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Understanding the Differences between Cast and Extruded Acrylic

Written by Aleesha Crimmins

Apr 21, 2021 10:01:38 AM

 

Acrylic is a versatile substrate, excellent for a wide range of applications. Such as trade show displays, building signs, POP retail graphics and so much more (see our Applications Assistant to ensure you find the right products to suit your needs). Many people who frequently use acrylic in the signage industry eventually ask themselves why they need to use cast acrylic vs extruded acrylic. So, let us break down why the physical, mechanical, and chemical properties make a difference. 

Differentiating Qualities

1. Thermal Stability

Cast acrylic has a great thermal stability standpoint. It is less likely to bend, chip or melt during routing, ultimately limiting the likelihood that it will clog your router drill bit. Extruded acrylic will soften as the temperature increases over 195 degrees F making it ideal for pan-formed signs because of its ability to mold easily. 

2. Chemical Resistance

Cast acrylic offers the best chemical resistance in the acrylic category, especially when applying solvent cleaners or paints to the surface. Another factor to consider is outdoor exposure; due to cast withstanding a wide variety of chemical and outdoor exposure, it lends to be better for cleaning than extruded.

Tip: Generally, it is best practice to use an alcohol/water mixture when cleaning cast acrylic and paints with low or no VOC when painting on cast acrylic.

Common Applications

The cast acrylic sheets have a higher molecular weight which makes machining these sheets very easy to do. The chemical and outdoor resistance allows for a level of dependability that customers love. Extruded acrylic sheets have a low molecular weight and are excellent for general signage, illuminated signage, thermoforming, framing, and making displays. The design of both cast acrylic and extruded acrylic provides durability for your signage and consistent results.

Routing & Engraving

The thickness ranges of cast acrylic make it the perfect candidate for applications that require routing or engraving. The superior physical and mechanical properties alone, enable easier processing than an extruded sheet in this instance.

Displays & Framing

Extruded acrylic is perfect for display applications because it can handle chemicals for cluing and working with adhesives. The high-quality optical characteristic of extruded sheets makes it the ideal acrylic for framing applications. 

Push Thru Letters

When creating a push thru letter for an illuminated sign application, it is generally best to use cast acrylic, especially on any acrylic that is ½” or greater in thickness. Doing so will give the end-user the cleanest look and create less labor for the shop fabricating the job.

acrylic-PushThruLetters

Cast and Extruded Ideal Applications

                               Cast                                                               Extruded 

        Acrylic-ApplicationExamples

Time & Money Saving

As mentioned, cast acrylic is thicker than other acrylic substrates you can choose. This characteristic can ultimately save you time and money. It all comes down to processing.

                           Cast Acrylic                                                                             Extruded Acrylic

           Cast-BuildingSign                                          Extruded-OfficeSign

                                                                             

Easier routing leads to less clean-up. When routing cast acrylic, you can use a lower speed because of its high heat tolerance. This gives you a nice, clean edge right off the router table versus a rough edge, where polishing is needed to get rid of unwanted acrylic particles that may have melted themselves to the sheet. Easier routing also leads to less wear and tear on your router bits, so they will last longer and will not require a change so frequently.

Partner with Grimco

Grimco offers a variety of acrylic options, with our most recent addition being Chemcast Cast Acrylic! Check out our Chemcast Cast Acrylic Sheets page to learn more, and if you have any questions, be sure to open a chat at the bottom of the page to talk to a Grimco representative.

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