napkin holder

Try This: Bending Acrylic with a Laser

Josh Stephens is the owner of Lasers Plus. Formerly, he was the lead applications expert for Trotec Laser. He has been in the industry for over seven years.

To bend acrylic, you have to warm it up. Traditionally, an acrylic bending machine is used after the cutting process. But did you know that you can skip the costly extra machine, and bend acrylic with your laser?

The further you bring the work piece out of focus, called defocusing, the larger the beam diameter gets, and brings less power to the work piece. At a certain distance, the laser is not cutting through the acrylic, it simply heats it until it melts.

Below are the steps needed to create a beautiful napkin holder without any acrylic-bending machine.

Step 1: Prepare the table
In order for the material to bend freely, it needs to be supported at a distance above the working table higher than the length you want to bend. For this, you can be creative; for example, with wooden blocks, bottles or even laser-cut acrylic supports.
Important—when placing supports, make sure they are not under the part of material that is to be folded.

Step 2: Step by step
1. Engraving
After placing your material, the laser will engrave the work piece. The engraving areas are filled in black.

2. Cutting the outline
Next, the laser will cut the outline to be bent, but not release the piece from the original material. In the file, this cutting line is marked in red.

3. Heating and bending 
The laser moves the table down and brings the material out of focus. As described above, the material will not be cut or engraved, only heated. It is important that the material is not heated too fast or at too high of a temperature to avoid the formation of bubbles. If the edge is warm enough, the cut will slowly rotate down. The bending lines are blue in the CorelDraw document.

4. Cutting the final edges
The last cutting step will separate the finished piece from the material, and the napkin holder is ready. The last cutting lines are colored with green in the file.

Step 3: Laser settings

Import the PDF file into CorelDraw and send it to the laser.  

Parameters:

Engraving (black): Power: 55%; Speed: 100%; Frequency: 5,000 ppi; Air Assist: OFF
Cutting (red and green): Power: 100%; Speed: 0.5%; Frequency: 20,000Hz; Air Assist: ON
Bending (blue): Power: 35%; Speed: 2.20%; Frequency: 20,000Hz; Passes: 9; Z-Offset: 90mm; Air Assist: OFF

Step 4: Clean and ready
Clean the napkin holder after laser processing with water and a soft cloth. Please note that the bending edges can still be warm or even hot.

Tips:

  • Make sure that the laser you are using has a deep enough Z-axis to accommodate the bent portions of the design. 
  • You can also remove cutting lamellas for strategic support placement if that option is available on your laser.