Example report describing main analysis results and optimization solutions Moldflow analysis report

 

Analysis target

Product information

 

Mold information

 

Two-plate mold, four side gates.
One water channel on fixed mold side and two water channels on movable mold side.
Molding process parameters
Molding machine parameters:
Haitian 1000T
Screw diameter: 100mm
Maximum stroke: 48cm
Maximum injection pressure: 211Mpa
Maximum injection rate: 700cm^3/s

 

Molding material properties
BASF: Ultramid B3GM35 Q641 GF15%M25%(PA6)

 

Analysis results list
Fill Time (Animation)
Temperature at Flow Front
Pressure
Clamp Force
Maximum Shear Rate
Shear Stress at Wall
Weld Lines
Air Traps
Volumetric Shrinkage at Ejection
Frozen Lay Fraction
Sink Mark Estimate
Sink Mark Shaded
Circuit Coolant Temperature
Temperature Part at the End of Cooling
Deflection(X/Y/Z/all deflection cause)

 

Filling flow is relatively balanced, there is no obvious stagnation phenomenon, and plastic melt reaches each end at the same time.
If local area is gray at the end of filling, it means that product is short shot.
If flow is unbalanced, stagnation, over-pressure holding, etc. may occur. Flow pattern can be balanced by optimizing gate position and number, runner arrangement and size, product structure and wall thickness.

 

Generally, flow front temperature is acceptable within 20℃ of recommended material temperature (280℃). If wave front temperature is too high, material is easy to burn and degrade. If wave front temperature is too low, weld lines and flow marks are obvious, and even short shots occur.
Flow front temperature is uniform by adjusting filling speed, gate position and speed, product wall thickness, and using low-viscosity materials.

 

Maximum injection pressure: 74.3MPa. Please select an injection molding machine with appropriate specifications. Pressure in cavity: 42MPa. If pressure in cavity is greater than 80MPa, product is prone to flash.
Injection pressure can be reduced by adjusting filling speed, gate position and speed, product wall thickness, using low-viscosity materials, increasing mold temperature and material temperature.

 

Maximum clamping force: 373.2T. Please choose an injection molding machine with appropriate specifications.
Reduce clamping force requirement by adjusting filling speed, gate position and speed, product wall thickness, using low-viscosity materials, reducing number of cavities, increasing mold and material temperatures.

 

Maximum shear rate: 43054 1/S
Generally, do not exceed maximum shear rate allowed by molding material (as shown on page 8, maximum shear rate allowed by material is 60000 1/s. Non-transparent parts can be relaxed to three times. The smaller maximum shear rate of transparent parts, the better appearance quality). If shear rate is too high, material is easy to degrade, and product is prone to surface defects such as impact marks.
Shear rate can be reduced by increasing gate size and reducing injection speed through gate.

 

Maximum shear stress on flow channel system: 2.8MPa Maximum shear stress on product: 0.4MPa
Maximum shear stress on general product should not exceed value allowed by molding material (as shown on page 8, maximum shear stress allowed by material is 0.5MPa). If shear stress is too large, product is prone to cracking.
Shear rate can be reduced by increasing wall thickness at maximum shear point, reducing injection speed, using low-viscosity materials, and increasing material temperature.

 

Weld lines will be formed between every two ribs.
Generally, when weld line butt angle is less than 75 degrees, wavefront temperature is low, and there is obvious air entrapment in weld line area, weld line will be more obvious. This affects appearance and strength of product.
Weld lines can be eliminated or reduced by optimizing gate position, product structure and wall thickness.

 

Trapped gas in cavity cannot be discharged in time, which may easily lead to surface blistering, air inclusion inside product, and incomplete injection molding.
Please strengthen exhaust in purple ball area. If trapped gas occurs at parting surface, exhaust can be strengthened by adding exhaust grooves; if trapped gas occurs in the middle of product, gas can escape through gap between ejector pin or slider.

 

Generally, when demolding, volume shrinkage values of adjacent areas differ by >2%, and product surface is prone to shrinkage.
Volume shrinkage can be reduced by optimizing product wall thickness, placing gates in thick wall areas, and increasing pressure retention.

 

Frozen Layer Fraction reflects solidification order of product. At 6.3 seconds, red area of product has solidified, resulting in insufficient pressure holding at installation hole, so volume shrinkage is large and surface shrinkage is prone to occur.
When product is 100% solidified, cold runner system solidifies more than 50%. Product can be removed. Therefore, molding cycle of product is determined to be 31S (excluding opening and closing time).
Molding cycle can be shortened by optimizing cooling water channel layout, reducing thickness of local wall thickness area, and optimizing cold runner size.

 

Generally, dent value is >0.03mm, and surface shrinkage is obvious.
Dent depth can be reduced by increasing basic wall thickness, reducing wall thickness of reinforcing ribs and bolt columns, and increasing pressure retention.

 

Shaded area shows results of dent analysis. Circled area is more obvious to naked eye.

 

Generally, temperature difference between coolant inlet and outlet is controlled within 2~3℃, indicating that cooling water circuit layout is reasonable.
Temperature difference between inlet and outlet can be reduced by reasonably arranging cooling system, optimizing long series water circuit into multiple parallel water circuits.
Product surface temperature at the end of cooling

 

At the end of cooling, temperature difference of most areas on the surface of product is relatively uniform, but temperature is higher in local grooves.
Generally, at the end of cooling, temperature difference of product surface is within 10℃, indicating that cooling effect is good.
For areas with high local temperatures, surface temperature of product can be ensured to be uniform by adding cooling water channels, baffles, fountains, beryllium copper inserts, etc.

 

The overall deformation of product is shown in above picture, magnified 3 times.

 

Maximum deformation of product in X direction is 2.6mm. Please confirm whether it meets assembly requirements.

 

Main reasons for X-direction deformation of this product are uneven shrinkage and fiber orientation.
X-direction deformation can be reduced by optimizing gate position and product structure.

 

Product shrinks evenly in Y direction. Please set a reasonable shrinkage rate when designing mold.

 

The overall deformation of product in Z direction is 8.5mm. It does not meet assembly requirements.
As can be seen from figure, corners with ribs are almost deformed. Consider adding ribs in other corners.

 

Main reason for Z-direction deformation of this product is fiber orientation.
Deformation can be reduced by optimizing gate position and product structure.
Analysis results are listed