What is shear stress
Shear stress is an internal force generated during molten plastic flow.
When polymer flows through:
- runners
- gates
- narrow channels
the material experiences deformation and friction.
This changes flow behavior.
How shear stress affects plastic material
High shear stress increases:
- material temperature
- internal friction
- deformation rate
This may change:
- viscosity
- mechanical properties
- surface quality
In extreme situations, the material may degrade.
Small runners and excessive shear
Runners and gates that are too small increase shear stress.
This may create:
- burn marks
- cosmetic defects
- dimensional variations
- unstable production
Runner geometry therefore becomes extremely important.
Importance of temperature control
Material temperature continuously changes during flow.
If temperature becomes too high, several problems may appear:
- polymer degradation
- color variations
- loss of mechanical properties
Correct thermal management improves stability and quality.
Mold flow simulation and shear analysis
Modern mold flow software allows engineers to simulate:
- shear stress
- pressure
- temperature
- flow speed
This helps optimize:
- runner design
- gate systems
- filling performance
- production stability
Simulation reduces engineering mistakes and costs.
Integration with modern engineering
Modern molds are becoming increasingly complex.
Hot runner systems, hydraulic components and mechanical movements must integrate perfectly.
Parametric platforms such as Vega Cylinders allow engineers to:
- configure hydraulic cylinders online
- download 3D CAD models
- verify dimensions
- accelerate mold engineering
This improves integration and development speed.
The future of polymer simulation
In the future of injection molding:
- industrial AI
- advanced simulation
- parametric CAD
- real-time manufacturing
will become increasingly interconnected.
Companies capable of controlling material behavior will achieve higher quality and efficiency.
