6 Length 1 15 0.075 15.075

7 Length 2 15.5 0.0775 15.5775

8 Length 3 19 0.095 19.095

5. Simulation of CAM BUSH in Injection Moulding Process

Analysis done for the part “CAM BUSH” to study and calculate the flow pattern, fill time and packing time by considering cooling system which will affect the part performance. Also determine the clamp force and injection pressure requires for the mould which will help to select the exact injection moulding machine and approximate cycle time. Polymer  selected for  analysis is NYLLON-66.Cooling holes diameter is 12mm.Gate diameter    is

1.25. The global mesh density setting defines the nominal edge length for elements. The smaller the global edge length, the larger the total number of element on the model. The global setting is the single most important setting to get an acceptable mesh on the part. We can optionally also set a local mesh density on selected surfaces/regions created by importing geometry from, for example, an IGES, step, para solid, or native CAD format. This is typically done to ensure that small details in the model are properly represented, while meshing most of the part with a lower mesh density to optimize the total number of elements. The mesh is a web that consists of elements, with each element containing a node at every corner. The mesh provides the basis for a mould flow analysis, where moulding properties are calculated at every node. The mesh types supported by the software are midplane mesh, surface or fusion mesh, volume mesh. The Midplane mesh provides the basis for the Flow analysis. These meshes consist of trinode triangular element that forms a one dimensional representation of the part, through its centre. Every moulding process is supported by the mid-plane mesh. The surface mesh provides the basis for the flow analysis. This mesh consist of a mixture of different types, including regions with traditional midplane element and surface (double-skin) shell elements. The surface mesh can be 3 or 6 noded plane, straight-edged triangles. The volume mesh provides the basis for the 3D Flow analysis. These meshes consist of 4-noded, tri-element, solid tetrahedral elements. The density of the mesh is the number of elements per unit area. In general, the more elements there are in the mesh, the more detailed the analysis results, but the longer the analysis time. The mould flow fusion capability allows us to perform detailed analyses directly on a thin-wall, surface mesh model is imported from Mould flow plastic Advisers or an External CAD packages.. The connectors are inserted automatically at locations determined according to the geometrical features of the model. A boundary edge is an element edge that is not connected to any other elements. Boundary edges are valid in mid plane model but must not be present in surface meshed fusion model. Boundary edges indicate holes or tears in the mesh and must be corrected either in the original CAD system used to create the model, or using mesh editing tool in mould flow plastic in sight. Following these guidelines the mesh type suited for the component is a fusion mesh. Element used for meshing is 3noded triangular element. Meshed model can be seen in below figure.

Fig.3: Mesh Model

After meshing with a suitable mesh density, we may need to clean up the mesh .normally some cleanup is necessary if the mesh was translated in from another system. MIP provides a mesh statistics report to check the quality of the mesh and a series of diagnostic displays to locate and highlight specific problems. To clean up the mesh, there is a mesh repair wizard and a mesh tool box. The mesh repair wizard is an automated tool that will find and fix most mesh problems.. To perform an analysis, we need to select a suitable material in the material database. In most cases the material to use will be prescribed so we need to locate that material in the database and use it for all analysis work. In other cases, one of the analysis objectives may be to determine a suitable material. There are several techniques available to find a specific grade of material, assess the quality of the material data, fine a substitute material, and compare materials within the select material dialog.