Parameters extrusion

We have created structured networks in whey proteins using mild heat and shear, to create reversible TWPs. By understanding on a molecular basis, the effects of shear, ways of creating new functionality can be developed. This will enable development of extrusion parameters that permit controlled denaturation of whey proteins. 

Numerous carriers were produced from different recipes and in different sizes and shapes in a 1 kg/min lab scale extruder and subsequently calcinated under different conditions in a furnace. The recipes included different types of diatomaceous earth, different types and amounts of binder and variation of the water content of the paste, which is a critical extrusion parameter. The shapes included among others rings, multiple-holed rings, finned rings, and trilobes, whereas normal cylindrical pellets were not made due to their well-known inferior activity to pressure drop ratio. 

Optimization of the extrusion parameters can be difficult because of the delicate balance between the blowing agent expansion and part shaping. Part warpage and shrinkage are sometimes difficult to predict. 

Extrusion parameters, such as basket temperature, extrusion rate, and die design, can be adjusted to suit a particular formulation and granule size. This is an empirical process based on experience. Extrusion characteristics represent an intimate interplay between press parameters and dough properties, the latter predominating. What is wanted is maximum production rate of a smooth, dense, homogeneous strand of these qualities, smoothness is perhaps most sensitive to extrusion conditions. 

Table 13.2. Influence of extrusion parameters on the filled length.

Tomer G, Podczeck F, Newton JM. The influence of type and quantity of model drug on the extrusion/spheronization of mixtures with microcrystalline cellulose. I. Extrusion parameters. Int J Pharm 2001 217 237 8. 

A variety of flaws can occur in the shaped article, and their elimination is a primary concern. Commonly, a practical approach involving modifications of the formulation of the powder mixture, the extrusion parameters and the die design is used to reduce the problems associated with the formation of flaws. 

Recent experience concerning the preparation of Yl Ci Oy powder and its fabrication into a variety of shapes is detailed. The fabrication techniques used were dry pressing, tape casting, and extrusion. Parameters found to affect superconductor quality are noted. 

It was reported that phosphorylation during extrusion required less reagents than by the use of classical phosphorylation. The response of various starch varieties to extrusion parameters was similar.1552... 

This work shows the acquired experience in the preparation at pilot-scale of a novel propane ammoxidation catalyst based on a partially nitrided V-Al mixed oxide obtained hy co-precipitation. A systematic investigation of the different parameters controlling the preparation of the catalyst via a co-precipitation route at different scales was carried out. At lab-scale (50 to 100 g), the preparation parameters optimized were precipitation pH, V/Al atomic ratio, V concentration in solution and nitridation conditions, while at pilot-scale (1 kg), the optimized parameters were precipitation and ageing time, solution/solid ratio during the washing step, drying and calcination conditions, and extrusion parameters. Our results show that the optimum preparation conditions for the VAION system are pH = 5.5, V/Al atomic ratio = 0.25, concentration of V species in solution = 30.10 M. This catalyst shows the highest selectivity and yield in acrylonitrile. The samples prepared at different scales show the same activity profile in the propane ammoxidation reaction. 

HaO/solid ratio used in the washing step, drying protocol, extrusion parameters (type and concentration of peptizing agents, solid/solution ratio and mixing time) and nitridation conditions. Because of the limited space available, this communication only reports the main effects brought by the adjustment of some of these parameters. 

Benbow and co-workers have done work using a press resembling a simplified capillary rheometer [14-16]. Here, the connection between the extrusion pressure and the extrudate delivery rate was determined for different paste-like materials. The results were used to formulate a mathematical description in which up to six parameters must be experimentally determined. The mathematical approximation enables one to calculate special extrusion parameters such as the extrusion pressure. 

Benbow JJ, Oxley EW, Bridgwater J (1987) The Extrusion Mechanics of Pastes - the Influence of Paste Formulation on Extrusion Parameters. J Chem Eng Sci vol. 42 No 9 pp 2151-2162 Benbow JJ, Lawson TA, Oxley EW (1989) Prediction of Paste Extrusion Pressure. J Ceramic Bulletin vol. 68 No 10 pp 1821-1824 Benbow JJ, Jazayeri SH, Bridgewater J (1988) J Ceram Trans ACS 2 pp 624-634... 

Benbow JJ, Oxley EW, Bridgwater J (1987) The Extrusion Mechanics of Pastes - the Influence of Paste Eormulation on Extrusion Parameters. J Chem Eng Sci vol. 42 No 9 pp 2151-2162... 

Pelissari, F. M., Yamashita, F., and Grossmann, M. V. E. (2011). Extrusion parameters related to starch, chitosan active films prperties. International Journal of Food Scierwe ami Technology, 46,702-710. 

The purpose of the instrumentation and control system (Fig. 2.14) is to measure and control important processing parameters. Without the data provided by this system, it would be very difficult to maintain a safe and efficient process and to troubleshoot extrusion problems. The data provides a window to the process, since we cannot see inside the extruder (and probably would not find it very useful if we could). Monitoring an extrusion line has been likened to monitoring a patient in a hospital we certainly want to measure the patient s vital signs, such as body temperature and blood pressure. Similarly, we need to monitor extrusion parameters, so the system does not become unstable, leading to a dangerous situation or to the production of costly scrap. 

Table 2.1 Influence of Extrusion Parameters on the Filled Length...

The reactive extrusion was performed in an APV Baker MPF50 fully wiped corotating twin-screw extruder. The maximum screw length used was 14 D. The extruder utilized five heating zones and the barrel wall was kept at a uniform temperature of 130°C in the last four zones. The first zone, closest to the feed port, was kept at a temperature of 120°C. The amount of monomer-initiator mixture fed to the extruder ranged from 1.5 to 4.5kg/h. The pressure in the die varied between 0 and 13 bar. After every adjustment of the extrusion parameters samples were collected when the extruder had reached steady state. In order to stop the reaction immediately the samples were directly frozen in liquid nitrogen at the outlet of the extruder. 

Keywords extrusion die, die design, biaxially-oriented PP (BOPP), heat sealing, manifold, coextrusion, extrusion parameter, process control, flow. 

A requirement for successful co-extrusion is the control of the rheological properties of the feed material and of the extrusion parameters to produce an extrudate with the required uniformity of structural features. After the final extru-... 

Similarly to case study 2, Fig. 7.23 demonstrates shows the variations of the elastics modulus and yield stress of PLA filaments produced using different temperatures in the extruder using different 3D printers. By fixing the extrusion parameters such as deposition velocity and screw rotation velocity, it is possible to observe that the different temperatures of the extruder nozzle produce strands with different mechanical properties. 

---