Plastic injection mold design
Plastic Injection mold design principles generally include the following:
One-way flow
Flow Balance
Constant pressure gradient
Maximum shear stress
Weld / Weld marks placed
Avoid stranded
To avoid underflow
Frictional heating can be controlled
Heat flow valve
Acceptable flow / cavity ratio
The following is the basic interpretation of the principles of mold design.
One-way flow of design principles is to ensure that the filling process, the plastic should flow in one direction, and keep a straight flow front. This leads to the generation single-direction positioning.
Balanced flow of movement of all the paths should be balanced and that is, at the same time filling the same pressure.
The most efficient way of filling the pressure gradient is the pressure gradient (pressure drop on the unit length) along the flow path is a fixed time.
Maximum shear stress the maximum shear stress
When shear stress in the fill material should be less than the maximum critical shear stress values depend on the materials and applications.
Welding / fusion place to place in the least sensitive parts of the weld and fusion line.
Avoid staying alone may prevent fluid flow path is divided into thick and thin flow path where the set gate.
Avoid undercurrent undercurrent through the gate to ensure the settings to avoid the fluid filled region in the last encounter.
Friction heating design for the control of the friction heat flow, increasing the melt temperature of the cavity, which will be in the product low stress, rather than plastic does not cause long-term degradation due to plastic at high temperature.
Thermal heat flow valve design flow valve system to ensure the gate to freeze just when filling the cavity has been fully completed and packing it to avoid filling in the mold after the packing or have been back.
Channel / cavity design than the high-pressure drop flow system so that the minimum material flow rate was a low-flow channel / cavity design.
In the usual mold design process, basic design principles to be followed, to ensure the rational Plastic injection mold design of die nature of these principles to the injection molding CAE analysis results of the analysis provide the basis.
