Acrylic Sheet

Acrylic sheet is a rigid transparent thermoplastic sheet, most commonly PMMA (polymethyl methacrylate), used as a glass alternative where clarity, low weight, and weather resistance matter. Typical properties include density around 1.18–1.19 g/cm³, refractive index 1.49, light transmission about 92–95%, and tensile strength roughly 65–75 MPa. It is easy to cut, drill, edge-finish, solvent-bond, and thermoform, but scratch-sensitive and heat-sensitive during machining.

On a CNC router, acrylic is common for sign faces, light panels, machine guards, display covers, architectural inserts, and decorative millwork reveals because it cuts cleanly and keeps optical clarity when parameters are controlled. Successful machining depends on chip evacuation and heat control. Acrylic softens locally if the cutter dwells, feed is too slow, or the spindle rubs instead of shearing, leaving fused chips, edge haze, and re-melted flute marks. Typical practice uses sharp single-flute or O-flute tooling with rigid workholding to prevent chatter, and feeds that produce large chips to carry heat away rather than powdering the edge. In millwork assembly, acrylic is often solvent-bonded or mechanically retained in frames, so tolerances must account for thermal expansion, brittle-overload at fasteners, and stress from overclamping. Being lightweight but dimensionally sensitive, installers leave controlled clearance in grooves, rabbets, and captured-panel details to avoid cracking from seasonal movement or assembly preload.