Cutting & Machining
Cutting and machining Plaskolite acrylic sheet is easy. Table saws, panel saws and scoring tools make clean cuts, while table routers, joiners and edge finishers achieve desired edge effects.
Scribing & Breaking
For Plaskolite acrylic sheet up to 1/4” thick, score repeatedly along a straight edge with a plastic cutting tool, or Fletcher Terry Knife. Score to penetrate 1/3 through the sheet. Align the score with the edge of the table and apply gentle pressure to break the sheet along the score line (See Fig. 2).
Plaskolite acrylic sheet can be cut with a variety of equipment. The selection of blades is critical with regards to the quality of the edge finish.
Table and Panel saws are the best options for high volume straight cuts. Material can be stacked to cut several sheets at one time. When cutting, the saw blade should protrude through the sheet approximately 1/4” (See Fig. 3). Saw blades, specifically designed for cutting acrylic sheet, are commercially available.
CIRCULAR SAW BLADE SPECIFICATIONS (See Fig. 4):
Rake angle 0-10°
Clearance angle 10-15°
Blade teeth 80 per 10" blade
Tooth design (See Fig. 5)
Band, scroll, and sabre saws are best for cutting intricate shapes and curves. Again, blade selection and proper feed rate is important to minimize melting or chipping. These saws are excellent for creating templates for vacuum or hand routing, and trimming off excess scrap material.
Routers are one of the most versatile pieces of equipment available to trim Plaskolite acrylic sheet. Bit selection is important, and tools specifically designed to rout acrylic are commercially available. Use a down- ward spiral router bit to prevent masking from fraying. Routers produce a high quality machined edge, ready for finishing, provided the following formulas are followed:
Chip Load = Feed Rate/(RPM X # cutting edges)
Feed Rate = RPM X # cutting edges X chip load
Speed (RPM) = Feed Rate/(# cutting edges X chip load)
Hand routers are best used for low volume work. With a bearing-mounted, flush trim bit, the router can trim around a clamped template.
Pin, table and vacuum routers (hand routers mounted under a table) are more convenient to rout around intricately shaped templates (See Fig. 6).
Circle routers can cut round parts by securing the acrylic sheet to a turntable, then rotating the sheet around the stationary router.
Computer Numerically Controlled (CNC) routers are used for high volume, intricate, precise acrylic parts. The part is designed on a CAD/CAM system and geometry is programmed directly into the CNC machine. Many of the variables; feed rate, RPM, bit diameter, depth of cut are adjustable for optimum cutting performance.
CNC laser cutters are used to cut virtually any shape part from Plaskolite acrylic sheet. This form of cutting produces a clean, polished edge without saw chips. It is well suited for cutting small intricate parts that are difficult to hold down with other cutting processes. Paper masked, or sheet with 3 mil laser cuttable film perform best for this operation.
Many methods are used to produce a desirable edge finish.
Shapers and table routers can machine square, beveled, bull nose, ogee, and other decorative edges (See Fig. 7).
Jointers are used to square and prepare edges for cementing or hand finishing. Multiple sheets can e stacked to increase efficiency (See Fig. 8).
Edge finishing machines with diamond cutting wheels, produce an edge with a polished look, excellent for cementing.
Mills can be used to create precisely machined parts.
Drilling holes is performed best on a drill press with commercially available plastic cutting drill bits. Guidelines for drilling include:
The bit should enter the Plaskolite acrylic sheet at a slow feed rate, then a steady rate producing two continuous spiral chips, finally exiting through the acrylic slowly, eliminating chipping.
To reduce heat build up, and removal of material, peck feeding may be necessary when drilling thick acrylic sheet.
Place a scrap piece of acrylic or plywood beneath the sheet to be drilled. This will eliminate chipping as the bit passes through.
Standard twist drill bits can be used, provided modifications to the bit are performed. These modifications will allow the bit to scrape rather than cut through the acrylic sheet (See Fig. 9).
For optimum cutting and machining quality, certain guidelines should be followed.
Always use sharp tools/blades reserved for cutting acrylic sheet.
Whenever possible use tools/blades specifically designed with proper geometry for cutting acrylic sheet.
Use proper and constant feed rates, and RPMs. To prolong tool/blade life, apply the fastest feed rate that gives a satisfactory edge.
Eliminate vibration of the acrylic sheet through clamping or other hold-down methods.
Align all fences and tables parallel to the cutting device.
Machine Plaskolite acrylic sheet with a conventional cut rather than a climb cut.
Machine of f as little acrylic as possible. Two passes may be necessary for thicker acrylic; one to rough out the part, then a final skin cut. For jointers and shapers, trim a maximum of 1/32” per pass.
When necessary, direct compressed air or an atomized spray of a water soluble coolant toward the tool/blade.
If all of the above suggestions are followed, heat buildup will be held to a minimum, melting and chipping should not occur, and the edges of the Plaskolite acrylic sheet will be ready for finishing or further fabrication.
After all cutting and machining, internal stresses occur. To reduce the possibility of crazing, (small hairline fissures) during cementing, bending, and forming, annealing is recommended.
Heat Plaskolite acrylic sheet for 5 to 6 hours at 130 to 150°F in a forced air oven. Cool the sheet slowly to at least 110°F.