- Moldflow Analysis
- Packing Analysis
- Cooling Analysis
- Warpage Analysis
Flow Front Temperature
The mid-stream temperature when the flow front reaches each point. This result is used to identify appropriate fill speed, as well as determine areas of excessive shear heating or excessive cooling in thin areas. Ideal result shows a uniform temperature distribution.
Melt Front Advancement
The position of the flow front at regular intervals as the cavity fills. Each color contour represents the parts of the mold that were being filled at the same time. At the start of injection, the result shows red, and the last places to fill are dark blue. If the part is a short shot, the section that did not fill has no color. In a part with a good fill time result, the flow pattern is balanced.
Pressure at Switchover
The injection pressure when the flow analysis algorithm changed from the velocity control to pressure control. This results is used to determine how well the flow is balanced, and whether or not the part will fill easily enough.
Shear Rate
The rate of shear strain in the cavity at the end of fill. The shear rate should be less than the maximum recommended for the material. Regions above the limit could be subject to material degradation, embrittlement and poor surface finish. Used primarily to size gates and runners.
Shear Stress
The tendency for the moving layers of polymer melt to drag along slower or frozen layers. It is directly related to the viscosity and shear rate of the material, and should be less than the maximum recommended for the material. It can also be considered a measure of the level of material orientation locked into the part. Filling speed, wall thickness, and melt temperature are major factors.
Weld Lines
Indicated by red or purple lines, they are areas where two flow fronts have converged. The presence of weld lines may indicate a structural weakness and/or a surface blemish.
Air Traps
Indicated by red circles or purple dots, they are empty areas in the cavity surrounded by melt fronts. These areas are potential areas of burning or voiding and should be vented if possible, or eliminated by part modification or gate relocation.
Clamp Tonnage
The resultant value of the pressure distribution over the entire part. It is a history of the force resultant from filling and packing pressure that acts to open the mold. A good clamp tonnage history result should show that the maximum clamp tonnage applied is not more than approximately 80% of the machine limit, allowing 20% as a safety factor.
Percent Frozen
The thickness of the frozen layer as a percentage of the wall thickness, at the end of fill or pack. This result can help determine if the part or gate is sufficiently frozen at the end of packing to make sure the part is adequately packed. It can also help determine part design problems with thin areas.
Pressure Profile
A time series history of the actual pressure at the nozzle showing the pressure during both filling and packing phases of the molding cycle. A profiled packing pressure is often used during the packing phase to make the shrinkage more uniform across the part.
Volumetric Shrinkage
Not to be confused with linear shrinkage, it is the shrinkage for each area as a percent of the original volume. It should be uniform across the part to reduce warpage, and should be less than the recommended maximum value for the material. As a rough guide, volumetric shrinkage is 3 X linear shrinkage. This can also be used to detect sink marks. Negative values indicate over-packing.
Average Part Temperature
The average plastic temperature across the whole element thickness, calculated at the end of cooling time. This profile is based on the average mold surface temperatures for the cycle. This result can be used to check that the polymer temperature is below the ejection temperature for the material at the end of cooling, so that the part can be successfully ejected.
Bottom Temperature
The average temperature of the plastic/mold interface at the bottom side of the element, during the cycle.
Coolant Temperature
An acceptable temperature rise is between 3-5 °F. This result can be used to identify which channels should be looped together.
Flow Rate (coolant)
This result should be used to check that the sum of the coolant flow rates in each circuit is less than the coolant pump capacity. Used in conjunction with the Reynolds Number result, it helps to determine if turbulent flow can be achieved.
Mesh Orientation
Each finite element used to create the simulation model has a top and bottom side, indicated by the colors blue and red, respectively. The model is setup such that all topsides are pointing toward the cavity side, and all bottom sides are pointing toward the core side. This aids in interpreting cooling results.
Time to Freeze
The time for each area to freeze to ejection temperature, measured from the start of the cycle. Helps to identify areas where ejector pins may or may not be placed to obtain faster cycle time.
Top Temperature
The average temperature of the plastic/mold interface at the topside of the element, during the cycle.
Temperature Difference
The difference of the averages in temperature between the top and bottom sides (top minus bottom) of the element during the cycle.
Reynolds Number
A measure of the ratio of inertial forces to viscous forces in a flowing fluid. A value above 4000 should be used for lines actively involved in cooling. This ensures turbulent flow, and thus better heat transfer.
Turbulent Flow
Flow characterized by small, high frequency fluctuations superimposed on the mean motion of a fluid. This allows the fluid to have better heat transfer characteristics, thus providing more rapid, efficient cooling. Turbulent flow is onset at a Reynolds number of approximately 4000.
Constraints
Points on the simulation that are fixed in certain degrees of freedom (translation or rotation) to keep the part from undergoing rigid body translation or rotation during warpage analysis.
Deflection Results (X, Y, Z, Total)
The deflections of the part relative to the reference plane defined when specifying the boundary conditions for the warpage analysis.
Reference Plane
Defined by three constraint points, this is a plane relative to which the warpage deflections are measured.
Material Orientation
The material orientation direction for each element. Material orientation direction can affect the warpage of a part since shrinkage parallel and perpendicular to flow direction is different.