At Industrial Plastic Solutions to bend Acrylic a strip heater with an element running between two water-cooled tubes, made from stainless steel is used. The tubes should be adjustable so that the gap between the two tubes can be increased or decreased depending upon the thickness of material that one is bending.
For example 3mm acrylic the gap should be set to 12mm, for 6mm material the gap should be set to 18mm, for 8mm material the gap should be set to 24mm – 26mm etc. Rule of thumb is generally 3 times the thickness of material equals the gap between tubes.
When bending Polycarbonate it is essential that the sheet is free from moisture, which will in turn prevent bubbles from appearing in the material. If bubbles do appear it is generally due to leaving material upon the strip heater for too long, or the heat is set to high. Polycarbonate generally is bent while the material is hot but not as pliable as Acrylic. If using this method it will help reduce chances of bubbling.
Polishing Acrylic, can be done in a couple of ways first is to buzz the edges, so that a smooth surface is created removing the coarser saw marks and then using a buff to give that glass edge finish. Or one can flame polish the acrylic using hydrogen and oxygen setup, which delivers a far superior finish which is not unlike that of glass. In some instances small pieces of acrylic can be bent using a hot air gun and forming them over a piece of tube.