Cast vs. Extruded Acrylic: The Manufacturer’s Guide to Choosing the Right Sheet

To the naked eye, they look identical. Both are clear, plastic sheets.

But to a laser cutter or a CNC router, Cast Acrylic and Extruded Acrylic are two completely different materials.

In my 30 years at Jinbao Plastic, I have seen hundreds of clients waste money by buying the "cheaper" sheet, only to have it melt on their CNC bed or crack during installation.

If you are a distributor or fabricator, understanding the technical difference between these two production methods is critical for your profitability. Here is the definitive comparison.

1. The Manufacturing Process (Why It Matters)

Direct Answer:
Cast Acrylic (Cell Cast): Made by pouring liquid MMA (monomer) into a glass mold and baking it. It is a slow, labor-intensive process, resulting in a hard, chemically resistant sheet with a slightly variable thickness.
Extruded Acrylic: Made by pushing molten acrylic pellets through steel rollers. It is a continuous, high-speed process, resulting in a softer, cheaper sheet with perfectly uniform thickness.

2. Laser Cutting & Engraving (The "Frosted" Look)

If your clients are sign makers using CO2 lasers, this is the most important section.

• Engraving:

• Cast Acrylic: Turns a beautiful frosty white when engraved. This contrast makes it the #1 choice for awards, signage, and plaques.

• Extruded Acrylic: Engraves clear/gray. It provides poor contrast and looks "muddy."

• Cutting:

• Cast Acrylic: Cuts cleanly with a polished edge.

• Extruded Acrylic: Can melt and leave a gummy residue or burrs on the edge if the laser speed isn't perfect.

3. Machining & Chemical Resistance

• CNC Routing: Cast acrylic is harder and melts less. Extruded acrylic is softer and can "gum up" your router bit if you run it too fast.

• Chemicals: Cast acrylic has a stronger molecular structure (higher cross-linking). It resists perfume, lotions, and harsh cleaners better. Extruded acrylic is prone to "crazing" (micro-cracks) when cleaned with solvents.

• Application Tip: Never use extruded acrylic for perfume displays or hospital environments.

4. Thermoforming & Bending

Here is where Extruded Acrylic shines.

• Because it is softer, Extruded Acrylic heats up faster and bends easier. It is the preferred material for vacuum forming large skylights or simple line-bent display stands.

• Cast Acrylic has "thermal memory." If you reheat a bent cast piece, it will try to return to its original flat shape.

5. Thickness & Price

• Price: Extruded is generally 10-15% cheaper than Cast because the manufacturing is automated.

• Thickness Tolerance:

• Extruded: Extremely precise (+/- 5%). Essential for fitting into aluminum channels or tight fixtures.

• Cast: Variable (+/- 15%). The sheet might be 3.0mm in the center and 2.8mm at the edge.

Quick Selection Table

Conclusion: Which Should You Stock?

• Buy Cast Acrylic If: You sell to sign shops, laser engravers, or high-end display manufacturers. (Jinbao offers 200+ colors in Cast).

• Buy Extruded Acrylic If: You need high-volume, budget-friendly clear sheets for glazing, simple bending, or vacuum forming.

At Jinbao Plastic, we operate dedicated lines for both types. We don't guess; we supply the exact spec you need.

Need a price list for both grades?

Contact us today. We can load a mixed container so you can offer your customers the right tool for the job.

• Email: jinbao@jinbaoplastic.com

• WhatsApp: +86-13969152622

About the Author:

Alan FAN is the CEO of Jinan Jinbao Plastic Co., Ltd., established in 1996. With 35 production lines and nearly 30 years of export experience, he helps global distributors navigate the technical nuances of acrylic manufacturing to maximize their profitability.