The simplest method of forming acrylic sheet along a straight line is to use a strip heater. Strip heaters are typically used to for the rapid production of simple boxes, and frames. They are generally limited to straight line bends. The process is usually used for small parts where the length of the bend is relatively short. Longer bends over 24 inches tend to bow, what we call the banana effect.
Strip heaters work well with thinner gauges, less than 1/8 inch. Thicker gauges up to 1/4 inch can also be bent when a V-groove the length of the bend is cut prior to forming.
After heating, the acrylic sheet should be bent quickly. The piece should be held in a fixture until cool. In production, a number of strip heaters and fixtures can be arranged so as to make several folds in one operation.
Acrylic sheet should be heated to temperatures from 290°F to 350°F. These are sheet temperatures. The formability of cell cast acrylic sheet changes little within these temperature ranges. However, the formability of extruded acrylic sheet changes greatly. Higher temperatures may reduce the tear resistance of extruded sheet and may impair its physical properties. This is the main reason why extruded sheet should not used in aquarium manufacture. However, is is perfectly fine for use in non pressure loading applications such as shelves, sumps and similar.