Xplorer_UserGuide

SolidWorks Plastics AdviserFlow Result (3)Fill Time (3)Pressure at End of Fill (5)Pressure at Packing Switch Time (7)Temperature at End of Fill (7)Central Temperature at End of Fill (8)Average Temperature at End of Fill (8)Bulk Temperature at End of Fill (8)Flow Front Central Temperature (9)Temperature Growth at End of Fill (10)Shear Stress at End of Fill (10)Shear Rate at End of Fill (11)Skin Material Ratio at End of Fill (12)Volume Shrinkage at End of Fill (12)Freezing Time at End of Fill (13)Frozen Layer Fraction at End of Fill (13)Cooling Time (15)Temperature at End of Cool (17)Sink Mark (17)Birefringence at End of Fill (18)Gate Filling Contribution (18)Ease of Fill (19)Frozen Area at End of Fill (19)Clamping Force (19)Short shot (20)Velocity Vector at End of Fill (21)Weld Lines (22)Air Trap (24)Gate Location Index (24)Material Reactive Conversion at End of Fill (24)Curing Time at End of Fill (24)Pack result (25)Pressure at End of Packing (25)Temperature at End of Packing (25)Central Temperature at End of Packing (25)Average Temperature at End of Packing (25)Bulk Temperature at End of Packing (26)Shear Stress at End of Packing (26)Shear Rate at End of Packing (27)Skin Material Ratio at Post-Filling End (27)Volume Shrinkage at End of Packing (28)Temperature at Post-Filling End (28)Central Temperature at Post-Filling End (28)Average Temperature at Post-Filling End (28)Freezing Time at Post-Filling End (29)Frozen layer fraction at Post-Filling End (29)Residual Stress at Post-Filling End (29)Birefringence at End of Fill (29)Frozen Area at Post-Filling End (30)Material Reactive Conversion at Post-Filling End (30)Curing Time at Post-Filling End (30)Results Items HelpFlow Result Fill TimeThis presents the flow front position of fluid at regular intervals. The same flow front regions are the same color. Blue regions mean the beginning of injection and red regions mean the end of injection.The utilities of “set color range” and “dynamic show” can indicate the flow front pattern, welding line and air trap position. From the flow front pattern, we can understand flow balance condition and whether the over-packing is occurred for cavity or not.There are three methods to present Fill Time.1. User Defined Scale Adjust min or max range bar to show fill time.2. AnimationClick to Play/Pause/Stop the animation of result.3. Iso-Surf ModeClick Iso-Surf Mode and Play to display.Iso-Surf Mode is only used in Solid style.Note : Check weld line and air trap to show the forecasts.Pressure at End of FillPressure is defined as normal force per unit area. In filling process, the injection force by means of screw is used to push the fluid material into the cavity. The force is propagated via the fluid and result in a pressure distribution in cavity. The pressure profile presents the decreasing from the inlet gates to downstream position since the flow length is increasing in flow direction. It is noted that the pressure of flow front position is as one atmosphere since the flow front contact with air. For a constant flow rate, the inlet gate pressure is increasing with time since the contact area of fluid with cavity is growing.The very high pressure is required for part with thin cavity since the flow resistance is enlarge and the solidification may be occurred during filling process, therefore, if the injection pressure is not enough, the short shot may be occurred.The maximum pressure occurs at gate location and gets decreasing from the gate location to downstream position, as shown in the following diagram.You can also adjust percentage to show pressure of filling progressClick Clipping Plane mode to display pressure distribution at end of fill. This is only used in Solid styleYou can also switch clipping planes and adjust the view.Pressure at Packing Switch TimeAt packing switch point, the control type is from the flow rate control changed to pressure control. This profile presents the pressure distribution in cavity at this moment.Temperature at End of FillTemperature is a physical property of matter that quantitatively expresses the common notionsof hot and cold. Generally, for thin thickness region, the cooling effect results in lower temperature in such region. On the other hand, the high thickness region is with higher temperature.Note :Click Clipping Plane mode to display temperature distribution of clipping plane at end of fill. This is only used in Solid style.You can also switch clipping planes and adjust the view.In Solid style, surface temperature is equal to mold wall temperature.Central Temperature at End of FillIn FLOW-PACK, the central temperature distribution is defined as the melt temperature of central position between to two surface faces for each region. Generally, the central position with a more far distance from mold wall presents a high melt temperature. The temperature of central position may be drop quickly for the part of very thin cavity, and the short shot may be occurred.Average Temperature at End of FillThis distribution defined as the simple averaged melt temperature between to two wall faces for each region. If such distribution is serious non-uniform, the part shrinkage and warpage may be occurred.Bulk Temperature at End of FillThe temperature changes of flow front during the filling process are considered with some parameters like time, location and thickness but without flow velocity, so bulk temperature is used. The bulk temperature with a physical significance since such is a measurable temperature during fluid flow . The definition of bulk temperature is a fluid velocity weighted average temperature across two surface faces for each region. If the velocity field is zero, then the bulk temperature is same as average temperature. Generally, a high bulk temperature is presented in the region with high convection since the velocity weighed is pointed. And, such temperature will be reduced when the flow velocity is suddenly degraded. The distribution of bulk temperature could provide the information whether the over-heating is occurred during the process.In Shell Style, the definition of bulk temperature is a fluid velocity weighted average temperature across the part (or cavity) thickness. That isT uTdz udz bulk b bb b =−+−+∫∫Where u is the velocity, b is one half part (or cavity) thickness. +b and -b are the positive and negative side of mold cavity, respectively.In Solid Style, the definition of node bulk temperature is based on weighted average of volume velocity around such node neighbor cells. That is∫∫∫∫===Ni V i i N i V i i bulk i i dV u dV uT T 11)( Wherei u and i V is the cell i velocity and volume, respectively.Note:According to velocity parameter of filling process, the bulk temperature has more reference than average temperature. The bulk temperature gap from high temperature regions to low temperature regions could cause non-uniform shrinkages and warpages.Flow Front Central TemperatureThis presents the flow front temperature of fluid at every time step. Since the fountain flow effect is occurred at flow front region, the flow front central temperature could be approached as whole flow front region temperature.Note :In Shell styleWhen the fountain flow reaches to each region, the temperature distribution on shell surface means the flow front region temperature.In Solid styleFlow Front Central Temperature is different from that in Shell style.It actually means the temperature distribution at each region when the flow reachesClick Clipping Plane mode to display temperature distributionIt is only used in Solid styleYou can also switch clipping planes and adjust the view.Temperature Growth at End of FillIn the actual process, the polymer melt undergoes shear heating during the filling stage. The temperature during cavity might be higher than inlet melt temperature.The temperature could rise as much as 30 °C, depending on the injection speed and the material properties. Generally, we recommend that the temperature growth doesn’t above 30 °C since resin degradation might be occurred at such condition.Shear Stress at End of FillShear stress is defined as the shear force per unit area, and the direction of shear force is parallel with the forced plane. This shear stress distribution presents the wall shear stress of whole part at end of fill. Generally, high shear stress will introduce the molecular orientation into a high tensile strength, and reduce the surface finish of part, so the high shear stress should be avoided.Whereτ= the shear stressF = the force appliedA = the cross-sectional area of material with area parallel to the applied force vectorNote :Shear stress should be less than the suggested max. shear stress of the material.Slower flow rate can reduce shear stressIncreasing flow front temperature can also reduce shear stressSuggested material Max. shear stress(Mpa) for variousgeneric materialsMaterial Grade MpaABS 0.28ASA 0.30HDPE 0.22LDPE 0.11PA 6 (Nylon 6) 0.31PA 66 (Nylon 66) 0.31PA 12 (Nylon 12) 0.31PC 0.50PEI 0.50PES 0.50PET 0.41PMMA 0.41POM (ACETAL) 0.45PP 0.26PPE (PPO) 0.47PPS 0.50PS 0.24PVC 0.20SAN 0.33Shear Rate at End of FillShear rate is defined as the change of shear strain per unit time. For a special region with zero velocity gradient presents the zero shear rate and the wall position also presents near zero shear rate since the solidification is occurred in such area.Suggested material Max. shear rate(1/sec)for various genericmaterialsMaterial Grade 1/secABS 1.2x104ASA 5.0x104HDPE 6.5x104LDPE 4.0x104PA 6 (Nylon 6) 1.0x105PA 66 (Nylon 66) 1.0x105PA 12 (Nylon 12) 1.0x105PC 4.0x104PEI 4.0x104PES 5.0x104PET 4.0x104PMMA 2.1x104POM (ACETAL) 4.0x104PP2.4x104 PPE (PPO) 5.0x104 PPS 2.3x104 PS 4.0x104 PVC3.2x104 SAN 3.8x104Skin Material Ratio at End of FillFLOW-PACK will estimate the ratio of skin material and core material forthe various region of part when the parameter of co-injection process is ready since FLOW-PACK can simulate the co-injection process. For special planarregion, the skin material distribution is defined as the ratio of skin material and core material across the thickness direction, which is between 0 and 1. Additionally, the value 1 and 0 present the material across the thickness are pure skin and pure core material, respectively.For the co-injection process, the first material(skin material) is injected to fill the mold cavity. When the occupied volume of cavity reaches a specified value, such as 60% ~ 70% of cavity volume, the injection is then switched to fill the second material(core material). So, the second material would be located in the core area of part. If the value of this switch is too small, the flow front of the second material may be excess the flow front of the first material. In such case, FLOW-PACK would exhibit a warring message and continue the process of filling.Generally, the recycled material is used as the second material, which saves the material and the surface finish is maintained.Volume Shrinkage at End of FillPolymer material is compressible since the specific volume of material is function of pressure and temperature. The part temperature will reduce to room temperature after ejection, so the density distribution of part will be changed. Additionally, since the total mass of part does not change, the shrinkage of part volume would be occurred. The filling shrinkages present the volume shrinkage in filling end is defined as)1.()(1atm of Temp Room end filling S end filling ρρ−=where the ρ is the averaged density across the thickness direction of part.SolidWorks Plastics accepts the compressible or incompressible density model for analysis. The results would present the shrinkage distribution for the compressible model and zero for incompressible model.Note :Basically, the part area with high temperature presents a high shrinkage. The warpage tendency could occur since the part shrinkage distribution is non-uniform, and high shrinkage could cause internal voids or sink marks.Volume Shrinkage at end of fill result uses colors distributions to indicate percentage of volume shrinkage.If percentage of volume shrinkage is minus, it means the region of cavity is expansion.Freezing Time at End of FillThe local area material will be frozen when there temperature is below glassy transition temperature. Freezing Time represents such the materials of each region need taken how much time to reach freeze temperature and become solid.Frozen Layer Fraction at End of FillThe local area material will be frozen when there temperature is below glassy transition temperature. This value represents the thickness fraction of the frozen layer. It ranges from zero to one. A higher value indicates a thicker frozen layer (or thinner flow layer) and higher flow resistance. As the thickness of the frozen layer increases, the thickness of the flow layer is also reduced. It is noted that excessive high pressure is required to fill parts in which hesitation occurs early in the filling stage.Note :Frozen layer fraction has very significant effects on the flow resistance. Reducing filling time can reduce frozen layer fraction.Frozen Layer Fraction at end of fill is only used in shell styleCooling TimeIn SolidWorks Plastics, the cooling time is based on that each location temperature is below than ejectiontemperature and it's until 90 % volume of part temperature less than ejection temperature.temperature and become solid. This usually represents 80%~90% of totalcycle time.Cooling time stage is between the filling end stage and post-filling end stage, showed in point D to point F of Fig. 1Two major factors affecting the cooling time are mold temperature and melt temperature. Increasing melt and mold temperature will increase the cooling time. These conditions will increase the cycle time.So Lower mold temperature makes shorter cycle time and brings benefits in improved economic performance.To get an economy and acceptable cooling time, part thickness should be as uniform as possible. Required cooling time increases rapidly with part thickness.In theory, cooling time is proportional to the square of the thickest part thickness or the power of 1.6 for the largest runner diameter.In other words, doubling the thickness quadruples the cooling time.Temperature at End of CoolWhen the mold wall temperature is based on the specified value, then such temperature distribution is defined as the 90% part temperature < material ejection temperature. If such distribution is seriousnon-uniform, the part shrinkage and warpage may be occurred. From this temperature at every position of part, it could be provided as reference for cooling channel design.Sink MarkSink marks are depressions on the surface of injection molded plastic parts caused during the plastic cooling process. Thicker sections of plastic will cool at a slower rate than others, and will yield a higher percentage of shrinkage in that local area. After the material on the outside has cooled and solidified, the core material starts to cool. Its shrinkage pulls the surface of the main wall inward, causing a sink mark. The following design rules could be avoid sink mark occurred.1. Part thickness should be uniform, if possible2. The thickness of rib or bosses should be 50% ~ 80% of the attached wall thickness.3. Avoid using gates that are too small since which can prevent full packing of the cavity.4. Fill thicker sections first to allow them to be packed before the thinner sections freeze off.This sink mark is based on linear shrinkage of material, it's from PVT data.Birefringence at End of FillMulti-mode compressible Leonov model (nonlinear viscoelastic model) is used to predict flow induced residual stress. Birefringence includes flow induced birefringence and thermal induced birefringence. Due to flow induced residual stress and thermal residual stress, respectively, flow birefringence and thermal birefringence. The stress optical law is used to predict birefringence, in particular, two different stress-optical coefficient is used to predict the flow-induced birefringence and thermal birefringence, respectively. The birefringence componentsΔnxy, Δnyz andΔnxz are measured in the XY plane, YZ plane and XZ plane, respectively, in the direction of the light.Gate Filling ContributionAt end of filling, the material is fully filled cavity. For multi gates injection, the color index could indicate each location material is from what gate. And such results could help to understand the whether the input material is balance or not.Note :For exampleIn following diagram, the colors distributions indicate filled regions.Green region is filled by gate 1 and blue region is filled by gate 2.Ease of FillThis can help user to understand that the part can be successfully filled or not. The “green” color region indicates such area could be filled under normal injection pressure. The “yellow” color region indicates such area drop excesses 70% of maximum injection pressure. The “red” color region indicates such area drop excesses 85% of maximum injection pressure, and it need note about the injection pressure is enough or not, the user could be increase maximum injection pressure to ensure the part can be successfully filled.Frozen Area at End of FillThe local area material will be frozen when there temperature is below glassy transition temperature. This value represents the regions of the frozen layer. It ranges from zero to one. The “green” color region (value=1) indicates such the materials reach freeze temperature and become solid. The “red” color region (value=0) indicates such the materials do not reach freeze temperature.Clamping ForceClamping force refers to the force applied to a mold by the clamping unit of an injection molding machine. In order to keep the mold closed, this force must oppose the separating force, caused by the injection of molten plastic into the mold. The required clamping force can be calculated from the cavity pressure inside the mold and the shot projected area, on which this pressure is acting. If X-Y plane is the parting plane, then Z-direction clamping force is the required clamping force. The calculated clamping force can be used to select a proper machine that will prevent part defects, such as excessive flash.Short shotFor flow rate control, if the injection pressure exceeds the machine maximum injection pressure or after the packing switch point. Then the control type is from the flow rate control changed to pressure control, and the flow rate maybe drops rapidly. Short shot error will be occurred when the ratio of the current flow rate and initial flow rate is less than 0.001 or unreasonable flow rate is detected. The following design rules could use to avoid short shot occurred.1. Use the proper processing temperature recommended by the resin suppliers.2. Always fill the thick areas before filling thin areas.3. Increase the number and/or size of gates.4. Increase the injection pressure.Velocity Vector at End of FillVelocity Vector at end of fill shows the direction and speed of nodesAdjust number and length to display vectorWeld LinesA (visible) line that flow front flow together in opposite directions during mold filling process. On a finished part that may cause weakening or breaking of the component.The following design rules could reduce weld lines effect on the part.1. Adjust the gate position and dimension or part thickness to shift the welding lines in low stress or lowvisibility areas.2. Let welding line form at higher temperature and under a high packing pressure.Note :Select fill time and check weld linesAdjust to observe weld linesCheck Weld Lines and play Fill Time animation:The display of weld line is based on the mesh qualityAir TrapWhen the air is caught inside the mold cavity, it becomes trapped by converging polymer flow fronts during filling process. Air-trap locations are usually in areas that fill last. Lack of vents or undersized vents in these areas are a common cause of air traps and the resulting defects. Another common cause is that the tendency of polymer melt fill preferentially in thicker sections(race-tracking). The following design rules could reduce air trap effect on the part.1. Avoid a large thickness ratio in part, to minimize the race tracking effect of melt.2. Place the vent in the areas of mold that fill last.Gate Location IndexWhen the flow is unbalanced, portions of the flow front reach the end of the cavity while other portions are still moving. Melt-front area changes abruptly whenever such an unbalanced situation occurs. Balanced flow has a minimum variation of melt-front area in the cavity. For a given complex part geometry, the gate location index can provide user a reference initial condition to reduce minimizing melt-front area deviation in the cavity.Material Reactive Conversion at End of FillSince the variation of the pressure and temperature during the reactive injection molding process, the chemical reaction is occurred for the process. The degree of heat released could be used to designate the degree of conversion. Additionally, the range of such conversion value is between 0 and 1. Generally, the conversion is rising when the time is increasing, and the small conversion distribution is desirable for mold filling process.Curing Time at End of FillCuring time stage is between the filling end stage and post-filling end stage, the simulation will be executed until the materials reach 80 percentage of reactive eject conversion, and the materials will become solid.Pack resultPressure at End of PackingPressure is defined as normal force per unit area. In filling process, the injection force by means of screw is used to push the fluid material into the cavity. The force is propagated via the fluid and result in a pressure distribution in cavity. The pressure profile presents the decreasing from the inlet gates to downstream position since the flow length is increasing in flow direction. It is noted that the pressure of flow front position is as one atmosphere since the flow front contact with air. For a constant flow rate, the inlet gate pressure is increasing with time since the contact area of fluid with cavity is growing.The very high pressure is required for part with thin cavity since the flow resistance is enlarge and the solidification may be occurred during filling process, therefore, if the injection pressure is not enough, the short shot may be occurred.Temperature at End of PackingTemperature is a physical property of matter that quantitatively expresses the common notionsof hot and cold. Generally, for thin thickness region, the cooling effect results in lower temperature in such region. On the other hand, the high thickness region is with higher temperature.Central Temperature at End of PackingIn FLOW-PACK, the central temperature distribution is defined as the melt temperature of central position between to two surface faces for each region. Generally, the central position with a more far distance from mold wall presents a high melt temperature. The temperature of central position may be drop quickly for the part of very thin cavity, and the short shot may be occurred.Average Temperature at End of PackingThis distribution defined as the simple averaged melt temperature between to two wall faces for each region. If such distribution is serious non-uniform, the part shrinkage and warpage may be occurred.Bulk Temperature at End of PackingThe temperature changes of flow front during the filling process are considered with some parameters like time, location and thickness but without flow velocity, so bulk temperature is used. The bulktemperature with a physical significance since such is a measurable temperature during fluid flow. The definition of bulk temperature is a fluid velocity weighted average temperature across two surface faces for each region. If the velocity field is zero, then the bulk temperature is same as average temperature. Generally, a high bulk temperature is presented in the region with high convection since the velocity weighed is pointed. And, such temperature will be reduced when the flow velocity is suddenly degraded. The distribution of bulk temperature could provide the information whether the over-heating is occurred during the process.In Shell Style, the definition of bulk temperature is a fluid velocity weighted average temperature across the part (or cavity) thickness. That isT uTdz udz bulk b bb b =−+−+∫∫Where u is the velocity, b is one half part (or cavity) thickness. +b and -b are the positive and negative side of mold cavity, respectively.In Solid Style, the definition of node bulk temperature is based on weighted average of volume velocity around such node neighbor cells. That is∫∫∫∫===Ni V i i N i V i i bulk i i dV u dV uT T 11)(Wherei u and i V are the cell i velocity and volume, respectively.Shear Stress at End of PackingShear stress is defined as the shear force per unit area, and the direction of shear force is parallel with the forced plane. This shear stress distribution presents the wall shear stress of whole part at end of fill. Generally, high shear stress will introduce the molecular orientation into a high tensile strength, and reduce the surface finish of part, so the high shear stress should be avoided.Whereτ = the shear stressF = the force appliedA = the cross-sectional area of material with area parallel to the applied force vectorShear Rate at End of PackingShear rate is defined as the change of shear strain per unit time. For a special region with zero velocity gradient presents the zero shear rate and the wall position also presents near zero shear rate since the solidification is occurred in such area.Skin Material Ratio at Post-Filling EndFLOW-PACK will estimate the ratio of skin material and core material forthe various region of part when the parameter of co-injection process is ready sinceFLOW-PACK can simulate the co-injection process. For special planarregion, the skin material distribution is defined as the ratio of skin material and corematerial across the thickness direction, which is between 0 and 1. Additionally, thevalue 1 and 0 present the material across the thickness are pure skin and pure corematerial, respectively.For the co-injection process, the first material(skin material) is injected to fill themold cavity. When the occupied volume of cavity reaches a specified value, such as60% ~ 70% of cavity volume, the injection is then switched to fill the secondmaterial(core material). So, the second material would be located in the core area ofpart. If the value of this switch is too small, the flow front of the second material maybe excess the flow front of the first material. In such case, FLOW-PACKwould exhibit a warring message and continue the process of filling.Generally, the recycled material is used as the second material, which saves thematerial and the surface finish is maintained.。