Answer: Cast acrylic and extruded acrylic are two types of acrylic (polymethyl methacrylate, or PMMA) that differ in their manufacturing processes, properties, and applications.
Below is a breakdown of the main differences offered by Petro Extrusions.
Manufacturing Process
- Cast Acrylic: Made by pouring liquid methyl methacrylate into a mold between two sheets of glass. The liquid is then polymerized into solid sheets with the help of heat or UV light. This method allows for larger and thicker sheets with more uniform color distribution.
- Extruded Acrylic: Produced by extruding heated methyl methacrylate through a die to form a continuous sheet. This process is faster and more cost-effective, creating thinner and more uniform sheets in terms of thickness.
Properties of Cast Acrylic vs Extruded Acrylic
- Optical Clarity: Cast Acrylic generally offers slightly better optical clarity and less internal stress, making it ideal for applications where transparency is critical.
- Impact Resistance: Extruded Acrylic tends to have better impact strength than cast acrylic, making it more suitable for applications where physical durability is a concern.
- Machinability:
- Cast Acrylic can be more easily machined, cut, and polished due to its molecular structure. It’s less prone to cracking or chipping during fabrication.
- Extruded Acrylic might show more stress lines when machined or cut, which can affect the final appearance if not handled properly.
- Thermal Properties: Both types have similar heat resistance, but cast acrylic can handle thermal forming better without distorting as much.
- Color Consistency and Distribution:
- Cast Acrylic usually has better color consistency throughout the sheet, especially with colored or tinted acrylics.
- Extruded Acrylic might show slight color variation along the length of the sheet due to the manufacturing process.
Applications
- Cast Acrylic: Commonly used for aquariums, display cases, signage, art pieces, and where optical quality is paramount. Its versatility in thickness and size makes it suitable for large-scale applications.
- Extruded Acrylic: Often favored for glazing, skylights, picture framing, and other applications where cost, impact resistance, and thinner sheets are beneficial. It’s also widely used in mass-produced items due to its lower cost of production.
Petro Extrusion provides custom and stock Acrylic profiles and tubing to satisfy all your extrusion needs. To make sure we provide the best solution, contact us, either online or by phone (800-229-3338).
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