DIE DEVELOPMENTS | MACHINERY
Recent advances in extrusion dies include new technology to make fluoropolymer medical tubes, microduct pipes and coated pipe – and software that
cuts die development time
Tooling skills: extrusion die developments
Dies are at the heart of both pipe and profile development – and, for efficient production, they need to be designed and made as quickly and efficiently as possible. US-based Plastic Flow has developed an
updated version of its PolyXTrue extrusion die design software, which it says can reduce the number of fine-tuning iterations required. “Virtual fine-tuning and optimisation of extrusion dies using our software reduces the number of fine-tuning iterations and die development time by at least 50%,” said Mahesh Gupta, president of Plastic Flow. He said that customers typically report a 70-75%
reduction in the number fine-tuning iterations when they use PolyXTrue as an integral part of their extrusion die design process. The software is also available in a pay-per-execution (PPX) version. One advance is improved accuracy of the level-set method for coextrusion simulation, says Gupta. The software has been completely rewritten to improve the accuracy of predicted layer struc- ture. For most coextrusion dies, coextrusion simulation techniques in level-set method and mesh partitioning techniques now give almost the same layer structure in the final product. Robust- ness of the level-set algorithm for simulating the
www.pipeandprofile.com
flow in different types of coextrusion dies has also been improved in the new version, he says. In addition, the algorithm for enforcing the symmetry condition in post-die extrudate distortion has been updated to accurately satisfy symmetry – including the change in extrudate shape due to non-uniform exit velocity as well as due to cooling shrinkage. Also, as well as plotting the results along the cut planes parallel to the XY, YZ and XZ planes, results in the new version can also be plotted along other cut-plane orientations. The ability to calculate the flow rate through a quadrilateral or an annulus on a cut plane has also been implemented for non-coor- dinate cut planes. The material database in the new version is twice the size of that in the last release. This includes the structural analysis parameters needed for accurate prediction of extrudate shrinkage. These parameters have also been added for many of the previously existing materials in the database. “The graphical user interface (GUI) has also been updated to make the software more effective and user friendly,” he added. These new features include: a command bar
with shortcut buttons for common or useful features; the ability to shift and rotate a calibrator
Summer 2024 | PIPE & PROFILE EXTRUSION 37
Main image: Pressure and evolution of layer structure in a window profile die predicted by PolyXTrue
IMAGE: PLASTIC FLOW
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50
