Typically, acrylic blanks are manufactured using two methods: extrusion and casting. The first method is used to manufacture sheets, while the other is used to manufacture sheets and any other kind of form. Acrylic thickness from using both methods usually varies from 1.5 to 25 mm.
Such a variety of thicknesses makes acrylic a good choice for cutting out flat emblems and signs. Let’s see which kind of blanks have better properties for CNC acrylic cutting.
Extrusion consists of melting large volumes of acrylic pellets in a special tank and extruding the resulting liquid through a specifically formed whole – an extrusion nozzle. Casting acrylic is similar to casting any other material. The pellets are melted and poured into a casting form, which is later cooled down and extracted.
Extruded and Cast blanks behave differently under a cutting tool. Extruded acrylic has more leftover tensions so it is more susceptible to cracks and overall more brittle. That’s why machining it is a disaster. In addition, extruding makes its properties anisotropic, so you are basically machining different materials along the X and Y axes.
If you want to use acrylic CNC machining for your manufacturing process, pick only cast blanks. Extruded ones are not worth the effort.
