How to Bend Acrylic Sheets

Acrylic is an extremely versatile material used in the manufacturing of a huge variety of products--ranging from signage, desktop awards and desk accessories to internally illuminated signs, skylights and aircraft windshields. This material has many attractive characteristics, including exceptional durability and extreme optical clarity. Acrylic is also easy to work with. This allows it to be fabricated into many different shapes and sizes. One of the easiest ways to form acrylic is through a process called thermobending, which involves heating the plastic to soften it and then bending it into a shape to create products such as counter signs, picture frames, business card holders and display racks.

Things You'll Need

• Strip heater
• Bending fixture
• Saw or engraving machine

Instructions

1. 

   Use a strip heater and a bending fixture. This is one of the easiest and cheapest ways to bend acrylic. A strip heater features a long, straight, electrical heating element. A bending fixture is a device designed to bend the acrylic and then hold it in place while it cools. You can buy strip heaters and bending fixtures from engraving machine suppliers and some acrylic sheet suppliers. You can also create your own bending fixtures.

2. Determine the angle of the bend and the thickness of the acrylic sheet. Most strip heaters can accommodate up to 1/4-inch-thick sheets. For thicker sheets or sharp angles, you can achieve a sharp, straight bend by first sawing or engraving a V-shaped groove along the bend line approximately one-quarter to half the thickness of the material.

3. Select an appropriate temperature and time by checking the strip heater manufacturer's guidelines. A 1/4-inch-thick piece of acrylic can usually be completely heated at about 300 degrees F for about 8 minutes. You may want to make a test bend or two to determine the best settings.

4. Remove the protective masking before heating the acrylic. If you leave the masking on, it may be extremely difficult to remove after heating.

5. Position the acrylic on the strip heater. The area to be bent should be directly over the heating element, running parallel to it. Place the sheet so the heated side of the sheet is the same as the outside of the bend.

6. After heating, quickly bend the sheet and clamp it in a bending fixture to allow it to cool. The acrylic should completely cool in just a few minutes.

Tips & Warnings

• The heated side of the acrylic shouldn't touch the heating element, to avoid bubbling and sticking. Use the strip heater's supports or wood shims to elevate the material. Under-heating the acrylic can create cracks; overheating can create blisters and bubbling. If the ends of the bend are slightly distorted, you can correct this by cutting and polishing the edges.

• Don't heat acrylic beyond 350 degrees F, as the material is highly combustible. Fumes emitted by heating acrylic are potentially toxic; always work in a well-ventilated area.

Resources

• Read this Article in Spanish
• The Engravers Journal for strip heater manufacturers