Kerf cut: Cutting technique for bending applications

Cutting technique for bending applications

Putting waves in rigid sheet materials with the laser cutter

Rigid sheets of material like wood or acrylic can be made flexible by cutting bending cut geometries, or "kerf cuts", into them. There are many different shapes and designs that each give different bending behaviours. We have tested a variety of materials like wood and acrylic from 1/8" to 3/16" thick and chosen a few for you. Here, you may find the corresponding graphic templates for download.


Which cutting techniques are there?

Kerf 1: Straight cut lines

Straight cut lines provide a stable radius to bend around.  The larger the distance between each cutting line, the wider the bending radius. Depending on the file and the material, a distance of up to 1/64" between each line can be used.

Kerf 2: Small waves

The small wave pattern is interconnected, making the rigid material bendable. This design can be used on materials that are up to 1/8" thick. The bending radius is very wide for this technique.

Kerf 3: Large honeycombs

Using large honeycombs, the curves get tapered at either end and then are cut from the sheet. This technique is common in model making. Because the honeycombs are so large, even wooden boards up to 3/16" thick can be made flexible.
The honeycombs can easily be pulled apart and bunched together, properties that work will with connections like those in bracelets.

Kerf 4: Wavy cut line

Like the first kerf cut, this technique is made completely from cut lines, but has different, more flexible bending properties.

Kerf 5: Honeycombed cut line

Because of the way that the pattern is designed, this cut allows for flexibility in every direction. This property makes it good for many different artistic applications, such as bag design.

Kerf 6 and 7: Narrow and wide waves

These patterns are general purpose, well suited for a large variety of materials. The shape of each cut line gives both stability and flexibility. 

Kerf 8: Triangular shape

This pattern's unique shape can be bent in every direction and is often used as a design element in itself.
The triangular design for this technique works well with materials up to about 1/8" thick. From 3/16" on, the material becomes too rigid and inflexible.

Download

Below you can find every graphic necessary for our kerf cuts ready to download.

Download Kerf Cut graphic templates

Cutting technique on wood

Wood is typically great for these bendable cutting techniques. However, the type of wood used must be carefully considered. The following notes should be followed:

  • Plywood
    Plywood works very well with flexible applications. If you glue the sheets, the wood becomes capable of bending in every direction within a very small radius.
  • Solid wood
    When using solid wood sheets that have a thickness from 3/16", cutting techniques that have recesses, like Kerf 6, are a lot more flexible than a straight cut or one without recesses (e.g., Kerf 1). With solid wood, make sure to always cut in the direction of the grain. If the cut lines are done across the grain, the wood becomes easier to break and is less bendable as a result.
  • MDF
    MDF, like plywood, is really easy to work with. Because it has a mix of grains, you do not need to purposely align the cut lines.

Cutting techniques on acrylic

Cutting techniques on acrylic best serve rigid bends (e.g., boxes) or situations where the bending radius does not change often. Putting a constant load on the cutting pattern, like a book, can cause the webs to break.

When processing acrylic, pay attention to the following points:

  • For the bendable cuts, use a lens that is 2" or more. Since the acrylic melts, if the lens has too small a focal length, the cut area could immediately fuse back together.
  • We suggest that you use a cutting distance that is roughly 1 to 1.5 mm. If the material still melts even though you have the correct lens, move the cut lines further from each other. However, if you put them too far apart, the bend's flexibility will go down.

Important points to get your desired bending result:

To summarize, these are the main things to consider when you make your graphic:

  • Material properties
  • Direction of the grain
  • Distance between the cuts
  • Material thickness

Do you need more information and tips?

If you have any more questions about material processing or other kinds of laser applications, feel free to contact us. Our laser experts would be happy to assist you. Additionally, Trotec Academy provides training courses for different topics in laser technologies. We would be happy to schedule an appointment with you.

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