The Experts below are selected from a list of 7863 Experts worldwide ranked by ideXlab platform
Michael Sylvester Packianather - One of the best experts on this subject based on the ideXlab platform.
-
Micro-injection moulding: factors affecting the replication quality of micro features
4M 2006 - Second International Conference on Multi-Material Micro Manufacture, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Abstract Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating micro features is one of the most important process characteristics and constitutes a Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research investigates the effects of three processing and one geometric factor on the surface quality of micro features in three different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed and placement density of micro features. In this investigation, the mould temperature was set in the conventional range. The study revealed that in general, increasing the barrel temperature, mould temperature and the injection speed improves the polymer melt fill in micro cavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials, and could be adverse in specific conditions. Varying the placement density of micro features does not affect the melt fills.
-
micro injection moulding factors affecting the achievable aspect ratios
The International Journal of Advanced Manufacturing Technology, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The aspect ratios achievable in replicating micro features are one of the most important process characteristics and constitute a major Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research studies the effects of five process and one size factors on the achievable aspect ratios, and the role they play in producing micro components in different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed, holding pressure, the existence of air evacuation and the sizes of micro features. The study revealed that the barrel temperature and the injection speed are the key factors affecting the aspect ratios of micro features replicated in PP and ABS. In case of POM, in addition to these two factors, the mould temperature is also an important factor for improving the replication capabilities of the micro-injection moulding process. For all three materials, an increase of feature sizes improves the melt flow. However, the melt fill of micro features does not increase linearly with the increase of their sizes.
-
investigation of micro injection moulding factors affecting the replication quality
Journal of Materials Processing Technology, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating micro-features is one of the most important process characteristics and constitutes a Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research investigates the effects of three processing and one geometric factor on the surface quality of micro-features in three different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed and distance between micro-features. In this investigation, the mould temperature was set in the conventional range. The study revealed that in general, increasing the barrel temperature, mould temperature and the injection speed improves the polymer melt fill in micro-cavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials, and could be adverse in specific conditions. Varying the distance between micro-features does not affect the melt fills.
Stefan Simeonov Dimov - One of the best experts on this subject based on the ideXlab platform.
-
Micro-injection moulding: factors affecting the replication quality of micro features
4M 2006 - Second International Conference on Multi-Material Micro Manufacture, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Abstract Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating micro features is one of the most important process characteristics and constitutes a Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research investigates the effects of three processing and one geometric factor on the surface quality of micro features in three different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed and placement density of micro features. In this investigation, the mould temperature was set in the conventional range. The study revealed that in general, increasing the barrel temperature, mould temperature and the injection speed improves the polymer melt fill in micro cavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials, and could be adverse in specific conditions. Varying the placement density of micro features does not affect the melt fills.
-
micro injection moulding factors affecting the achievable aspect ratios
The International Journal of Advanced Manufacturing Technology, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The aspect ratios achievable in replicating micro features are one of the most important process characteristics and constitute a major Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research studies the effects of five process and one size factors on the achievable aspect ratios, and the role they play in producing micro components in different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed, holding pressure, the existence of air evacuation and the sizes of micro features. The study revealed that the barrel temperature and the injection speed are the key factors affecting the aspect ratios of micro features replicated in PP and ABS. In case of POM, in addition to these two factors, the mould temperature is also an important factor for improving the replication capabilities of the micro-injection moulding process. For all three materials, an increase of feature sizes improves the melt flow. However, the melt fill of micro features does not increase linearly with the increase of their sizes.
-
investigation of micro injection moulding factors affecting the replication quality
Journal of Materials Processing Technology, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating micro-features is one of the most important process characteristics and constitutes a Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research investigates the effects of three processing and one geometric factor on the surface quality of micro-features in three different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed and distance between micro-features. In this investigation, the mould temperature was set in the conventional range. The study revealed that in general, increasing the barrel temperature, mould temperature and the injection speed improves the polymer melt fill in micro-cavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials, and could be adverse in specific conditions. Varying the distance between micro-features does not affect the melt fills.
C A Griffiths - One of the best experts on this subject based on the ideXlab platform.
-
Micro-injection moulding: factors affecting the replication quality of micro features
4M 2006 - Second International Conference on Multi-Material Micro Manufacture, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Abstract Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating micro features is one of the most important process characteristics and constitutes a Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research investigates the effects of three processing and one geometric factor on the surface quality of micro features in three different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed and placement density of micro features. In this investigation, the mould temperature was set in the conventional range. The study revealed that in general, increasing the barrel temperature, mould temperature and the injection speed improves the polymer melt fill in micro cavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials, and could be adverse in specific conditions. Varying the placement density of micro features does not affect the melt fills.
-
micro injection moulding factors affecting the achievable aspect ratios
The International Journal of Advanced Manufacturing Technology, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The aspect ratios achievable in replicating micro features are one of the most important process characteristics and constitute a major Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research studies the effects of five process and one size factors on the achievable aspect ratios, and the role they play in producing micro components in different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed, holding pressure, the existence of air evacuation and the sizes of micro features. The study revealed that the barrel temperature and the injection speed are the key factors affecting the aspect ratios of micro features replicated in PP and ABS. In case of POM, in addition to these two factors, the mould temperature is also an important factor for improving the replication capabilities of the micro-injection moulding process. For all three materials, an increase of feature sizes improves the melt flow. However, the melt fill of micro features does not increase linearly with the increase of their sizes.
-
investigation of micro injection moulding factors affecting the replication quality
Journal of Materials Processing Technology, 2007Co-Authors: Stefan Simeonov Dimov, C A Griffiths, Michael Sylvester PackianatherAbstract:Micro-injection moulding is one of the key technologies for micro-manufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating micro-features is one of the most important process characteristics and constitutes a Manufacturing Constraint in applying injection moulding in a range of micro-engineering applications. This research investigates the effects of three processing and one geometric factor on the surface quality of micro-features in three different polymer materials. In particular, the following factors are considered: barrel temperature, mould temperature, injection speed and distance between micro-features. In this investigation, the mould temperature was set in the conventional range. The study revealed that in general, increasing the barrel temperature, mould temperature and the injection speed improves the polymer melt fill in micro-cavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials, and could be adverse in specific conditions. Varying the distance between micro-features does not affect the melt fills.
Paul Steinmann - One of the best experts on this subject based on the ideXlab platform.
-
Control of minimum member size in parameter-free structural shape optimization by a medial axis approximation
Computational Mechanics, 2018Co-Authors: Oliver Schmitt, Paul SteinmannAbstract:We introduce a Manufacturing Constraint for controlling the minimum member size in structural shape optimization problems, which is for example of interest for components fabricated in a molding process. In a parameter-free approach, whereby the coordinates of the FE boundary nodes are used as design variables, the challenging task is to find a generally valid definition for the thickness of non-parametric geometries in terms of their boundary nodes. Therefore we use the medial axis, which is the union of all points with at least two closest points on the boundary of the domain. Since the effort for the exact computation of the medial axis of geometries given by their FE discretization highly increases with the number of surface elements we use the distance function instead to approximate the medial axis by a cloud of points. The approximation is demonstrated on three 2D examples. Moreover, the formulation of a minimum thickness Constraint is applied to a sensitivity-based shape optimization problem of one 2D and one 3D model.
-
Manufacturing Constraints in parameter–free shape optimization
PAMM, 2014Co-Authors: Oliver Schmitt, Jan Friederich, Paul SteinmannAbstract:Structural shape optimization has become an important tool for engineers when it comes to improving components with respect to a given goal function. During this process the designer has to ensure that the optimized part stays manufacturable. Depending on the Manufacturing process several requirements could be relevant such as demolding or different kinds of symmetry. This work introduces two approaches on how to handle Manufacturing Constraints in parameter-free shape optimization. In the so–called explicit approach equality and inequality equations are formulated using the coordinates of the FE-nodes. These equations can be used to extend the optimization problem. Since the number of the additional Constraint equations may be very large we apply aggregation formulations, e.g. the Kreisselmeier-Steinhauser function, if necessary. In the second approach, the so–called implicit method, the set of design nodes is split in two groups called optimization nodes and dependent nodes. The optimization nodes are now handled as design nodes but the dependent nodes are coupled to the optimization nodes in such a way that the Manufacturing Constraint is fulfilled. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)
David Kennedy - One of the best experts on this subject based on the ideXlab platform.
-
two level layup optimization of composite laminate using lamination parameters
Composite Structures, 2019Co-Authors: Carol Ann Featherston, David KennedyAbstract:Abstract This paper provides an efficient method for performing global layup optimization of composite laminates with buckling and Manufacturing Constraints. The optimization problem is divided into two stages and is based on the use of lamination parameters. During the first stage, exact finite strip analysis and continuous optimum design are employed for buckling optimization of the lamination parameters and laminate thickness. In the second stage, a logic-based procedure combining the branch and bound method with a global layerwise technique is employed to find the optimal stacking sequences to match the optimized lamination parameters obtained in the first stage. In order to ensure the optimized layup can be used in practice, four Manufacturing Constraints are added into the logical search process, and the feasible region for the lamination parameters with a Manufacturing Constraint which requires at least 10% of each of four possible ply orientations is studied. By comparing the logic-based method with the use of a genetic algorithm for searching stacking sequences under different requirements, the high efficiency and ability to achieve a global optimal result of the logic-based method are demonstrated.