Waterjet cutting uses a high-pressure stream of water — typically at 40,000 to 90,000 PSI — directed through a small orifice to erode material along the cut path. For most industrial applications, an abrasive medium such as garnet is entrained in the water stream, producing an abrasive waterjet capable of cutting virtually any material including metals, composites, ceramics, glass, stone, and plastics of any thickness. The cutting action is purely mechanical and hydraulic: no heat is generated at the cut zone.

Laser cutting uses a focused beam of high-intensity light — typically a CO2 laser for plastics and non-metals, or a fiber laser for metals — to vaporize or melt material along the cut path. The process is extremely precise and fast, with a very narrow kerf, and produces an exceptionally clean edge on materials that respond well to thermal cutting, particularly cast acrylic. The limitation is inherent to the process: the cutting action generates heat, creating a heat-affected zone (HAZ) at and near the cut edge.

The heat-affected zone is the most significant differentiator between waterjet and laser cutting for engineering applications. Waterjet produces no HAZ whatsoever — the cut is entirely cold, and the material properties at and adjacent to the cut edge are identical to the bulk material.

For acrylic, laser cutting's HAZ is actually beneficial: the material melts and resolidifies at the cut line, producing a flame-polished, optically clear edge that requires no secondary finishing. This is the one application where laser cutting produces an edge quality that waterjet cannot match.

For polycarbonate, the story reverses: laser cutting tends to produce a stress-crazed, frosted edge rather than a polished one, and the HAZ can introduce residual stress that compromises the edge's mechanical integrity. For polycarbonate, waterjet or CNC routing typically produces a superior result.

Waterjet cutting handles material thickness that is beyond the practical range of laser cutting without any meaningful degradation in edge quality. A waterjet can cut through 6 inches of engineering plastic, composite laminate, or metal plate with the same process — only cutting speed changes with thickness, not edge quality or process viability.

Laser cutting becomes progressively less effective as material thickness increases. Beyond approximately 0.75 to 1 inch in most plastics, laser cutting speed drops sharply, edge quality degrades, and the HAZ deepens.

PVC and CPVC cannot be laser cut under any circumstances because the thermal decomposition generates chlorine gas — a serious health and equipment hazard. Waterjet cuts PVC and CPVC cleanly, safely, and without any chemical hazard. Similarly, highly filled composite plastics, fiber-reinforced laminates, and carbon fiber composites are better suited to waterjet cutting.

Laser cutting's speed advantage is most pronounced in thin sheet work — typically under 0.5 inch — where it outpaces waterjet considerably in cutting rate. For thin acrylic signage, display components, and decorative panels where the flame-polished edge is the desired result, laser cutting is faster and produces the better finish.

Plastic-Craft Products holds ISO 9001:2015 and AS9100D quality management certifications covering fabrication operations including waterjet and laser cutting. For aerospace and defense programs, the AS9100D certification means the documentation chain extends through the cutting operation — not just the material sourcing.

Choose waterjet when: the material is PVC, CPVC, or any chlorine-containing plastic; the material thickness exceeds approximately 0.75 to 1 inch; the part is composite, filled, or laminate; the application requires no HAZ at the cut edge; or the part requires simultaneous cutting of plastic and metal in the same setup.

Choose laser when: the material is cast or extruded acrylic in thin-to-medium sheet and an optically polished edge is required; intricate geometry with very tight internal radii or fine detail features is needed in thin sheet; cutting speed is a primary production cost driver; or the application is decorative, display, or signage work where the flame-polished edge is a design requirement.