Cut Polycarbonate the Best Way

Want to work with polycarbonate sheets for your next DIY or construction project? Properly cutting this versatile thermoplastic takes the right tools and techniques to get clean, precise results.

Read on to learn the ideal way to cut polycarbonate for your specific application.

Choosing the Right Cutting Tools

Having the proper cutting tools makes all the difference when working with polycarbonate plastic. Here are some of the most common and effective options:

• Utility Knife: Best for scoring and snapping thinner polycarbonate sheets up to 3mm thick.
• Table Saw: Ideal for straight cuts in medium to thick polycarbonate from 3mm to 12mm.
• Circular Saw: Portable convenience for straight or angled freehand cuts in sheets under 10mm.
• Jigsaw: Cuts intricate internal shapes and curved outlines in polycarbonate sheets up to 10mm thickness.
• Router: Using special bits, routers cut edges with decorative profiles in medium density sheets.
• Laser Cutter: Extreme precision with computer-guided laser cuts for sensitive materials.
• CNC Machine: Automated versatility for high-volume polycarbonate jobs over 20mm thickness.

Always match your cutting tool to the thickness and grade of polycarbonate you are working with. For example, a standard table saw would struggle to cut 12mm cast polycarbonate, while a utility knife can't slice halfway through a 10mm extruded sheet.

Blade Characteristics

Saws used for cutting polycarbonate must have sharp, fine-toothed blades between 60-80 teeth to cleanly slice rather than tear the plastic's surface. Look for specialty plastic-cutting blades or those designed for stable synthetics like acrylic or polypropylene.

Ideally, choose smaller, densely packed teeth no wider than 2.5mm with a tooth geometry featuring a low rake angle and deep gullets to avoid material chipping. With most power saws, adjusting to a high rotational speed (RPM) between 4000-6000 also leads to cleaner, safer polycarbonate cuts by rapidly shearing the material.

The Right Blade for the Job

To optimize cuts and blade life, match your saw blade to the specific task:

• Crosscut blades for slicing across sheet width
• Rip blades for cuts along the length
• Hollow ground blades reducing friction
• Alternative bevel tooth patterns to chip ejection

Proper Prep Work and Safety Steps

Having the right mindset and workspace setup drastically improves cutting results. Before firing up your saw implement these vital preparations:

Planning Cuts

• Carefully measure cut lines and mark with a non-permanent tool like a wax pencil.
• Secure the polycarbonate workpiece using clamps to prevent unintended movement.
• Calculate cuts to minimize waste material for cost efficiency.
• Wear eye protection, ear protection, and an approved respirator mask.
• Prepare dust collection with a vacuum extractor or protective drapes.

Environment

Cut polycarbonate sheets on a flat, vibration-dampening surface offering ample clearance around the work area. Provide strong overhead lighting while eliminating flammable items nearby. For electric saws, use a GFCI power source kept away from water sources to prevent shocking.

Manual Cutting Techniques

While basic in nature, properly scoring and snapping polycarbonate sheets manually still takes skill. Follow these pointers to precision score thin sheets under 5mm thickness using a standard utility knife.

Scoring the Cut

• Use a fresh blade and straightedge guide for straight score lines.
• Make 2-3 incremental light passes instead of one deep cut, scoring at 0.15mm depth.
• Score on the scrap side of line, 0.5mm away, for precise cut edge location.
• Cut over sacrificial wood support to protect sheet's surface finish.

Controlled Snapping

After scoring, avoid tearing or cracking by:

• Line up a thin stick precisely along the score line.
• Have a helper evenly pull up the scrap end.
• Apply increasing bend pressure concentrated at the score line until separation.
• Inspect cuts to identify technique improvements.

Cutting Polycarbonate with Saws

For sheets over 5mm or complex shapes, sawing offers the best solution for cutting polycarbonate precisely. We'll cover tips for circular, band, jig, scroll, and other saw varieties.

Getting Started

Prepare your saw by:

• Securing an appropriate fine-tooth blade (60+ teeth).
• Setting speed between 2500-4500 RPM.
• Adjusting cut depth to 0.5mm above sheet.
• Providing sturdy workpiece support against tear-out.

In Progress Cutting

When actively cutting, good practices include:

• Smooth, steady blade feeds without forcing or binding.
• Applying low-tack tape strips along cut lines.
• Using compressed air or mister to keep cuts cool.
• Allowing blade teeth to chip away evenly.

Cut Completion

Finish trimming cuts properly by:

• Fully retracting the blade before any adjustments.
• Leaving a bridge uncut at edges to prevent cracking.
• Not forcing, twisting, or vibrating the workpiece.
• Incrementally optimizing feed speed and pressure.

Automated Cutting Systems

For rapid, high-volume fabrication polycarbonate shops rely on computer-controlled cutting machines. Here's an introduction to harnessing laser cutters and CNC routers.

Laser Cutting Benefits

Ideal for detailed 2D vector graphic sheet designs by:

• Generating clean, narrow 0.10mm kerf width.
• Achieving tolerance accuracy down to +/- 0.005mm
• Leaving smooth polished edges needing minimal post-processing.

CNC Router Advantages

Powerful for cutting thick or large format sheets by:

• Using rigid compressed air cooled spindle.
• Programming directly from 3D CAD files.
• Simultaneously engraving markings.
• Accepting larger table sizes over industrial lasers.

By practically eliminating scrap rework and tooling costs, laser and CNC cutting achieves fast job turnaround for accuracy results hard to match manually. Always extract exhaust fumes directly at the cut point.

No matter what polycarbonate cutting method, focus on making burr-free cuts by:

• Carefully controlling heat generation.
• Tuning feed rate and tool rotation speed.
• Using a sharp blade with ideal geometry.
• Applying minimal pressure; letting the tool cut.
• Providing rigid workpiece backup support.