Extrusion processing parameters

Lin, S., Huff, H. E., and Hsieh, F. (2002). Extrusion process parameters, sensory characteristics, and structural properties of a high moisture soy protein meat analog. /. Food Sci. 67 (3), 1066-1072. 

As stated above, extrusion die design is a complex task because the extrudate product dimensions depend not only on the die design (die shape), but also on the polymer properties and extrusion process parameters. The following are general recommendations for extrusion die design ... 

Extrusion Process Parameters and Raw Material Properties for Devolatilization... 

Extrusion process parameters were temperature zones 100 °C, 150 C, 160 °C, and 170 °C screw speed of 500 rpm the temperature of plasticized mass in the head at 165-175 °C and the melt pressure in the entering of the head 56-61 bar. Under these technological conditions, the plasticized mass was extruded, and later on it was filled in the press. After filling and closing the mold, it was put to the press and compressed maintaining the pressure of 14.3 MPa for 5 min in order to cool. 

The first task was to produce carriers from different recipes and in different shapes as shown schematically in Fig. 8. The raw materials diatomaceous earth, water and various binders are mixed to a paste, which is subsequently extruded through a shaped nozzle and cut off to wet pellets. The wet pellets are finally dried and heated in a furnace in an oxidising atmosphere (calcination). The nozzle geometry determines the cross section of the pellet (cf. Fig. 3) and the pellet length is controlled by adjusting the cut-off device. Important parameters in the extrusion process are the dry matter content and the viscosity of the paste. The pore volume distribution of the carriers is measured by Hg porosimetry, in which the penetration of Hg into the pores of the carrier is measured as a function of applied pressure, and the surface area is measured by the BET method, which is based on adsorption of nitrogen on the carrier surface [1]. 

Grob, C. and Wortberg, J., Optimizing Purging Time at Product Change in Blown Film Extrusion by Selective Modification of Process Parameters, SPE ANTEC Tech. Papers, 50, 261 (2004)... 

Table 7.2 Some Typical Processing Parameters for the Extrusion of Nonferrous Metals...

Another parameter of interest in the extrusion process is screen pressure, as that has been shown to affect the size of the final pellets as shown in Figure 24 (31). The extruder can be fitted with a suitable pressure transducer to monitor the pressure drop associated with extrusion. One such... 

Lovgren K, Lundberg PJ. Determination of sphericity of pellets prepared by extrusion-spheronization and the impact of some process parameters. Drug Dev Ind Pharm 1989 15 2375-2392. 

Two extrusion products, regular and sucrose-free (abbreviated Reg and SF) Duraromes, were encapsulated at MCP Foods using patented processing parameters (14). The SF matrix was composed of maltodextrin, polyhydric alcohols and emulsifiers, while the Reg matrix consisted of maltodextrin, sucrose and emulsifiers. 

Film. The blown film process is most commonly used in the production of PB film from resins with melt indexes from 0.3 io 10 g/10 min at a melt temperature of200-215DC using conventional equipment. Mechanical properties of blown PB film depend on the degree of orientation and other processing parameters. PB film can be sealed ai 100 220 (1. Another technique for the PB film production consists of film casting from the melt on polished chilled rolls and co-extrusion or lamination with other films. 

Rheological Properties and Process Parameters of Polymer Extrusion.. 57... 

The lumped-parameter model approach becomes particularly useful when dealing with the plasticating extrusion process discussed in the next subsection, where, in addition to melt flow, we are faced with the elementary steps of solids handling and melting. 

In the total interaction diagram of Fig. 13.6, as the system yields for reactive extrusion, several positive feedback loops can be distinguished, due to which a disturbance in a process parameter can be amplified which may lead to an unstable operation. In this way, three different possible sources of instabilities can be distinguished ... 

The full potential of the hydrostatic extrusion technique became apparent in 1974, when the production of ultra high mudulus polyethy lenes with stiffnesses up to 60 GPa were reported The main process parameter in hydrostatic extrusion is the nominal extrusion ratio Rj, the ratio of the billet cross-sectional area to that of the die exit (assuming deformation occurs at constant volume, which is a very good approximation). Because polymers can exhibit die swell in extrusion, it is convenient also to define an actual extrusion ratio R, based on the ratio of the initial and final billet cross-sections. R is, of course, direcUy comparable to the draw ratio in tensile drawing (assuming plug-flow) and in practice R R for all but the lowest reduction ratios. 

Technical constraints are often imposed on the design of the monolith geometry by the extrusion process, as well as by the mechanical properties of the extrudate the specific SCR application (e g., high-dust vs. low-dust) is also crucial for the definition of the catalyst geometrical features. Here, attention is paid to the influence that the monolith parameters (wall thickness, channel size, channel shape) have on both DeNOx reaction and SO2 oxidation in order to advance guidelines for optimization of the catalyst geometry. 

The design of the extrusion screw has a significant influence on the efficiency of the hot-melt extrusion process. The function of the screw is to transfer the material inside the barrel and then to mix, to compress, and to melt the polymeric materials and to pump the molten mass through the die. Several parameters are used to define the geometrical features of the screw (Fig. 2). 

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