What is shear heating
Shear heating is the temperature increase caused by internal friction during molten plastic flow.
When polymer flows through:
- runners
- gates
- narrow channels
thermal energy is generated.
This changes material behavior.
Why excessive shear heating is dangerous
Excessive shear heating may create:
- material degradation
- color variations
- burn marks
- loss of mechanical properties
Viscosity may also change rapidly.
This makes the process less stable.
Runners and gates that are too small
Runners and gates that are too small increase:
- material speed
- internal friction
- shear stress
This generates additional heat.
Optimized geometry reduces the problem.
Importance of injection speed
Injection speed that is too high increases:
- shear heating
- turbulence
- flow instability
Speed must be carefully controlled.
Correct balance improves:
- surface quality
- stability
- repeatability
Temperature control and hot runners
In hot runner systems, thermal management becomes even more important.
Small thermal variations may worsen:
- viscosity
- filling behavior
- final quality
For this reason, simulation and process control are critical.
Mold flow simulation
Mold flow software allows engineers to simulate:
- shear stress
- temperature
- flow speed
- material behavior
This helps prevent problems before mold manufacturing begins.
Integration with modern engineering
Modern molds integrate:
- hot runner systems
- hydraulic components
- core pulling systems
- automated movements
Platforms such as Vega Cylinders allow engineers to:
- configure hydraulic cylinders online
- download 3D CAD models
- verify compatibility
- accelerate engineering workflow
This improves engineering precision and development speed.
The future of thermal management
In the future of injection molding:
- industrial AI
- advanced simulation
- automation
- real-time manufacturing
will become increasingly interconnected.
Companies capable of controlling shear heating and temperature will achieve higher quality and efficiency.
