3D FEM Study of the Flow Uniformity of Flat Polypropylene Film/Sheet Extrusion Dies

2020 ◽  
Vol 841 ◽  
pp. 375-380
Author(s):  
Dastan Igali ◽  
Asma Perveen ◽  
Dong Ming Wei ◽  
Di Chuan Zhang ◽  
Almagul Mentbayeva

Coat-hanger dies are widely used in the extrusion of polymer sheets and films. However, when designing the flat film/sheet extrusion dies manufacturing companies still facing difficulties in achieving the flow uniformity of the polymer melt. This affects the product quality and tool life. This study examines the existing extrusion die design which is used in in the industry in Kazakhstan for polypropylene sheet production and proposes better geometry of a die. These die geometries will be tested for flow uniformity in terms of velocity and pressure at the outlet.

2012 ◽  
Vol 152-154 ◽  
pp. 301-305
Author(s):  
Jian Yi Pan ◽  
Yao Wang ◽  
Zhao Yao Zhou ◽  
Shou Bin Dong

In order to improve the service life of extrusion dies with long cantilever structure, a design scheme of porthole die for half-hollow profiles with long cantilever was introduced. Using numerical simulation method, compared with conventional method for the half-hollow porthole design method of a typical profile die model, the equilibrium of the material flow at the outlet, the stress and deformation of the die were analyzed in detail. With selection of the cantilever thickness shrinkage as the objective function, experiment was done to verify the result of simulating analysis. The results indicated that there was only little difference for the equilibrium of material flow between the two design schemes, but the stress load and deformation of the design scheme were greatly improved.


Author(s):  
Nooman Ben Khalifa ◽  
A. Erman Tekkaya

A new innovative direct extrusion process, helical profile extrusion (HPE) is presented, which increases the flexibility of aluminum profile manufacturing processes. The application fields of such profiles can be seen in screw rotors for compressors and pumps. The investigations concentrate on experimental and numerical analyses by 3D-FEM simulations to analyze the influence of friction and the material flow on the twisting angle and contour accuracy. By means of finite-element method (FEM), the profile shape could be improved by modifying the die design. The numerical results were validated by experiments. For these investigations, a common aluminum alloy AA6060 was used. Mainly, the friction in the die influences the twist angle and the shape of the helical profile. Two die coatings were analyzed, but the friction was not substantially decreased in any of these cases. Although there is no efficient practical solution for reducing the friction in extrusion dies using tested die coatings, the required profile contour could be achieved by new die designing and by modifying the material flow. However, increasing the twist angle is limited due to geometrical aspects of this technology, namely, by the ratio of the volume to the contact area with the die for the displaced metal.


2005 ◽  
Vol 128 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Douglas E. Smith ◽  
Qi Wang

It is common for materials processing operations to have adjustable features that may be used to improve the quality of the final product when variability in operating conditions is encountered. This paper considers the polymer sheeting die design problem where variability in operating temperature or material properties, for example, requires that the die be designed to perform well under multiple operating conditions. An optimization procedure is presented where the design variables parametrize both stationary and adjustable model variables. In this approach, adjustable features of the die cavity are modified in an optimal manner consistent with the overall design objectives. The computational design approach incorporates finite element simulations based on the Generalized Hele-Shaw approximation to evaluate the die’s performance measures, and includes a gradient-based optimization algorithm and analytical design sensitivities to update the die’s geometry. Examples are provided to illustrate the design methodology where die cavities are designed to accommodate multiple materials, multiple flow rates, and various temperatures. This paper demonstrates that improved tooling designs may be computed with an optimization-based process design approach that incorporates the effect of adjustable features.


2008 ◽  
Vol 367 ◽  
pp. 125-136 ◽  
Author(s):  
Lorenzo Donati ◽  
Luca Tomesani

This work summarizes the outcome of recent research by the authors on modeling the formation of seam welds in aluminum extrusion and on evaluating the related mechanical properties on the final products. A profile with a seam weld in the middle section was produced with different die designs in order to investigate the relation between die design and local welding parameters, such as contact pressure, temperature, time of contact, strain and strain rate paths. The local welding conditions were evaluated by complete thermo-mechanical 3D FEM simulation of the processes. Specimens were extracted from the profiles and tensile tested, the resulting mechanical properties being discussed with respect to the local welding conditions. The possibility to adopt criteria for assessing the welding quality is discussed, together with the effect of high speed damage cracking.


2021 ◽  
Vol 58 (3) ◽  
pp. 217-230
Author(s):  
Valeriu V. Jinescu ◽  
Mihail Juganaru ◽  
Cosmin Jinescu ◽  
Nicoleta Sporea

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.


Author(s):  
Beril Gu¨mu¨s¸ ◽  
Bu¨lent Ekici

Manufacturing companies need to improve their production technology with improved dimensional accuracy at lower cost in order to manufacture sheet metal based products. Scrap shedding is an issue that should be examined at the cutting and sheet metal forming operations. In order to extend the life cycle of the cutting moulds, scrap shedding should be identified. When scrap shedding has not been taken into consideration, scraps have accumulated in the moulds reducing the production quality and causing deformation of the mould, increasing the production cost by obligating to perform extra transactions. This study becomes more focused upon the analysis of scrap shedding. In order to simulate the scrap shedding LS-Dyna and Pam Stamp software have been used. For examining of the scrap shedding an automotive part was chosen. In order to realize scrap shedding having any problems, new improvements have been suggested. Design of Experiments techniques which provide important advantages to engineering studies have been examined. By means of experimental design techniques the scrap shedding design process was also added to the classical mold design approach via a less quantities of simulations.


2004 ◽  
Vol 23 (2) ◽  
pp. 111-124 ◽  
Author(s):  
Yihan Huang ◽  
C. Richard Gentle ◽  
J. Barry Hull

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