with wheat up to 100–110° C, when the performance of the extruder was 300–320 kg/h, the digestibility of starch extruded corn and grain mixture is increased to 85 and 68 mg of glucose per 1 g of the product (hereinafter mg/g), respectively. For wheat, this indicator is lower and, accordingly, is 50 mg/g. When heated during the extrusion of corn to a temperature of up to 120–140° C, the digestibility of starch was 100–110 mg/g, and for the grain mixture – 80–83 mg/g. At this temperature, the digestibility of the starch of extruded wheat corresponded to 60–65 mg/g. The optimal moisture content of feed in the process of extrusion for the purpose of forming pellets is 18%. Studies of the extrusion effect on the carbohydrate complex of processed feed have shown that the destruction of starch in the extruded product increases. Thus, the content of soluble carbohydrates increases by 27–32%, and the digestibility of starch increases twice in extruded feed compared to unprocessed.

Effects of extrusion operating conditions and blend proportion on the physicochemical and sensory properties of teff-rice blend extruded products

The effects of extrusion conditions, teff-to-rice blend ratio (25-100%), feed moisture content (21-25%) and barrel temperature (130- 150°C) on the physico-chemical properties and the sensory attributes of extruded product from teff-rice blend was investigated. The physico-chemical properties (specific length, bulk density, expansion, water absorption index (WAI), water solubility index (WSI) and hardness), and sensory acceptability (flavor, color, texture and overall acceptability) were significantly (p<0.05) influenced by the extrusion conditions. Increasing barrel temperature resulted in higher expansion, lower density, reduced hardness and higher WAI, and WSI. Increase in the proportion of teff resulted in increased density, hardness, and WSI whereas increase in teff proportion brought about a decrease in expansion and WAI. Increasing feed moisture content resulted in higher density, lower expansion, higher WAI, lower WSI, higher hardness and lower crispness. The sensory scores reduced with increase in the proportion teff. The numerical optimization revealed that the optimal extrusion conditions for the best result were extrusion temperature of 150°C, feed moisture content of 21.2% and blending ratio of 40% teff with a desirability value of 0.901. The graphical optimization revealed that the best results were found between 140 to 150°C, 21 to 22% feed moisture and 25 to 46% of teff proportion.

Accurate Simulation of the Four Modes of Post-Die Extrudate Shape Distortion

A combined flow, thermal and structural analysis is employed to simulate post-die extrudate distortion in different profile dies. All four factors which can cause extrudate distortion, namely, nonuniform exit velocity distribution, extrudate shrinkage, extrudate draw down, and deformed shape of the calibrator or sizer profile, are simulated. To analyze the effect of exit velocity variation on extrudate distortion, the parameterized geometry of a simple profile die is optimized using an extrusion die optimization software. The simulation results presented for a bi-layer profile die successfully demonstrate how gradually changing profile shape in successive calibrators/sizers can be used to simplify the die design for extrusion of complex profiles. The predicted extrudate shape and layer structure for the bi-layer die are found to accurately match with those in the extruded product.

Predictive Tools for in-Line Isothermal Extrusion of 6xxx Aluminum Alloys

During the last fifty years, the metal forming of aluminum alloys advanced significantly, leading to a more competitive market on which production rate and overall quality are kept as high as possible. Within the aluminum industries, extrusion plays an important role, since many industrial products with structural or even aesthetic functions are realized with this technology. Especially in the automotive industry, the use of aluminum alloys is growing very fast, since it permits a considerable weight loss and thus a reduction of the emission. Nevertheless, the stringent quality standards required don’t allow the use of extruded aluminum alloys produced for common building applications. An important parameter that can be used as an index of the quality of the extruded product is the emergent temperature: if the temperature at the exit of the press is kept constant within a certain limit, products with homogeneous properties and high-quality surface are obtained and the so called “isothermal extrusion” is achieved. As extrusion industries are spread all over the world with different levels of automation and control, a universal but simple on-line tool for determining the best process condition to achieve isothermal extrusion is of particular interest. The aim of this work is to implement this model, which allows evaluation of the thermal gradient which has to be imposed on the billet. Several experiments have been carried out on an industrial extrusion press, and the outer temperature was recorded and compared with the simulated one to demonstrate the model consistency.

Conjoint Analysis for Optimizing the Level of Ingredients in Millet and Pulse based Ready-To-Eat (RTE) Extruded Product

The present study was performed using conjoint analysis for optimizing the ingredients level in the development of millet and pulse-based Ready-To-Eat (RTE) extruded products. Conjoint analysis is a multivariate technique used to understand the preference of the product by the consumer, and it is helpful to formulate the prediction about the different ingredient levels in the product. Also, it is called “Trade-off analysis”. The experimental design of treatments with several card ID lists about 9 numbers with different levels of ingredients used for developing the extruded product. The primary level of raw material was barnyard millet (Echinochloa esculenta) (40 %, 50 %, 60 %), chickpea (Cicer arietinum) (10 %, 20%, 30%) and Maize Zea mays (40 %, 50%, 60%). These principle levels of ingredients give more combinations so sensory panel members may give irresponsible and inappropriate results. The statistical tool conjoint analysis will reduce the number of treatments for optimizing the product. The selection of ingredients level in the development of millet and pulse based RTE extruded products was based on relative importance and utility estimate of quality attributes, which was given by conjoint analysis software program through panelist rank for sensory attributes using of 9 point hedonic scale. Hence, the ingredients combinations were found to be barnyard millet (60%), chickpea (20 %), and Maize (40 %). These combinations were optimized based on their higher level of relative importance and utility estimate.

Effects of feeding ISA brown and Shaver white layers breeder with sources of n-3 fatty acids on hatching eggs profile, apparent embryonic utilization of egg components and body composition of day-old chicks

Effects of feeding ISA brown and Shaver white breeders sources of n-3 fatty acids (FA) on egg components, apparent embryonic utilization (AEU) of egg components, and hatching body composition were examined. A total of 240 female and 30 male per each strain were fed either: 1) Control (CON), 2) CON + 1 % of dried microalgae (DMA), as a source of docosahexaenoic acid or 3) CON + 2.60 % of dry extruded product consisting of full-fat flaxseed (FFF), as a source of α-linoleic acid for 30 days. Eggs were incubated, and the residual yolks (RY) sampled at hatch (DOH) for AEU of dry matter (DM), minerals, and organic matter (OM). Feeding n-3 FA sources reduced the AEU of OM and minerals resulting in a higher ratio of RY to body weight (P = 0.002). Feeding FFF increased body fat and decreased lean in Shaver white hatchlings compared with CON (P < 0.05). The body mineral was reduced by feeding DMA compared to other treatments (P < 0.05). The change in body composition in response to feeding of n-3 sources was associated with the change in AEU of DM, OM, and minerals, not the concentration of these components in the yolk.