The difference between cast acrylic sheets and extruded acrylic sheets

Manufacturing Process

Cast Acrylic Sheet
- Produced by pouring liquid MMA (Methyl Methacrylate) monomer into molds, then cured through heat or chemical polymerization.  
- Results in a molecularly uniform structure with internal stresses minimized.  

Extruded Acrylic Sheet
- Made by pushing melted PMMA pellets through a die (extrusion machine), then cooled and cut into sheets.  
- Faster, continuous production but may retain slight internal stresses.

Thickness Tolerance Surface Quality

Cast Acrylic Sheet 
- Superior thickness consistency ( ±1mm tolerance).  
- Optically clearer with glossier surfaces, ideal for precision applications (e.g., lenses, displays).  

Extruded Acrylic Sheet:  
- Slightly wider thickness variations.  
- May have minor surface lines or imperfections from extrusion. 

Mechanical & Chemical Properties
Cast Acrylic Sheet:  
- Higher molecular weight - Better chemical resistance (solvents, fuels).  
- More impact-resistant** and less prone to cracking during machining.  

Extruded Acrylic Sheet:  
- Softer and more thermoformable (easier to bend at lower temperatures).  
- Prone to stress cracks when laser-cut or drilled near edges.  

Fabrication Applications

Cast Acrylic Sheet:  
- Preferred for CNC machining, engraving, and polishing (cleaner edges).  
- Common uses: Aquariums, aircraft windows, high-end signage, medical devices.  

Extruded Acrylic Sheet:  
- Better for continuous thermoforming (e.g., curved displays).  
- Cost-effective for large-scale projects: Light covers, protective barriers, simple signage.  

Cost Availability

Cast Acrylic Sheet:  
- More expensive due to slower production.  
- Wider range of colors/thicknesses (1.5mm-300mm).  

Extruded Acrylic Sheet:  
- Lower cost and faster lead times.  
- Typically limited to ≤10mm thickness for standard grades.