What is the difference between Cast & Extruded Acrylic?

What is the difference between Cast and Extruded Acrylic?

NCA Ltd have, for over 40 years, been a specialist plastic fabrication firm. Throughout our many conversations with our clients, the differences between cast and extruded acrylic have been discussed at length. In this week’s blog post we explain both what the differences between the two are as well as the benefits of both. 

 

Regardless if they are formed through casting of through extrusion, acrylic polymers are materials that are the result of a chemical reaction between a monomer and a catalyst.Lighter in weight than glass and often a substitute for it, acrylic, also known as Plexiglas or Lucite, is prized for its transparency and strength.

Glass moulds are used to create Cast Acrylic and is where the liquid ingredients and mixed together – the mold giving the shape of the object. Whilst more labour intensive, thus more expensive, casting yields a harder and more uniform final product. This is because casting creates a greater chemical resistance compared to extrusion and is preferred in certain uses such as those involving fragrances, lotions or solvents. Cast acrylic is available in an almost infinite range of colours and is more pliable than extruded acrylic meaning it is both stronger and less likely to melt, bend or chip during its production. Cast acrylic is often more desirable than extruded acrylic as it is not limited in thickness making it a better option for larger structures. 

Benefits of Cast Acrylic

  • Greater range of thickness
  • Lightweight and rigid
  • Low water absorption
  • Excellent optical properties
  • Good electrical and UV resistivity
  • Resistance to long-term exposure to sunlight and weathering

 

Benefits of Extruded Acrylic

  • Thermoformable
  • Less expensive than glass or cast acrylic
  • Excellent optical properties
  • More impact resistant than glass
  • Good electrical and UV resistivity

Acrylic extrusion is a manufacturing technique where the acrylic monomers are first heated before being fed into barrels where the chemical process takes place. Extruded acrylic is Extrusion is a continuous manufacturing production method where acrylic monomers are first heated then fed through barrels where the chemical process occurs. 

Generally, extruded acrylic costs less than cast acrylic and is more stable meaning that the thickness across the sheets is more consistent. Because extruded acrylic is softer than cast acrylic is easier to cut, rout and can be polished more cost effectively. 

Extruded acrylic is less susceptible to dirt, lint, or particulate contamination in the production process and, because of its lower melting point, it is better suited to cementing and thermoforming than ast acrylic. 

At NCA Ltd our experienced teams of engineers can assist you in exploring which type of acrylic to use on your project. Experienced in the design and production of plastic products, our specialist team work with each client to create cost effective solutions to solve real world problems. For more information on our services and to discuss your requirements, contact our team via nca@ncaltd.co.uk or on 01928 790209.