Case Study

Whirlpool Uses Ansys Polyflow for Refrigerator Liner Thermoforming Simulation for Thickness Prediction

“Using Ansys Polyflow® for thermoforming simulation helps us to solve a major challenge for the manufacturing team regarding liner thickness prediction in the thermoforming process.”

— Dr. Biswadip Shome Director, Simulation Based Design / Whirlpool of India Ltd.

Introduction

Thermoforming is widely used for mass production of refrigerator liners. Liner thickness distribution variation is an important quality parameter, which has been traditionally controlled by trial and error. This typically involves choosing different input sheet thicknesses and process parameters (temperature, pressure, etc.), which wastes material and manufacturing time. A thermoforming simulation could predict liner thickness and its distribution quickly and efficiently, eliminating such waste.

Challenges

Thermoforming simulation is a problem of estimating viscosity and strain coupled with heat transfer and contact algorithms under governing equations of conservation of mass and momentum. Preparing a robust finite element model, incorporating comprehensive material modeling and mapping actual production environment conditions to quantifiable loads and boundary conditions are major challenges. Other hurdles include incorporating fluid-tomold contact and release algorithms, along with conjugate heat transfer across contact surfaces.

 Engineering Solution

• Ansys Polyflow offers different equations to model the strain rate and temperature dependence of viscosity.
• Ansys Polyflow offers various material models and contact algorithms to effectively replicate the thermoforming process and predict accurate outcomes.
• The adaptive mesher of Polyflow helps to refine the sheet mesh when it comes in contact with the mold to closely follow mold geometry.

Engineering Solution

• Ansys Polyflow offers different equations to model the strain rate and temperature dependence of viscosity.
• Ansys Polyflow offers various material models and contact algorithms to effectively replicate the thermoforming process and predict accurate outcomes.
• The adaptive mesher of Polyflow helps to refine the sheet mesh when it comes in contact with the mold to closely follow mold geometry.