Extruded acrylic sheet (XT)
PMMA - Poly(methyl methacrylate)
Extruded acrylic sheet is an economical, high quality material with a narrow thickness tolerance. Its optical clarity is also very good, second only to clear cast acrylic sheet.
Extruded acrylic sheet is commonly referred to as Perpex® and Plexiglas® both of which are in fact manufacturer brand names.
Extruded clear acrylic sheet is produced by an extrusion process. Acrylic resin pellets are heated to a molten mass which is continuously pushed through a die, the position of which determines the thickness of the sheet produced. Once through the die, the molten mass looses temperature and can be trimmed and cut to the required sheet sizes. The continuous nature of the extruded acrylic production process produces larger batches than that of cast acrylic production making it a more economical material.
Key features
• Excellent optical clarity
• High gloss finish
• Hard wearing
• Weather resistant
• Easy to work with/fabricate
• Lightweight
Typical applications:
• Glazing
• Signage
• Furniture
• Model and display cases
• Retail display
• Point of sale
• Point of purchase
Working with extruded acrylic sheet:
Cutting
We cut acrylic panels to size using a circular saw and a CNC router. But acrylic sheet can also be cut with hand tools. Most hand tools designed for use for wood or soft metal can be used on acrylic.
Circular saws, band saws and jigsaws and are all suitable but for small jobs a fine-toothed hacksaw is easy recommended. Ensure the material is fixed securely and use light controlled pressure to achieve a good finish.
If cutting large amounts of material using a powered saw a tungsten carbide tipped blade would be a sensible investment.
Laser cutting
Laser cutting machines cut acrylic by melting, burning or vaporizing the material. Laser cutting is exceptionably accurate and capable of cutting incredibly intricate designs from a CAD file. The laser cutting process leaves a nice smooth edge so further edge finishing is not necessary.
Polished edges
When acrylic sheet is cut, the saw blade leaves an unfinished matte finish to the surface of the edges. This can be polished out to crystal clear, high quality finish by either diamond or flame polishing.
Diamond polishing
A diamond edge-polishing machine polishes the edge of the acrylic by running a rotating, diamond tipped wheel along the edge of the material. Diamond polishing leaves a clean and crisp edge. Curved edges cannot be diamond polished.
Flame polishing
Acrylic edges can also be flame polished by running a blowtorch type gar-air flame along the edge. Flame polishing can be used to polish a curved edge when diamond polishing cannot.
Drilling holes in extruded acrylic
Standard wood working drill bits are suitable for drilling holes in acrylic. Be sure to use another piece of material (scrap wood or acrylic is perfect) underneath the panel to act as a backstop. This will ensure the drilling will not blowout the panel as the drill exits the material.
Do not under any circumstances use a centre punch on any acrylic panel, its very likely to damage It’s a good idea to start by drilling a small pilot hole to help locate the drill.
Be patient and drill at a steady speed and pause regularly to remove any swarf collecting around the drill, not doing so is likely to cause over heating and in turn will damage the hole.
When approaching the other side of the panel, continue to drill through it and into the backstop to ensure the exit hole does not splinter.
Cleaning
Start by blowing and brushing any loose dirt and dust from the material.
With a mild solution of lukewarm water and a drop of standard washing up liquid and a soft cloth, wipe clean any more stubborn dirt and grime.
Gently rinse with clean water before dabbing dry with a mircofibre cloth to ensure water spots do not develop.
Polishing scratches
Specialist acrylic polish can be used to polish out fine scratches, however T-cut car polish achieves great results too.